Introduction to RAON & Detector Systems for Nuclear Physics

Transcription

1 3 rd Japan-Korea PHENIX Collaboration Meeting RIKEN, Japan, November 2014 Introduction to RAON & Detector Systems for Nuclear Physics Byungsik Hong (Korea University) Outline - Plan for RAON and LAMPS in Korea - Observables - Status of R&D - Summary 27 November rd Japan-Korea PHENIX Meeting 1

2 RAON LEBT ECR-IS (10keV/u,12 pμa) RFQ (300keV/u, 9.5 pμa) MEBT SCL1 (18.5MeV/u, 9.5 pμa) RAON is a unique facility that has both IF and ISOL systems. IF and ISOL systems can run independently, serving more users at the same time. IF and ISOL can be combined for more variety of RI beams at higher energies. Charge Stripper Low-Energy Experimental Area SCL2 (200MeV/u, 8.3 pμa for U +78 ) (600MeV, 660 μa for p) SCL3 (18.5MeV/u) Post Accelerator Driver LINAC MEBT RFQ ECR-IS CB HRMS Atom/Ion Trap RF Cooler ISOL Target Cyclotron (p, 70 MeV, 1 ma) ISOL system High-Energy Experimental Area μsr Medical research IF Target Fragment Separator IF system 27 November rd Japan-Korea PHENIX Meeting 2

3 Beam Parameters of RAON Driver Linac Post Acc. Cyclotron Particle H + O +8 Xe +54 U +79 RI beam proton Beam energy (MeV/u) Beam current (pμa) Power on target (kw) > November rd Japan-Korea PHENIX Meeting 3

4 KOBRA F0 RI production target at F0 D1 F1 D2 F2 Stage 1 W1 Korea Broad Acceptance Recoil Spectrometer and Apparatus at low-energy experimental area with beams up to 18.5 MeV/u F3 Stage 2 Maximum magnetic rigidity Mass resolution (M/DM) Dispersion Momentum stage1 Angular stage2 ~3 T m < 200 ~2 cm/% 14% 40 mrad (H) 200 mrad (V) W2 F4 Focal plane detection system at F5 D3 F5 27 November rd Japan-Korea PHENIX Meeting 4

5 F0 D1 F1 RI production target at F0 D2 F2 W1 Experimental target and detection system at F3 F3 KOBRA W2 Focal plane detection system at F5 F4 27 November rd Japan-Korea PHENIX Meeting 5 D3 F5 SCL1 ECR SCL3 SCL2 Stable ion beams via SCL1 or SCL3 RIB via ISOL+SCL3 ECR ISOL Stage 1 (F0~F3): Production and separation of RIBs by inflight method with high-intensity stable ion beams from ECRs Experimental target at F3 (available space of 2~3 m): In-beam g-ray spectroscopy, Symmetry energy & charged particle spectroscopy, etc. Stage 2 (F3~F5): Big-bite spectrometer with Wien filter

6 Target and Detection Systems for KOBRA D1 D2 Supersonic gas-jet target F1 F0 F2 Windowless gas target Beam swinger (optional) W1 F3 Si-array Gamma-array Active target Gas-jet target High-power solid target Polarized H/He target W2 F4 D3 JENSA, USA F5 27 November rd Japan-Korea PHENIX Meeting 6

7 Target and Detection Systems for KOBRA Gamma array -16X(4-fold 32 segmented Clover HPGe) -First half of full array: ~2018 -Second half of full array: after 2019 Number of clovers Distance from target to detector surface Angle coverage Digital electronics 16 for full array mm 85% for 4p TIGRESS or GRETINA Beam tracking detectors Si-array 27 November rd Japan-Korea PHENIX Meeting 7

8 Low-Energy LAMPS (LAMPS-L) Si-CsI Array Charged particles & g s E/E ~10-2 Particle ID Scintillator Array Neutrons Acceptance=100~300 msr E/E ~5.0X10-2 via TOF Si-CsI Scintillator array 27 November rd Japan-Korea PHENIX Meeting 8

9 High-Energy LAMPS (LAMPS-H) Solenoid Spectrometer + Dipole Spectrometer + Neutron Detector Array 27 November rd Japan-Korea PHENIX Meeting 9

10 High-Energy LAMPS (LAMPS-H) For the various Coulomb breakup experiments Gamma Array 27 November rd Japan-Korea PHENIX Meeting 10

11 Physics Topics/Observables to be Covered by LAMPS Low-energy KOBRA in LE Expt. area Nuclear symmetry sub-saturation density Fusion reaction cross section Dipole emission Yield & the polar angle dependence Intermediate-Mass Fragments Charge equilibration/isospin mixing/neck fragmentation High-energy HE Expt. area Nuclear symmetry supra-saturation density Ratio of mirror nuclei & π /π + Isospin diffusion parameter Collective flow Dipole emission For example, peak position of GDR and yield of PDR 27 November rd Japan-Korea PHENIX Meeting 11

12 Dipole Emission in Fusion N 1 /Z 1 N 2 /Z Sn+ 58 Ni at 10 MeV C. Rizzo et al., PRC 83, (2011): SMF Collective dipole bremsstrahlung radiation during the charge equilibration process Relative position of CM s for n & p: NZ D( t) X p ( t) X n ( t) A Photon emission probability with E γ = ħω dp de g 2e 3p c 2 3 E g NZ A 2 D '' ( ) 2 Similar effect in (ID)QMD model [Wu et al., PRC81, (2010)] 27 November rd Japan-Korea PHENIX Meeting 12

13 Dipole Emission in Fusion 132 Sn AMeV C. Rizzo et al., PRC 83, (2011) Asystiff Asysoft More g emission for Asy-soft Fusion Breakup Stronger angular dependence for Asy-soft Larger E sym at ρ < ρ 0 (Asy-soft) emits g earlier with stronger q asymmetry 27 November rd Japan-Korea PHENIX Meeting 13

14 Dipole Response at High Energies O. Wieland et al., PRL 102, (2009) AMeV A. Klimkiewicz et al. (LAND), PRC 76, (2007) Radioactive nuclei: Virtual photon absorption followed by neutron emission or by gamma decay The strength increases with the isospin asymmetry 27 November rd Japan-Korea PHENIX Meeting 14

15 PDR and Symmetry Energy A. Carbone et al., PRC 81, (2010) Red = RMF Blue = Skyrme L = 64.8 ± 15.7 MeV ΔR~Lδ 27 November rd Japan-Korea PHENIX Meeting 15

16 Charge Equilibration Charge equilibration In fusion, dipole oscillation is important In deep inelastic coll., dipole oscillation is overdamped: Diffusion of charges D t) D(0) exp ( t / d d E sym Degree of equilibration governed by contact time and symmetry energy Observable: N/Z of light charged particles emitted by PLF as a function of dissipated energy: (N/Z) CP vs. E diss E cm E kin (PLF + TLF) E diss /E cm E. Galichet et al., PRC 79, (2009) 27 November rd Japan-Korea PHENIX Meeting 16

17 Isospin Transport/Diffusion F. Rami et al., FOPI, PRL 84, 1120 (2000) B. Hong et al., FOPI, PRC 66, (2002) R i 2 N AB ( N N AA N BB N AA BB R i = 0 for complete isospin mixing ) / 2 M.B. Tsang et al., PRL 92, (2004) stiff soft R i = +1 R i = -1 Symmetry energy drives system towards equilibrium Isospin diffusion occurs only in asymmetric collision system A+B Soft E sym causes large diffusion & fast equilibrium as R i 0 27 November rd Japan-Korea PHENIX Meeting 17

18 π /π + Particle Ratios E E sym sym ( ρ / ( ρ / ρ ρ 0 0 ) ) Central density n/p 3 H/ 3 He n/p 3 H/ 3 He M. A. Famiano et al. RPL 97, (2006) Stiff E sym FOPI, Nucl. Phys. A 781, 459 (2007) Soft E sym b/b max < 0.15 at 400 AMeV 27 November rd Japan-Korea PHENIX Meeting 18 (N/Z) reaction system Stiff E sym

19 Time Projection Chamber h=-0.7 (127 o ) h=1.6 (24 o ) Beam 400 mm Target 150 mm 500 mm 300 mm 900 mm Simulation with triple GEM readout using Garfield++ Gas mixture: Ar 90%+CO 2 10%, Voltage for each foil: 450 V <Gain>~1.4Χ10 6, <Drift velocity>~50 mm/ms <Dispersion> after 60 cm (maximum drift distance) < 3 mm 27 November rd Japan-Korea PHENIX Meeting 19

20 Time Projection Chamber Central Au+Au at 250 AMeV (IQMD) Color scale: the number of electrons in each pad Pad Shape: hexagon Total number of pads >20,000 for 5 mm 2.5 mm Signal processing GET: General Electronics for TPC 27 November rd Japan-Korea PHENIX Meeting 20

21 Design of Prototype TPC Half-size prototype TPC Outer field cage Triple GEM Cathode PAD 150 mm Inner field cage 490 mm November rd 진도관리 Japan-Korea 중간평가 PHENIX (LAMPS) Meeting Bottom Al frame for PAD & GEM

22 Prototype TPC-Pad Plane Hexagonal shape: 5 & 2.5 mm 500 mm gap between two pads Multi-layer PCB board 16 pin SMD type connectors 5 mm pad (207 ch) 2.5 mm pad (735 ch) 27 November rd Japan-Korea PHENIX Meeting 22

23 Prototype TPC-GEM Trapezoidal shape Thickness: 75 mm Area: 160X120 mm 2 Triple layers for each pad 27 November rd Japan-Korea PHENIX Meeting 23

24 Prototype TPC-Field Cage 35 mm thick and 2 mm wide Cu strips 500 mm gap between adjacent strips Mirror strips on the back 1 MW resistors with 0.1% var. TPC body: G10 + Aramid honeycomb 1MW resistor(0.1%) Cross-section of field-cage body Al Mylar GRP G10 HoneyComb GRP Mirror strip PI Field strip 27 November rd Japan-Korea PHENIX Meeting 24

25 Prototype TPC-Assembly Inner Field Cage installed Outer Field Cage installed Prototype TPC assembled Prototype TPC : back 27 November rd Japan-Korea PHENIX Meeting 25

26 Neutron Detector Array veto Cross section of each bar: 10Χ10 cm 2 Construction of the real-size prototype detector and test with radiation sources Dimension: 0.1Χ0.1X2.0 m 3 Sources: 60 Co and 252 Cf 27 November rd Japan-Korea PHENIX Meeting 26

27 LAMPS-H Neutron Array Assembly of the real-size prototypes (2 m long) 60 Co 252 Cf 27 November rd Japan-Korea PHENIX Meeting 27

28 LAMPS-H Neutron Array g n 252 Cf Watt spectrum: dn de e ae sinh 27 November rd Japan-Korea PHENIX Meeting 28 be a=0.88 MeV -1 and b=2.0 MeV -1 B. Watt, Physical Review 87, 1037 (1952)

29 Summary 1. RAON project New opportunity will be in Korea for heavy-ion reactions with radioactive-ion beams. First beam on target: ~2019 for LAMPS-L and ~2021 for LAMPS-H 2. KOBRA Nuclear structure and astrophysics 3. LAMPS Nuclear symmetry energy below and above ρ 0 Low- and high-energy LAMPS setups to be constructed. 27 November rd Japan-Korea PHENIX Meeting 29