Photofission

Photofission

The ALTO facility Georgi Georgiev, CSNSM, Orsay, France The ALTO facility 15 MV 50 MeV 360 staff members 250 outside users (30 countries) /y Stable beams 3928 h /y 25% light ion beams 984 h 75% heavy ion beams 1964 h RIB 360 h /y Stable and radioactive installations within a unique facility Program Advisory Committee • R.F. Casten (Chairman) • E. Balanzat – Caen • D. Balabanski – Bucharest • S. Grévy - Bordeaux • E. Khan – Orsay • A. Maj - Krakow • P. Regan – Surrey • P. Reiter – Cologne • B. Rubio – Valencia • J.-C. Thomas – GANIL • A. Tumino – Catania • C. Trautmann - GSI Experimental areas Split-pole Isol Bacchus production cave Isol Licorne mass separator and low-energy RIB lines ORGAM & MINORCA e LINAC cluster, molecular & droplets beams Radioactive beam lines Stable beam w/o spectrometer Stable beam with spectrometer A bit of history mid - 90’s SPIRAL project ca 1964 : mass spectrometry SPIRAL2 : increase the mass range activities in Orsay introduction of the ISOL technique at GANIL - beginning of the 70’s : d vs e driver option the ISOCELE ISOL setup End 90’s, beginning 2000’s at the Orsay SC (now proton therapy center) ISOL activity back at IPN: PARRNe end 70’s/beginning 80’s, upgrade of the SC ISOCELE2 end 80’s, first online laser ion source at beginning 90’s PILIS activity IPN: PILIS moves to ISOLDE/CERN → COMPLIS setup INAUGURATION 2013 BEDO commissioning green light from French nuclear 2012 safety authorities 2011 first laser ionized RIB 2010 building of the low energy beam lines + laser ion source 2009 Commissioning : tests 84Ga -> 84Ge b-decay and radiation safety measurements 2008 TIS vault 2007 UCx target on line with e-beam – production yields measurements 2006 First e-beam extracted 2005 RF system 2004 construction of the LINAC bunker 2003 81Zn -> 81Ga b-decay arrival of the LINAC cavity from 2002 decommissioned LEP injector 83Ga -> 83Ge b-decay 2001 exploratory photo-fission experiment at CERN 2000 1999 initial idea of a R&D test bench for the SPIRAL2 project at the Orsay Tandem 1998 Photofission First proposed RIB facility based on photo-fission: William T. Diamond, Chalk River, 1998 20 µA 25 MeV e- + 40 g/cm2 238U 1.5 1011 f/s 238U(γ,f) cross section from J.T.Caldwell et al., PRC 21 (1980) 1215 figures from Y. Oganessian et al., NPA 701 (2002) 87c Photofission at CERN-LPI e- LEP injector: 50 MeV e- F Ibrahim et al, EPJA 15 (2002) Photofission at Alto electron linac 10 µA, 50 MeV target & ion source 1011 photofissions /s Parrne mass separator Photofission at Alto measured mass-separated yields for 100 nA 50 MeV e- similar to 1 µA 26 MeV d therefore projected gain of 100x at 10 µA of e- Production pps /10 µA e- 5 108 – 5 109 108 – 5 108 5 107 – 108 107 – 5 107 5 106 – 107 106 – 5 106 5 105 – 106 105 – 5 105 extrapolation from the 104 – 105 systematic yield Stable measurements made in June 2006 at 100 nA primary intensity (excursions up to 10µA was possible during the commissioning phase) F Ibrahim et al, International Topical Meeting on Nuclear Research Applications and Utilisation of Accelerators, Vienna (2009) Target and ion source standard Isolde target with external oven for mass marker ∅ = 14 mm L = 140 mm ρ = 3.2 g/cm3 T ≤ 2000 °C further target optimisation is possible: f/cm3/s e- energy deposit in first 2.65 cm 3 Fluka fission rate in 3.2 g/cm UCx target M Cheikh et al, NIM B 266 (2008) Target and ion source developments Higher yields by increasing Accelerate release of Ln and other 3 UCx density up to 13 g/cm chemically reactive elements through Control porosity fluorinated molecular beams Reduce pellet thickness Physics: B(E2) through fast timing test case 137,139Cs B Hy et al, NIM B 288 (2012) 34 B Roussière et al, EPJA 47 (2011) Ensar ActiLab: IPN, Cern, Ganil, INFN Collaboration IPN, CSNSM, INRNE-Sofia, Tandar-Buenos Aires Rialto: Resonant laser ionisation at Alto S. Franchoo et al. Mezzanine of the mass separator/RIB zone Nd:Yag pump laser (532 nm, 90 W) 2 dye lasers (540-850 nm, 8W @ 30W pump, 10 ns pulse width, 3 GHz line width) BBO doubling units (270-425 nm, >100 mW) Rialto: Resonant laser ionisation at Alto First step 2011, 2012: Gallium with two ionisation schemes 2013: Zinc with frequency tripling 2014: Off-line chamber for development of laser schemes Collaboration IPN Orsay, Isolde, Univ. Manchester, Univ. Mainz Second step electron multiplier ohmic heating 1 1 Zn: 4s4p P1 → 4s4d D2 laser b-decay spectroscopy in the N=50 region more than 10 years of experiments in the 78Ni region at the PARRNe mass separator (Tandem/ALTO) D. Verney et al. Present limit of structure knowledge (at least few excited states are known) hot plasma ionization (1 µA deuteron primary beam) O. Perru PhD – def. 10th December 2004 Eur. Phys. J. A 28, 307 (2006) surface ionization (2-4 µA electron primary beam) M. Lebois PhD – def. 23th September 2008 PRC 80, 044308 (2009) As82 B. Tastet PhD – def. 13th May 2011 Ge79 Ge80 Ge81 Ge85 Ge86 PRC 87, 054307 (2013) D. Testov PhD – def. 17th January 2014 Ga80 Ga79 Ga82 Ga83 Ga84 Ga85 laser ionization Zn81 Zn82 (10 µA electron primary beam) K. Kolos PhD – def. September 2012 PRC 88, 047301 (2013) hot plasma ionization (1 µA deuteron primary beam) PRC 76 (2007) 054312 laser ionization BEDO: Beta decay at Orsay D. Verney et al. Bedo setup Bedo setup in gamma mode in neutron mode 4 small Exogam JINR neutron clovers detector Tetra fast timing LaBr3 LaBr3 up to 5 Ge detectors ε = 5-6% 80 3He tubes ε(252Cf) = 53% 4π β trigger borated polyethylene shielding BGO anti-Compton Tetra: Beta-delayed neutron emission 82Ge 83Ge βn P = 85(4)% 83Ga n N=50 T1/2=0.312s this work βγ βnγ laser-ionised 83Ga beam 4π neutron detector 4π β & 1 Ge detector D Testov et al., submitted to NIM Approved experiments to be scheduled 132Sn region β-γ and β-n experiments mid-shell Ln’s ● Penionzhkevich et al. β-γ fast-timing ● Didierjean et al. ● Roussière et al. ● Lozeva et al. ● Gottardo et al. ● R. Li/M. Ramdhane et al. TAS measurements program ● A.Algora/M. Fallot/A. n-rich Se Porta/B.Rubio/J.L. β-γ and β-n experiments Tain et al. ● Kurtukian Nieto et al. n-rich Ge β-γ and β-n experiments ● Duchêne et al. N=50 β-γ experiments ● Etile – Verney et al. ● Astier et al Low-energy radioactive ion beams at Alto Parrne mass separator Identification station TETRA (existing) POLAREX TAS (project) (project) MLL Trap (project) BEDO/TETRA (existing) LINO (project) LINO: Laser-induced nuclear orientation b-delayed spectroscopy of laser-polarized beams ground and isomeric state properties of 110-126Ag and 128-133In β-decay of polarized 121-126Ag and 128-133In 100Sn 132Sn r process rp process • more accurate theoretical lifetimes of the N=82 isotones below 129Ag • shell quenching vs deformation D. Yordanov et al. • shell effect in radii French ANR funding scheme requested LINO: Laser-induced nuclear orientation polarisation by optical pumping µ & Q from nuclear magnetic resonance β-delayed spectroscopy of laser-polarized beams Polarex: Nuclear Orientation On-Line CSNSM off-line validation Preparation at Alto Rejuvenation of dilution cryostat 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 Tas: Total Absorption Spectroscopy Proposed roadmap at Alto: • Phase 1: install Valencia-Surrey TAS@ALTO (12 BaF2) 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 LaBr3 or CeBr3 for Alto then Spiral-2 IFIC, Valencia Subatech, Nantes University of Surrey, Guildford University of Jyväskylä Ciemat, Madrid Initiate the physics for Spiral-2 at Ganil: Desir, S3, NFS DETRAP MONSTER TETRA BEDO BESTIOL LINO b-NMR LUMIERE BELEN TETRA TONNERRE BEDO MLL Trap Si-Cube TAS CRIS PIPERADE LINO GPIB REGLIS LPCTrap RIALTO NFS LICORNE ► Stable and Radioactive beam facility ► R&D on ISOL & RIB ► low-energy physics program based on photo-fission ► R&D and physics at ALTO pave the way to Spiral-2 at Ganil: initiate physics program, train new generation of ISOL physicists, develop instruments and methodologies .

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