RI (SLOWRI) 1. Status of SLOWRI development 2. SLOWRI at RIBF

Transcription

1 RI (SLOWRI) 1. Status of SLOWRI development 2. SLOWRI at RIBF

2 - - - Heavy Ion Cyclotron SLOWRI@RIKEN-RIBF Universal Slow RI-Beam Facility Fragment Separator Target 100 MeV/u RI beam Degrader ~1MeV/u Stopping & Cooling of RI-Beams in He Gas RF IonGuide Edc Eeff SPIG RF Carpet ISOL pure slow RI to experiments BigRIPS + RF Ion 1. Wide Range of Nuclides No Chemical Processes in Production & Separation 2. High Purity No Isobar No Isotone Contamination 3. Small Emittance ~1π mm mrad (20 kev), ~10 evμs Short Bunch 4. Variable Energy Range 1-50 kev Slow Beam, <1eV Trapped RI, 1MeV/u (future option) 5. Human Accesibility during On-line Exp.

3 TM RF Ion Guide nozzle 0.7mmΦ He 100Torr x 2m 200 mmφ 2MeV/u E DC < 10 V / cm 2 ~ 150 cm / Vs finally stick to the cathode (E(r,t) = E rf (r)cos(ωt), τ v : relax time) E effmaxin gas mµ 2Vrf2 = er Edc + µ : mobility Eeff - e2 1 2 F = E rf (r) 2 2 4m (Ω + 1 / τ v ) ~ + v = µe DC RF gradient Field: Barrier - Static Field: transports ions + (0~10MeV/u) 2r0 electrode distance M.Wada et al, NIM B204 (2003) 570.

4 0 Radius [mm] 3

5 RIKEN RIPS(D1)+RF ion guide Present On-line Setup

6 On-line test setup at RIKEN RIPS RF Carpet SPIG (60cm) Gas Cell (2mx40cmφ) IonTrap Q-mass 4 diff. pumping

7 SPIG RF six-pole ion beam guide made of ６-0.5mmφ Mo rods transports ions to high vaccum. Cylinder DC-Electrodes in Gas Cell RF Carpet Central part is made of RF ring-electrodes with 0.28mm interval. An exit of 0.7 mmφ is located at the center. SPIG & Nozzle

8 Laser Spectroscopy of Trapped Be ions He gas channeltron rf carpet gas cell chenneltron 50 laser beam linear quadrupole Paul trap mass filter for spectroscopy SPIG cylindrical dc electrodes wedge degrader potential [V] -10 Isotope Shift (Be10 - Be9) for the first time (104) GHz next step: Hyperfine Splitting of Be-7 and Be-11 for nuclear magnetic moment (Be-7) & Bohr-Weisskopf effect (Be-11) Fluorescence Intensity [counts/0.5 s] Laser Cooled Be-10 ions in on-line trap!0 = 957, (10)(586)GHz Tion = 0.8 K Laser Frequency [+957,400 GHz]

9 Intensity dependence of the RF IonGuide Efficiency [%] Overall Efficiency εionguide MeV/u 8 Li Intensity [cps] Yield Yield of Slow 8 Li [cps] Overall Efficiency: ~5% max (Ion guide Efficiency: ~33% max) Yield of 8Li: 24 kcps max from 100 MeV/u Fragment Separator RIPS efficiency 1 Space-Charge effect Intensity charge density Intensity efficiency 1 charge density charge density: ~ C / mm 3 A. Takamine et al, RSI, 76 (2005)

10 New Ion Guide Gas Cell - Fully covered RF carpets (planer & cylindrical) - Cryogenic cooling by thermal isolation - Accelerate just behind a short SPIG

11 Cyclotron-RF-Ionguide SPIG-Trap RF-Rings He N Thin Degrader S High Energy Ion Beam I. Katayama et al. / Cyclotron ion guide for energetic radioactive nuclear ions Long stopping length >10 m - Short drift path < 30cm - Isolated high space-charge & drift path ure 2. A trajectory of a 5 MeV/u 11 Be 4+ ion coming out of a proper Ta energy degrader at R = 50 cm 5000 Pa He gas. The ion starts with an azimuthal velocity of v x = m/s and v z = 10 5 m/s at (x 0, y 0, z) = ( 500, 0, 3) mm. The charge state of ion is assumed to follow a charge ilibrium given in [8]. Magnetic field is taken to be B z = B 0 (1 0.25r/R) and B r = 0.25B 0 z/r th B 0 = 17 kg. The result shows (a) the ion orbit in (z, r)-plane, and (b) the ion orbit in (x, y)-plane. Ideal condition for: Fast extraction & High Intensity

12 Magnet for Cyclotron Ion-guide prototype AVF pole 130mm gap 850 mmφ brought to RIKEN from KEK

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14 SLOWRI ISOL overview B1 exp room 10m x 30m H 2.5m (option) B2 exp room 8.5m x 14m H 8m lift spiral staircase Decay Studies (tape transport) B3 exp room 9m x 11m H 2m Buncher collinear laser spectroscopy combined trap for HFS DAQ Hut 3m x 5m (calm) Experimental Rooms B3 exp room (bottom) main experimental setups B2 exp room (gas cell floor) tall devices B1 exp room (top) post accelerator (future option Vertical & Horiz. Mass Sepa. Simultaneous Operation (Sharing, Monitoring) isol-dh isol-dv Quad-Q Buncher Buncher MR-TOF-MS Laser Hut 3m x 5m (clean) Gas Cell 1 m long, 40 cm φ, 100 Torr Dual layered cell for cooling Full covered RF carpet gas cell shield shutter )12 )12 nqd!! "##$!!!"#$ (' %&'' "#$%&'($)* *+,-./#0 6 Def BigRIPS D5 HEBT ) Branch from BigRIPS at D5 New n.c. DQQ to gas cell

15 Three Experimental Rooms B1 exp room 10m x 60 30m H 2.5m (option) B2 exp room 8.5m x 14m H 8m lift spiral staircase Decay Studies (tape transport) B3 exp room 9m x 11m H 2m Buncher collinear laser spectroscopy combined trap for HFS DAQ Hut 3m x 5m (calm) Buncher Laser Hut 3m x 5m (clean) isol-dh isol-dv Quad-Q Buncher MR-TOF-MS gas cell

16 U Bi Pb Pb Pb Tl Tl Hg Hg Hg Hg Hg Hg Hg Estimated Yield of Slow RI-Beams Er Er W W Ta Hf Hf Hf Hf Hf Lu Yb Yb YbYb Yb Yb Yb Tm Er Er Er Er Ho Pt Ir Os Os Os Os Re W Au Pt Pt Pt Ir Os Pt Dy Dy Dy Dy Dy Dy Dy with U 10 pna Xe 0.5 pu!a Kr 0.5 pu!a Ba Ba Sm Nd Nd Pr Ce Ce Ce La Ba Ba Ba Ba Ba NdNd Eu Sm Nd Tb GdGd Gd Gd Gd Eu Sm Sm Gd Cs Xe XeXe Xe Xe Xe Xe I Te Te Sb Te Te Te Sb Sn SnSn Sn Sn Sn SnSn Sn Sn In Cd Cd Cd Cd Cd Cd Cd Pd Ag Pd PdPd Ag Pd Pd Rh Ru Ru Ru Ru Ru Ru Ru Mo MoMoMo MoMo Nb Zr Zr Zr Zr Y Ni Zn Cu Ni Ni Ni Ge Ga Zn Zn Zn Cu Ni Kr Kr Br Se Se SeSe As Ge Ge Ge Ge Ga Sr Sr Sr Sr Rb Kr Kr Kr Kr Br Se Assuming present performance Including T1/2 and Space charge effect Ar Cl S S S P Si Si Si Al MgMgMg Na Ne NeNe F O O O N N C C B B Be Li Li He He H H Ca K Ar Cl S Co Fe Fe Fe Fe Mn Cr Cr Cr V Ti Ti Ti Ti Ti Sc Ca Ca Ca Ca K Ar 10 7 cps!%&'!"#$ 1 cps!!"#$ ($$)*+,-!#./$/,0!#/.12.*3,"/ Yslowri = Ybigrips*εtrans*εstop*Veff 4,"5)6+,-!7!89!/11/"0:!;#3"/!<=3.-/!/11/"0 Veff :Effective Volume = { 1.0 (T1/2 > 0.4 s) T 1/2 / 0.4 Lifetime effect Space-charge { 1.0 ( Edeposit < 4.3 MeV*10 4 /s) effect Edeposit -0.5 Edeposit 1.2A MeV/ion (>Na)

17 Planned & Possible SLOWRI 1. Mass Measurements (MR-TOF-MS) 2. Charge Radii (Collinear Laser Spectroscopy) 3. Hyperfine Structure (Trap, Laser-MW Spectroscopy) 4. T1/2, Qβ, B.R.(βγ-delayed particle spectroscopy) 5. Fundamental Symmetry (β-decay in free space) 6. Highly charged RI (EBIT) 7. Antiprotonic Radioactive Atoms 8. Inbeam-γ, Astrophysics (post acceleration) 9....

18 Candidate Nuclides to be measured at RIBF U primary beams: U 10 pna Xe 500 pna Kr 500 pna Z=50 Ru Cd Cd Ag Pd Pd PdPd Rh Ru Ru Ru Ru Ru Ru Z=82 Ce Sm Nd Nd Pr Ce Ce La Ba Ba Ba Ba Ba Ba Ba Cs Xe XeXe Xe Xe Xe Xe I Te Te Te Te Te Sb Sb Sn SnSn Sn Sn Sn SnSn Sn Sn In Cd Cd Cd Cd Cd Ag Pd Pd NdNd Eu Sm Nd Lu Yb Yb YbYb Yb Yb Tm Er Er Er Er Er Er Ho Dy Dy Dy Dy Dy Dy Dy Tb GdGd Gd Gd Gd Gd Eu Sm Sm Bi Pb Pb Pb Tl Tl Hg Hg Hg Hg Hg Hg Hg Au Pt Pt Pt Pt Pt Ir Ir OsOs Os Os Os Re W W W Ta Hf Hf Hf Hf Hf Yb (A):BigRIPS (B):SLOWRI >0.01cps >0.0001cps Mo MoMoMo MoMo Nb Zr Zr Zr Zr Y Z=28 Zn Cu Ni Ni Ni Ni Co Fe Fe Fe Fe Mn Cr Cr Cr V Ti Ti Ti Ti Ti Ge Ga Zn Zn Zn Cu Ni Kr Kr Br Se Se SeSe As Ge Ge Ge Ge Ga Sr Sr Sr Sr Rb Kr Kr Kr Kr Br Se N=82 1 ppm Sc Ar Cl S S S P Si Si Si Al MgMgMg Na Ne NeNe F O O O N N C C B B Be Li Li He He H Ca K Ar Cl S Ca Ca Ca Ca K Ar N=28 N=50 1 ppb Accuracy of known mass Boxes: known mass nuclei Audi et al NPA 729(2003)3

19 Collinear Laser Spectroscopy Precision measurements of atomic transition energy Comparison in isotopes Isotope Shift (E0) Charge rms radii Ion Beam (30keV) accel-decel gap fluorescence detector charge exchange field ionizer & detector Laser (3 colors) Interaction region 1) Charge radii of RI have been measured exclusively by IS measurements Nucleus Studied by Optical Spectroscopy 2) Limited elements, because No slow RI beams &/or No good laser radiations SLOWRI provides UNEXPLORED nuclides H-J. Kluge, Hyp. Int. 74(1992)287.

20 BeGan ( βγn counter) T1/2, Qβ, Branching Ratio measurements for pure RI at low background absolute efficiency: β 90%, γ 5%@1MeV, n 40%

21 Nuclear 1. hfs spectroscopy in trap 2. optical pumping in collinear + βnmr 3. optical pumping in semiconductor +βnmr 4. NMR-Oriented Nuclei 5. PAC for isomer states

22 2. Optical Pumping in Collinear Beam + βnmr

23 3. Optical Pumping in Semiconductor + βnmr Applicable to Elements in III, IV, V group

24 5. Perturbed Angular Correlation for Isomer states TI/TD-PAC with Crystal Ring

25 Be RIBF 1st beam on-line Mass SLOWRI Design SLOWRI Construction Cyclotron Ionguide Development SLOWRI Experiments