1. SksMinus status 05 HB meeting 2008/5/16 白鳥昂太郎

2. Contents  Helium target

3. Helium target status Designed by Ishimoto-san 335 mm  Optimize Target length : 335 mm (very tight length)  Target shape : Cylinder → Elliptic cylinder, material selection  Arm design : HBJ frame  Test Cooling test by refrigerator Existent vacuum chamber with the same arm length Hyperball-J (Frame outer size)

4. Points  Arm design : No interference to HBJ frame  Target shape : Not cylinder ? Material : Al or CFRP As small background as possible Thickness : Enough thickness to pressure or thin surface with additional parts

5. Arm design Hyperball-J (Frame outer size)

6. Arm design Target arm cannot be changed ! 1. The design is the unique solution of the design for the tilted arm. 2. 45°is the limit to connect the target cell. →The tile angle can be smaller, if the Helium target refrigerator moves to the upstream. But, the upstream part of the target cell length has to be longer. In addition, the connection structure is very thigh to change.

7. Target shape

8.  Cylinder target is much better than ellipse cylinder target. Target outer cell becomes larger ! The thickness of surface becomes thicker. There is no good method to make thinner ellipse cylinder target than cylinder target. Ishimoto-san and company have no experience to make such an ellipse cylinder target. ⇒ R&D  The diameter of 220 mm is the limit, if the inner cell diameter is 120 mm.  Cooling time can be faster with the change of the heat exchanger. (And, at first by using liquid Helium, it can be much faster.)

9. Refrigerator  Ishimoto-san has 2 refrigerators and 1 compressor. We can use 1 set of refrigerator and compressor. If possible, he wants to buy 1 compressor. Cost: refrigerator : 230 万円, compressor : 230 万円, set : 450 万円  The structure of heat exchanger will be changed for the Helium cooling. In previous his test, the structure is for the liquid Hydrogen target.

10. Refrigerator From compressor Helium duct Heat exchanger Vacuum pump port Helium buffer tank

11. Pictures

12. Summary  Target arm : To change Hyperball-J frame  Target shape : Cylinder (Ellipse cylinder R&D) ⇒ Design is finished, after those things are fixed. And, Ishimoto-san will estimate the total cost.  Test : To cool Helium to the liquid with the refrigerator optimize.

13. Plan 図面⇒干渉チェック HBJ の干渉を見て避けるような geometry でシ ミュレーション