1. HD target

2. outline HD target overview TC leak test by He detector purify HD
SC（Storage Cryostat）
cooling system test
superconducting magnet test

3. HD target overview

4. Characteristics of polarized HD target
Polarization Method
HD target is polarized by the static method using “brute force” at low
temperature (10 mK) and high magnetic field (17 T).
It takes about 2-3 months to polarize the target.
Advantage and disadvantage
HD molecule does not contain heavy nuclei such as Carbon and Nitrogen.
Good for experiments observing reactions with small cross section
The HD target needs thin aluminum wires (at most 20% in weight) to
insure the cooling.
Polarization
H : 90 % D : 60 %
Relaxation Time
30 days at 200 mK and 1 T during the experiment.
Target Size
25 mm in diameter mm in thickness

5. HD target transportation
RCNP Osaka university
Transfer Cryostat 1
From RCNP to SPring-8
Storage
Cryostat
BL33LEP SPring-8
Experiment
In Beam Cryostat
Transfer Cryostat 2
Dilution
Refrigerator K+ g
HD Target K-

6. Dilution refrigerator
Leiden Cryogenics
DRS-3000　(He3-He4)
Cooling power 　　 　
　　　3000μW at 120 mK
Lowest temperature 　
　　　 6 mK
Magnetic Field 　　　　
　　　17 T
Homogeneity of Magnetic Field
　　　5×10-4 for 15 cm

8. Two Transfer Cryostats
Right : used at RCNP
Left : used at SPring-8

9. outer vacuum chamber (OVC)
SC（Storage Cryostat）
outer vacuum chamber (OVC)
LN2 bath
LHe bath
main bath
superconducting magnet
target

10. IBC（In Beam Cryostat） for BL33LEP
2.5cm
Al wire

11. TC leak test by He detector

12. He detector

13. Step0: turn to “0”, then wait until “P” saturate3 1 2 4 5
OPEN P D
closed
outside

14. Step1: turn to “1”, then wait until “P” zero3 1 2 4 5
OPEN P D
closed
outside

15. Step2: turn to “2”, then wait until green LED light3 1 2 4 5
OPEN P D
closed
outside

16. Step3: open “3” 3 1 2 4 5
OPEN P D
opening
outside

17. Step4: turn “to 4”, if “P” increase now, the pipe is broken then wait until “D” zero3 1 2 4 5
OPEN P D
opened
outside

18. Step5: turn on “5”, adjust the unit of concentration start measurement (see “D”)3 1 2 4 5
OPEN P D
opened
outside

19. purify HD

20. purify HD

21. Distillator top D2 solid, H2 gas, HD liquid middle
D2 solid, H2 gas, HD gas
bottom
D2 solid, H2 gas, HD gas

22. HD～99.999％ H2
H2～50％
H2～2％
2 week
2 week
HD～50％
HD～96％
H2～4~6％
HD~95%
D2～2％

23. principle of concentration sensor
use filament to ionize gas
H2+
AMP
(amplifier)
sensor
ionize gas here
HD+
digital data
D2+
In amplifier, use different gain for each gas PC

24. SC（Storage Cryostat）
cooling system test

25. outer vacuum chamber (OVC)
SC（Storage Cryostat）
outer vacuum chamber (OVC)
LN2 bath
LHe bath
main bath
superconducting magnet
target

26. four thermometers in SC

27. Step 1
Evacuate the OVC for at least 24 hour before pre-cool system

28. For pre-cool LHe bath, we fill LN2 to LHe bath.
The Allen Bradly carbon resistance sensor in liquid helium bath reached ohm. It is close to 77 K

29. Transfer the LN2 from LHe bath to LN2 bath. we fill LHe to LHe bath.
The level of liquid nitrogen rose from 9.2% to 80%.
The Allen Bradly carbon resistance sensor in liquid helium bath reached 2691 ohm (around 6~7 K)

30. Transfer the LN2 from LHe bath to LN2 bath. we fill LHe to LHe bath.
We start pumping gas from main bath. The Allen Bradly carbon resistance sensor in liquid helium bath reached 4033 ohm (around 4~5 K) ,the temperature in bottom of main bath reached K, the temperature in top of main bath reached K. Temperature cannot drop more. The level of helium gas drop down. We find the helium tank empty.

31. pumping the main bath We remove the helium gas from main bath.
The temperature in top of main bath rose from K to K.
The temperature in bottom of main bath drop down from K to K .
The temperature keep around 1.53 K.

32. Test of SC cooling system is finished.

33. superconducting magnet test
SC（Storage Cryostat）
superconducting magnet test

34. Hall probe magnet sensor
Electrons (not Conventional current!)
Hall element, or Hall sensor
Magnets
Magnetic field
Power source

35. We installed a Hall probe into main bath in SC.

36. superconducting magnet
Zero the current.
Increase current, reach to middle current we set before ,then reach to max current we set before (Heater on）
Turn off Heater when reach the magnetic field intensity we need.
Decrease the current to middle current we set before, then zero the current.
Keep the persistent mode when we use superconducting magnet.
Increase current, reach to middle current we set before ,then reach to max current we set before (Heater off）
Heater on (Quenches) (dangerous!!)
turn off the heater. turn off the power supply. superconducting magnet test finish.

37. before we start test make the following electrical checks
magnet resistance
magnet to cryostat isolation
switch heater resistance
switch heater to cryostat isolation
magnet to switch heater isolation
(isolation values should typically be >1 MΩ unless otherwise stated)
open all of doors in experiment building.
take off everything with magnetic.

38. Typical calibration curve of Hall probe

39. The magnetic field of about 1 Tesla was confirmed by using a Hall probe.
Heater on
16:21
Heater on
16:30
persistent mode
28Mins
Heater off
15:53
Amps
Heater on
15:38 mV

40. Bonus

43. Physics objectives To investigate the ss content in the nucleon
by the gp -> fp (gn -> fn) reaction
To know the structure of the proton and neutron correctly is the
fundamental desire.
To determine the spin-parity of Q+ particle
Although I do not follow recent theoretical studies, to fix the initial nucleon spin and photon polarization must be important.
3 To study the reaction mechanism of the hyperon photoproduction
Recently some interesting results measuring the double polarization observables appeared.
Advanced studies need the polarized nucleon target.

44. pressure controller
concentration
sensor
bottom
middle
top
throw gas out
pressure
monitor
Distillator

45. concentration measurementD B F A H I C
gas here
gas here
gas here E
gas here
gas here
0. A ,B should closed, open D and G, measure background.
1. open A, get gas for top of Distillator. J G
2. close D, open B, then close B, now gas in C.
gas outside
3. open D, then close D, now gas from C to E
4. control pressure by F, see J the pressure should be 9.0x10-7 mbar
5. measure gas concentration by RGA (Residual gas Analyzer)
6. close the software RGA
7. open G, then close G throw the gas away