ALTO - facility for stable and radioactive beam studies. G. Georgiev

Transcription

1 ALTO - facility for stable and radioactive beam studies G. Georgiev

2 ENSAR2 kick-off meeting, Caen, March 2016 The ALTO facility 15 MV Users ~120 ~ Beam-time 1752 h 3600 h 2712 h 2232 h 3816 h 219 UT 450 UT 339 UT 279 UT 477 UT

3 Experimental areas γ-spectroscopy Bacchus Split-Pole spectrometer ISOL production cave e LINAC ISOL experimental cave (~100 m 2 ) Radioactive beam lines cluster, molecular & droplets beams ENSAR2 kick-off meeting, Caen, March 2016 Stable beam w/o spectrometer Stable beam with spectrometer

4 ENSAR2 kick-off meeting, Caen, March 2016 The ALTO PAC Richard Casten Yale, USA, Chair Dimiter Balabanski ELI-NP, Romania Emmanuel Balanzat CIMAP/GANIL, France Marcella Grasso IPN Orsay, France Stéphane Grévy Bordeaux-Gradignan, France Adam Maj IFJ PAN Kraków, Poland Paddy Regan Univ. Surrey, UK Peter Reiter Univ. Koeln, Germany Berta Rubio CSIC-Univ. Valencia, Spain Jean-Charles Thomas GANIL, France Christina Trautmann GSI, Darmstadt, Germany Aurora Tumino Kore Univ. Enna & LNS-INFN Catania, Italy Call for proposals once a year

5 Stable-beam Studies at ALTO

6 MINORCA at ALTO (June 2014 March 2015) Campaign managers: I. Matea and G.G. ENSAR2 kick-off meeting, Caen, March ORGAM CS HPGe x 0.1% 8 Miniball TC at ~14 cm from target 7.3% 1.33 MeV ancillary detectors: - Orsay plunger (OUPS) - particle detector - DSSD

7 MINORCA physics cases Campaign managers: I. Matea and G.G. ENSAR2 kick-off meeting, Caen, March 2016

8 Lithium Inverse Cinematics ORsay NEutron source ENSAR2 kick-off meeting, Caen, March 2016 Sample H target 100nA 7 Li MeV γ γ n-induced fission of 238 U n n n n TIPS tagging of 10 7 n/s/cm 2 isomer partners LICORNE Exoticity EXILL SF J. Wilson, M. Lebois et al. Testing ground for NFS@SPIRAL2

9 ENSAR2 kick-off meeting, Caen, March 2016 Is 100 Ru an E(5) nucleus? T. Konstantinopoulos et al. 88 Sr( 14 C, 2n) 100 Ru : MeV 14 C <1.5 pna Orsay Universal Plunger System (OUPS) RDDS (2 +, 4 +, 6 + ) : DSAM (8 + ) : * 12 plunger dist. from 1 um to 1 mm 6.5*10 8 γ γ coincidences collected

10 ENSAR2 kick-off meeting, Caen, March 2016 DSAM for the 8 + Fit with DSAM code for 3 different detector angles T. Konstantinopoulos et al.

11 Lifetime measurements in 113 Te D. Cullen et al. To understand the evolution of collectivity in Te isotopes and in nuclei as we approach N~Z~50 Reaction: 54 Fe ( 63 Cu, 3pn) at 245 MeV using MINORCA+OUPS Successful data collection.at the initial stage of analysis.. ENSAR2 kick-off meeting, Caen, March 2016 Courtesy B.S. Nara Singh

12 ENSAR2 kick-off meeting, Caen, March 2016 Courtesy B.S. Nara Singh Lifetime measurements in 113 Te D. Cullen et al. γ γ matrix: Gate on 724keV (19/2 - to 15/2 - ) and analyze 587 kev (15/2 - to 11/2 - ) in the projected spectrum Shifted component Partial data and very preliminary Doppler Corrected 4000 μm 900 μm 600 μm Stopped component 300 μm 200 μm 130 μm

13 Pear-shaped nuclei in the N~88 region ENSAR2 kick-off meeting, Caen, March 2016 Courtesy M. Komorowska P. Butler, M. Zielinska et al. Octupole collectivity in 146 Nd and 148 Sm through Coulomb excitation

14 Coulomb excitation of 146 Nd and 148 Sm ENSAR2 kick-off meeting, Caen, March 2016 Courtesy M. Komorowska P. Butler, M. Zielinska et al. 146 Nd 148 Sm

15 Anti-Compton shields for Miniball A collaboration work between IPN, Orsay and IKP, Cologne 2 cables 3/4 PMts Socket assembly (IPNO fabrication) Spring Cover Plug Cables Free space between the plugs and the Ring = 20 mm Due to the modification of the PMts tube, the fixation on the Ring must be modified ENSAR2 kick-off meeting, Caen, March 2016 Courtesy I. Matea

16 Radioactive Ion Beams at ALTO

17 Progress in the RIB instrumentation (so far) ENSAR2 kick-off meeting, Caen, March modes, 3 commissioning's, 3 physics results BEDO setup in gamma mode 4 small EXOGAM clovers BEDO setup in neutron mode Dubna neutron detector TETRA BEDO setup fast timing mode LaBr3 IPN, coll. CSNSM, IPHC IPN, coll. JINR (Russia), IPHC IPN, coll. CSNSM, TANDAR (Argentina), INRNE (Bulgaria) PhD: A. Etilé (CSNSM) PRC 91, (2015) PhD: D. Testov (IPN) NIM A815, 96 (2016) M.A.Cardona, D.Hojman, B.Roussière, I.Deloncle et al. to be submitted

18 Shape coexistence in the 78 Ni region by β-delayed conversion-electron spectroscopy of Ge s Shape coexistence throughout the nuclear chart Heyde & Wood Rev. Mod. Phys. 83 (2011) 1467? 78 Ni

19 Are there intruder configurations at Z>28, N=49 ENSAR2 kick-off meeting, Caen, March Ge 82 33As 49 (1) large number of 1 + states in the N=50 region (responsible for the half-life of the mother nucleus, possible consequences on the r-process) intruder states As Z=33, N=49 A. Etilé et al. PRC (2015) νd 5/2 νg 9/2 500 kev only (influence of couplings to 2p-2h and tensor interaction) (2) lowering of 1p 2h (intruder) states an indication for shape coexistence in the close vicinity of 78 Ni?

20 Experimental setup PARRNe on line mass separator PARRNe β-decay and identification station β-delayed CE and γ-spectroscopy LN 2 -cooled SiLi detector BEDO β-decay station ENSAR2 kick-off meeting, Caen, March 2016 Courtesy D. Verney

21 Experiment at the PARRNe identification station search for E0 transitions Ge collection point (surface ionized) 80 Ga beam ( pps) tape counting position photo multiplier Ge γ-detection ε β = 20% ε (1MeV) = 0.7% ε e- = 14% Plastic scintillator SiLi β-detection Cryogenic finger X and e - detection ENSAR2 kick-off meeting, Caen, March 2016 Courtesy D. Verney

22 The observation Compatible with the T 1/2 for the 3 isomer in 80 Ga [T 1/2 (3 )=1.3±0,2 s; Verney et al. PRC 87 (2013)] A situation very similar : populated in the 3 72 Ga decay [Rester et al NPA 162 (1971)] s 1/2 d 5/2 50 g 9/2 First evidence of shape coexistence in the 78 Ni region Gottardo, Verney et al. submitted to PRL ENSAR2 kick-off meeting, Caen, March 2016 Courtesy D. Verney

23 Present RIB setups and near-future projects ENSAR2 kick-off meeting, Caen, March 2016 Parrne mass separator Identification station TETRA (existing) TAS (existing) MLL Trap (project) Mass measurements POLAREX (project) LTNO ( 3 He/ 4 He) LINO (project) BEDO (existing) Laser-Induced nuclear orientation (µ,q, J p )

24 LINO: Laser-induced nuclear orientation ENSAR2 kick-off meeting, Caen, March 2016 polarisation by optical pumping µ & Q from nuclear magnetic resonance β-delayed spectroscopy of laser-polarized beams

25 LINO: Laser-induced nuclear orientation ENSAR2 kick-off meeting, Caen, March 2016 β-delayed spectroscopy of laser-polarized beams ground and isomeric state properties of Ag and In β-decay of polarized Ag and In 100 Sn 132 Sn rp process D. Yordanov et al. r process more accurate theoretical lifetimes of the N=82 isotones below 129 Ag shell quenching vs deformation shell effect in radii

26 ENSAR2 kick-off meeting, Caen, March 2016 Polarex: Nuclear Orientation On-Line CSNSM off-line validation Rejuvenation of dilution cryostat Preparation at Alto Structural integration & beam-line design CSNSM Orsay LPSC Grenoble IPN Orsay INM Paris University of Tennessee University of Maryland University of Oxford University of Novi Sad C. Gaulard et al.

27 MLL trap - high-precision mass measurements at ALTO ENSAR2 kick-off meeting, Caen, March 2016 E. Minaya et al.

28 ENSAR2 kick-off meeting, Caen, March 2016 The timeline LINO: - beamline elements being presently built and purchased; - setup elements (charge-exchange cell, detection chamber etc. ) under construction to be ready by the end of first experiments foreseen for 2017 POLAREX: - fridge tested off-line at CSNSM (8 mk achieved) in move to ALTO possibly in off-line and near-line experiments in on-line experiments in 2018 MLL-trap: - superconducting magnet warmed up and being prepared to move to Orsay (May June 2016) - construction of beamlines and RFQ cooler-buncher till end of off-line tests in on-line tests and measurements from 2019 on

29 ENSAR2 kick-off meeting, Caen, March 2016 ENSAR summary ALTO facility 1 Sept Dec Number of beam hours Est. number of users Est. number of projects The ENSAR2 numbers

30 ALTO/ ν-ball hybrid spectrometer workshop th 20th May, at the IPN Orsay 30

31 ENSAR2 kick-off meeting, Caen, March 2016 Thank you!

32 ENSAR2 kick-off meeting, Caen, March 2016 Conclusions ALTO a small-scale facility for stable and radioactive beams that provides physics results with considerable impact Gamma-ray spectroscopy has been providing strong contributions to the nuclear structure studies at ALTO ISOL - RIB studies (beyond standard beta-decay) start already providing results with significant impact The R&D and the physics program at ALTO a step towards a nextgeneration ISOL RIB facility address physics cases, train ISOL physicists, develop instruments and methodologies

33 ENSAR2 kick-off meeting, Caen, March 2016 The bottle neck The two high-priority setups Radioactive Ion Beams and Split-Pole are shearing the same experimental hall e LINAC Split-Pole spectrometer ISOL production cave ISOL experimental cave

34 ENSAR2 kick-off meeting, Caen, March 2016 TETRA Installed on an independent beamline. First experiment in November December 2015 (see talk of D. Verney)

35 26 Al nucleosynthesis in massive stars N. de Séréville & A. M. Laird N-SI-36 Astrophysical motivation: Gamma-ray emission associated with 26 Al observed in our galaxy. 26 Mg coming from 26 Al decay observed in presolar grains 26 Al yields depends strongly on reactions 26 Al(n,p) 26 Mg and 26 Al(n,α) 23 Na Need for better 27 Al spectroscopy (E R, Jπ, Γ p, Γ α ) above neutron threshold (S n = 13 MeV) Credit: MPE Garching / R. Diehl 26 Al(n,p) 26 Mg and 26 Al(n,α) 23 Na in massive star Populating resonances with the 27 Al(p,p') 27 Al* reaction Split-Pole spectrometer (ALTO) + DSSSDs in reaction chamber 30 new states above neutron threshold in 27 Al S. Benamara, N. de Séréville et al, PRC 89, (2014) ENSAR2 kick-off meeting, Caen, March 2016 Adsley et al. to be submitted

36 ENSAR2 kick-off meeting, Caen, March 2016 TDRIV on H-like ions: 24 Mg beam: 24 MeV (5 MeV/u) target: 2.4 mg/cm 2 93 Nb reset Foil: 1.7 mg/cm Au Previous measurement: g(2 + ) = 0.51 (2) R.F. Horstman et al., NPA 248, 291 (1975) Our result: g(2 + ) = (13) A. Kusoglu et al. PRL 114, (2015) 24 Mg 2 + state USD shell model: g(2 + )=0.544 High-accuracy g-factor measurements are essential for constraining the theories!

37 ENSAR2 kick-off meeting, Caen, March 2016 RDDS: 4 + and 6 + T. Konstantinopoulos et al. τ(4 + ) = 3.4 (10) ps Τ(6 + ) = 9.4 (15) ps *Monte Carlo simulation performed to fit the lineshapes

38 Tas: Total Absorption Spectroscopy Proposed roadmap at Alto: Phase 1: install Valencia-Surrey (12 BaF 2 ) at existing beam line, for nuclei of interest that could be easily selected Phase 2: more challenging cases with laser ion source for selection, in parallel with development of dedicated TAS beam line Phase 3: synergy with Bedo and Tetra for βn emitters and more exotic isotopes. Common measurement campaigns with complementary beam lines? in parallel, new detector developments combining higher resolution with efficiency such as LaBr 3 or CeBr 3 for Alto then Spiral-2 IFIC, Valencia Subatech, Nantes University of Surrey, Guildford University of Jyväskylä Ciemat, Madrid

39 Time dependent recoil in vacuum for Goals: Precise and independent measurement of the nuclear g-factor Determination of the hyperfine interactions for g-factor measurement on neutron-rich nuclei towards 78 Ni Experiment: Development of 12 C target for plunger measurement (IPN Orsay) 56 Fe beam delivered by IPN Tandem Detection setup: 8 MiniBall clusters 12 ORGAM detectors CSNSM particle detector (8-fold segmented annular plastic) OUPS plunger Na-like 56 Fe ions

40 Setup optimization and analysis Beam energy optimization to approach the optimal charge state distribution Several condition to clean the spectrum from: Reactions with the C foil Coulomb excitation in the target backing and stopper Plunger offset determined using the known lifetime of 56 Fe 2 + and the velocity

41 Preliminary results MINIBALL analysis performed using the segment information Similar behavior for ORGAM and MINIBALL detectors Further analysis needed to understand the pattern of the in-flight and stopped component

42 ENSAR2 kick-off meeting, Caen, March 2016

43 Studies of the electronic Box to be fixed on the existing screws ENSAR2 kick-off meeting, Caen, March 2016 Courtesy I. Matea