E852 Documentation: Detector Positions

This page is designed to be a repository of information on the positions of detectors for E852.

1995 Survey (postscript)

Target Center

X Position = .560" (1.4224 cm)

Y Position = 0.0" (0.0 cm)

Z Position = 70" (177.8 cm)

Source: Survey Log dated 12-22-94 (TA)

CsI

X Position = .560" (1.4224 cm)

Y Position = 0.0" (0.0 cm)

Z Position of downstream end = 84.139" (213.713 cm)

Source: Survey Log dated 12-22-94 (TA)

LGD

Z Position on front face = 280.475" (712.407 cm)

Source: Eric Scott (TA)

EV/BV

X and Y Position varies. Must be determined from motor readout.

Z Position = 274.93" (698.32 cm)

Source: Measurement by Todd Adams

Coordinates For Target,DEA and LGD

A note on positioning before 1994 run

Detector positions for 1997 run (proposal)

There are 2 possible scenarios:

1. Beam is parallel to the target at its center; normals to TDX4 and LGD have ~3mrad angle with MPS center line (variant I);
2. TDX4 and LGD are perpendicular to MPS center line; beam has ~3mrad angle at the target center (variant II).

	95 run	97 run (Var.I)	97 run (Var.II)
MPS magnet rotation angle, mrad	32.8(max)	29.0	32.8(max)
Beam angle at the target center, mrad	-4.5	0.0	3.7
X of beam at the target center, cm	1.42	1.66	2.33
Beam angle at DEA center, mrad	-24.1	-14.9	-11.1
X of beam at DEA center, cm	-0.26	0.76	1.89
X of DEA center to shadow LGD, cm	~ -3.5	-1.17	0.04
Beam angle at LGD mid-depth, mrad	-43.6	-30.4	-26.6
X of beam at LGD mid-depth, cm	-18.0	-11.5	-8.6

Variant II seems to be the better choice.