1. Overview installation of Polarized Target 14th Crystal Ball Meeting
0.- Hydrogen Target Length
1.- Polarized target tests
2.- Rail System for ‘Frozen Spin’ mode
3.- CB Frame / Electronics
4.- Schedule
14th Crystal Ball Meeting
Edinburgh
September
Andreas Thomas

2. Note: Hydrogen Target Length
New Xray picture of 30mm cell at
[R.Kondratiev, O.Kostikov, A.Thomas]
Results:
3 cm cell mm h - Bump
5 cm cell mm standard
10 cm cell mm High luminosity

3. Components of the polarized target for the Crystal Ball detector
He3/He4 Roots
4000m3/h
Vacuum system
Components of the polarized target
for the Crystal Ball detector
Targetmaterial
H-Butanol
D-Butanol
Mikrowaves
70GHz
Dynamic
Nuclear
Polarization
Superconducting
Polarization magnet
5Tesla
NMR-Apparatus
106MHz
Polarisation meas.
Horizontal He3/He4 Dilutionrefrigerator
(20mKelvin)
with internal
Holding coil

4. Internal Holding coil · Current leads (46A): Copper T=300K  70 K
HTc Supracond. T= 70K  K
NbTi 200mm T= 4K  K
Internal
Holding coil
1.3Kelvin
??? Tesla at 46A
L=136mm, d=48mm, 4 layers
Support Copper-tube d=0.3mm

5. Full test with new insert and butanol target in June – July 2009

6. Polarizing
magnet
He4(liq)

7. Start

11. Stop

12. Calibration of the Holding coil field
B0=2.5Tesla
F= 106MHz
Observe shift of NMR-Signal depending on
holding coil current

13. B0=2.5Tesla
F= 106MHz
46A ~ 0.895Tesla

14. Internal transverse Holding coil
Coil tested at 4.2K
Henry Ortega
Started PhD in Mainz
Different layers are
used to
optimize the
homogeniety.

15. Simulation
Ideal case for dipole magnet:
“Racetrack” coil: magnetic field highly non-uniform and not appropriate for a cylinder.
“Saddle” coil: winding must fit to the so-called overlapping ellipse or “cosine” shape of current distribution (Wilson 2002 & Ašner 1999).

16. 4-layer dipole:
N1=N2=138
N3=N4=78
150mm

17. High Field Solenoid or
Transverse Field

18. The degree of polarization PT of the target protons (run in May ´98) :
Measurement of the degree
of proton polarization
with online NMR during
GDH data taking
New NMR  [N.Frömmgen]

19. Polarization method Crystal Ball Cryostat Polarizing magnet Polarizing
Rail system needed
Microwaves NMR
Microwaves
Polarizing
magnet
Polarizing
magnet
External magnet 2.5 T
Polarize with microwaves
Internal holding coil 0.7 T
Remove external magnet
Move CB detector in.
Data taking.
Repolarization

20. Rail system to Move the CBall, TAPS and Magnet
ACAD
rails
J.Rosche
Chassis
J.Ahrens
Electronics
A.Starostin
P.Pedroni
Move magnet
transverse
A.Thomas

21. Rails are beeing aligned
and fixed:
R.Kondratiev
O.Kostikov

22. Heavy load cars will be mounted
by J.Ahrens next week

23. Electronics has to be mounted
partially on CB frame:
A.Starostin
A.Lapik
M. Korolija

24. Schedule
1.- Polarized Target - tests in dilution mode reproduced successfully
- transverse coil tested at 4K
- DNP measured
- Colleagues from Dubna in Mainz Nov.-Dec.
2.- Rail system for CBall - Cables dismounted, Rails beeing aligned now
- First move of CB next week
- DAPHNE in storage hall, TOF detectors?
- Installation of part of electronics in CB-Frame?
3.- Installation of PT in CBall - Start in October
- Test beam in December for intensity dependent relaxation time etc.
- Transverse or Longitudinal coil.