IPUs of CTF3: Formulae for position and current calculation

Position calculation (alignment errors not included)

A_H, B_H, A_V, B_V - pick-up slopes and offsets for horizontal and vertical planes measured on a lab test bench, they are listed in the table below

DH_CAL+, DH_CAL-, DV_CAL+, DV_CAL-, S_CAL+, S_{CAL -} - signal amplitudes from the calibration with the Calibration Current Generator pulses; the values are from both, positive and negative calibration

DH, DV, S - signal amplitude measured

Error [mm] ± (0.1 + 1 %) for positions < 5 mm

Beam current calculation

Calibration current I_CAL = 0.3 A ± 0.1%, 1.5 or 150 ms

Pick-Up coefficients

BPM	AH	BH	AV	BV
402	15.23	-0.08	15.27	0.10
502	15.34	-0.03	15.33	0.04
590
690	15.14	0.02	15.28	0.06
790	15.34	0.08	15.25	0.03
825
890	15.04	-0.07	15.02	0.16

The coefficients are believed to be measured with the error not larger than some ± 20 mm

Amplifier gains

Gain	GD [V/V]	GS [V/V]
Low gain (beam current < 10 A)	5.8	1.85	3.1
High gain (beam current < 1 A)	58	18.5	3.1
The exact gain values are measured during the online calibration and they are expected to not differ by more than 2 % from the table values.

(c) M.Gasior, AB/BDI/PI. Last updated: 22/10/03.