330 likes | 427 Views
ISOLDE – High-lights and Future Plans. Maria J. G. Borge , CERN, PH-Dept. A Few Facts. ISOLDE is the CERN radioactive beam facility In operation since 45 years The largest selection of isotopes of any ISOL facility worldwide Provides low energy or post-accelerated beams
E N D
ISOLDE – High-lights and Future Plans Maria J. G. Borge , CERN, PH-Dept
A Few Facts • ISOLDE is the CERN radioactive beam facility • In operation since 45 years • The largest selection of isotopes of any ISOL facility worldwide • Provides low energy or post-accelerated beams • Run by an international collaboration • Open to users from around the world
ISOLDE at CERN ISOLDE PSB PS LINAC2 Facility To be exchanged by LINAC4 To be upgraded in intensity (2uA->6uA p to ISOLDE) and energy (1.4->2GeV)
ISOL elements Isotope production via reactions of light beam with thick and heavy target PSB upgraded in intensity (2uA->6uA p to ISOLDE) and energy (1.4->2GeV)
Produced Nuclei • Over 20 target materials and ionizers, depending on beam of interest operated at high temperature • U, Ta, Zr, Y, Ti, Si, … • 3 types of Ion-sources • > 700 nuclides of over 70 chemical elements produced Reported by Thierry Stora Target
ISOLDE physics topics Applied Physics Implanted Radioactive Probes, Tailored Isotopes for Diagnosis and Therapy Condensed matter physics and Life sciences Nuclear Physics Nuclear Decay Spectroscopy and Reactions Structure of Nuclei Exotic Decay Modes Fundamental Physics Direct Mass Measurements, Dedicated Decay Studies - WI CKM unitarity tests, search for b-n correlations, right-handed currents Atomic Physics Laser Spectroscopy and Direct Mass Measurements Radii, Moments, Nuclear Binding Energies Nuclear Astrophysics Dedicated Nuclear Decay/Reaction Studies Element Synthesis, Solar Processes • Many beams • Good beam purity and quality • High intensity f(N,Z)
Physics & Users • Physics interest: • Nuclear structure from decay and reactions • Nuclear gs properties via atomic techniques • Nuclear astrophysics • Fundamental interactions • Solid-state physics • Bio- and medical physics Around 450 users (7% of CERN’s total) 25 countries; 100 institutions 175 experiments (in 4 years) 90 active experiments in 2011 • User requirements: • Higher energy for the post-accelerated beam • More beams (intensity wise and different species) • Better beams (High purity beams, low emittances, more flexibility in the beam parameters) => Need upgraded facility : HIE-ISOLDE Project
Experimental hall Target stations HRS & GPS PS-Booster 1.4 GeV protons 3×1013 ppp Mass-sep. HRS WITCH ISCOOL RILIS REX-ISOLDE Travelling setups NICOLE Post-accelerated beams MINIBALL and T-REX Collection points Travelling setups Elisa Rapisarda COLLAPS Magdalena Kowalska CRIS ISOLTRAP Susanne Kreim TAS
COLLAPS – Ne charge radii Laser spectroscopy & Massses Intrinsic density distributions of dominant proton FMD configurations Geithner et al, PRL 101, 252502 (‘08) Marinova et al, PRC84, 034313 (‘11)
WITCH Weak InteractionTrap for Charged particles -> fundamental studies Goal: determine bn correlation for 35Ar with (a/a)stat 0.5 %
WITCH -> energy spectrum of recoiling ions with a retardation spectrometer Use a Penning trap to create a small, cold ion bunch June 2011 data 35Ar First high-statistics run in Nov 2011: under analysis PRESENT 16 Nov 2012 M. Beck et al., Eur. Phys. J. A47 (2011) 45 M. Tandecki et al., NIM A629 (2011) 396 S. Van Gorp et al., NIM A638 (2011) 192
REX-ISOLDE Total efficiency : 1 -10 % 1+ to A/Q = 3 – 4.5
Post-accelerated beams Travelling setups MINIBALL
REX-ISOLDE • First spin-polarized beam (8Li) produced with tilted foils after the REX linac (300 keV/u). • REX separator and linac successfully tested with A/q=2 => important for TSR. • Difficult 6He beam through REX to Optical Time Projection Chamber (OTPC). βd • 21Na(p,α)18Ne to study 22Mg states. • 30Mg(p,p’) to study 31Mg excited state by its Analogue Resonance • Characterize 13Be from analogue resonance sin 13B populated by 12Be(d,n) with MAYA d α
Experimental set-up: T-REX &MINIBALL • MINIBALL • 24 HPGe • 6-fold segmented • e ≈ 3% @ 1.3 MeV beam beam … shown is GEANT4 Implementation of set-up Talk by Elisa Rapisarda!
Near Future: HIE-ISOLDE project • Approved Dec 2009 • Offically started Jan 2010 • Yacine Kadi project Leader • Budget 40 M$ Energy Upgrade: The HIE-ISOLDE project construction of the SC LINAC to upgrade the energy of the post-accelerated radioactive ion beams to 5.5 MeV/u in 2015 and 10 MeV/u by 2017 Tomorrow Yacine kadi Intensity Upgrade: The design study for the intensity upgrade, also part of HIE-ISOLDE, started in 2011, and addresses the technical feasibility and cost estimate for operating the facility at 10 kW once LINAC4 and PS Booster are online. Richard Catherall
The ISOLDE Collaboration ISOLDE is run by a collaboration comprising 13 countries and CERN. Each country pays a annual fee of 60 KEuros. This budget is used to support experiments, buy common equipment and consumables, pay some personnel (visitors, secretary….) and contribute to upgrades (HIE-ISOLDE…) Each county has a representative on the Isolde Collaboration Committee which meets three times a year. The chair is currently Dr Yorick Blumenfeld (France)
Summary and outlook • The Future of ISOLDE is bright. • With nearly 50 year of operation ISOLDE remains as pioneering ISOL-installation both at the level of designing new devices and production of frontier Physics. • ISOLDE experiments cover many techniques enabling to answer many physics questions. • Synergies between the different experiment techniques hunting for isolating very pure beams has been lately very successful Complementarity is important!
Coulomb excitation & Transfer @ Miniball Geg detectors CD – detector Double sided Si strip detector DE-E detector Miniball setup: highly efficient gamma detectors and particle detector Beam dump PPAC detector REX- ISOLDE Observables: Transition energies and intensities Information: reduced transition matrix elements => Study collectivity and deformations E <3 MeV/u target Beam Beam impurities Miniball + T-REX setup (Si detector barrel):gamma detectors and particle identification Typical reactions: one or two-nucleon transfer (d,p), (t,p) … In inverse kinematics Observables • energies of protons (+ Eg) (single-particle) level energies • angular distributions of protons (+ g-rays) spin/parity assignments • (relative) spectroscopic factors particle configurations
Coulomb excitation of 72Kr Coulex Spectra - number of counts in 710 keV depends on the shape of 72Kr Oblate 72Kr expected The technique Doppler Corrected for 104Pd target excitation Doppler Corrected for 72Kr projectile excitation: 150 counts in 710 keV line
Decay studies Travelling setups
Beta-delayed fission • Beta-delayed fission is believed to affect the abundance of heavy elements as it contributes to recycling heavy elements in the course of the r-process. • N/Z ratio too exotic for current facilities and U-Cf region too close to stability for challenging models. P-rich region offers a very challenging group to probe our understanding of the process. • 180,182Tl, 192,194,196At, 200,202Fr have been studied at ISOLDE. 180Tl 194At 196At βDF 180Tl 180Hg*90Zr+90Zr (?) Fr: L.Ghys, Ph.D thesis KULeuven At: V. Trusdale, Ph.D thesis U of York Tl: PRL 105 (2010) 252502
New setups in the summer • Successful experiments with new setups & by new groups: • 6He with opt. time-proj. chamber (Warsaw); • 21Na and 31Mg with REX scattering chamber (Lund and Tokyo); • 34Mg with fast tape-station (Bucharest) • 12 Be with active target MAYA (Leuven, GANIL);
Motivation for the TSR • 1. Higher intensities and cooler beams than in-flight storage rings • 2.Compared to thick experimental target and direct beam from the post-accelerator: • + no background from a target container or a beam dump • + reduced energy straggling for projectile and reaction products in thin target • + smaller beam size ‐> improved kinematic corrections for reaction products • + decreased detector dead-time as CW beam (REX and HIE-ISOLDE pulsed) • Possibility to use extracted beam with excellent optical qualities
Physics Cases discussed for the TSR • Half-life measurements of 7Be in different atomic charge states • Capture reactions for astrophysical p-process • Nuclear astrophysics through transfer reactions • Nuclear structure through transfer reactions • Long-lived isomeric states • Atomic effects on nuclear half-lives • Di-electronic recombination on exotic nuclei • Atomic physics experiments • Neutrino physics 10.Laser spectroscopy experiments in the storage ring
Targets p+ p+ p+ p+ p+ p+ • Over 20 target materials and ionizers, depending on beam of interest • U, Ta, Zr, Y, Ti, Si, … • Target material and transfer tube heated to 1500 – 2000 degrees • Operated by robots due to radiation Target Target Converter Converter Target Standard
Ionization • Surface • Plasma • Lasers
Going beyond the limits with the LIST • Neutron-rich beams at ISOLDE are limited by the high isobaric contamination from Fr and Ra. • The Laser Ion Source Trap can suppress those beams by up to a factor 2000. • The first decay spectroscopy of 219Po has been performed as well as hfs studies on 216-219Po. D.Fink, Ph.D thesis U. of Mainz