Polarized solid Targets for AFTER Physics at A Fixed Target ExpeRiment using the LHC beams ECT, Trento, February 4 - 13, 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

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

HD radiation 0.30 moderate ?

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 12.8 9.3 28.9 30.00 12

Dynamic Nuclear Polarization (DNP) T = 1 K

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

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

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

HYDILE

HD Target Transport Cryostat

HD polarization: IBC In Beam Cryostat : 3He-4He dilution refregirator for experiment 250 mk 1.0 T Perspective View Al wire 2.5cm

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

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) 103011

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 !

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

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

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)

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

HD Target: NMR Measurements Field = 0.85 T – Temperature = 1.8 K Sample 1 [H2] = 2.0 10-4 [D2] = 1.7 10-3 Sample 2 [H2] = 6 10-4 [D2] = 9.0 10-4 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