Progress on the UK Contribution to FATIMA FATIMA Workshop, Grenoble, July 2012 Paddy Regan CNRP University of Surrey Guildford, GU2 7XH

UK Fast-Timing Array Part of discrete STFC funded NuSTAR Project (also included projects for R3B and FAIR) People: –U. Brighton (Alison Bruce, Oliver Roberts [PDRA]) –Surrey (Paddy Regan, Zsolt Podolyak, Christopher Townsley) – U. West of Scotland (John Smith, Kieran Mullholland [PhD]) –STFC Daresbury (Ian Lazarus-DAQ) –U. Manchester (David Cullen, Andy Smith - design of holding structure). Task to design, build and commission ‘stand alone’ fast-timing gamma-ray array for use with AIDA at focal plane of (S)FRS at GSI/FAIR as part of DESPEC collaboration. Design (and budget) is for a modular, 30 (...or up to 36 later perhaps…) element array consisting of 1.5” x 2” LaBr 3 cylinders.

What we have ordered (end of June 2012), co-ordinator, Dr. C. Townsley: 31 LaBr 3 detectors (2” x 1.5” cylinders) 19 to U. Brighton (Alison Bruce, Oliver Roberts) 12 to U. Surrey (Regan, Podolyak, Townsley) Cost £186,852

Initial Uses of (UK) Fatima Detectors (pre-DESPEC c.2017) 21 detectors to go RIKEN (3 x 7 element clusters) for use in EURICA array from ~Oct/Nov –Use in (for example) 170 Dy beta-decay proposal. ~8 detectors available for use with from early/mid 2013 for use in 235 U(n,f) experimental campaign and/or Lohengrin experiments.

LaBr 3 cylinder detectors to be coupled to (30) Hamamatsu R9779 PMTs anode (timing) dynode (energy) outputs 28 Hamamatsu PMTs with mu metal shield cases ordered May 2012 (£26,267)

Prototype AIDA Enclosure Prototype mechanical design Based on 8cm x 8cm DSSSD evaluate prior to design for 24cm x 8cm DSSSD Compatible with RISING, TAS, 4  neutron detector 12x 8cm x 8cm DSSSDs 24x AIDA FEE cards 3072 channels Design complete Mechanical assembly in progress In –beam test on the FRS approved (S390) Hope to be scheduled in the 2 nd half of 2011

Possible Geometries (around AIDA)? Hybrid ‘Crucifix ’ hybrid ‘Crucifix’ (3 x 12 = 36 detectors)

2 x 3 design around AIDA stopper geometry.

36 cylinders 24 cylinders 30 cylinders

simulations by O. Roberts, U. Brighton

Possible DAQ Solutions OPTION 1: Orthodox: –analogue, QDC for energy and TDCs for timing- common AIDA/FRS start.) OPTION2: Mixed – XIA for energies and 10ns time stamp (ms isomer spectroscopy); TDCs with common FRS/AIDA start for ns  LaBr 3 timing. OPTION 3: Fully digital: –Digitiser with FPGA (FATIMA ultimate solution)

LaBr 3 PMT Delay QDC V862 CFD V812 TDC V1290A Energy Time Current Gate Stop Common Start AIDA or Beam V1495 (2xA395A 1x A395D) User Logic Clk sync TS For 30 channels: 2x V812 CFD (16ch) 2x N638 xlators (16ch) 8x Phillips 794 G+D (4ch) 1x V1290A TDC (32ch) 1x V862 QDC (32ch) 1x A967 adapter 30x N108 delay (2x64ns) 1x v1495 with 2x A395A ECL inputs and 1 A395D NIM i/o 1 VME crate + CPU 2 NIM crates (N108s don’t need crates) G+D 794 anode dynode ECL-NIM 726/N638 N108 BNC Robinson Nugent HD Flat Robinson Nugent HD Flat Diff ECL X16 Diff ECL single Lemo NIM Lemo NIM Diff ECL X16 Lemo Analogue Lemo Analogue Lemo Analogue Diff ECL X16 x2 Robinson Nugent HD Flat Diff ECL X16 x2 A967 adapter Diff ECL X16 x2 Lemo-RN adapters Option 1- Analogue QDC Lemo NIM Optional -See notes

LaBr 3 PMT XIA DGF4 Energy & TS Time Current Stop For 30 channels: 2x V812 CFD (16ch) 1x V1290A TDC (32ch) 8x DGF4 (4ch) 1 VME crate and CPU I Camac crate PC with 9 USB ports to read DGF4s anode dynode Option 2- Partially digital (XIA) BNC Diff ECL X16 Lemo Analogue TDC V1290A Common Start AIDA or Beam Diff ECL X16 x2 CFD V812 Clk & sync SMA (XIA supply BNC adapter)

LaBr 3 PMT Time, Energy & TS Current For 30 channels: 8x V1751 (4ch)/STR3305 (4ch) 1 VME crate and CPU Or 8x Perseus + AD uTCA crate and CPU Digitiser with FPGA e.g. V1751, STR3305, or Perseus+AD5000 anode dynode Should we use dynode or anode? Dynode used for timing in analogue setup Option 3- Fully digital (FATIMA based) Clk & sync

While we are waiting… A number of ‘test’ (and new physics) experiments at the Bucharest tandem using the mixed Ge-LaBr 3 array (including 3 ‘UK’ LaBr 3 dets). Results / Experiments include –I  =4 - intruder state half-life in 34 P 19 (f 7/2 → d 3/2 M2 single particle decay) – N=80 I  =6 + half-lives ( 138 Ce) – 186 W( 7 Li,  p) reactions, e.g., 188 W (I  =2 + ) – 208 Pb(7Li,a2n) 209 Bi (sp decays)

Expected, E 1/2 dependence of FWHM on gamma-ray energy. T.Alharbi et al., Applied Radiation and Isotopes, 70, 1337 (2012)

P.H. Regan Applied Radiation and Isotopes, (2012) R(%)= [  E  / E  

Tests with 152 Eu source (measure lifetime of I  = keVlevel in 152 Sm

T 1/2 =1.38 ns

18 O( 18 O,pn) 34 P.  ~20 mb T 1/2 (I  =4 - ) = 2.0(1) ns Mostly f 7/2 → d 3/2 M2 transition

{1876,429}  =470(10)ps {1048,429} T 1/2 =2.0(1)ns

34 P 19 (Simple) Nuclear Shell Model Configurations 20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  I  = 2 + [  2s 1/2 x ( 1d 3/2 ) -1 ]I  = 4 - [  2s 1/2 x 1f 7/2 ] Theoretical predictions suggest 2 + state based primarily on [  2s 1/2 x ( 1d 3/2 ) -1 ] configuration and 4 - state based primarily on [  2s 1/2 x 1f 7/2 ] configuration. M2 decay can go via f 7/2 → d 3/2 (  j=  l=2) transition. 15 protons 19 neutrons

34 P 19 (Simple) Nuclear Shell Model Configurations 20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  I  = 2 + [  2s 1/2 x ( 1d 3/2 ) -1 ]I  = 4 - [  2s 1/2 x 1f 7/2 ] Theoretical predictions suggest 2 + state based primarily on [  2s 1/2 x ( 1d 3/2 ) -1 ] configuration and 4 - state based primarily on [  2s 1/2 x 1f 7/2 ] configuration. M2 decay can go via f 7/2 → d 3/2 (  j=  l=2) transition. 15 protons 19 neutrons

34 P 19 (Simple) Nuclear Shell Model Configurations 20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  I  = 2 + [  2s 1/2 x ( 1d 3/2 ) -1 ] Theoretical predictions suggest 2 + state based primarily on [  2s 1/2 x ( 1d 3/2 ) -1 ] configuration and 4 - state based primarily on [  2s 1/2 x 1f 7/2 ] configuration. M2 decay can go via f 7/2 → d 3/2 (  j=  l=2) transition. M2 s.p. transition

20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  20 1d 5/2 2s 1/2 1d 3/2 1f 7/2  I  = 2 + [  1d 3/2 x ( 2s 1/2 ) -1 ]I  = 4 - [  2s 1/2 x 1f 7/2 ] Theoretical predictions suggest 2 + state based primarily on [  2s 1/2 x ( 1d 3/2 ) -1 ] configuration with some small admixture of [  1d 3/2 x ( 1s 1/2 ) -1 ] 4 - state based primarily on [  2s 1/2 x 1f 7/2 ] configuration. E3 can proceed by f 7/2 → s 1/2 (  j=  l=3 transition). Admixtures in 2 + and 4 - states allow mixed M2/E3 transition. 15 protons 19 neutrons

T 1/2 =2ns {1048}{429} ‘Prompt’  T~480ps {429}{1876} P.J.Mason et al., Phys. Rev C85, (2012) T 1/2 <2ps

138 Ce 80

{815,467} {815,165}

…partial fusion reactions (low cross-sections)

Lifetime of first-excited 2 + in 188 W 186 W( 7 Li,  p) 188 W, 33 MeV Reaction mechanism is a mix of incomplete fusion and low- energy transfer. ~54 hours beam time Analysed by P.J.R. Mason. T. Shizuma et al. Eur. Phys. J. A30, 391 (2006) 296 keV gate (HPGe)432 keV gate (HPGe) Contaminants are 186 Os 189 Ir

Lifetime of first 2 + in 188 W Estimate of 188 W 2 + half-life from this short run gives unusual behaviour in B(E2). Time difference keV Contaminated by 186 Os [t 1/2 (2 + ) = 875(15) ps]

Fast-timing following  - decay….

190 Os levels from EC decay of 190 Ir Yamazaki et al., NPA131 (1969) P.J. Mason et al., 186 W( 7 Li,2n) 191 Ir performed at Bucharest Tandem

P.J.Mason et al., private communication T 1/2 from  t of 187keV and (361 or 371)} = 375 (20) ps 190 Os levels from EC decay of 190 Ir Yamazaki et al., NPA131 (1969)

….the (near) future 21 detectors to EURICA 7/8 detectors for