Status and Prospective of HIRFL Experiments on Nuclear Physics Hushan Xu Institute of Modern Physics, CAS, Lanzhou KITPC: Relativistic Many-body Problems for Heavy and Superheavy Nuclei Jun 8-Jun 27, 2009 Beijing

OUTLINE Introduction to HIRFL –Beam facilities –Experiment sites Present Status & prospective of the equipments for nuclear physics experiment –SHANS: SHN, dripline neclei, atomic physics, … –RIBLL1: spectroscopy and reaction of exotic nuclei, nuclear astrophysics, … –CSRe: high precision mass and decay measurements, atomic physics with HCI, … –ETF: RIB related physics, high density nuclear matter,… Summary & Future Development

Introduction to HIRFL: Beam facilities N CSRm CSRe SFC SSC SFC:  10 AMeV (H.I.), 17~35 MeV (p) SSC:  100 AMeV (H.I.),  110 MeV (p) CSRm:  1000 AMeV (H.I.),  2.8 GeV (p) RIBLL1: RIBs at tens of AMeV RIBLL2: RIBs at hundreds of A MeV CSRe: storage ring with deceleration RIBLL2 RIBLL1

Introduction to HIRFL: Exp. Sites ① Low energy site in general ② Atomic physics exp. site SHANS ③ SHANS - Spectrometer for Heavy Atom and Nuclear Structure ④ Heavy ion irradiation exp. site RIBLL1 ⑤ RIBLL1 – 1st Radioactive Ion Beam Line in Lanzhou 10 ETF ⑥ ETF – External Target Facility at CSR ⑦ CSRe – Experimental Ring ⑧ PISA ⑨ Tumor therapy site HPLUS

Present Status & Prospective of the Main Equipments for Nuclear Physics Experiment SHANS: Spectrometer for Heavy Atom and Nuclear Structure RIBLL1: 1st Radioactive Ion Beam Line in Lanzhou CSRe: Experimental Ring of CSR ETF: External Target Facility at CSRm

SHANS ProductionProduction A/Z selectionA/Z selection Collection & cooling ， q=+1Collection & cooling ， q=+1 Primary A selectionPrimary A selection Z selection ， q=+2Z selection ， q=+2 A selection (Z, A determined)A selection (Z, A determined) Decay measurement,…Decay measurement,… RFQ 2 D1 D3 RFQ 2 D2 Slit 1 Slit 2 Q9,10,11 Laser Q12,13,14 Q15,16 Q1,2,3 Reaction Chamber Target Gas Filled Separator Q4 Q5,6 Q7,8 Detector or Trap RFQ 1 Spectrometer for Heavy Atom and Nuclear Structure

Gas-Filled Recoil Separator - GFRS ConfigurationQv-D-Qv-Qh Trajectory length6.5 m Acceptance 280  mm  mrad (h) 450  mm  mrad (v) Central trajectory radius1.8 m Bending angle of D 52  Max. magnetic rigidity2.88 Tm Differential Pumping System Reaction Chamber Detection Chamber Test by  source Testing with target recoils To be tested with typical reactions

RFQ Cooler and Buncher Under construction

LaserMulti-step Resonant Ionization Laser Multi-step Resonant Ionization Gaol: SHE regionGaol: SHE region No wave lenghth scanning needed

Next at SHANS Step 1 GFRS –Tested by the reaction(s) with known cross-section –Aiming at Z=110 region –Searching for the new isotopes at SHN region… RFQ –Tested with ion source09-10 –Combined with LMRI or/and GFRS… LMRI –Set up a system to produce 1+ ions09-10 –Systematic measurement of the 2nd ionization energy of the heavy atom: from known to unknown & compared with theoretic calculation… LPT –Manufactory of the Lanzhou Penning Trap09-10 –Testing... Step 2 Combining GFRS, RFQ, LMRI and LPT together PROBLEM: Beam Intensity

Future Plan for SHN at HIRFL

RIBLL 1: 1st Radioactive Beam Line in Lanzhou Nucl. Instr. Methods A 503 (2003)496 Equipped with Clover det. for  detection Neutron Ball & Wall Si-strip Array CsI(Tl) Array Built in the end 1990s Total reaction cross-section momentum distribution Elastic scattering  -delayed neutron emision p-p correlation function Resonance states

Examples of the Results from RIBLL1 Elastic scattering of weakly bound nuclei (IMP) 17 F/ 17 O angular dispersion plots Different slop reflects different component of the nuclear force starting to be effective

Angular dispersionClassical deflection function “turning angle”  “nuclear rainbow angle” Same angle

M ain conclusions A possible way to extract the “nuclear rainbow angle” from experiment measurement. The ratio of the “turning angle” over grazing angle could be a measure of the diffuseness of the surface of a nucleus

β-delayed neutron spectra and  spectra of 21 N (PKU) 21 N  -delayed n-spectrum 21 N  -delayed n-spectrum  -spectrum 68.8 AMeV 26 Mg+ 9 Be  21 N (0.5 pps)

M ain conclusions  Half-life of 21 N: T 1/2 = 82.9  1.9 ms  13 group of  -delayed neutrons observed, total branch ratio is 88.7  4.2%  5 new levels of 21 O assigned New level scheme proposed for 21 N and 21 O The experimental setup works even for the beam intensity at the level of 0.5 pps !

Part of the Planned Exps. in Focusing on A< 40 region Decay spectroscopy of 25,26,27 P 6 He knock-out reaction Decay spectroscopy of neutron-rich O, F, Ne isotopes

CSRe Status of CSRe –ToF detector for mass measurement as IMS (running) –Schottky detctors for mass & decay measurement (under testing) (under testing) –Electron cooler (under testing) –Cluster-jet target (under testing) Recent nuclear physics exps. at CSRe –Mass measurement: IMS, SMS, ToF –Decay measurement: SMS

Mass & Decay Measurement at CSRe: NOW The end of 2007: test run The end of 2008: 1st physics run RIBLL2 ＋ CSRe Isochronous mass spectrometer 36 Ar  RIB 78 Kr  RIB Preliminary

78Kr Run 53Co g 53Co m 53Fe g 53Fe m Preliminary A=2Z-1

Mass Excess NuclidesME IMP ME AME ME AME- ME IMP Setting 71 Br-56602(133)-57060(570)-458(585)A=2Z-1 71 Br-56618(137)-57060(570)-442(586)A=2Z+1 71 Kr-45978(1470)-46920(650)-942(1607)A=2Z-1 71 Kr-46470(327)-46920(650)-450(728)A=2Z+1 67 Se-46966(512)-46490(200)#476(550)A=2Z-1 65 As-47418(567)-46980(300)#438(641)A=2Z-1 63 Ge-46677(263)-46910(200)#-233(330)A=2Z-1 Unit: keV ＃标记为理论预言值 ; 71 Kr A=2Z+1 设置下的值是通过 71 Br 质量值经衰变能导出的。

New isomer states, new isotopes,…; checking the nuclear model 112 Sn, 124 Xe beams Mass & Decay Measurement at CSRe: NEXT 09-10: try to accelerate Xe/Bi at CSR 78 Kr beam 136 Xe beam Bi-U beams Bending energy, Shell structure, shape evaluation, … Origin of the element, nuclear synthesis, … PLB,664(2008)162

ETF I: External Target Facility, Phase I

ETF II: External Target Facility, Phase II New Detectors  -ball (CsI(Tl) array + Clover) TPC (at target region) Si-strip array (behind TPC) MWPC (inside dipole) Possible Physics For RIB Physics For EoS of asymmetry nuclear matter For high baryon density matter To be constructed within 3 years

EoS of Asymmetry Nuclear Matter symmetry energy B.A. Li, Nucl. Phys. A708, 365 (2002) uncertainty Very limited experimental evidences to constrain the E sym at higher density Critical constrain to the radius of the neutron star

Can be done at ETF? B.A. Li, Nucl. Phys. A708, 365 (2002) Density reachable at CSR energies n/p ratios,   /   ratios Nucleon differential flow Hard photons IMFs: isospin transport / diffusion / isoscaling Possible observables Detector system: 2 years? Proposals Detailed simulation Working package

PISA Shipped from FZJ to IMP in 2008 Nucl. Instr. & Methods A 519 (2004) nn scattering cross section at CSR energies L-G phase transition of nuclear matter Spallation process: measuring the spectra of LCP, extracting the excitation energy, and comparing with model calculations  mainly focusing on the requirements from the applications Comparison of R AA & R pA at CSR energies as a part of the energy scanning from RHIC energy down to CSR energy Running as an external target exp. in the end of 2009.

Summary & Future Development Possible Exps. –SHN at GFRS  within one year –Mass measurement at CSRe  started –RIB Physics at RIBLL1 & ETF  started & within one year –Decay measurement at CSRe  within one year? –Density dependence of E asym at ETF  two years later –pA or AA at PISA  within one year Main Problem –Beam intensity Future Development –Hadron Physics at GeV energies

Hadron Physics at GeV energies HPLUS Hadron Physics LanzhoU Spectrometer

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