heep

Vertical beam position in OOP offsets 03/27/06

Mark pointed out that the first data point below can not be used because it has the electron in the HMS rather than the SOS. To use this setting the equation used to determine the vertical offset was changed to
xptar_sos -(0.43-1.14*hsp/ssp)*d + P_hms/P_sos*xptar_hms = 0

Ebeam Phms/Psos    Centriod of ssxptar+(hsp/ssp)*hsxptar [mrad]
----- ----------   -----------------------------------------
2038      1.94             3.50
4021      2.03             5.15
5012      2.89             7.78
5766      2.33             6.29

The fitted line is -3.42 + 3.96(P_hms/P_sos) [mrad]

Vertical beam position in OOP offsets 03/23/06

The heep runs were replayed with all of the previously determined heep offsets. The previously determined oop offsets were in the Analyzer, but were not written to the ntuple xptar variables.

Plots of ssxptar*ssp+hsxptar*hsp are here (bottom right in each panel).

Plots of xptar_e+(P_p/P_e)*xptar_p are here (bottom right in each panel).

Instructions from Mark about fitting the OOP offsets.

Using the new plots, new results were generated for the vertical beam position.

Ebeam Phms/Psos    Centriod of psos*xptar_sos+phms*xptar_hms [MeV*rad]
----- ----------   -----------------------------------------
2038      1.94             3.16
4021      2.03             8.17
5012      2.89             13.75
5766      2.33             10.51

I fit a straight line to these values and obtained
intercept = -12.655 [MeV*rad]
slope     = 9.3808 [MeV*rad]

However, from the first equation in Mark's instructions, it looks like I should be plotting
xptar_e + P_p/P_e*xptar_p vs. P_p/P_e
So I did that and here are the results
(Mark also pointed out that the Phms/Psos column should actually be P_p/P_e, which produced the reciprocal for the 2038 setting)

Ebeam P_p/P_e    Centriod of xptar_e+(P_p/P_e)*xptar_p [rad]
----- ----------   -----------------------------------------
2038      0.52             0.0018
4021      2.03             0.0051
5012      2.89             0.0081
5766      2.33             0.0063

Intercept = 0.277 [mrad]
slope     = 2.60 [mrad]

Using the second table
0.277 = 0.43*d - off_sos , if off_sos = 2.6mr then d = 6.7mm
2.60 = -(1.14*d+off_hms) , if off_hms = -1.1mr then d= 1.3mm

These beam offsets do not look even close to the BPM position of 0 +- 0.3mm.

Fit to the results in table 1 (Y axis has the units of MeV*rad)

Fit to the results in table 2 (Y axis has the units of mrad)