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Double Polarized DD-Fusion Research at Petersburg Nuclear Physics Institute

Explore the main 4-nucleon fusion reaction as a testing ground for microscopic calculations with systematic spin correlation coefficient measurements, enhancing cross section, and suppressing neutrons. Follow the history of the PolFusion collaboration's experiments on polarized deuterium fusion. Learn about trajectory control of fusion products and the optimization of magnet systems. Discover the design, cooling system, dissociator, and other elements of the ABS beam at Petersburg Nuclear Physics Institute.

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Double Polarized DD-Fusion Research at Petersburg Nuclear Physics Institute

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  1. Petersburg Nuclear Physics Institute DOUBLE POLARIZED DD-FUSION P. Kravtsov for the PolFusion collaboration P. Kravtsov

  2. Double polarized dd-fusion The main 4-nucleon fusion reaction – good testing ground for microscopic calculations t + p d + d 3He + n • Systematic measurements of the spin-correlation coefficients • Cross section increase • [R.M. Kulsrud et al., Phys. Rev. Lett. 49, 1248 (1982)] • 3He+d → 4He+p : Factor ~1.5 at 430 keV • [Ch. Leemann et al., Annals of Phys. 66, 810 (1971)] • Neutrons suppression • Quintet suppression factor • [H. Paetz gen. Schieck, Eur. Phys. J. A 44, 321–354 (2010)] • [Deltuva and Fonseca, Phys. Rev. C 81 (2010)] • Trajectories control of the fusion products P. Kravtsov

  3. History (Polarized) Deuterium Fusion experiments P. Kravtsov

  4. The Quintet suppression factor Direct experiment required! P. Kravtsov

  5. Measurement of the polarization correlation coefficients in reactions 2H(d, p)3H and 2H(d, n)3He at low energies. History B.P. Ad’jasevich, V.G. Antonenko 1976 P. Kravtsov

  6. PolFusion PolFusion collaboration Petersburg Nuclear Physics Institute, Russia Forschungszentrum Jülich, Germany Cologne University, Germany Juelich ABS Polarimetry Detector SAPIS ABS KVI, Gronningen, Netherlands University ITMO, St.Petersburg, Russia POLIS students ABS ABS ABS Detector POLIS Exp. Hall Polarimetry Ferrara University, Italy P. Kravtsov

  7. Experiment layout (60000 events) P. Kravtsov

  8. Experiment layout (60000 events) P. Kravtsov

  9. ABS (based on SAPIS ABS) Magnet system optimization Before optimization After optimization ~6000 L/s P. Kravtsov

  10. Trajectories simulation • True 3-dimensional simulation • Multipole magnetic field model Magnetic field model of the multipole magnets A. Vasilyev, S. Sherman, Preprint PNPI-2720 (2007) P. Kravtsov

  11. Permanent multipole magnets • 3-dimensional FEM calculations • Cheap NdFeB magnets Magnetic field model of the multipole magnets K. Ivshin et al., Preprint PNPI-2925 (2013) P. Kravtsov

  12. ABS dissociator • Water cooling • Vacuum system • Control system • Dissociator • Magnet support • RF units Cooled nozzle (70-300K) plasma P. Kravtsov

  13. Ferrara ABS • 4 times higher intensity • Compact design P. Kravtsov

  14. Degree of dissociation and intensity measurements Two-coordinate table • QMS • Compression tube • Faraday cup P. Kravtsov

  15. POLIS Ion source 2010 P. Kravtsov

  16. POLIS. Control system. • compact (high channel density) • widely used in our systems at BNL, FZJ, PSI, GSI and AIRBUS test rig • VERY old (is not supported 10 years) • failed to work in KVI before departure P. Kravtsov

  17. POLIS. New control system (cooling + vacuum). P. Kravtsov

  18. POLIS. Current state. • Water cooling • Vacuum system [pressure : 2·10-7 mbar] • Control system [vacuum and cooling only] • Magnets • Dissociator • RF units P. Kravtsov

  19. Cooling system • System parameters: • Liquid-air heatexchanger • Cooling power: 100kW • Coolant: water + 10% ethanol • Flowrate: 1.4 l/s • Temperature drop: 30-50°C P. Kravtsov

  20. Polarimetry ABS beam: Lamb-shift Polarimeter Ion beam: Lamb-shift Polarimeter or Nuclear Reaction Polarimeter LSP: Ed<=4keV, short-term measurements NRP: Ed>=19keV, long-term measurements (target deuterium is renewed by the beam) Proof of principle: L. Kroell. Diploma thesis, 2010. FZJ – RWTH. P. Kravtsov

  21. Interaction chamber and detector system Readout electronics connectors Helmholtz coils NdFeB permanent magnets Detector system Interaction chamber P. Kravtsov

  22. Detector system. PIN diodes version. • 4- detector setup with 51% filling • ~ 576 Hamamatsu Si PIN photodiodes (S3590-09) • 1 cm2 active area • 300 um depletion layer • good energy resolution (17 keV for 1 MeV Carbon ions at RHIC) Square detector elements (4x4 diodes) Standard PCB assembly with spring through-hole mounting (no solder!) P. Kravtsov

  23. Detector test bench Alpha-source: 239Pu + 240Pu = 80.4% 238Pu + 241Am = 19.6% 234U + 235U + 238U 241Am P. Kravtsov

  24. PIN-diode measurements: Dead layer thickness Alpha-source: Pu239 + Pu240 = 80.4% Pu238 + Am241 = 19.6% Dead layer measurements: P. Monich. Bachelor thesis, 2011. ITMO University. D≤1μm P. Kravtsov

  25. PIN-diode measurements: Surface scan P. Kravtsov

  26. PIN-diode measurements: Hydrogen vacuum Test condition: 10-4 mbar hydrogen Experiment condition: 10-5÷10-6mbar P. Kravtsov

  27. Readout electronics CSP from ATLAS CSC [BNL] Readout requirements: • 600 channels • Total count rate≤ 1kHz • Standard interface (Ethernet?) • Event synchronization for coincidence trigger Junnarkar et al. IEEE Nuclear Science Symposium Conference Record (2005) P. Kravtsov

  28. Readout electronics: module diagram P. Kravtsov

  29. Readout electronics prototype P. Kravtsov

  30. Readout electronics: test signal Test pulse ~ 1 MeV P. Kravtsov

  31. Working Plan • Infrastructure • Experimental hall preparation March 2011 • Platform for electronics May 2011 • Water cooling system June 2013 • Assemble and run the POLIS source • Mechanical assembling June 2011 • Vacuum+ water distribution system March 2012 • Control system February 2012 • Adjustments and tuning End 2013 • Solid target experiment Spring 2014 • Upgrade of the SAPIS ABS • Vacuum system December 2012 • Magnet system design February 2013 • Dissociator design June 2013 • Transition units design March 2013 • ABS tests and tuning December 2013 • Detector system • Interaction chamber April 2011 • PIN-diod measurements September 2012 • Mechanical support design Spring 2012 • Readout electronics design Fall 2012 • Electronics production December 2013 P. Kravtsov

  32. Thank you! P. Kravtsov

  33. P. Kravtsov

  34. BACKUP P. Kravtsov

  35. Charge sensitive preamplifier (CSP) CSP from ATLAS CSC [BNL] P. Kravtsov

  36. Hyperfine states P. Kravtsov

  37. Count rate P. Kravtsov

  38. Data situation Tagishi et al.; Phy. Rev. C 46 (1992) 1155-1158 [Analysing Powers: 2H(d,p)3H, solid target] Becker et al. Few Body Sys. 13 (1992) [Analysing Powers] Imig et al. Phys.Rev. C 73 (2006) [Spin-Transfer Koeff.] All experiments were performed at solid targets P. Kravtsov

  39. The Formula Spins of both deuterons are aligned: Only pz(qz) and pzz(qzz) ≠ 0 Only beam is polarized: (pi,j ≠ 0, qi,j = 0) σ(ϴ,Φ) = σ0(ϴ) · {1 + 3/2 Ay(ϴ) py + 1/2 Axz(ϴ) pxz + 1/6 Axx-yy(ϴ) pxx-zz + 2/3 Azz(ϴ) pzz } P. Kravtsov

  40. Unpolarized cross sections R. E. Brown, N. Jarmie, Phys. Rev. C 41 N4 (1990) P. Kravtsov

  41. Polarization measurement P. Kravtsov

  42. Deuterium polarization P. Kravtsov

  43. Initial detector system • 4- rotational gimbal support • step motors with good angular resolution (~0.01 degree) P. Kravtsov

  44. Experimental hall 2009 2010 Sep 2011 May 2011 P. Kravtsov

  45. Experimental hall. Equipment layout P. Kravtsov

  46. Electronics platform P. Kravtsov

  47. Participating Institutions Petersburg Nuclear Physics Institute, Russia Forschungszentrum Jülich, Germany Cologne University, Germany KVI, Gronningen, Netherlands University ITMO, St.Petersburg, Russia Ferrara University, Italy Financial support: ISTC project #3881 Deutsche Forschungsgemeinschaft Ministry of Science and Education P. Kravtsov

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