1 / 36

Nuclear physics: the ISOLDE facility

Nuclear physics: the ISOLDE facility. Lecture 2: CERN-ISOLDE facility. Magdalena Kowalska CERN, PH-Dept. kowalska@cern.ch on behalf of the CERN ISOLDE team www.cern.ch/isolde. Outline . Aimed at both physics and non-physics students. Lecture 1: Introduction to nuclear physics

alexa
Download Presentation

Nuclear physics: the ISOLDE facility

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nuclear physics:the ISOLDE facility Lecture 2: CERN-ISOLDE facility Magdalena Kowalska CERN, PH-Dept. kowalska@cern.ch on behalf of the CERN ISOLDE team www.cern.ch/isolde

  2. Outline Aimed at both physics and non-physics students • Lecture 1: Introduction to nuclear physics • This lecture: CERN-ISOLDE facility • Types of radioactive ion beam facilities • ISOLDE within CERN • Beam production at ISOLDE • Lecture 3: Physics of ISOLDE

  3. Open questions in nuclear physics 2 kinds of interacting fermions How to answer the questions: Study nuclei with very different numbers of protons and neutrons (NuPECC long-range plan 2010)

  4. RIB facilities • Two main types of (complementary) RIB facilities: • ISOL (Isotope Separation On-Line) and In-Flight RIB: Radioactive Ion Beam Rare Isotope Beam Light beam heavy beam

  5. RIB facilities comparison

  6. RIB facilities worldwide • Existing and in preparation ISOL-type In-Flight After B. Sherill

  7. ISOLDE – short history First beam October 1967 Upgrades 1974 and 1988 New facility June 1992

  8. ISOLDE at CERN

  9. ISOLDE within CERN accelerators ISOLDE PSB PS LINAC2

  10. ISOLDE elements Isotope production via reactions of light beam with thick and heavy target Separator Target Production – ionization – separation

  11. Ion beam intensity • Number of extracted ions (yield) is governed by: primary particle flux x reaction cross section x number of target particles x efficiencies According to Ulli Koester:

  12. Production channels

  13. Production 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

  14. Inside a standard target

  15. Ionization • Surface • Plasma • Lasers After U. Koester

  16. Beam extraction and separation • All produced ions are extracted by electrostatic field (up to 60kV) • The interesting nuclei are mass selected via magnetic field • Lorentz force: depends on velocity and mass • m/dm <5000, so many unwanted isobars also get to experiments U To experiments = =

  17. Production, ionization, extraction target Target+ vacuum+ extraction Ion energy: 30-60keV robots

  18. Separation Magnet separators (General Purpose and High Resolution)

  19. Post-acceleration Increase in charge state A/q selection Ion trapping and cooling REX accelerator Rf acceleration 3MeV*A beam to experiment

  20. Production and selection - example Facility

  21. Example – astatine isotopes • How to produce pure beams of astatine isotopes (all are radioactive)? • Use lasers to ionize them • And determine for the first time the At ionization potential S. Rothe et al, Nature Communications 4 (2013), 1835

  22. Extracted nuclides More than 700 nuclides of over 70 chemical elements delivered to users – by far largest choice among ISOL-type facilities (experience gathered over 40 years)

  23. Experimental hall Decay spectroscopy Coulomb excitation Transfer reactions Laser spectroscopy Beta-NMR Penning traps Target stations HRS & GPS PS-Booster 1.4 GeV protons 3×1013ppp Mass-sep. HRS WITCH ISCOOL RILIS REX-ISOLDE Travelling setups NICOLE Post-accelerated beams MINIBALL and T-REX Collection points Travelling setups COLLAPS CRIS ISOLTRAP TAS

  24. Facility photos

  25. Experimental beamlines

  26. HIE-ISOLDE upgrade High Intensity and Energy ISOLDE Works on-going First post-accelerated beam in 2015/2016

  27. 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 f(N,Z)

  28. Summary • Two complementary types of RIB facilities • ISOL and in-flight • Several dozen facilities worldwide and new ones coming • ISOLDE at CERN • ISOL-type facility which uses protons from PSB • Elements: production target, ionization, extraction, separation, (post-acceleration) • Largest variety of beams worldwide • Upgrade project: HIE-ISOLDE • ISOLDE research topics: • Nuclear physics • Atomic physics • Nuclear astrophysics • Fundamental studies • Applications • => Lecture 3

  29. Reaction probability

  30. Reaction probability • Primary beam type and energy are important

  31. Research with radionuclides 34Ne: 10 protons + 24 neutrons Does it exist? ? = Mean field relative abundance fp-shell 28 20 sd-shell mass 8 p-shell 2 s-shell Nuclear physics Strong interaction in many-nucleon systems Nuclear driplines Astrophysics Nucleo-synthesis, starevolution Abundances of elements Fundamental studies Beyond standard model (neutrino mass, …) Applications, e.g. Solid state physics, life sciences

  32. Properties of radio-nuclides • Different neutron-to-proton ratio than stable nuclei leads to: • New structure properties • New decay modes => Nuclear models have problems predicting and even explaining the observations • Example - halo nucleus 11Li: • Extended neutron wave functions make 11Li the size of 208Pb • When taking away 1 neutron, the other is not bound any more (10Li is not bound)

  33. EURISOL • Future European RIB facility

  34. Isotope identification in-flight

  35. REX post-accelerator • EBIS • Super conducting solenoid, 2 T • Electron beam < 0.4A 3-6 keV • Breeding time 3 to >200 ms • Total capacity 6·1010 charges • A/q < 4.5 • Nier-spectrometer • Select the correct A/q and separate the radioactive ions from the residual gases. • A/q resolution ~150 REXEBIS MASS SEPARATOR Optional stripper ISOLDE ISOLDE beam Primarytarget 7-GAP RESONATORS 9-GAP RESONATOR IH RFQ Rebuncher 60 keV 0.3 MeV/u 3.0 MeV/u 2.2 MeV/u 1.2 MeV/u REXTRAP Experiments • REX-trap • Cooling (10-20 ms) • Buffer gas + RF • (He), Li,...,U • 108 ions/pulse • (Space charge effects >105) Linac Length 11 m Freq. 101MHz (202MHz for the 9GP) Duty cycle 1ms 100Hz (10%) Energy 300keV/u, 1.2-3MeV/u A/q max. 4.5 (2.2MeV/u), 3.5 (3MeV/u) Total efficiency : 1 -10 % 18 May 2009 New opportunities in the physics landscape at CERN 35

  36. HIE-ISOLDE Quarter-wave resonators (Nb sputtered) • SC-linac between 1.2 and 10 MeV/u • 32 SC QWR (20 @ b0=10.3% and 12@ b0=6.3%) • Energy fully variable; energy spread and bunch length are tunable. Average synchronous phase fs= -20 deg • 2.5<A/q<4.5 limited by the room temperature cavity • 16.02 m length (without matching section) • No ad-hoc longitudinal matching section (incorporated in the lattice) • New beam transfer line to the experimental stations

More Related