User name R. Michaels
Log entry time 00:49:18 on July23,2004
Entry number 129337
Followups:
keyword=Dipole field scanBackground Studies -- Dipole Field Scan
started at 21:00 7/22
We will increase the fields on Left arm in steps, to simulate
inelastic trajectories. Fields are increased on dipoles and
quads, by adjusting the momentum setting. Septum magnet are
kept fixed for this scan. The Right arm also remains at its
nominal field settings.
Run..... Field (P & %) ... Det1/bcm1 (%) ...... Det2/bcm1 (%)
.......................... cutting that bcm1>10000 (beam on).
3061 ... 2.971 .... 0 .... 4.23 .. 100%... 4.048 .. 100%
3062 ... field changing
3063 ... 3.0007 ... 1 % .. 0.029 ... 0.69% .. 1.464 .. 36.1 %
During increases of field, the L-arm dipole would dip to much
lower current before recovering. E.g. for change to 2% it dipped
to 830 Amps and took about 50 minues to recover. The runs during
L-arm field change should be considered production for R-arm.
3064 ... field changing (good R-arm production)
3065 ... 3.03042 ... 2 % .. 4.78e-3 ... 0.11% ... 1.65e-2 .. 0.41 %
3066 ... field changing (R-arm prod.)
3067 ... 3.08984 ... 4 % .. 2.1e-2 .... 0.50% ... 1.93e-2 .. 0.47 %
3068 ... field changing (R-arm prod)
3069 ... junk
3070 ... 3.16 ...... 6.4 % .. 4.81e-3 .. 0.11% .. 1.17e-2 .. 0.29 %
Apparently 3.16 GeV is an administrative limit (software won't
permit us to go higher). We tried to change the current; this
worked for the quads but the dipole refused to go above 3.16 GeV.
Tried/failed to page a likely expert. Will ask around tomorrow.
Below is a plot of the HAPPEX DAQ results for det1 and det2.
It levels off. Hmmm... I hope the pedestals are correct.
We didn't run the spectr. DAQ scan because I think we may want
to repeat this anyway with a higher admin. limit.
Next up: septum magnet scan.
FIGURE 1
