Geometry of the Spectrometer Detector Packages

Tables  5.1 and  5.2 give geometry information for the electron arm and hadron arm detector packages. The values in the tables indicate the position of the central point of the detector. The origin of coordinate system (0,0,0) is located at the intersection of the mid plane of the spectrometer and the nominal focal plane ( $\sim$ middle of the Bottom VDC ).

Table 5.1: Locations of the detectors on Electron Arm in mm.

detector	location	location	width	width	BEAM		ENVELOPE
	actual	IDEAS model	X	Y	X(+)	X($-$)	Y
VDC1*	0		1942	271	843	- 824	+/- 57
VDC2*	572		1942	271	932	- 911	+/- 85
S1	1311	1321	1718	356	696	-1022	+/- 163
AERO	1646		199	414	709	- 888	+/- 182
GAS	2535		2200	650	886	-1110	+/- 279
S2	3358	3378	2197	540	897	-1124	+/- 285
preSHOW	3502	3546	2400	700	925	-1158	+/- 301
SHOW2	3780	3912	2400	900	964	-1207	+/- 322

Table 5.2: Locations of the detectors on Hadron Arm in mm.

detector	location	location	width	width	BEAM		ENVELOPE
	actual	IDEAS model	X	Y	X(+)	X($-$)	Y
VDC1*		0	1942	271	843	- 824	+/- 57
VDC2*		500	1942	271	932	- 911	+/- 85
S1		1287	1760	360	675	- 845	+/- 163
AERO		1617	1872	414	709	- 888	+/- 182
SC1		1837	1780	480	738	- 924	+/- 198
GAS		2409	2200	650	857	-1073	+/- 263
SC2		2952	2080	640	865	-1083	+/- 268
S2		3141	2220	640	877	-1099	+/- 274
Analyzer		3495	2190	680	916	-1147	+/- 296
SC3		3907	2540	1000	1099	-1343	+/- 457
SC4		4264	3170	1500	1382	-1645	+/- 705
S3		4477	3600	1550	1437	-1704	+/- 752