Status of the (future) PreSPEC Decay Campaign

GSI Meeting 1st March 2011

To Remember?

• Dates / schedule for ‘decay experiments’ in PreSPEC – earliest 2013 / 2014 (depending on AGATA dates).

• Decay campaign experiments ideas to be based on (many using AIDA).– Isomer/beta-delayed gamma-ray spec.– TAS / decay heat – Beta-delayed neutrons (Monster / Belen)

60 attendees at Brighton Workshop to discuss Physicscase.

http://npg.dl.ac.uk/PRESPEC-11/

35 different (physics) presentations on ‘decay physics’(including a significant number of theory talks).

Main themes:

1) Shell model physics around magics2) Decay heat ; 3) Proton-drip line physics4) r-process physics (Pn etc.)5) Prolate/oblate shape co-existence

Three main topics?• (AIDA-based) Decay Spectroscopy (Zsolt Podolyak)

– Beta-delayed gamma (rp-process; r-process)– Isomer decays (78Ni; 132Sn; 208Pb, 100Sn, 56Ni, N=82 proton

drip-line…)– Fast-timing (LaBr3(Ce) array with/without (RISING Ge).

• TAS based, decay heat expt. (Alejandro Algora)– Fission fragments / 132Sn / 78Ni

• BELEN / MONSTER (Iris Dillman)– Pn / beta-delayed neutron experiments; r-process path

(~78Ni; 132Sn; 208Pb; 192Hf, 194W)

Other meetings and Organisation?

• Fast Timing ‘collaboration’ meeting in Madrid, Mon. 28th March 2011 (organiser, Luis Fraille).

• Follow up: Idea to submit the LoI for the PreSPEC Decay for the (2nd?) G-PAC in 2011.

• It is CLEAR that beam-time will be VERY precious…(perhaps only 3-4 weeks in 2014?)…

• How do we focus? (single fast-timing array / combined with RISING?)

Physics Motivation

4- 2305

• Recent study of neutron-rich, N=19 nucleus34P identified low-lying I=4- state at Ex=2305 keV.

• Spin and parity assigned on basis of -ray DCO and polarization measurements.

• I=4-→ 2+ transition can proceed by M2 and/or E3.

• Aim of experiment is to measure precision lifetime for 2305 keV state → obtain B(M2) and B(E3) values.

• Previous studies limit half-life to 0.3 ns < t1/2 < 2.5ns

Lifetime gives a direct comparison with sdfp-shell model calculations, i.e., including (intruder) negativeparity (neutron) f7/2 and p3/2 orbitals.

T1/2 ~1.5 ns4- decay in 34P.LaBr3-LaBr3 coincs only.

P.J. Mason et al., Bucharest, Surrey, Brighton, FSU, Notre Dame, Sofia, Kolkata

While we are waiting?• Some ‘test / parasitic beam time at GSI’ for e.g., BELEN

under the PreSPEC heading.

• Other ‘fast-timing’ experiments (to learn and do physics) at Bucharest (N=80 isotones and 188W) (to be approved).

• Simulations and first testing for the DESPEC fast-timing array – Oliver Roberts (UK STFC funded @ Brighton) ; plus other European groups (Spain, Romania, Koln, Sofia etc.)

• Possible NuPNET funding ?