Post date: Mar 25, 2014 3:27:19 AM
Our plan for today is to do the COD measurement and use the D1 coils (on the D magnets either side of the RF cavity) to do correction. This is the first time this has been attempted so we will see how it goes.
Suzie asked for the horizontal triangle plate monitor to be connected in as well.
We will also attempt replacing the pre-amp on the vertical bunch monitor S7 lower plate to try to eliminate the ringing that is currently being observed (use one of the new ones) and see if it makes a difference.
This morning Shinji presented an update on the analysis from the vertical BPM data. He solved a problem with the analysis of the double plate BPM data - the bunch shape was slightly different between upper and lower plate so it was creating a large difference in signal prior to peak finding. The correct method is to first do peak finding and then take the difference.
Shinji has also calculated the tune from the coherent oscillations in the data (using both plates) and we can compare to the same calculation by Ishi-san using single plate data.
Mao Takabatake presented her work from her masters thesis including the transport efficiency, energy measurement and dp/p measurement. This was great and has provided us with lots of information about the linac pulse structure and injection line.
Post date: Mar 25, 2014 6:32:32 AM
We have measured the data using rf-ON radial probe method with F1, F5, F7.
Data files are here: https://drive.google.com/folderview?id=0B0q-OKLCj0rkc0ZZMEh5Z1ZTMU0&usp=sharing
We will now excite the D1 coil and repeat the measurement to see if we can achieve better COD correction. (Max current 300A so we will try 100A and 200A).
Update: the main corrector coil current was 468A, the acceleration scheme used the k value correction scheme so the acceleration rate is slightly different from the Nov'13 measurements. The excitation current used was 140A for the D1 coil.