| ID |
Date |
Author |
Status |
Type |
Category |
Location |
Title |
|
364
|
Tue Sep 17 12:48:13 2024 |
Ronic Chiche | Fixed | info | mechanics | ThomX igloo | Finding correct motors position and parameters to keep the lock during a move | this morning with Daniele, we did a quite long run with this motor position and it seems we don't lose the lock too much.
the motor positions are:
MOT.03 (M4): -186 500 steps
MOT.06 (M1): -797 500 steps
we got 85kW after CEP optimization and rough alignment optimization.
| Ronic Chiche wrote: |
|
this morning, I try to find a new region for MOT.03 and MOT.06 where we can move them without unlocking the cavity.
I started from the position:
MOT06 : ~ -785 000
MOT03 : ~ -200 000
and I do -10 000 steps (dz = 10k x 6nm = 60µm) at a time on both motors.
previously a good region for MOT.06 was -900 000 !
I moved also the laser cavity by 40µm to cancel the beating with the RF frequency.
MOT06 : ~ -795 000
MOT03 : ~ -191 000
Max power after optimazing the CEP ~ 65kW => I need to realign => 78kW
I need to increase the D parameter on the PID to compensate the (85kW / 78kW ratio).
I changed the MOT.03 and MOT.06 speed to 30steps/s => it seems a bit better.
but I still see some lock losses during a move.
.... to be continued...
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363
|
Mon Sep 16 12:03:30 2024 |
Ronic Chiche | Fixed | info | mechanics | ThomX igloo | Finding correct motors position and parameters to keep the lock during a move | this morning, I try to find a new region for MOT.03 and MOT.06 where we can move them without unlocking the cavity.
I started from the position:
MOT06 : ~ -785 000
MOT03 : ~ -200 000
and I do -10 000 steps (dz = 10k x 6nm = 60µm) at a time on both motors.
previously a good region for MOT.06 was -900 000 !
I moved also the laser cavity by 40µm to cancel the beating with the RF frequency.
MOT06 : ~ -795 000
MOT03 : ~ -191 000
Max power after optimazing the CEP ~ 65kW => I need to realign => 78kW
I need to increase the D parameter on the PID to compensate the (85kW / 78kW ratio).
I changed the MOT.03 and MOT.06 speed to 30steps/s => it seems a bit better.
but I still see some lock losses during a move.
.... to be continued...
|
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362
|
Mon Sep 9 11:00:43 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | this morning, with Vincent :
- we added the 10Hz trigger to the CH2 on the remote scope (192.168.229.21) to check the synchronization at the right timing.
CH1 : 33MHz RING
CH2 : LINAC/RING synchro signal
CH3 : 500MHz RING
CH4 : 33MHz FPC
we successfully lock both laser on FPC (87kW for 33% amp ratio) and FPC on 500MHz RF.
we saw the result on the scope.
suprisingly, the FPC/RF lock seems much robust than before.
the only problem is the MOT.06 which make the lock being lost at almost every move.
one reason could be the rust on the mechanics... we can try to change the position of both plan mirror motors to work in a proper region.
before, it was working well at -900 000 steps on MOT.06, now it is -780 00.
it's a quite long travel...
end of this posts thread
| Ronic Chiche wrote: |
|
I changed a little bit the locking parameters (see picture) for the RF/FPC loop and it locked rapidely.
I asked Vincent to connect on the same scope the synchro signals to check if the FPC lock was OK => he connected 33MHz signals coming from the laser and from the 33MHz RF generator.
=> the signals are not locked even when the FPC seems to be locked to the RF.
=> it can be normal because he forgot to connect also the synchro trigger signal which gives the moment of synchronization of the machine... to be finished on Monday.
| Ronic Chiche wrote: |
|
now, the Ring RF frequency is set to 500.067MHz.
so the CFP/laser frequency should be 500.067MHz/15 = 33.3378MHz.
the frequency was set to 33.378MHz !!! => it explains the frequency shift only on the 33MHz beating => I corrected the frequency on the generator and informed Nicolas Delerue.
=> now, I can try to lock the CFP to the RF frequency.
| Ronic Chiche wrote: |
|
after redoing the alignment of the CVBG, we got back the initial power in the FPC (87kW)
now, I checked the RF locking signals on the 2nd oscilloscope.
I get a strange ratio between the 33MHz beating and the 500MHz beating signals.
beat @ 33MHz ~ 40kHz !
beat @ 500MHz ~ 700Hz !
maybe the 33MHz generator frequency is not matching the 500MHz RF frequency ?
| Ronic Chiche wrote: |
|
amplifier power measurement before the compressor CVBG.
we used a mirror in between the amplifier output and the compressor + a 2-mirror periscope to match the powermeter height.
amp ratio (%) power (W)
0 0.7
10 1.65
20 13
30 25
40 37.7
50 50.5
60 62
70 74
80 86
90 99
100 110
we had an alarm @100% of amplifier ratio => the reason is not clear... maybe it's coming from a discrepency between some internal measurement and the expected value.
we checked the power after the alarm => still OK
conclusion, the amplifier seems to be OK... we need to redo the alignment of the compressor CVBG.
| Ronic Chiche wrote: |
|
After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
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361
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Fri Sep 6 17:27:20 2024 |
Ronic Chiche | Under Process | issue | mechanics | lasers and optics | detectors and electronics | ThomX igloo | 20Hz oscillation in the locking between Laser and FP-cavity | could it be possible this 20Hz oscillations comes from anouncements in the bunker, puting the housing+table in vibration ?
(there are such anouncements during restricted access) => to be asked to Harold
| Ronic Chiche wrote: |
|
measure to be done next week to check the 20Hz noise on the laser amplifier signal:
- install a DET10 in reflection of the FP-cavity to get a high BW and measure the 500MHz harmonic.
- do the beating with the 500MHz Ring RF generator
- with the laser motor try to be close to the 500MHz Ring RF frequency => beating frequency below 1kHz
- send the beating signal to some RF spectrum analyzer to use its large dynamic range.
for example, with the Siglent RF spectrum analyzer, it is possible to detect easily a peak @ -96dBm <=> 3.5µV rms
so, one should be able to make the measurement @ 500MHz or even @ 33MHz even if the phase sensitivity is lower :
for example V0=100mV peak beating signal @ f0=33MHz should produce a 20Hz noise signal of:
dV ~ V0 * dphi = V0 * 2*pi*f0*dt = 200µV rms with jitter dt=10ps rms
| Ronic Chiche wrote: |
|
what does this 10ps phase jitter mean in term of cavity length variations ?
L = L0 + dL sin(2pi fm t) = L0 (1 + dL/L0 sin(2pi fm t))
F = c / L ~ F0 - F0² dL / c sin(2pi fm t) with F0 = c / L0
d/dt(phi) = 2pi F => phi = 2pi F0 t + F0² dL / (c fm) cos(2pi fm t) => dphi = F0² dL / (c fm)
dphi = 2pi F0 dt => dL = L0 * 2pi fm dt
dt rms = 10ps @ fm = 20Hz of modulation frequency <=> dL rms = 10 nm (L0 = 9m)
| Ronic Chiche wrote: |
|
yesterday I did 2 tests to try to understand the origin of the 20Hz oscillation which is dominant in the remaining 10-20ps rms jitter between the transmitted pulses and the RF reference generator.
10ps rms jitter is equivalent to phase jitter dphi = 2*pi*f0*dt = 2mrad rms @ 33MHz or 30mrad rms @ 500MHz.
with V0 = 1Vpeak of beating signal amplitude, the equivalent rms beating voltage is dV = V0 * sin(dphi) ~ V0 * dphi = 2mV rms @ 33MHz or 30mV rms @ 500MHz
1) I did a beating between the internal photodiode of the laser with an external 33MHz oscillator (the photodiode is too slow to use higher harmonic).
the difficult part is to see the 2mV rms noise on a 2Vpp oscillating signal, so I locked the external 33MHz reference oscillator with the beating signal => see first plot.
there is no trace of 20Hz oscillation in the beating signal => the lock is too good and removed the oscillation ?
2) I did a beating between the photodiode in reflection of the FP-cavity (so the signal is not coming only from the oscillator but is going also through the Alphanov amplifier) with the 500MHz RF Ring generator.
I cannot the lock the generator anymore, so the measurement is done in open loop. I adjust the laser Frep with the motor to try to cancel the beating frequency => see 2nd plot
there is no trace of 20Hz oscillation in the beating signal => it is in contradiction with the previous post : "conclusion: the 20Hz oscillation is coming from the laser cavity" ?!?
maybe we need a more complex measurement scheme with the possibility to measure in the same time the 10-20ps rms jitter coming from the locked FP-cavity transmitted signal/500MHz Ring generator
AND the beating signal between the laser or amplifier with 500MHz local reference generator... to be done...
| Ronic Chiche wrote: |
|
this afternoon, we did 2 tests to better understand this 20Hz oscillation:
- we locked the amplified laser directly to the 500MHz ring reference oscillator, without any intermediate locking to the FP-cavity => no change
the 20Hz oscillation is still present in the correction signal of the laser PZT.
- we switched OFF the controller of the hexapod => no change.
conclusion:
the 20Hz oscillation is coming from the laser cavity
or is coming from "outside" and could be measured, maybe at a higher level, with an external "noises & vibrations measurement system".
| Ronic Chiche wrote: |
|
this morning, we tried to find the origin of the 20Hz oscillation.
- we switched OFF the laser Smaract motors controller => no change
- then, we addionally disconnected the FP-cavity PZT cable from the Laselock (we put a charge of 1kohm) => no change
- then, we switched ON the laser Smaract motors controller and switched OFF the FP-cavity motors controllers => no change
in conclusion, we don't really know where this instabillity comes from.
the amplitude is roughly 1Vpp (when the oscillation is at its maximum) on the laser PZT <=> length oscillation of ~20nm pp
could it come :
- from the air cooling regulation with pressure variation ?
- from vibrations of the hexapod below the table ?
or is it from inside of the laser or FP cavities ?
see these posts for the first measurements on this issue: https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/257
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360
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Fri Sep 6 17:21:51 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | I changed a little bit the locking parameters (see picture) for the RF/FPC loop and it locked rapidely.
I asked Vincent to connect on the same scope the synchro signals to check if the FPC lock was OK => he connected 33MHz signals coming from the laser and from the 33MHz RF generator.
=> the signals are not locked even when the FPC seems to be locked to the RF.
=> it can be normal because he forgot to connect also the synchro trigger signal which gives the moment of synchronization of the machine... to be finished on Monday.
| Ronic Chiche wrote: |
|
now, the Ring RF frequency is set to 500.067MHz.
so the CFP/laser frequency should be 500.067MHz/15 = 33.3378MHz.
the frequency was set to 33.378MHz !!! => it explains the frequency shift only on the 33MHz beating => I corrected the frequency on the generator and informed Nicolas Delerue.
=> now, I can try to lock the CFP to the RF frequency.
| Ronic Chiche wrote: |
|
after redoing the alignment of the CVBG, we got back the initial power in the FPC (87kW)
now, I checked the RF locking signals on the 2nd oscilloscope.
I get a strange ratio between the 33MHz beating and the 500MHz beating signals.
beat @ 33MHz ~ 40kHz !
beat @ 500MHz ~ 700Hz !
maybe the 33MHz generator frequency is not matching the 500MHz RF frequency ?
| Ronic Chiche wrote: |
|
amplifier power measurement before the compressor CVBG.
we used a mirror in between the amplifier output and the compressor + a 2-mirror periscope to match the powermeter height.
amp ratio (%) power (W)
0 0.7
10 1.65
20 13
30 25
40 37.7
50 50.5
60 62
70 74
80 86
90 99
100 110
we had an alarm @100% of amplifier ratio => the reason is not clear... maybe it's coming from a discrepency between some internal measurement and the expected value.
we checked the power after the alarm => still OK
conclusion, the amplifier seems to be OK... we need to redo the alignment of the compressor CVBG.
| Ronic Chiche wrote: |
|
After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
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359
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Fri Sep 6 15:20:20 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | now, the Ring RF frequency is set to 500.067MHz.
so the CFP/laser frequency should be 500.067MHz/15 = 33.3378MHz.
the frequency was set to 33.378MHz !!! => it explains the frequency shift only on the 33MHz beating => I corrected the frequency on the generator and informed Nicolas Delerue.
=> now, I can try to lock the CFP to the RF frequency.
| Ronic Chiche wrote: |
|
after redoing the alignment of the CVBG, we got back the initial power in the FPC (87kW)
now, I checked the RF locking signals on the 2nd oscilloscope.
I get a strange ratio between the 33MHz beating and the 500MHz beating signals.
beat @ 33MHz ~ 40kHz !
beat @ 500MHz ~ 700Hz !
maybe the 33MHz generator frequency is not matching the 500MHz RF frequency ?
| Ronic Chiche wrote: |
|
amplifier power measurement before the compressor CVBG.
we used a mirror in between the amplifier output and the compressor + a 2-mirror periscope to match the powermeter height.
amp ratio (%) power (W)
0 0.7
10 1.65
20 13
30 25
40 37.7
50 50.5
60 62
70 74
80 86
90 99
100 110
we had an alarm @100% of amplifier ratio => the reason is not clear... maybe it's coming from a discrepency between some internal measurement and the expected value.
we checked the power after the alarm => still OK
conclusion, the amplifier seems to be OK... we need to redo the alignment of the compressor CVBG.
| Ronic Chiche wrote: |
|
After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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358
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Fri Sep 6 12:10:51 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | after redoing the alignment of the CVBG, we got back the initial power in the FPC (87kW)
now, I checked the RF locking signals on the 2nd oscilloscope.
I get a strange ratio between the 33MHz beating and the 500MHz beating signals.
beat @ 33MHz ~ 40kHz !
beat @ 500MHz ~ 700Hz !
maybe the 33MHz generator frequency is not matching the 500MHz RF frequency ?
| Ronic Chiche wrote: |
|
amplifier power measurement before the compressor CVBG.
we used a mirror in between the amplifier output and the compressor + a 2-mirror periscope to match the powermeter height.
amp ratio (%) power (W)
0 0.7
10 1.65
20 13
30 25
40 37.7
50 50.5
60 62
70 74
80 86
90 99
100 110
we had an alarm @100% of amplifier ratio => the reason is not clear... maybe it's coming from a discrepency between some internal measurement and the expected value.
we checked the power after the alarm => still OK
conclusion, the amplifier seems to be OK... we need to redo the alignment of the compressor CVBG.
| Ronic Chiche wrote: |
|
After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
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357
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Fri Sep 6 11:56:53 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | detectors and electronics | ThomX igloo | fixing CVBG issue | this morning with Daniele, we realigned the amplifier beam axis on the iris position.
it was pretty fast an easy => we got rapidely some resonance and we locked back to 87kW @33% amp ratio after tuning CEP and alignment.
we tried to play on the L-shape but we didn't a clear effect.
we also played on the 1/2 and 1/4 waveplates to tune the polarization.
we see very clearly the locked reflected signal changing without almost changing the transmission !
Aurélien suggested to slightly focusing the beam in the DET36 photodiode to have a better estimation of the coupling.
presently, the beam is clearly larger than the DET36 photodiode area which artificially increases the measured coupling.
(I cannot use a DET100 because I need 500MHz BW to get some RF signal for beating with the 500MHz reference signal).
I added a +75mm lens in front of the DET36 reflection signal photodiode => now, the beam is rougly 1-2mm diameter, centered on the DET36.
when I optimize the alignment and the CEP, I get 86-87kW in the CFP and 45% coupling => cf plot
end of the CVBG issue posts.
| Ronic Chiche wrote: |
|
1) this morning, I aligned to CFP to get back 82kW in the cavity for 33% of amplifier ratio.
thus, we can ajust the iris positions on the optical table to fix the CFP optical path before touching the CVBG.
2) we aligned the 5 iris. all of them were misaligned by 1-2mm, principaly vertically (maybe because we had to change the CFP frequency some time ago to match the new RF frequency?).
3) we opened the compressor box and found out the beam on the last mirror was really on the border => we have to move it.
=> we recorded several beam profiles at 20-70% of amplifier ratio (see images before realignement)
above 50% of amplifier ratio, the beam is deformed.
=> we realigned the 2 last mirrors of the compressor and compensate the axis displacement with the 2 inches injection mirrors at the output of the compressor to get back the telescope axis.
amplifier ratio (%) power after compressor (W)
0 0.286
10 0.91
20 8.6
30 16.7
40 25.5
50 34.5
60 42.5
70 50.0
80 57.0
90 64.0
100 70.0
the power is back => OK ! :-)))
we took some images with the beam profiler at high power after the realignement (see images after realignement)
tomorrow, we have to realign the amplifier beam axis to the CFP axis.
| Ronic Chiche wrote: |
|
the CVBG of the compressor module seems to have an issue.
here is the plan of the work :
1) faire des résonances avec la CFP
2) ajuster les iris d'alignement du faisceau de l'ampli pour être sur de ne pas perdre la référence de l'axe de la CFP
3) installer des wedges haute puissance à proximité du compresseur + beam profiler
4) verifier la forme du faisceau au beam profiler en fonction de la puissance de l'ampli
5) ouvrir le boîtier du compresseur
6) prendre des images du boîtier à la caméra thermique en fonction de la puissance
7) éventuellement shunter le 2e CVBG avec un D shape et regarder le mode et caractéristique en sortie d'ampli.
8) ajuster l'injection dans le premier CVBG ou le second ou les deux en fonctions des résultats précédent
here are some useful logbook posts:
D-shape + images thermiques du compresseur qui peuvent servir de référence :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/147
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/150
post des images du faisceau en fonction de la puissance de l'ampli :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/135 (et autres posts du fil)
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/195 (et autres posts du fil)
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356
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Thu Sep 5 09:53:10 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | detectors and electronics | ThomX igloo | fixing CVBG issue | 1) this morning, I aligned to CFP to get back 82kW in the cavity for 33% of amplifier ratio.
thus, we can ajust the iris positions on the optical table to fix the CFP optical path before touching the CVBG.
2) we aligned the 5 iris. all of them were misaligned by 1-2mm, principaly vertically (maybe because we had to change the CFP frequency some time ago to match the new RF frequency?).
3) we opened the compressor box and found out the beam on the last mirror was really on the border => we have to move it.
=> we recorded several beam profiles at 20-70% of amplifier ratio (see images before realignement)
above 50% of amplifier ratio, the beam is deformed.
=> we realigned the 2 last mirrors of the compressor and compensate the axis displacement with the 2 inches injection mirrors at the output of the compressor to get back the telescope axis.
amplifier ratio (%) power after compressor (W)
0 0.286
10 0.91
20 8.6
30 16.7
40 25.5
50 34.5
60 42.5
70 50.0
80 57.0
90 64.0
100 70.0
small power drop for ratio < 40% compared to previous measurements : https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133
the power is back => OK ! :-)))
we took some images with the beam profiler at high power after the realignement (see images after realignement)
tomorrow, we have to realign the amplifier beam axis to the CFP axis.
| Ronic Chiche wrote: |
|
the CVBG of the compressor module seems to have an issue.
here is the plan of the work :
1) faire des résonances avec la CFP
2) ajuster les iris d'alignement du faisceau de l'ampli pour être sur de ne pas perdre la référence de l'axe de la CFP
3) installer des wedges haute puissance à proximité du compresseur + beam profiler
4) verifier la forme du faisceau au beam profiler en fonction de la puissance de l'ampli
5) ouvrir le boîtier du compresseur
6) prendre des images du boîtier à la caméra thermique en fonction de la puissance
7) éventuellement shunter le 2e CVBG avec un D shape et regarder le mode et caractéristique en sortie d'ampli.
8) ajuster l'injection dans le premier CVBG ou le second ou les deux en fonctions des résultats précédent
here are some useful logbook posts:
D-shape + images thermiques du compresseur qui peuvent servir de référence :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/147
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/150
post des images du faisceau en fonction de la puissance de l'ampli :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/135 (et autres posts du fil)
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/195 (et autres posts du fil)
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355
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Thu Sep 5 09:51:22 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | detectors and electronics | ThomX igloo | fixing CVBG issue | the CVBG of the compressor module seems to have an issue.
here is the plan of the work :
1) faire des résonances avec la CFP
2) ajuster les iris d'alignement du faisceau de l'ampli pour être sur de ne pas perdre la référence de l'axe de la CFP
3) installer des wedges haute puissance à proximité du compresseur + beam profiler
4) verifier la forme du faisceau au beam profiler en fonction de la puissance de l'ampli
5) ouvrir le boîtier du compresseur
6) prendre des images du boîtier à la caméra thermique en fonction de la puissance
7) éventuellement shunter le 2e CVBG avec un D shape et regarder le mode et caractéristique en sortie d'ampli.
8) ajuster l'injection dans le premier CVBG ou le second ou les deux en fonctions des résultats précédent
here are some useful logbook posts:
D-shape + images thermiques du compresseur qui peuvent servir de référence :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/147
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/150
post des images du faisceau en fonction de la puissance de l'ampli :
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/135 (et autres posts du fil)
https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/195 (et autres posts du fil)
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354
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Fri Aug 30 17:59:01 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | amplifier power measurement before the compressor CVBG.
we used a mirror in between the amplifier output and the compressor + a 2-mirror periscope to match the powermeter height.
amp ratio (%) power (W)
0 0.7
10 1.65
20 13
30 25
40 37.7
50 50.5
60 62
70 74
80 86
90 99
100 110
we had an alarm @100% of amplifier ratio => the reason is not clear... maybe it's coming from a discrepency between some internal measurement and the expected value.
we checked the power after the alarm => still OK
conclusion, the amplifier seems to be OK... we need to redo the alignment of the compressor CVBG.
| Ronic Chiche wrote: |
|
After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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353
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Fri Aug 30 12:05:38 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | After the summer power shutdown, I restarted all the equipements and got quickly ~80kW for 33% amplifier ratio with CEP optimization and without Alignment optimization.
CEP motor position : -506µm
| Ronic Chiche wrote: |
|
this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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|
|
|
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352
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Fri Aug 30 10:50:45 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | this morning with Daniele, we are measuring the amplifier power just before the FP-cavity.
Casemate temperature @19.5°C
@0% : 205mW
@10%: 755mW
@20%: 7.44W
@30%: 14.3W
@33%:16.3W
@40% : 20.3W
@50% : 24W
@60% : 26W
=> there is a power issue !!!
the normal casemate temperature should be in between 21 and 22°C.
cf this post (https://elog.lal.in2p3.fr/FPC/THOMX+commissioning/133) to get previous amplifier power.
=> it seems we need to redo the compressor CVBG alignment !
first, we will check the amplifier power before the compressor.
| Ronic Chiche wrote: |
|
after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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|
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|
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351
|
Tue Aug 27 12:31:19 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | after doing some alignment (walking procedure on the Y axis), and CEP optimization, I got 83kW for 33% on the laser amplifier with a coupling of ~60%
=> we have to check the input power after the amplifier.
I adjusted the FP and laser cavity motors to have a small 33MHz detuning with the RF reference (~10 Hz of beating @ 33MHz)
pb : I don't see the 500MHz beating signal => to be checked
during the motion of the FP-cavity motors, I observed a systematic delock when moving MOT.06 on P1z and no delock with MOT.03 on P4z when I move by 10 steps.
Kevin checked that both IcePap controller have the same configuration and then, the problem is maybe coming from the rust observed on the mechanic.
| Ronic Chiche wrote: |
|
we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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350
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Tue Aug 27 11:33:24 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | we had to move the laser cavity motor to find the resonances and change a lot the CEP.
the CEP motor is at -524.1µm
we got ~75kW in the FP cavity without alignment but with CEP optimization.
the coupling (the cyan color) is ~ 62% !
=> we need to do some alignment
| Ronic Chiche wrote: |
|
I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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349
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Tue Aug 27 10:19:08 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | I refilled the chiller and the stabilized temperature is @ 25°C
we started the 3rd stage of the Alphanov amplifier at 30% => PD_OUT is fluctuating around 1-1.4W => it's not related to the real output power !
the photodiode connected to the scope CH2 is around 210mV @ 50ohms
we clearly see some small peak on the transmission signal (scope CH1) => we need to optimize the laser cavity length and the CEP
| Ronic Chiche wrote: |
|
temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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|
348
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Tue Aug 27 09:59:18 2024 |
Ronic Chiche | Fixed | info | lasers and optics | detectors and electronics | software | ThomX igloo | restarting CFP system after the long summer shutdown (RF section conditionning) and Alphanov amplifier issue | temperature in the casemate ~ 19.5°C stable
this morning, I measured the power directly at the output of the fiber coupler (through the output fiber), after the strecher : ~5mW
then, I connected the EOM used for the PDH technic : ~2.5mW
then, I connected the fiber of the EOM to the Alphanov amplifier input fiber.
LAL Alphnov software :
PD_IN = 3.289mW
PD_PULSE = 33.372MHz
=> nothing to do ! :-)))
I switched ON the preamplifier (3rd stage @ 0%) => PD_Preamp2 = 152.44mW
|
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347
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Tue Jul 23 09:37:24 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | ThomX igloo | Alphanov amplifier issue | picture of the connectors used to carry signals between the amplifier pump module and the rack under the table.
DB13W3 standard has been used to carry high current on the 3 dedicated pins:
https://en.wikipedia.org/wiki/DB13W3
the connectors are male types on both sides of the cable, and then female on the pump module and rack : see the 2 pictures.
| Ronic Chiche wrote: |
|
Guillaume and Julien Bour from Alphanov will come on wednesday 24/07 to have a first look and check the amplifier.
to prepare their intervention, I tested this morning the OneFive oscillator : it's still working at 33MHz.
and we have ~5mW in the LAL software without the EOM.
so, we are in "standard" conditions.
| Ronic Chiche wrote: |
|
the present situation is :
Guillaume asked me to disconnect the "Laser head" cable from the pump diode module, installed on the optical table.
on the pump diode module, the connector has several small pins and 3 larges pins : A1, A2, A3.
if the diode of the preamplifier (not the ones of the last stage) is alive, the impedance between A2 and A3 should be around 5 ohms and not HiZ.
I checked several days ago the impedance between all these 3 pins to avoid any error on the schematics.
the impedance is always HiZ.
then, Guillaume thinks the diode is dead.
we are waiting for further tests or procedure.
| Ronic Chiche wrote: |
|
FYI : to access special menus on the Alphanov software,
login : "Administrator"
pwd : no password
to modify parameters in these special menus :
login : "Alphanov"
pwd : "AE32HF56J"
| Ronic Chiche wrote: |
|
Yesterday, we received the controller back from Alphanov
and I tested it immediately in the optical room.
if the software is properly talking to the controller, everything works normally.
then, one just have to remember that is mandatory to have the software properly connected to let the controller start electrically (power supply activated on the main boards)
Today, I installed it in the casemate with all the connections to the laser input, output, laser head, safety connections, etc...
and it works properly.
- The power in the fiber from the strecher is at 6.3mW.
the software reads 5.3mW but after a long fiber... then it is OK.
=> one strange thing : it detects 100MHz instead of 33MHz => to be reported to Alphanov !
- Amplifier output power measured after 2 mirrors :
0% => 230 mW
10% => 880 mW
20% => 8.8W
30% => 17W
which are the numbers we had before.... then we are back to normal conditions to continue the commissioning.
| Ronic Chiche wrote: |
|
Today, I did a Teams meeting with Guillaume.
He didn't see any problem with the controller.
normally, the controller will be shipped to the lab tomorrow.
I attach an updated schematic of the internal electronics boards and how they are connected to the PSS.
1- when the black switch button is ON, only the Arduino board, which deals with the software in ON.
2- then, one needs to switch ON the big green button => an internal relay allows the power supply to reach the LAL safety board + Central board + MMD boards but these boards are not powered !
3- then, one needs to turn the key ON => the software can access the Arduino board
4- then, start the software => the white LED of the big green button is ON => all the boards are now powered
depending on the safety signals connected to the controller, it will be possible or not to start the diode supplies (with MMD boards).
the 24V DC coming from an external power supply in replacement of the PSS 24V supply is not mandatory to access the software:
we will only see some buttons (Relai 1 and 2 in the software) to be RED (OFF).
| Ronic Chiche wrote: |
|
The laser amplifier controller has been sent yesterday and received today by Alphannov.
they should do the assessment quickly...
| Ronic Chiche w |
|
I just tested the fuse inside the black ON/OFF switch on the rear panel => it is OK ! :-(
| Ronic Chiche wrote: |
|
on Monday morning 7/11, we tried to restart the Alphanov amplifier which was not turned on since end of april 2022, but it didn't start.
we did a standard "turn ON" procedure :
- check the safety button on the front panel (which has to be released).
- switch on the black switch on the rear panel.
- push the green button on the rear panel
- turn on the key on the front panel
- push the start button on the front panel
normally after switching on the black switch on the rear panel, a light shines in between the red and green big button on the read panel.
but nothing in that case. we just ear a weak "rotating fan" noise coming from the inside of the rack.
normally, after pushing the green button on the rear panel, the start button on the front panel comes to blue.
but nothing in that case.
normally, after pushing the green button on the rear panel and turning the key, the start button on the front panel comes to red.
but nothing in that case.
we tried anyway to connect the amplifier with a computer, just in case of...
but the Alphanov software is not able to connect to the amplifier.
One possible issue could be a dead fuse inside the black ON/OFF switch on the rear panel => one has to check it !
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346
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Mon Jul 22 09:54:24 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | ThomX igloo | Alphanov amplifier issue | Guillaume and Julien Bour from Alphanov will come on wednesday 24/07 to have a first look and check the amplifier.
to prepare their intervention, I tested this morning the OneFive oscillator : it's still working at 33MHz.
and we have ~5mW in the LAL software without the EOM.
so, we are in "standard" conditions.
| Ronic Chiche wrote: |
|
the present situation is :
Guillaume asked me to disconnect the "Laser head" cable from the pump diode module, installed on the optical table.
on the pump diode module, the connector has several small pins and 3 larges pins : A1, A2, A3.
if the diode of the preamplifier (not the ones of the last stage) is alive, the impedance between A2 and A3 should be around 5 ohms and not HiZ.
I checked several days ago the impedance between all these 3 pins to avoid any error on the schematics.
the impedance is always HiZ.
then, Guillaume thinks the diode is dead.
we are waiting for further tests or procedure.
| Ronic Chiche wrote: |
|
FYI : to access special menus on the Alphanov software,
login : "Administrator"
pwd : no password
to modify parameters in these special menus :
login : "Alphanov"
pwd : "AE32HF56J"
| Ronic Chiche wrote: |
|
Yesterday, we received the controller back from Alphanov
and I tested it immediately in the optical room.
if the software is properly talking to the controller, everything works normally.
then, one just have to remember that is mandatory to have the software properly connected to let the controller start electrically (power supply activated on the main boards)
Today, I installed it in the casemate with all the connections to the laser input, output, laser head, safety connections, etc...
and it works properly.
- The power in the fiber from the strecher is at 6.3mW.
the software reads 5.3mW but after a long fiber... then it is OK.
=> one strange thing : it detects 100MHz instead of 33MHz => to be reported to Alphanov !
- Amplifier output power measured after 2 mirrors :
0% => 230 mW
10% => 880 mW
20% => 8.8W
30% => 17W
which are the numbers we had before.... then we are back to normal conditions to continue the commissioning.
| Ronic Chiche wrote: |
|
Today, I did a Teams meeting with Guillaume.
He didn't see any problem with the controller.
normally, the controller will be shipped to the lab tomorrow.
I attach an updated schematic of the internal electronics boards and how they are connected to the PSS.
1- when the black switch button is ON, only the Arduino board, which deals with the software in ON.
2- then, one needs to switch ON the big green button => an internal relay allows the power supply to reach the LAL safety board + Central board + MMD boards but these boards are not powered !
3- then, one needs to turn the key ON => the software can access the Arduino board
4- then, start the software => the white LED of the big green button is ON => all the boards are now powered
depending on the safety signals connected to the controller, it will be possible or not to start the diode supplies (with MMD boards).
the 24V DC coming from an external power supply in replacement of the PSS 24V supply is not mandatory to access the software:
we will only see some buttons (Relai 1 and 2 in the software) to be RED (OFF).
| Ronic Chiche wrote: |
|
The laser amplifier controller has been sent yesterday and received today by Alphannov.
they should do the assessment quickly...
| Ronic Chiche w |
|
I just tested the fuse inside the black ON/OFF switch on the rear panel => it is OK ! :-(
| Ronic Chiche wrote: |
|
on Monday morning 7/11, we tried to restart the Alphanov amplifier which was not turned on since end of april 2022, but it didn't start.
we did a standard "turn ON" procedure :
- check the safety button on the front panel (which has to be released).
- switch on the black switch on the rear panel.
- push the green button on the rear panel
- turn on the key on the front panel
- push the start button on the front panel
normally after switching on the black switch on the rear panel, a light shines in between the red and green big button on the read panel.
but nothing in that case. we just ear a weak "rotating fan" noise coming from the inside of the rack.
normally, after pushing the green button on the rear panel, the start button on the front panel comes to blue.
but nothing in that case.
normally, after pushing the green button on the rear panel and turning the key, the start button on the front panel comes to red.
but nothing in that case.
we tried anyway to connect the amplifier with a computer, just in case of...
but the Alphanov software is not able to connect to the amplifier.
One possible issue could be a dead fuse inside the black ON/OFF switch on the rear panel => one has to check it !
|
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|
|
|
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|
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345
|
Wed Jun 19 09:14:14 2024 |
Ronic Chiche | Fixed | issue | lasers and optics | ThomX igloo | Alphanov amplifier issue | the present situation is :
Guillaume asked me to disconnect the "Laser head" cable from the pump diode module, installed on the optical table.
on the pump diode module, the connector has several small pins and 3 larges pins : A1, A2, A3.
if the diode of the preamplifier (not the ones of the last stage) is alive, the impedance between A2 and A3 should be around 5 ohms and not HiZ.
I checked several days ago the impedance between all these 3 pins to avoid any error on the schematics.
the impedance is always HiZ.
then, Guillaume thinks the diode is dead.
we are waiting for further tests or procedure.
| Ronic Chiche wrote: |
|
FYI : to access special menus on the Alphanov software,
login : "Administrator"
pwd : no password
to modify parameters in these special menus :
login : "Alphanov"
pwd : "AE32HF56J"
| Ronic Chiche wrote: |
|
Yesterday, we received the controller back from Alphanov
and I tested it immediately in the optical room.
if the software is properly talking to the controller, everything works normally.
then, one just have to remember that is mandatory to have the software properly connected to let the controller start electrically (power supply activated on the main boards)
Today, I installed it in the casemate with all the connections to the laser input, output, laser head, safety connections, etc...
and it works properly.
- The power in the fiber from the strecher is at 6.3mW.
the software reads 5.3mW but after a long fiber... then it is OK.
=> one strange thing : it detects 100MHz instead of 33MHz => to be reported to Alphanov !
- Amplifier output power measured after 2 mirrors :
0% => 230 mW
10% => 880 mW
20% => 8.8W
30% => 17W
which are the numbers we had before.... then we are back to normal conditions to continue the commissioning.
| Ronic Chiche wrote: |
|
Today, I did a Teams meeting with Guillaume.
He didn't see any problem with the controller.
normally, the controller will be shipped to the lab tomorrow.
I attach an updated schematic of the internal electronics boards and how they are connected to the PSS.
1- when the black switch button is ON, only the Arduino board, which deals with the software in ON.
2- then, one needs to switch ON the big green button => an internal relay allows the power supply to reach the LAL safety board + Central board + MMD boards but these boards are not powered !
3- then, one needs to turn the key ON => the software can access the Arduino board
4- then, start the software => the white LED of the big green button is ON => all the boards are now powered
depending on the safety signals connected to the controller, it will be possible or not to start the diode supplies (with MMD boards).
the 24V DC coming from an external power supply in replacement of the PSS 24V supply is not mandatory to access the software:
we will only see some buttons (Relai 1 and 2 in the software) to be RED (OFF).
| Ronic Chiche wrote: |
|
The laser amplifier controller has been sent yesterday and received today by Alphannov.
they should do the assessment quickly...
| Ronic Chiche w |
|
I just tested the fuse inside the black ON/OFF switch on the rear panel => it is OK ! :-(
| Ronic Chiche wrote: |
|
on Monday morning 7/11, we tried to restart the Alphanov amplifier which was not turned on since end of april 2022, but it didn't start.
we did a standard "turn ON" procedure :
- check the safety button on the front panel (which has to be released).
- switch on the black switch on the rear panel.
- push the green button on the rear panel
- turn on the key on the front panel
- push the start button on the front panel
normally after switching on the black switch on the rear panel, a light shines in between the red and green big button on the read panel.
but nothing in that case. we just ear a weak "rotating fan" noise coming from the inside of the rack.
normally, after pushing the green button on the rear panel, the start button on the front panel comes to blue.
but nothing in that case.
normally, after pushing the green button on the rear panel and turning the key, the start button on the front panel comes to red.
but nothing in that case.
we tried anyway to connect the amplifier with a computer, just in case of...
but the Alphanov software is not able to connect to the amplifier.
One possible issue could be a dead fuse inside the black ON/OFF switch on the rear panel => one has to check it !
|
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|
|
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