AGS Ggamma=7.5 B-field Scan Procedure ( Polarization vs. B-field)

6/12/09

The purpose of the scan is to find the width of the polarization dip (as a measure of the resonance strength). Currently, this setup is on AGS user2. We have Ggamma-meter(Gpm/Ags/Polarized_protons/Ggamma_Bfr.mon) now. For the B-field scan, we need to document the Ggamma from the Gpm and the rf frequency from the labview program. For good quality data, we need both Ggamma and horizontal tune to be flat on the flattop(presumably is done before the scan). The vertical tune is going to be above 8.96 (in the spin tune gap).
The study would be to look around Ggamma=N+Qx and M-Qx. Given the fact that the Qx is 8.72, we are looking around Ggamma=7.28 and 7.72. The B-field and rf frequency should be recorded in the Krisch sheet in spare columns.

1. B-field is changed from the AGS main magnet function. For every change of B field, the reverted-to-model should be done from opticscontrol application.
2. rf frequency are measured from labview program HP53310a_Linux-94.vi. It has been set up properly on MCR console 3.
3. The timing in the AgsOrbitDisplay application should be set to cover the whole range, 150-1750ms. The ramp is from 150-260ms; polarization measurement takes place between 600-1750ms.
4. Follow the recipe of "AGS Polarization Measurement at Ggamma=7.5" to change the ini file before start.
5. Take polarization measurement at the nominal field. Then moving to Ggamma value of 7.28. Take polarization measurements with field scan step of 10G. If the polarization dip is very sharp, a smaller step should be chosen.
6. Take polarization measurement at the nominal field. Then moving to Ggamma value of 7.72. To move the B-field, Move all five points on the flattop with SAME step. If Ggamma is not flat after change all of with same step, one need to go back to the regular flattop. Take polarization measurements with field scan step of 10G. If the polarization dip is very sharp, a smaller step should be chosen.
7. Follow the recipe of "AGS Polarization Measurement at Ggamma=7.5" to change the ini file after finish.

Haixin