The ring orbit has been re-established despite some difficulties after the shutdown.

The ring cavity has been started. Whatever the phase it kills the beam.
Two hypothesis:

1) It can be a frequency problem

2) It can be a transverse kick given by the cavity

About 1:

- Magnet current and frequency have been scanned but no effect.

About 2:

- We see betatron oscillation.

We see the beam lost by steps, not a continuous decrease.

https://elog.lal.in2p3.fr/THOMX/Commissionning/221202_190728/Screenshot_from_2022-12-02_18-02-36.png shows betatron oscillation with cavity tuned.

Next steps:

- Mesure FFT of BPM signal (VM, VC)

- "Open the ring" (kick the beam out of the ring) and study the effect of the cavity (phase, power) on the BPMs. (VK, IC)

- Scan betatron oscillation vs phase, orbit, power and frequency

- Slava: To catch the beam you should think like a beam.

Actions:

- Try to get remote control of RF synthetizer (ND)

See slides attached to the indico page https://indico.ijclab.in2p3.fr/event/8885/

Pb with BPM => visual check of electrodes + hardware swap

Pb with steerer => Need to identify who will do the intervention and when

Nicolas will ask Kevin for support.

Alignement: Slava got the data from Denis. Alignment is close from nominal values.
The beam quality is good enough to start working with the RF cavity. Even with low power in  RF cavity we would like to have a first control of voltage and phase from the control room (Thursday or Friday afternoon).

Some energy instabilities have been observed. Look at correlations (Vincent's measurements) + check that the current operating phase is optimal.

=> Check if position fluctuations are the same with one steerer on, TL/DP/PS.01 off + TL/SST1 and steerer off, TL/DP/PS.01 on + TL/SST2.

Optimum injection trajectory has been recorded on Friday.

Next meeting: 7th Novembre

To do list:

(0) Re-establish beam transport to ring

(0bis) Check energy jitter in TL/BPM.02 and TL/SST.02

(0ter) Measure emittance on TL/SST.03

(1) Try to merge TL optimised transport with ring injection transport => record beam size on TL/SST3 and position on TL/BPM.03 and TL/BPM.04 for current ring transport

(2) Improve charge transport at injection

(3) Measure and correct orbits

(4) Start MRSV

(5) Measure Tune

- 300 turns achieved.

- Probably more but limited by libera cut-off frequency.

- Need to measure the injection axis

- Need emittance measurement from the transfer line

- Several measurements are not possible because of lack of progress on the transfer line

New to do list:

(0) Re-establish beam transport to ring

(0bis) Check energy jitter in TL/BPM.02 and TL/SST.02

(1) Try to merge TL optimised transport with ring injection transport => record beam size on TL/SST3 and position on TL/BPM.03 and TL/BPM.04 for current ring transport

(2) Reduce betatron oscillations

(3) Measure and correct orbits

(4) Measure Tune

(5) BBA

(6) Improve charge transport at injection

(7) Start MRSV

Shift summaries for the ring for last week are at

https://elog.lal.in2p3.fr/THOMX/Commissionning/568

https://elog.lal.in2p3.fr/THOMX/Commissionning/570

https://elog.lal.in2p3.fr/THOMX/Commissionning/571

The problem with the pulse jumpis with 12ns delays has been identified and fixed (it was related to the synchronisation system).

The main issue identified last week is a problem with RI-C2/PS/QP.09, RI-C2/PS/QP.10 and RI-C2/PS/QP.12 which has been addressed after the meeting (see https://elog.lal.in2p3.fr/THOMX/Commissionning/572).

It is important that the laser energy and linac beam charge are checked and optimised every week.

See attached files.

An IHM to check some of these parameters has been created (git/panneaux/StatusInfoIHM_ring_vars.py) and added to Plateforme_IHM...

(1),  (2), (4) and (5) from last week have been done other items in progress.

New to do list:

(0) Re-establish beam transport to ring

(1) Monitor incident power on RF Gun

(2) Check energy jitter in TL/BPM.02 and TL/SST.02

(3) Use TL optimised transport when available

(4) Compare single pass and TbT BPM signals

(5) Test Alexandre's feedback code.

(6) Scan correctors to increase current on RI-C1/BPM.01 and RI-C2/BPM.06

(7) Start align beam in quadrupoles
 

Slides are at https://indico.ijclab.in2p3.fr/event/8750/

- There is a difference in BPM numbering in Tango and MML => we should stick to Tango names.

- Beam was very unstable during the past week

- Difficulties to have full current on RI-C1/BPM.01. Signal drops already significanty before RI-C2/BPM.06

- Fluctuations may have been observed on the RF Gun power => to be confirmed

- Fluctuations have been observed on the kicker => may be due to energy jitter

To do:

- Monitor incident power on RF Gun

- Re-establish transport

- Try to inject with optimised TL transport

- Compare single pass and TbT BPM signals

- Check energy jitter in TL/BPM.02 and TL/SST.02

- Scan correctors to increase current on RI-C1/BPM.01 and RI-C2/BPM.06

- Start align beam in quadrupoles

The following parameters are required for ring operations:

- At least 50pC on TL/DG/ICT.01 with std <20pC

- At least 20pC on TL/DG/ICT.02 with std <20pC

- Energy in the TL must be checked and must be 50 MeV =>  TL/BPM.02 SpX, SpY <1mm  with Std(SpX, SpY) <1mm with nominal value for TL/PS/DP.01

- Beam position must be checked on TL/DG/SST.01, TL/DG/SST.02 and TL/DG/SST.03 and be within the acceptance (see tickbox acceptance on IHM_SST).

- Beam size must be measured on TL/DG/SST.03 and be < 2mm FWHM

- Beam recipes for the LI and for the TL must be saved.

- Health check must be checked (no red entry).

- Beam centered on the last quadrupoles of the transfer line.

This list will evolve as we progress in the ring commissioning.

This entry is to be updated as the work progresses.

1) Re-establish beam transport to ring

2) Scan in time the septum

see script git/panneaux/Synchro/scan_septum.py

3) Scan in voltage the septum

4) Adjust timing of kicker by looking at induced noise on ICTs

5) Scan in time the kicker

git/panneaux/Synchro/scan_kicker.py

6) Scan in voltage the kicker

7) Transport further in the ring by playing with correctors

Note: When possible Alexandre will test his feedback code.

Status slides presented by Iryna available on indico at https://indico.ijclab.in2p3.fr/event/8749/

The beam parameters required for a good injection in the ring were discussed.

The following required parameters were identified:

- At least 80pC on TL/DG/ICT.01

- At least 20pC on TL/DG/ICT.02

- Energy in the TL must be checked and must be 50 MeV.

- Beam position must be checked on TL/DG/SST.01, TL/DG/SST.02 and TL/DG/SST.03 and be within the acceptance (see tickbox acceptance on IHM_SST).

- Beam size must be measured on TL/DG/SST.03 and be < 2mm FWHM

- Beam recipes for the LI and for the TL must be saved.

- Health check must be checked (no red entry).

- Beam centered on the last quadrupole of the transfer line.

ACTION: Nicolas will create an interface that displays as many as possible of the required parameters.

Suggestion by Viktor: check phase noise at the gun entrance: there might a phase noise issue.

=> Vincent (VC) is going to do that with Viktor (VI) during RF studies on 26th September

Planning for the coming week:

- Wednesday: Slava (+Iryna after the CoDEC)

- Thursday: Nicolas + all

- Friday: AG Pole. Alexandre and Vincent plus Slava

Current objectives:

1) Re-establish beam transport to ring

2) Scan in time the septum

3) Scan in voltage the septum

4) Adjust timing of kicker by looking at induced noise on ICTs

5) Scan in time the kicker

6) Scan in voltage the kicker

7) Transport further in the ring by playing with correctors

Note: When possible Alexandre will test his feedback code.

8h35  mise sous tension: PSS, LB9000, modulateur, chillers

but : test fonctionnement modulateur et RF sur la journée

8h55 démarrage modulateur et refroidissement

10h00 démarrage RF ( HV=1090V )

visualisation signaux RF avec taurus plot : Pic Prc Pis Prs et photodiode

 -->  taurus plot er/sy/rac.17-elr.01-rdp.03/waveform_cha er/sy/rac.17-elr.01-rdp.03/waveform_chb  er/sy/rac.17-elr.01-rdp.01/waveform_cha er/sy/rac.17-elr.01-rdp.01/waveform er/sy/rac.17-elr.01-rdp.04/waveform_cha er/sy/rac.17-elr.01-rdp.04/waveform_chb

13h00 RF en fonctionnement depuis 10h00 ( pas d'interlocks )

14h00 RF ok - pas d'interlock modulateur

15h00 RF ok - pas d'interlock modulateur

16h00 RF ok - pas d'interlock modulateur

17h00 RF ok - pas d'interlock modulateur

17h15 arret

bilan : aucun interlock modulateur de 10h a 17h, tres peu de claquages , vide bon (1e-9 mbar), regulation temperature canon et section ok.

9h30 redemarrage HM MO

- niveau 1 verifié (circuit eau, air comprimé, etat modulateur et SF6)

- ronde modulateur faite

- lancement IHM

      lancement IHM modulateur : pas de reaction

      accès à la casemate bloqué car sonde T3G est en défaut, redémarrage du système mesures radioprotection (LB 9000) ==> sonde T3G Ok

- ronde casemate faite

- démarrage modulateur en local

- utilisation de heath check pour redemarrer les servers

- demarrage modulateur HT = 1000 V et refroidissement a distance (sdc)

13h probleme de synchro : pas de synchro sur modulateur - a verifier

--> la notice synchro stipule de démarrer le laser photocathode en mode interne : mise sous tension du laser : ok

- la synchro externe modulateur fonctionne. HT = 1090 V , Frep = 10 Hz.

       visualisation de PiC et Prc dans le hall D1 et salle de controle sur oscillo : ok

--> pas trouvé comment visualiser les signaux RF avec interface Taurus

visualisation Pis et Prs

--> sauvegarde signaux RF sur clef usb

bilan : 3h de RF dans la canon et la section LIL, vide correct

test longue durée demain

17h15 arret

Les tests se sont bien déroulés, on observe bien les signaux correspondants au redpitayas demandés.

Il faudra faire une modification sur l'IHM car tango bloque par moment et cela "freeze" l'IHM que l'on doit complètement redémarrer.

Tests des redpitaya 4 voie 1 (Photodiode) et voie 2 (Q section)