Report on RISING (and some other Current UK work) @ GSI

Paddy ReganDept. of Physics

University of SurreyGuildford, GU2 7XH, UK

p.regan@surrey.ac.uk

RISING = Rare ISotope INvestigations at GSI

2 major ‘campaigns’ so far

1) ‘Fast’ (in-beam) Campaign

1) ‘Stopped’ (isomer/β-decay) Campaign

Big collaborations, need a steering committee..significant UKInvolvement (Simpson and Nolan) at this level

Major campaign using ‘retired EUROBALL’ cluster detectors for fragmentation-based nuclear spectroscopy.

Stopped-Beam Campaign to study decays from isomers and following β-decay.

Three experiments for ‘isomer only’ part ran in Feb/Mar’061. N=Z~43 nuclei (107Ag beam, PHR)2. N=126, ‘south’ ( 208Pb beam, Zsolt Podolyák)3. 54Ni/54Fe isospin symmetry (58Ni beam, Dirk Rudolph)

To run in June-July 2006 and Dec. 2006, • 130Cd isomers (136Xe beam, Andrea Jungclaus)• 130Cd via fission (238U beam, Magda Gorska) • Fission fragments for A~110 (238U beam, Alison Bruce)

‘Active stopper’ expts for 2007 (N~126, 170Dy, Tz=-1.)

primary beamPb @ 1GeV/u

Production targetCentral focus, S2

Final focus, S4

ΔE(Z2)

cueB

QA

βγρ

=

βγ→FTO

catcher

degraderdegrader

dipole, Bρ

scintscint

MW=x,y

scint(veto)

Use FRS@GSI or LISE3@GANIL to ID nuclei. Transport some in isomeric states (TOF~ x00ns).Stop and correlate isomeric decays with nuclei id.

eg. R. Grzywacz et al. Phys. Rev. C55 (1997) p1126 � LISEC.Chandler et al. Phys. Rev. C61 (2000) 044309 � LISEM. Pfützner et al. Phys. Lett. B444 (1998) p32 � FRSZs. Podolyak et al. Phys. Lett. B491 (2000) p225 � FRSM. Pfützner et al. Phys Rev. C65 (2002) 064604 � FRSM. Caamano et al., Eur.Phys. J. A23 (2005) p201 � FRS

In-Flight Technique Using Projectile Fragmentation

208Pb beam at 1 GeV/u allows production of ( high-spin isomers,

M. Pfützner et al. Phys Rev. C65 (2002) 064604

High spins (>35/2) populated

CHICO + GS data136Xe + 198Pt

Stopped RISING mechanical support frame:design construction by Liverpool/CLRC-Daresbury

Stopped Rising Array @ GSI: 15 x 7 element CLUSTERsPhotopeak efficiency 15-17% at 1.3 MeV. XIA-DGF electronics

• Main Aim:Observe 10+ isomer in 54Ni

(Isomer already known in mirror, 54Fe)

Fragmentation of 600 MeV/A 58Ni beam

(D.Rudolph et al.)

D. Rudolph et al., 58Ni fragmentation

145

3385

3240

451

1226

1392

54Ni 10+ isomer (Mirror of 54Fe)

New Line New Line - 1327 keV

Dirk Rudolph et al.,Feb/Mar ’06 RISING

Proton Radioactivity of 54Ni!

Fragmentation of 1 GeV/A 208Pb beam

Zs. Podolyák et al.Main Aim:

Spectroscopy of N=126 nuclei: 206Hg, 204Pt, 202Os

Additional:

New isomeric decays in 203Pt, 189Ta, 204Au,…

Reaction studies:148Tb I=27+; 147Gd I=(49/2)190Pb (hot fragmentation)204Pt (cold fragmentation)

Gamma-gamma analysis on 200Pt isomer (21 ns!), M. Caamano et al. Nucl. Phys. A682 (2001) p223c; Acta Phys. Pol. B32 (2001) p763 stripping effect to extend lifetime

B. Fornal et al., Phys. Rev. Lett. 87 (2001) 212501

• 206Hg (Z=80) is the most ‘neutron-rich’ N=126even-even isotope withstructural information todate….how robust is theN=126 shell ?

• Look at isomeric B(Mλ) for seniority isomers basedon proton (h11/2)-n states.

Iπ=10+ isomer, 2 proton cold knockoutfrom h11/2 orbitals. (< 100 ns half-life).

S. Steer, Zs. Podolyak et al., 208Pb fragmentation, RISING Mar’06

206Hg isomers, N=126, S. Steer, Zs. Podolyak et al., 208Pb RISING

5- isomer

10+ isomer

Relative isomeric ratios give insight into cold proton ‘knockout’ theory see J. Tostevin AIP Conf. Proc. 819 (2006) p523.

Podolyàk, Steer et al., 208Pb frag. RISING @ GSI Mar’06

N=126, 4 proton holes

March’06RISINGdata

Fragmentation studies: cold fragmentation (206Hg, 204Pt)hot fragmentation (190Pb)high-spin states 27ħ in 148Tb, (49/2) in 147Gd

148Tb

Z1

Z2

A/Q

Pos. at S4

148Tb

Tb

E. Werner-Malento, Zs. Podolyak et al.

Popu

latio

n of

stat

es (e

xper

imen

t/the

ory)

Angular momentum

Zs. Podolyák et al., Phys. Lett. B632 (2006) 203.

increased high angular momentum population

due to collective I

March 2006148Tb I=27 147Gd I=49/2

62Ga : S.M. Vincent al al., Phys. Lett. 437B (1998) 264D. Rudolph et al., Phys. Rev. C69 (2004) 034309

66As: R. Grzywacz et al., Nucl. Phys. A682 (2001) 41cR. Grzywacz et al., Phys. Lett. 429B (1998) 247

70Br: M. Karny et al., Phys. Rev. C70 (2004) 014310D.G. Jenkins et al., Phys. Rev. C65 (2002) 0644307 G. DeAngelis et al., Eur. Phys. J. A12 (2001) 51

74Rb: C.D. O’Leary et al., Phys. Rev. C67 (2003) 021301D. Rudolph et al., Phys. Rev. Lett. 76 (1996) 376

78Y ? 82Nb ? p3n reactions, β-delayed tagging ?86Tc: C. Chandler et al., Phys. Rev. C61 (2000) 044309

Iπ=0+ T=1 ground states from β-decay for 74Rb, 78Y, 82Nb, 86Tc and 90RhJ. Garces Narro et al., Phys. Rev. C63 (2001) 044307T. Faestermann et al., Eur. Phys. J. A15 (2002) 185

Summary of odd-odd N=Z Spectroscopy (to Mar. 06)

A.B. Garnsworthy et al.,

A.B. Garnsworthy et al.,

The Proposed Structure of 86Tc

850 keVE3 = 8.35x10-6 s

270 keVM2 = 1.1x10-6 s

581 keVM1 = 3.1x10-14 s

A.B. Garnsworthy et al., preliminary

Δl, Δj=3 ?g9/2 x p3/2

New Data point

-2000

-1000

0

1000

2000

3000

4000

0 20 40 60 80 100

A

E(T=

1-T=

0) (k

eV)

T=0 Dominant

T=1 More Competitive

40Ca

16O

56Ni

86Tc

The Trend Continues?!?

E(2+) for odd-odd N=Z T=1 states follows e-e trend with β2

86Tc74Rb

70Br66As

62Ga

208Pb region SUPER-FRS Yields

many μs isomersexpected

212Po, 18+, 65s

215Ra, 43/2-, 800ns

217Ac, 29/2+, 1μs

N=126, holes in 208Pb

UNILAC SIS

FRS

ESR

SIS 100/200

HESR

SuperFRS

NESR

CR

Next-generation RNB facilities - Fragmentation

J. Benlliure

“Facility for Antiproton and Ion Research (FAIR)” :

The Super-FRS and its Branches

NuSTAR- [Nuclear Structure Astrophysics and Reactions] Collaboration

R3B

EXLELISE

ILIMA

1) Daresbury Laboratory UK2) University of Liverpool UK3) University of Surrey UK4) UAM Madrid Spain5) Universidad de Salamanca Spain6) IFIC Valencia Spain 7) GSI Darmstadt Germany8) Universit ät zu Köln Germany9) IFIN-HH Bucharest Romania

10) University of Camerino Italy11) University of Jyvaskyla Finland12) University of Sofia Bulgaria13) Royal Inst. of Tech., Stockholm Sweden14) IReS Strasbourg France

Members of the DESPEC Ge array working group

• 11 February, 2005GSI, Germany

• 7 April, 2005Surrey, UK

• 4 November, 2005Madrid, Spain

• 22 February, 2006GSI, Germany

Meetings

http://www.ft.uam.es/Nuclear/Nuc_Exp_Inv_DESPEC_home.htm

DESPEC ‘active stopper’ funded in last round (Liv. + Edin. + DL. + RAL)

Array of stacks of segmented planar Ge detectors

standard geometrycube geometry

24 stacks of 3 planar Ge

Alternative: array of 6/8 Clover detectors

DESPEC gamma-ray arraymajor UK Grant to be:Surrey, Liverpool, CLRC,Daresbury, York, Brighton, Manchester, Paisley….

Schottky Mass Spectrometry

950 MeV/u 209Bi + Be Projectile FragmentsNew and Reference Masses in the same Spectrum

High Resolution and Sensitivity

accuracy: 30 keV

ILIMA will greatly extend our knowledge of masses

It will reach a large number of nuclei of importance in explosive stellarProcesses

ILIMA ‘boss man’ = Phil Walker.

It will give us a much better idea of where the drip-lines lie.

R3B-Reactions with Relativistic Radioactive Beams

Aim:- Kinematically complete measurements of reactions with high energy RNBs

- Broad programme – Heavy ion induced EM excitation- Knockout and breakup reactions- Light ion elastic, inelastic and quasi-free

scattering, Charge exchange

R3B/EXL UK Contribution : Target Recoil Detectors

EXL Si ArrayConstruction & Assembly@ LSDC

ASICFEEDAQ

R3B Si Array

Construction & Assembly

R3B/EXL Schedule for the next 7 years:2006-07 R&D, Tests, Prototypes2008-11 Production of Detection Systems 2010-11 Phase I commissioning (+first experiment)

2012 Phase II commissioning

TPC/Active Target

S287 Experiment - May 2005Physics Motivations

• Collective properties– Dipole strength distributions (electromagnetic

excitation)

• Single-particle properties– One-neutron Coulomb breakup– One-neutron knockout reactions– Quasifree hadronic scattering reactions

Reactions studies with relativistic RIBsaround N=40, along the Ni isotopic chain

The Dipole Response of Neutron-Rich Nuclei

Neutron-Proton asymmetric nuclei: low-lying dipole strength

Prediction: RMF (N. Paar et al.)

132Sn

100% of the E1 strength absorbed into theGiant Dipole Resonance(GDR)

Stable nuclei:120Sn

Vretenar et al. (RMF calculations)

Experimental Set-up: ALADIN – LAND

68, 70

, 72 Ni

550 A.MeV

CH2 target : Quasifree scattering reactionsC target : Knockout reactionsPb target : Electromagnetic Excitation

+ Plastic & CsI 2p array

A/Z vs Z for secondary beamoptimized for 72Ni

A/Z vs Z for secondary beamoptimized for 69Ni

A/Z vs Z for secondary beamoptimized for 56Ni (top), 57Ni (bottom)

ZnCu

NiCo

FeMn

Cr

Mixed secondary beam in Cave C

72Ni @ 500 AMeV

(~20 ions/sec)S. Paschalis, PhD student (Liverpool)

Quasifree Scattering PROGRAM at GSI/FAIR S296 Expt:( spokesperson: R. Lemmon et al. )-To be run in 2007

Test with a stable beam (12C) at the existing ALADIN/LAND set-up -> Test the QFS technique in inverse kinematics, commission and optimise the performance of the full detector system.

FUTURE PROGRAM at R3B:

-First stage: Use of unpolarised H target with exotic beams: (p,2p) and (p,pn) -> to map the evolution with the changing isospin.

-Second stage: Polarised quasifree hadronic scattering: analysing powers -> access to j-values and in-medium effects.

TARGET-RECOIL DETECTOR: Silicon-array

Characteristics:

Double-sided siliconmicrostrips sensors

-72x 41.3 mm2

-300 μm thickness

-640x384 strips

-associated electronics (ASIC)

41.3 mm

72 mm

8 detectors available and tested in November 2005 : (2 detectors purchased by UK institutions: Birmingham, Daresbury, Liverpool, Surrey).12C and 8B at Einc =350 A.MeV -> ΔE (FWHM) ~ 40-50 KeV

SIMULATIONS for QFS Experiments at GSI/FAIR12C(p,p’)12C at 400 A.MeV (GEANT4)

Test Experiment (GEOMETRY-1)

ΔE

(MeV

)

Ep’ (MeV)

<ΔE’>(FWHM) = 3.2 MeV GEANT4

R3B Target-Recoil Detector

Si Tracker

CsI Calorimeter

<ΔE’>(FWHM) = 1.0 MeV

B. Fernandez Dominguez (Liverpool)

EXL – Exotic Nuclei studied in light-ion induced reactions at the NESR

Schematic view of a cross-section of the EXL detector system, with the details shown on the right.

EXL- What information can we expect?

Elastic scattering -nuclear matter radii/distributions-haloes,skins,central densities

Inelastic scattering -surface collective states/electric giant resonances/analysing powers-bulk props.in asymmetric matter/compressibilty/soft modes

Charge exchange -GT/spin-dipole resonances/spin-isospin excns.-neutron skin/spin excns./stellar weak interaction rates

Transfer reactions -spectroscopic factors/s.p. particle and hole states/pair transfer-s.p.structure/spin-orbit interaction/pairing interaction

Quasi-free scattering -s.p.spectral function/cluster knockout-s.p.structure/nucleon-nucleon correlations/in-medium interactions

●First real programme of reaction studies with exotic nuclei in a ring.●Detector system will handle a widerange of different types of reaction.●Exclusive measurements-hence ofinterest with stable beams too.

Contributions to Future facilities : PANDA@FAIRDesign of magnetic solenoid (Glasgow)

RICH (Glasgow)Endcap DIRC (Edinburgh)

Grid computing technology (Glasgow)

Nucleon Polarimetry (Edinburgh)

p

Interaction point

SolenoidDipole

EM and hadroncalorimeters

RICH

Drift or wirechambers

Muon counters

Simulations (Glasgow/Edinburgh)