Hall A Target Configuration

David Meekins

July 17, 2006

Target Positions

The following table gives a list of target positions and materials. Note that the Loop 1 and Loop 2 fluids will be switched on July 24, 2006. The lead will remain in Loop 1.

Cryogenic target window thicknesses

Target	Entrance Window (mm) ± 0.005	Exit Window (mm) ± 0.005
Loop 1 4 cm	0.127	0.149
Loop 1 15 cm	0.114 (Pb 0.279)	0.174
Loop 2 4 cm	0.127	0.113
Loop 2 15 cm	0.118	0.040
Loop 3 4 cm	0.112	0.140
Loop3 15 cm	0.114	0.120

Optics target thicknesses

The optics target consists of 7 carbon foils cut from the same sheet. The foils are 99.5% chemically pure carbon. Each foil is 0.042 ± 0.001 g/cm². Foils are separated by 4cm.

Dummy target thicknesses

The dummy targets are made of Al 6061-T6. All foils are 0.259 ± 0.001 g/ cm².

Solid target ladder

The following table gives the target foil position, thicknesses and chemical purities.

Target Position	Purity	Thickness g/cm^2
BeO	99%	0.149 ± 0.001
C	99.95%	0.0838 ± 0.0005
Ta	99.5%	0.0202 ± 0.0001
Slanted C	99.95%	0.111 ± 0.001
Slanted Fe	99.5%	0.119± 0.001

The angle of the slanted target is roughly 30 degrees. The actual number can be found from the survey results.

Pictures