Cryogenic Target Shift
The Cryogenic Target
The Hall D cryogenic target consists of a tapered kapton target cell of 40 cm length, 2 cm diameter, a vacuum chamber, a pulse tube refrigerator, a compressor and its water cooling system, a gas manifold and panel, the electronic controls (PLC logic), support cart and safety storage tanks. The figure below show some of its main components.
Media: target_fig.pdf
The cell can be filled with liquid H2 (physics run) or gas H2 (empty run). It has a 130 um kapton wall and 75 um entrance and exit kapton windows.
Routine Operation
There are 3 routine operations:
- ""Fill target with LH2""
- ""Empty target (then target is filled with gaseous H2)""
- ""Target off""
"Target off" triggers the warm-up of the system.
If you did not receive target training, do not operate the target and call an expert.
Interlocks
When filled with LH2, P=18 psia and T=17K. Safety interlocks protect the target if the temperature decreases below 16K or the pressure decreases 16 psia.
If such event happens, the target should not be damaged. However, beam time will be lost. ""Call an expert immediately""
Detector Expert On Call
The individuals responsible for the operation of the Cryogenic Target are shown in the following table.
| Name | Extension | Date of qualification |
|---|---|---|
| SC EXPERT ON CALL | XXX-XXX | June 12, 2014 |
| Jlab Person | 269-xxxx | June 12, 2014 |
