Overview of RIBF H Sakurai RIKEN Nishina Center

Overview of RIBF H. Sakurai RIKEN Nishina Center

RIKEN RI Beam Factory (RIBF) Experiment facility Old facility RIPS GARIS 60~100 Me. V/nucleon SHE (eg. Z=113) ~5 Me. V/nucleon Accelerator SCRIT RILAC AVF f. RC To be funded In phase II Zero. Degree RRC SAMURAI SRC SLOWRI RI-ring IRC CRIB (CNS) <10 Me. V/nucleon New facility Big. RIPS SHARAQ (CNS) 350 -400 Me. V/nucleon Intense (80 k. W max. ) H. I. beams (up to U) of 345 AMe. V at SRC Fast RI beams by projectile fragmentation and U-fission at Big. RIPS Operation since 2007

SRC World’s First and Strongest K 2600 Me. V Superconducting Ring Cyclotron 400 Me. V/u Light-ion beam 345 Me. V/u Uranium beam Big. RIPS World’s Largest Acceptance 9 Tm Superconducting RI beam Separator ~250 -300 Me. V/nucleon RIB K 980 -Me. V Intermediate stage Ring Cyclotron (IRC)

Exploration of the Limit of Existence stable nuclei unstable nuclei observed so far drip-lines (limit of existence)（theoretical predictions) magic numbers ~300 nuclei ~2700 nuclei ~6000 nuclei 4000 species to be produced (1000 more new isotopes) protons New Element 278 113 04 July 23 18: 55 57 fb Projectile Fragmentation In-flight U fission & P. F. 78 Ni ~0. 1 particles/sec. (goal) (2007) 10 particles/sec. by by 10 pn. A 1 pm. A 350 Me. V/u U-beam neutrons

Liberation from Stable Region Shell Evolution : magicity loss and new magicity Spherical Deformed Shape ? Shell gap？ Single particle level？ Cluster formation? Role of 3 NF ? Magicity loss ？ 50、82、126、184 E(2+) Dynamics of new “material” : Neutron-skin（halo） Density distribution Neutron+ proton陽子・中性子 neutron 一様物質 matter neutrons Quantum-objects having two surfaces neutron skin Skin thickness？Density distribution？ Role of skin in reactions？ Pairing in skin？ di-neutrons? Exotic modes of skin？ r RIBF provides data for nuclei far from the stability line Challenges in establishing new frame work of nuclear physics

Challenge for r-process path and explosion in supernovae Synthesis up to U （r-process） unknown neutron-rich nuclei theoretical predictions only nuclear properties of heavy and neutron-rich nuclei Mass, life-time, decay mode Mass number Explosion mechanism of supernova No explosion in theoretical works Outer crust of neutron star Equation-of-State in asymmetric matter Higher density: 3 NF (T=3/2)? Dilute matter : BEC, cluster-formation? 1987 A

Experimental Devices available at the new facility in 2009 SHARAQ(2009~) High resolution spectrometer 2 nd Big. RIPS (2007~) 1 st production target Zero. Degree (2008~) Big. Dpol(2009~) For polarized deuteron only SRC

Delivery of tagged RI-beam Based on two-stage separator scheme T. Kubo et al. Cocktail beam Tagged beam To RI-beam delivery line & experimental set-ups TOF& E Dispersive focus A, Z, Q mixed B measurement Identify RI-beam species Z, A/Q by measuring E, B , TOF in an event-by-event mode using beam-line detectors on the 2 nd stage. Aim at tagging rate up to 1 x 106 pps. Standard Br-TOF-d. E-E Z, A, Q New Scheme Br-TOF-d. E Z, A/Q

Identification of new isotopes 125, 126 Pd T. Onishi et al, JPSJ 77 (08)083201. 125 (22 counts) 126 (3 counts) Total dose 3. 6 x 1012 for 25 hrs I ~0. 01 pn. A on average A/Q resolution(r. m. s): 0. 041% at Z=46 Br resolution (r. m. s): 0. 02% DT resolution (r. m. s. ): 40 psec Cf. 124 Pd 19 counts, 125 Pd(cand. ) 1 count at GSI, 1997 PLB 415, 111 (97); total dose ~1 x 1012

Programs at Big. RIPS/Zero. Degree in 2007 -2008 May 2007 345 A Me. V 238 U beam 0. 02 pn. A (max) Two new isotopes, 125, 126 Pd (Z=46), Onishi et al. JPSJ 77 (08) 083201 Proton number Z Nov. 2008 345 A Me. V 238 U beam 0. 4 pn. A(max) 45 new isotopes in Mn to Ba, JPSJ 79 (10) 073201 N=82 N=50 N=20 Dec. 2008 345 A Me. V 48 Ca beam Day-One Experiments for Island-of-Inversion 48 Ca beam 170 pn. A(max) 31 Ne 10 /sec/100 pn. A, 32 Ne 5 /sec/100 pn. A Neutron number N

Press-Conference on June 8 th, 2010 IOP physicsworld. com “Radioisotopes galore at RIKEN” http: //physicsworld. com/cws/article/news/42915

Setup of Day-One Experiments at Big. RIPS/ZDS In-beam gamma spectroscopy Coulomb breakup Big. RIPS+ZDS DALI-II Na. I-based gamma Detectors target total interaction cross sections at Big. RIPS 2 nd-stage Zero. Degree Spectrometer Experimental set-ups

Day. One Experiments in Dec. , 2008 -The first data in the “island-of-inversion” - Spectroscopy of 32 Ne and the “island-of-inversion” E(2+) = 722 ke. V N=20 345 A Me. V 48 Ca beam 170 pn. A(max) Island-of-inversion Doornenbal, Scheit et al. PRL 103, 032501 (2009) New states in 31, 32, 33 Na PRC 81, 041305 R (2010) 28 -32 Ne N=16 31 Ne 10 pps/100 pn. A 32 Ne 5 pps/100 pn. A A new candidate of halo nuclei 31 Ne via Coulomb breakup Nakamura et al. , PRL 103, 262501(2009) Total interaction cross sections for the neutron-rich Ne isotopes Takechi, Otsubo et al. , Niigata 2010 symposium 19 C 20 C 22 C 31 Ne Coordinated by Aoi

Next Generation Gamma-Detector System SHOGUN Scintilator based High res. Olution Gamma-ray spectrometer for Unstable Nuclei H. Scheit et al. simulation by Doornenbal

Low-lying Excited States in 24 O via (p, p’) - The First Missing Mass Spectroscopy at RIBF Spokespersons : Valerie Lapoux and Hideaki Otsu May, 2010 The state-of-art detector MUST 2 from France coupled with Big. RIPS/ZDS setup GOAL Characteristics of the N=16 new magic number ? … in O isotopes Structure of a drip-line nucleus, possible neutron-skin or halo EXCITATION ENERGY SPECTRUM FOR 24 O(p, p’)24 O* 24 O E(2+) Sn = 3. 7 Me. V + states above S 2 n = 6. 35 Me. V ? TOOLS Particle spectroscopy of UNBOUND states SET- UP Kinematics, (p, p’) reactions Beam time MUST 2 shielding Target Holder PPAC beam RIBF beam (unique intensities) + high-performance telescope array +large-acceptance spectrometer

The First Decay Spectroscopy at RIBF 2009 Dec. U beam to access A~110 region Intensity 0. 8 pn. A max. 0. 1 -0. 2 pn. A on average Sumikama, Nishimura, et al. Half life measurements for r-process nuclei Nishimura et al. , PRL in press Beta-gamma spectroscopy Sumikama et al. , in preparation Delayed gamma spectroscopy for isomers H. Watanabe et al. , PLB in press for 109 Nb STOP Detector ( Decay experiment ) Clovers (RIKEN) La. Br 3 (Milano) 9 layers of DSSD (RIKEN, TUS)

New Injector RILAC 2 to deliver more intense beam and more opportunities for SHE f. RC New Injector To deliver more intense Xe/U for the new facility Commissioning in Dec. 2010 RILAC 2+ 28 GHz SC-ECRIS AVF RILAC RRC GARIS (SHE) 300 days per year for SHE!! IRC Big. RIPS (RIBF) SRC

209 Bi + 70 Zn → 278113 36. 75 Me. V TOF 44. 61 ns 30. 33 mm + n K. Morita et al. , 73 2593 -2596 (2004) 278113 a 1 st chain 23 -July-2004 18: 55 (JST) a a 270 Mt 274111 36. 47 Me. V TOF 45. 69 ns 30. 08 mm CN 278113 a 11. 68 Me. V (PSD) 344 μs 30. 49 mm 11. 15 Me. V 6. 149+5. 003 (PSD+SSD) 270 Mt 9. 260 ms 30. 40 mm a a 274111 CN 11. 52 Me. V (PSD) 4. 93 ms 30. 16 mm 0. 88+10. 43=11. 31 Me. V (PSD+SSD) 34. 3 ms 29. 61 mm 10. 03 Me. V 2. 32 Me. V (escape) 1. 136+8. 894(PSD+SSD) 1. 63 s 266 Bh 7. 163 ms 29. 45 mm s = 23+30 -15 29. 79 mm a a 9. 08 Me. V (PSD) 9. 77 Me. V (PSD) 2 nd chain 2. 469 s 1. 31 s 2 -April-2005 2: 18 (JST) 262 Db 30. 91 mm 29. 65 mm s. f. 204. 05 Me. V(PSD) 40. 9 s 30. 25 mm s. f. fb 192. 32 Me. V(PSD) 0. 787 s 18 K. Morita et al. , JPSJ 76, 045001 (2007) 30. 47 mm

New Devices of RIBF To maximize the potentials of intense RI beams available at RIBF for several 100 – 1000 species Rare RI ring Zero. Degree mass Ozawa mass half-life 2013 excited states deformation charge radii to be funded 2008 matter radii charge distribution SLOWRI 2012 IRC-to-RIPS BT 2012 matter distribution gas-catcher multi-use Wada EM moments Ueno single particle states astrophysical reactions giant resonances to be funded exotic modes SAMURAI HI collisions (EOS) SCRIT Suda Yoneda SHARAQ spectrometer U Tokyo 2012 - 2009 - 2010 -

Summary Big. RIPS: 45 new isotopes in 4 days achieved with a U beam ZDS : New results for island-of-inversion region via in-beam gamma, transmission method, Coulomb dis. decay spectroscopy at A~110 missing mass spectroscopy with MUST 2 for O-24 two step alignments with RIB Big. Dpol: pol-d+p elastic scattering for 3 NF (p 2 p) for light and neutron-rich nuclei at a small spectrometer SAMURAI: is under construction, starting in 2012 SCRIT: will start to have e-RI scattering SHE: new linac RILAC 2 will give more opportunities since 2011 Other devices (SLOWRI, Rare RI-ring…) are to be funded Many opportunities for international collaborations !!