1. Polarized solid Targets for AFTER
Physics at A Fixed Target ExpeRiment
using the LHC beams
ECT, Trento, February , 2013
Technical Constraints Beam
- Target
- FoM
Dynamic Polarization - Principle
- Frozen Spin Targets
- NMR
Static Polarization Principle
- HD Polarization
Dynamic Polarization of HD for Hadron Physics
From HD to DT for future “Fusion Power Plants”
J-P DIDELEZ

3. Target heating and damages
Compass
50 µW
15 mK
1 nA = ±1 mW = ±10E10 p/s
5×10E8 p/s = ± 50 µW
Limit before damages ±10E15 p/cm2
Run duration < 23 days

4. HD radiation moderate ?

5. ρ stands for the density of the material
Figure of Merit (FoM)
FoM = ρ k (f P) 2
t -1 ~ ρ k (f P) 2
ρ stands for the density of the material
k corresponds to the ratio of the volume
occupied by the material to the volume
of the target cell
f is the dilution factor
BUTANOL C4H9OH
H H H H
H – C – C – C – C – O – H
H H H H
f = 1 if free protons can be identified
f = 1/4.2 if target protons can be identified
f = 1/7.4 if target nucleons cannot be identified
AFTER HD
0.14
H :~0.9 D :~0.3
0.95
0.95 12

6. Dynamic Nuclear Polarization (DNP)
T = 1 K

7. COMPASS Polarized Target
Since 2011, NH3 is used as polarization material.

8. Polarization measurement by NMR
NH3
ND3
ΔP/P = 3% ΔP/P = 8%

9. Static Polarization of HD
B/T > 1500
Dilution Refrigerator 10 mK and 17 T (B/T = 1700)

11. HYDILE

12. HD Target Transport Cryostat

13. HD polarization: IBC
In Beam Cryostat : 3He-4He dilution refregirator for experiment
250 mk T
Perspective View
Al wire
2.5cm

15. IDEAL Target Dynamic Polarization of HD 70 K Shield Liquid 4He (4.2 K)
Saddle coils
Micro Wave
Polarized HD or D2
NMR Coils
Liquid 3He (0.5 K)
Solenoid Coil

16. M. Temporal et al., Nucl. Fusion 52 (2012) 103011
Inertial
Fusion
At fixed G: EB / EA < 0.7
for G=100 EA = 880 kJ
EB = 510 kJ
EAmin = 450 kJ
EBmin = 290 kJ
for E = 1 MJ GA = 140
GB = 307
A:unpolarized DT
B:polarized DT
Isobaric model: energy gain G versus the driver energy E, and EB/EA versus G
M. Temporal et al., Nucl. Fusion 52 (2012)

17. Conclusions Several polarized targets could be used for
future CERN projects.
- The best FoM is obtained with 6LiD or
HD material.
- Static polarization of HD is still
problematic (TJNaF, Spring-8)
- Dynamic polarization of HD should be
revisited
for
Hadronic Physics fundamental research
Thermonuclear Fusion power plants
THE REAL PROBLEM IS TO FIND
A GOOD TEAM
TO BUILD A POLARIZED TARGET !

18. Evolution du Temps de Relaxation Spin-Réseau
Des Protons en fonction du vieillissement du HD

19. HYDILE Target 70 K Shield Liquid 4He (4.2 K) Saddle coils Polarized HD
Al Wires
Polarized HD
NMR Coils
Liquid 3He (0.5 K)
Solenoid Coil

21. Proton NMR Signal Signal (Volt) Frequency (MHz) 0.016 0.014 0.012 0.01
0.008
Signal (Volt)
0.006
0.004
0.002
41.78
41.8
41.82
41.84
41.86
41.88
41.9
41.92
-0.002
-0.004
-0.006
Frequency (MHz)

22. Dispositif de Distillation
Suivi des concentrations
Spectromètre de masse quadripolaire
Résultat de la distillation
Colonne de distillation
Distillateur
DNP = Échantillon pour la polarisation dynamique
Statique = Échantillon pour la polarisation statique

23. HD Target: NMR Measurements
Field = 0.85 T – Temperature = 1.8 K
Sample 1
[H2] =
[D2] =
Sample 2
[H2] =
[D2] =
T1D
T1D
Back conversion at room temp.
for 5 hours is 30%
T1H
T1H
Temps de Relaxation du HD distillé
en fonction des concentrations en
ortho-H2