Progress on the UK Contribution to FATIMA FATIMA Workshop, Grenoble, 19-20 July 2012 Paddy Regan...

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Progress on the UK Contribution to FATIMA

FATIMA Workshop,

Grenoble, 19-20 July 2012

Paddy ReganCNRP

University of SurreyGuildford, GU2 7XH

p.regan@surrey.ac.uk

UK Fast-Timing Array

• Part of discrete STFC funded NuSTAR Project (also included projects for R3B and HISPEC @ 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” LaBr3 cylinders.

What we have ordered (end of June 2012), co-ordinator, Dr. C. Townsley:

• 31 LaBr3 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. 2012. – Use in (for example) 170Dy beta-decay proposal.

• ~8 detectors available for use with EXOGAM@ILL from early/mid 2013 for use in 235U(n,f) experimental campaign and/or Lohengrin experiments.

LaBr3 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 2nd 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

LaBr3 array simulated full energy peak efficiencies around AIDA

0 500 1000 1500 2000 2500 3000 3500 4000 4500

gamma-ray energy (keV)

Crucifix (36 hybrids) 3 x 2 (30 cylinders) 2 x 2 (24 clyinders)

LaBr3 array simulated full energy peak efficiencies around AIDA

0 500 1000 1500 2000 2500 3000 3500 4000 4500

gamma-ray energy (keV)

Crucifix (36 hybrids) 3 x 2 (30 cylinders) 2 x 2 (24 clyinders)

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 LaBr3 timing.

• OPTION 3: Fully digital:– Digitiser with FPGA (FATIMA ultimate solution)

LaBr3 PMTDelay

QDC V862

CFDV812

TDCV1290A

Energy

Current

Common StartAIDA or Beam

V1495(2xA395A1x A395D)UserLogic

Clk sync

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 adapter30x N108 delay (2x64ns)1x v1495 with 2x A395A ECL inputs and 1 A395D NIM i/o1 VME crate + CPU2 NIM crates (N108s don’t need crates)

G+D794

dynode

ECL-NIM726/N638

N108BNC

RobinsonNugentHD Flat

Diff ECLX16

Diff ECLsingle

LemoNIM

Diff ECLX16

LemoAnalogue

Diff ECLX16 x2

RobinsonNugentHD Flat

Diff ECLX16 x2

A967adapter

Diff ECLX16 x2

Lemo-RNadapters

Option 1- Analogue QDC

LemoNIM

Optional-Seenotes

LaBr3 PMT

XIA DGF4

Energy & TS

Current

For 30 channels:2x V812 CFD (16ch)1x V1290A TDC (32ch)8x DGF4 (4ch)1 VME crate and CPUI Camac crate PC with 9 USB ports to read DGF4s

dynode

Option 2- Partially digital (XIA)

Diff ECLX16Lemo

Analogue

TDCV1290A

CommonStartAIDA or Beam

Diff ECLX16 x2

CFDV812

Clk & sync

SMA(XIA supply BNC adapter)

LaBr3 PMTTime, Energy & TS

Current

For 30 channels:8x V1751 (4ch)/STR3305 (4ch)1 VME crate and CPUOr8x Perseus + AD50001 uTCA crate and CPU

Digitiser with FPGAe.g. V1751, STR3305,or Perseus+AD5000

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-LaBr3 array (including 3 ‘UK’ LaBr3 dets).

• Results / Experiments include – I=4- intruder state half-life in 34P19 (f7/2 →d3/2 M2

single particle decay)– N=80 I=6+ half-lives (138Ce) – 186W(7Li,p) reactions, e.g., 188W (I=2+)– 208Pb(7Li,a2n) 209Bi (sp decays)

Expected, E1/2 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, 70 1125 (2012)

R(%)= [E/ E

Tests with 152Eu source (measure lifetime of I=2+ 121 keVlevel in 152Sm

T1/2=1.38 ns

18O(18O,pn)34P.~20 mbT1/2 (I=4-) = 2.0(1) nsMostly f7/2 →d3/2

M2 transition

{1876,429} =470(10)ps

{1048,429} T1/2=2.0(1)ns

34P19 (Simple) Nuclear Shell Model Configurations

I = 2+ [2s1/2 x (1d3/2)-1] I = 4- [2s1/2 x 1f7/2]

•Theoretical predictions suggest 2+ state based primarily on [2s1/2 x (1d3/2)-1] configuration and 4- state based primarily on [2s1/2 x 1f7/2] configuration.

•M2 decay can go via f7/2 → d3/2 (j=l=2) transition.

15 protons 19 neutrons 15 protons 19 neutrons

I = 2+ [2s1/2 x (1d3/2)-1] I = 4- [2s1/2 x 1f7/2]

I = 2+ [2s1/2 x (1d3/2)-1]

M2 s.p. transition

I = 2+ [1d3/2 x (2s1/2)-1] I = 4- [2s1/2 x 1f7/2]

•Theoretical predictions suggest 2+ state based primarily on [2s1/2 x (1d3/2)-1] configuration with some small admixture of [1d3/2 x (1s1/2)-1]

•4- state based primarily on [2s1/2 x 1f7/2] configuration.

•E3 can proceed by f7/2 → s1/2 (j=l=3 transition).

•Admixtures in 2+ and 4- states allow mixed M2/E3 transition.

T1/2=2ns{1048}{429}

‘Prompt’ T~480ps

{429}{1876}

P.J.Mason et al., Phys. Rev C85, 064303 (2012)

T1/2<2ps

138Ce80

{815,467}

{815,165}

…partial fusion reactions (low cross-sections)

Lifetime of first-excited 2+ in 188W

• 186W(7Li,p)188W, 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 186Os

Lifetime of first 2+ in 188W

•Estimate of 188W 2+ half-life from this short run gives unusual behaviour in B(E2).

Time difference 143-432 keVContaminated by 186Os [t1/2(2+) = 875(15) ps]

Fast-timing following - decay….

190Os levels from EC decay of 190Ir

Yamazaki et al., NPA131(1969) 169-179

P.J. Mason et al., 186W(7Li,2n)191Irperformed at Bucharest Tandem

P.J.Mason et al., private communication

T1/2 from t of187keV and (361 or 371)} = 375 (20) ps

190Os levels from EC decay of 190IrYamazaki et al., NPA131(1969) 169-179

….the (near) future• 21 detectors to EURICA

• 7/8 detectors for EXOGAM@ILL

Progress on the UK Contribution to FATIMA FATIMA Workshop, Grenoble, 19-20 July 2012 Paddy Regan...

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