The main task for today is to measure the revolution frequency without RF cavity with the spectrum analyzer.

Start-up of the machine.

After setting the previous setting, the orbit was very different. We checked the injector, the beam also was different (based on the beam images) and based on the RF plots we suspected that the timing of the laser has changed.

We changed the delays, reworked the transport but then it needed much more time to optimize the injection. We made the reseanoble storage but decided  to come back to the original settings (to be consistent in oour studies). After that, not clear why, the orbit came back to the expected values (as it was on Friday).

Start of the spectrum analyzer. Machine is set to the seetings from last Friday. Beam in the ring is not very stable. We had a few kV in the RF cavity for a short period of time.

Measurements without the RF power and one measurement with a small power (a few kV). Plots are attached. The screenshot was done for the different oribt (dipole values).  Prelimenary conclusions: At nominal lattice (with some scaling), we can keep the beam in the ring in the energy range, which corresponds to the attenuation of the RF section of 1.97-2.14 dB (nominal is 2.03 dB). This coresponds to the revolution frequency range of x30 => 500.33 - 500.47 MHz.

At this frequency, the  mean orbit changes from about ~-3 to +3 mm.

Taking into acount this freauency/orbit change (70 kHz - ~3mm), it means that to come to the nominal RF frequency of 500.02 MHz, the mean value of the orbit in radial direction should be increased by about ~18 mm. The calculations show also that to reach teh nominal frequency due to the energy change ~5-7%, the larmor radius in dipoles should be increased by ~20 mm. All this is in agreement with what we have measured today.

=> All this estimations are certainly prelimenary.

Problem with RF cavity. Mohamed tried to solve it during the day, No storing power. We need the RF cavity to continue our studies.