The high-resolution in-flight spectroscopy (HISPEC) project at FAIR Zsolt Podolyák, University of Surrey GANIL, 4-6 October 2005

High-resolution in-flight spectroscopy (HISPEC collaboration) 49 institutions, 20 countries

FAIR (Facility for Antiproton and Ion Research) (Darmstadt, Germany) fragmentation based radioactive beam facility 350m ~1GeV/u ~1012 ion/s fragmentation/fission fragment separator low-energy cave 0-100 MeV/u starts to operate ~2011

Low-energy branch: Mono-energetic energy buncher: (~500 MeV/u => 0-100 MeV/u) Principle: Very fast (ns) cooling Layout: Conceptional design by 2006: C.Brandau, Univ. of Surrey

in-flight and decay spectroscopy beam energy buncher

- high resolution gamma-ray spectroscopy + + Features isotopes of all elements; 3 MeV/u < E <100 MeV/u ions with short lifetimes (>100 ns) beam cocktail or mono isotopic beams isomeric beams - high resolution gamma-ray spectroscopy + + - high resolution particle spectroscopy + + - beams at Coulomb barrier energies - intermediate energy beams: 50-100 MeV/u HISPEC

Physics goals and observables Table 1: Experimental opportunities for high-resolution spectroscopy at the low-energy branch. Research field Experimental method (beam-energy range) Physics goals and observables Beam int. (particle/s) Nuclear structure, reactions and astrophysics Intermediate energy Coulomb excitation, In-beam spectroscopy of fragmentation products (E/A ~ 100 MeV) Multiple Coulomb excitation, direct and deep-inelastic, fusion evaporation reactions (E/A ~ 5 MeV; Coulomb barrier) Decay spectroscopy (E/A = 0 MeV) Medium spin structure, Evolution of shell structure and nuclear shapes, transition probabilities, moments, high spin structure, single particle structure, dynamical properties, transition probabilities, moments, half-lives, spins, nuclear moments, GT strength, isomer decay, beta-decay, beta-delayed neutron emission, exotic decays such as two proton, two neutron. 101...105 104...107 10-5...103 HISPEC DESPEC

Beam intensities High primary beam intensity ~1012 ion/s for 238U High transmission (SuperFRS)

Characteristics of the beam after the energy buncher Energy and angular spread of the beam: 300 MeV/u: sE ~ 0.3 MeV/u sa ~ 5 mrad 5 MeV/u: sE ~ 3 MeV/u sa ~ 20 mrad Characteristics of the beam after the energy buncher Courtesy of H. Weick

CDR p.65. Some physics questions with radioactive beam

Physics Example: the Zr isotopes (Z=40) 90Zr50 104Zr64 110Zr70 122Zr82 spherical deformed (β=0.45) spherical ? Coulomb excitation decay Lifetime: >1 s 1.2 s <1 s T.R. Werner, J. Dobaczewski, W. Nazarewicz, Z. Phys. A358 (1997) 169

HISPEC – Low energy cave (3-100 MeV/u) Particle tracking (Z,pos.,E) Identification (spectrometer) Charged particle det. γ-ray det.

RISING HISPEC …

Coulomb excitation at ~100 MeV/u 54Cr 56Cr counts 835keV counts 1006keV Eg Eg spectra are efficiency corrected Doppler corrected counts 880keV 58Cr B(E2) from double ratio (peak area/particles)/54Cr efficiency from 60Co source + Lorentz-boost Ng, Npro => s => B(E2)-Bestimmung möglich aber: relativ zu 54Cr ist es genauer B(E2) values: 54Cr 14.2 ± 0.6 W.u. (normalisation) 56Cr 8.7 ± 3.0 W.u. 58Cr 14.8 ± 4.2 W.u. Eg A.Bürger et al., Phys. Lett. B (2005).

Secondary fragmentation at ~100 MeV/u dE-E Si-CsI dE CATE E 2+ -> 0+ 4+ -> 2+ 6+ -> 4+ 8+ -> 6+ 50Cr 8+->6+ 6+ -> 4+ 4+ -> 2+ 2+ -> 0+ 46Ti M.Bentley et al.

HISPEC – Low energy cave (3-100 MeV/u) Particle tracking (Z,pos.,E) Identification (spectrometer) Charged particle det. γ-ray det.

Beam tracking and identifying detectors Most promising: Diamond CVD detectors (E/A=50-100 MeV) Carbon foil (electron emission) + multichannel plates (E/A=5 MeV)

Ideal for high velocity beams Advanced GAmma Tracking Array High photo-peak efficiency Good angular resolution <1degree FWHM=10 keV at β=50% = 5 keV at β=20% Ideal for high velocity beams see G.Duchene’s talk

Electromagnetic transition strength measurements (lifetimes) (plungers and fast scintillators) Plungers: Not stopper foil, but degrader foil has to work connected to gamma and charged particle detectors identification after reaction (to clean spectra from background) see C.Fransen’s talk

Particle identification after the target dE-E detectors, good Z resolution, bad A resolution (β spread) TOF + dE-E huge detector size needed Bρ + TOF + dE-E reduced transmission initially existing ALADIN magnet Later: dedicated magnetic spectrometer for E/A=3-100 MeV Meeting: Paris, 3 Oct. 2005

Letter of intent: physics HISPEC/DESPEC collaboration structure Management Board Spokesperson(HISPEC) Zsolt Podolyák / Wolfram Korten Spokesperson(DESPEC) Berta Rubio Deputy (HISPEC) Jan Jolie Deputy (DESPEC) Phil Woods Project manager (HISPEC) Juergen Gerl Project manager (DESPEC) Magda Gorska Technical Board member affiliation beam tracking and identification detectors J.M. Quesada University Sevilla, Spain AGATA J. Simpson CCLRC Daresbury,UK HYDE charged particle detectors for reaction studies I. Martel Huelva University, Spain Charged particle detectors for structure studies D. Rudolph Lund University, Sweden Plunger A. Dewald Koln University, Germany Magnetic spectrometer D. Ackermann GSI Darmstadt, Germany DSSD implantation and decay detector P.J. Woods Edinburgh University, UK DESPEC high resolution gamma detectors A. Jungclaus Universidad Autonoma de Madrid, Spain Neutron detectors D. Cano-Ott CIEMAT Madrid, Spain Total absorption spectrometer L. Batist PNPI Gatchina, Russia Fast timing with BaF2 H. Mach Uppsala University, Sweden Isomeric moments D. Balabanski Camerino University, Italy Electronics and Data acquisition J. Nyberg Collaboration Board The members are the signatories of the Memorandum of Understanding. 32 institutions, 15 countries Letter of intent: physics Technical Proposal evaluated by PAC

Summary HISPEC: high-resolution in-flight spectroscopy low-energy cave (0-100 MeV/u) Intermediate energy secondary fragmentation Coulomb excitation RISING Coulomb barrier energy experience needed (beam tracking …)

HISPEC – SPIRAL2 (GANIL) common points Physics AGATA + ancillary detectors Detector development + electronics + data acquisiton Tracking detectors Si detectors (HISPEC/DESPEC, R3B, EXL…) Electronics: ASIC Neutron detectors (DESPEC) …