Experiment POLFUSION

Transcription

1 Petersburg Nuclear Physics Institute National Research Center "Kurchatov Institute" Experiment POLFUSION A. Vasilyev for PolFusion collaboration 1

2 Collaboration Petersburg Nuclear Physics Institute, Russia Forschungszentrum Jülich, Germany Ferrara University, Italy Cologne University, Germany KVI, Gronningen, Netherlands Financial support: Russian Science Foundation 2

3 Goal of the experiment Investigation of 4-nucleons reaction with the both initial particles polarization at the kev energy (center of mass). 3 He p d + d t + p 3 He + n d d t n 3

4 History Kurchatov Institute B. Ad jasevich V. Antonenko

5 Aims of the experiment Measurements of the cross section polarized dd reaction Systematic measurements of spin-correlation coefficients [R.M. Kulsrud et al., Phys. Rev. Lett. 49, 1248 (1982)] 3 He+d 4 He+p : Factor ~1.5 at 430 kev [Ch. Leemann et al., Annals of Phys. 66, 810 (1971)] Measurements of neutrons suppression - Quintet suppression factor [H. Paetz gen. Schieck, Eur. Phys. J. A 44, (2010)] [Deltuva and Fonseca, Phys. Rev. C 81 (2010)] Angular distribution of the reaction products Investigation of the principle possibility polarized fuel for Fusion reactors Persistence of the Polarization in a Fusion Process [J.-P. Didelez and C. Deutsch. Few-Body Conference, Bonn (2009)] A. Vasilyev

6 The Quintet suppression factor σ1,1 QSF = σ σ 0 = ( 2σ + 4σ + σ + 2σ ) 1,1 1,0 0,0 1, 1 Direct measurements are necessary! 6

7 dd reaction experiments Unpolarized beam, unpolarized solid target Unpolarized beam, unpolarised gas target Polarized beam, unpolarized solid target Polarized beam, unpolarized gas 7

8 Scheme of the experiment 3 2+ He (0.8 MeV), 3 H + (1.0 MeV) d 0 (0.1 ev) ABS Ferrara (IUCF) ABS 16 I ~ 4 10 a t/s Target density ~ a t/cm Vector polarization: ± dd-polarimeter or LSP d Luminosity: /cm s count rate: ~ 120/h (30keV) 3 week beam time (60000 events) He + d + H 0 d 3 d 0 (0.1 ev) LSP + + n + e + p + e Lamb-Shift Polarimeter d + (1-32 kev) n (2.4 MeV), p (3.0 MeV) Ion source Polarized Ion Source Ion beam: I = 20 µ A ( d/s) E beam = 32 kev Vector polarization: ± 0.7 8

9 How to get polarized deuterons W/ Δ W I = 1 m I = 0, ± 1 F=3/2 F=1/2 F = I + m F +3/2 +1/2-1/2-3/2-1/2 +1/2 S = m S 1 2 = ± 1 2 S F = m F 1, 2 = ± or 1: m S= +1/2 m I= +1 2: m S= +1/2 m I= 0 3: m +1/2-1 S= m I= 4: m S=- 1/2 m I= -1 5: m =- 1/2 m = 0 S I 6: m =- 1/2 m = +1 S I ± 1 3, ± 2 2 P z Vector polarization N N P z = N + N + N χ = B/B c P zz Tensor polarization N 2N + N P zz = N + N + N χ = B/B c χ=b/b c B c =117 G ΔW= ev 9

10 Simple model of hydrogen polarized source dissociator (H H + H) 2 1st group of 6-pole magnets RF transition unit 2nd group of 6-pole magnets MFT on H MFT off 10

11 Polarized Atomic Beam Source (ABS) 11

12 POLIS 12

13 Detector System Primary electronics connectors Permanent magnets for holding field NdFeB Detector Detector s chamber 13

14 Detector s magnetic system Btotal Btransverse 250 Magnetic field, G Axis coordinate, mm A. Vasilyev

15 Formulas For the complete description we have to know 36 parameters For the beams with cylindrical symmetry : only p z (q z ) and p zz (q zz ) 0 If we have only one polarized deuteron: (p i,j 0, q i,j = 0) σ(θ,φ) = σ 0 (ϴ) {1 + 3/2 A y (ϴ) p y + 1/2 A xz (ϴ) p zz + 1/6 A xx-yy (ϴ) p xx-zz + 2/3 A zz (ϴ) p xz } 15

16 Detector system 4-π detector with filling 51% 576 Hamamatsu PIN photodiods (S ) active area of PIN diode: 1 cm 2 the depletion layer thickness: 300 um resolution 20-30keV 16

17 Electronics 600 channels Count rate 1kHz Standard interface -Ethernet Self-trigger Synchronization for coincidences analyses CSP from ATLAS CSC [BNL] Junnarkar et al. IEEE Nuclear Science Symposium Conference Record (2005) Detector 48 channel Waveform digitizer (WFD) ASF-48 ADC FPGA Concentrator FPGA 2x24-channel CSP Charge Sensitive Preamplifier + Shaper 6 x ADC 12 bit, 65MHz Self-triggered WFD 12 bit resolution count rate up to 50 khz 17

18 Readout electronics ASF-48 Concentrator CROS3 Power supply ASF48 (12+1) 18

19 Ion beam tests on the solid target deuterated Plexiglas 15 kev deuteron beam 19

20 Plans 2015 dd reaction of unpolarized atomic beam with ion beam kev 2016 Polarimetry kev energy of the ion beam beams polarization 2017 Systematic measurements 20

21 Backup 21

22 Доклады на конференциях K. Grigoryev et al., Double polarized dd-fusion experiment. SPIN Journal of Physics: Conference Series 295 (2011) P. Kravtsov et al., Double polarized dd-fusion. PSTP-2011, St.-Petersburg, Russia. R. Engels et al., Polarized Fusion. SPIN Physics of Particles and Nuclei, Vol. 45, No. 1, pp (2014). P. Kravchenko, Current status of physics analysis and data analysis software for PolFusion experiment in PNPI, Gatchina. Nuclear fusion with polarized nucleons. International meeting, Trento (2013). P. Kravtsov, Status of the double-polarized DD-Fusion Experiment. Nuclear fusion with polarized nucleons. International meeting, Trento (2013). R. Engels et al., Polarized Fusion: Can Polarization Help to Increase the Energy Output of Fusion Reactors? SPIN /07/15 А. Васильев 22

23 BACKUP 24/07/15 А. Васильев 23

24 Постоянные многополюсные магниты Трехмерный расчет поля Бюджетные NdFeB магниты Многополюсные неодимовые магниты для источника поляризованных атомов К. Ившин и др., Препринт PNPI-2925 (2013) B Bcalc B, T Angle, deg 24/07/15 А. Васильев 24

25 Polarization measurement B B B B B Photomultiplier t Atomic beam from the ABS Ionizer Wien filter Cs cell Spin filter Ionization of atoms Spin axis rotation Ions to metastable atoms Spin separation Quenching chamber Emission of photons Faraday Cup Ly-spectrum N(Ly- α ) 160 Pz(Ly- α) = m I =+1 Pzz(Ly- α) = MFT 3-4 SFT Pz = +1 te or 100 P teor = m I =0 zz m I = 1 N(Ly- α ) Pz(Ly- α) = P (Ly- α) = zz MFT 3-4 WFT te or P = -1 z teor P = +1 zz m I =+1 m I =0 m I = 1 N(Ly- α ) P α ) = 0 z Pzz(Ly- α) = WFT 1-4 m I =+1 SFT 2-6 m I = 1 te or Pz = 0 teor P = +1 zz m I =0 N(Ly- α ) m I =+1 m I =0 Pz(Ly- α) = Pzz(Ly- α) = WFT 1-4 SFT 3-5 te or Pz = 0 teor P = -2 zz m I = P z = 0.73±0.05 P z = 0.82± Magnetic field, a.u. Magnetic field, a.u. Magnetic field, a.u. Magnetic field, a.u P zz = 0.77±0.06 P zz = 1.17± /07/15 А. Васильев 25