Michiharu Wada for the SHE-Mass Collaboration KEK, Wako Nuclear Science Center

Size: px

Start display at page:

Download "Michiharu Wada for the SHE-Mass Collaboration KEK, Wako Nuclear Science Center"

Agnes Blake
5 years ago
Views:

1 Michiharu Wada for the SHE-Mass Collaboration KEK, Wako Nuclear Science Center NUSTAR Meeting 2018

Finger Print: Unique value for a nucleus Key values for NucleoSynthesis

2 Why Atomic Mass? Mass Deficit = Binding Energy B p p p p Σ constituents Atomic mass Atom is 1% lighter than constituents: Mass Deficits n n n n n n Most fundamental nuclear property Defines Stability, Decay mode, Structure Finger Print: Unique value for a nucleus Key values for NucleoSynthesis Derivation of mass Sn (n-separation energy) We saw the moment of Au Pt synthesis in n-star merger! r-process nova? G-Wave γ-flash optical H. Koura

3 note: many known masses were measured indirectly decay, reaction (660) mass spectrometry U Pb Tl Bi Pb Pb Pb Tl Pt Ir Hg HgHg HgHgHg Au Pt Pt Pt Pt Ir Hg W W Ta Os OsOsOs Re W Os Hf Hf Hf Hf Hf Lu Yb Yb Yb Yb Yb Yb Tm Yb Dy Dy Er Er Er Er Er Ho Dy Dy Dy Dy Dy Tb Er Sm GdGdGdGdGd Eu Eu Sm Sm Sm Gd Sn Cd Cd Te Te Sb Sn Sn Sn Sn Sn Sn Sn Sn In Cd CdCd Cd Cd Nd Nd Pr Ce Ce Ce La Ba Ba Ba Ba Ba Ba Ba Cs Xe Xe Xe Xe Xe Xe Xe I Te Te Te Sb Sn Sn NdNd Nd Ru Ag Pd Pd Pd Pd Rh Ru RuRuRuRu Ru Ag Pd Pd 350 c_unk1ppm2016_life.m Ni Zn Cu Ni Ni Ni Ni Co Fe Fe Fe Fe Mn Cr Cr Cr Ge Ga Zn Zn Zn Cu Ni Kr Kr Br Se Se Se Se As GeGeGe Ge Ga Mo MoMoMoMoMo Nb Zr Zr Zr Zr Y Sr Sr Sr Sr Rb Kr Kr Kr Kr Br Se log(t1/2) Ca Ar Cl S S S P Ca K Ar Cl S V Ti Ti Ti Ti Ti Sc CaCaCa Ca K Ar Si Si Si Al MgMgMg Na NeNeNe F O O O N N C C B B Be Li Li HeHe H H

4 Mass Measurements of Short-lived Nuclei Q-value (decay or reaction) In-flight spectrometer indirect direct Ultra Fast Low Precision TOFI, SPEG.. Universal Ambiguity from levels Penning Trap Storage Ring Electron Cooling Slow Ultra precision Very Slow High Precision New method MRTOF (multi-reflection TOF) ISOLDE, JYFL... GSI ESR IMP CSRe RIKEN RI-Ring Isochronous Fast Low Precision RIKEN, Giessen, ISOLDE.. Fast High Precision

forth for 200 times Open exit at predefined timing (5) Detect ions ToF 0,000 cycles in 3000s total 7000

5 MRTOF Mass Spectrograph Ion Trap Ion Mirror Ion Mirror TOF detector (Multi Reflection Time of Flight ) (1) Open entrance to inject Potential (V) k=k+ k=k- (2) (3) (4) Close entrance before coming back go back and forth for 200 times Open exit at predefined timing (5) Detect ions ToF 0,000 cycles in 3000s total 7000 events >90% are no ions different laps garbage ions can be discriminated by different number of laps

6 A= ppm precision 27 μs A=205 Counts / 2 ns n = 145 laps ToF( 250 Md 2+ ) = (2.1) ns ToF (ns) Y. Ito et al, PRL 120 (2018)02501 A= μs A=205 Counts / 6.4 ns bin 3 2 FWHM = 24.9(1) ns R = (12) 65 Cu TOF = (77) ns 65Cu(stable) 65 Zn 65 Ga ( 6.8 kcnts ) 64 ZnH R = (38) 65Ga(RI) δm/m = 3.5x -8 R = (20) R = (21) 65 Ge 225 laps TOF ( ns ) P. Schury et al, PRC 95(2017)011305(R) S. Kimura et al, IJMS 430, (2018)

7 Masses Measured in 2016 summer spring > 80 masses were measured in total 4 weeks beam time 6 first masses in trans-uranium elements (Es, Md isotopes) > 30 first direct mass measurements Z 0 known masses agree in 1σ with Penning Trap data, while a few discrepancy in old indirect measurements shortest T1/2 = ms, with precision 2x -7 No Md Fm Es Y. Ito et al, in preparation Y. Ito to PRL 120, 2501 (2018) M. Rosenbusch et al, PRC 97, (2018) P. Schury et al, PRC95(2017)011305R 90 Ac Ra Fr Rn At Po Bi Pb Pb Pb Tl Hg Pa Th Ac Ra Pu Np U U P. Schury et al, in preparation MRTOF (RIKEN-KEK) AME2016 (incl. indirect) Tl Ge,Br 80 Hg HgHg HgHgHg A 65 Au Pt Pt Pt Pt 120 S. Kimura et al, IJMS 430, Pt (2018) N

Typical Mass Measurements before MRTOF Shorter half-life, lower precision In-flight ppm Isochronous storage ring Cooled ions in storage ring blank zone

Knöbel et al., EP. J.A. 52 (2016)138, Chen et al, NPA882(2012)71 [d] Yu.A. Litvinov et al., Nucl. Phys. A756(2005)3. [e] http://research.jyu.

8 Typical Mass Measurements before MRTOF Shorter half-life, lower precision In-flight ppm Isochronous storage ring Cooled ions in storage ring blank zone 1 ppm 0.1 ppm Penning Traps 0.01 ppm [a] Y. Bai et al., AIP Conf. Proc. 455 (1998)90. [b] F. Sarazin et al., Phys. Rev. Lett. 84 (2000)5062. [c] R. Knöbel et al., EP. J.A. 52 (2016)138, Chen et al, NPA882(2012)71 [d] Yu.A. Litvinov et al., Nucl. Phys. A756(2005)3. [e] [f] [g] H.S. Xu et al IJMS349(2013)162 and others No devices for T1/2 ms, δm/m 0.1 ppm

9 MRTOF plays a role in Mass Measurements In-flight ppm Isochronous storage ring Cooled ions in storage ring MRTOF ISOLDE 1 ppm 219Ra 220Ra 0.1 ppm MRTOF RIKEN-KEK Penning Traps 0.01 ppm [a] Y. Bai et al., AIP Conf. Proc. 455 (1998)90. [b] F. Sarazin et al., Phys. Rev. Lett. 84 (2000)5062. [c] R. Knöbel et al., EP. J.A. 52 (2016)138, Chen et al, NPA882(2012)71 [d] Yu.A. Litvinov et al., Nucl. Phys. A756(2005)3. [e] [f] [g] H.S. Xu et al IJMS349(2013)162 and others still agree with Penning trap

10 RIKEN RILAC

12 Trap Trap Thermalize Thermalize 1.6 kev bunched beam 4.8m retrap

13 Gas Cell MRTOF

14 Masses of Super Heavy Nuclides 1. pin down masses of hot-fusion island 2. confirm A and Z of hot-fusion SHE Fm 99Es 140 1Md 2No 246 4Rf 249 3Lr 5Db 250 6Sg Bh Hs (Pb, Bi + Stable Ion) 1Ds 9Mt Rg Cn Nh spontanous fission (actinide + 48 Ca) Mc 114Fl Lv Og 117Ts

15 0.5 mg/cm 2 2 pμa 8.5 pb 4 /day@garis εtotal= % events/month! Fraction Mc Fraction Mc Nh Nh 279Rg Rg Time (s) Time (s) mass anchor for 278Nh anchor for even hot fusion SHE

Parallel Measurements @ 3 facilities of RIKEN RIBF RIBF Experiment Building GARIS Existing Facility prototype SLOWRI SLOWRI Superconducting ring cyclotron cyclotron RIPS SCRIT (Universal SLOW RI-beam

16 Parallel 3 facilities of RIKEN RIBF RIBF Experiment Building GARIS Existing Facility prototype SLOWRI SLOWRI Superconducting ring cyclotron cyclotron RIPS SCRIT (Universal SLOW RI-beam facility) SRC Zero-Degree SAMURAI Mass Ring SHARAQ frc Fixed frequency ring cyclotron cyclotron BigRIPS IRC Intermediate ring cyclotron cyclotron (Projectile Fragment Separator) New Facility RIBF Accelerator Building 400 MeV/u 50 pna (3x11 pps) 48Ca 500 pna (3x12 pps) 238U BigRIPS +SLOWRI 150 cm 00 He 2 ps a r T Ion mba r MR TO F m 30 c S/u P I igr MeV B Thermalize in He gas Extraction by RF-carpet Trap in Ion-Traps Mass measurements with MRTOF IS R A G 5 MeV/u KIS30SkeV 00 He 1 mb a r bar m 30 c m He 1 Pin Hole

5 MRTOF @ BigRIPS of RIBF With pure RI, T1/2, Mass, Pn

BigRIPS OEDO SLOWRI-MTOF RF CarpetGas Cell 既存設備 MRTOF-MS

17 5 BigRIPS of RIBF With pure RI, T1/2, Mass, Pn Beam dump, 2nd 3rd reaction products, with free WNSC-HPSP SLOWRI R ZeroDegree m PALIS-MTOF Cocktail beam of BigRIPS OEDO SLOWRI-MTOF RF CarpetGas Cell 既存設備 MRTOF-MS Utilize garbage ions at slits Multi-nucleon transfer products with MeV/u RI-beam KISS2-MTOF RI beam Bunching Trap

19 after their measurements, all garbage goes to F11 mass measurement can use them without extra charge What is expected?

20 TOF-all 4 77 (194) 82 (188) 83 (187) 84 (186) 79 (192) 80 (191) A=81 (n=190) 78 (193) (185) TOF A=78 78Cu (193) 78Ni (193) 84Ge (186) 84Ga (186) 3 2 TOF A=79 79Zn (192) 79Cu (192) 79Ni (192) Ga (191) TOF A=80 80Zn (191) 80Cu (191) 80Ni (191)

M. Wada, P. Schury, Y.Ito, F. Arai, S. Kimura, D. Kaji, H.

Niwase, S. Ishizawa, T. Tanaka, A.Takamine, M. Reponen, T.

MacCormick, H. Koura, K. Morita, A. Ozawa, H.

Center for Accelerator-based Science, RIKEN Institute of

Atomic Energy Agency Department of Physics, Kyushu

22 M. Wada, P. Schury, Y.Ito, F. Arai, S. Kimura, D. Kaji, H. Haba, K. Morimoto, M. Rosensuch, I.Murray, J.Y.Moon, T. Niwase, S. Ishizawa, T. Tanaka, A.Takamine, M. Reponen, T. Sonoda, Y. Hirayama, Y.X. Watanabe, H. Miyatake, M. MacCormick, H. Koura, K. Morita, A. Ozawa, H. Wollnik Wako_Nuclear Science Center, IPNS, KEK Nishina Center for Accelerator-based Science, RIKEN Institute of Physics, Tsukuba University Advanced Science Center, Japan Atomic Energy Agency Department of Physics, Kyushu University Institute of Basic Science, Korea University Paris-Scaley, France New Mexico State University, USA

Development of a gas cell-based laser ion source for RIKEN PALIS

Hyperfine Interact (2013) 216:103 107 DOI 10.1007/s10751-013-0817-6 Development of a gas cell-based laser ion source for RIKEN PALIS T. Sonoda M. Wada H. Tomita C. Sakamoto T. Takatsuka T. Noto H. Iimura