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

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30

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0 500 1000 1500 2000 2500 3000 3500 4000 4500

gamma-ray energy (keV)

Sin

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y p

ea

k d

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

LaBr3 array simulated full energy peak efficiencies around AIDA

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0 500 1000 1500 2000 2500 3000 3500 4000 4500

gamma-ray energy (keV)

Sin

gle

s fu

ll en

erg

y p

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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

Time

Current

Gate

Stop

Common StartAIDA or Beam

V1495(2xA395A1x A395D)UserLogic

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 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

anode

dynode

ECL-NIM726/N638

N108BNC

BNC

RobinsonNugentHD Flat

RobinsonNugentHD Flat

Diff ECLX16

Diff ECLsingle

LemoNIM

LemoNIM

Diff ECLX16

LemoAnalogue

LemoAnalogue

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

Time

Current

Stop

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

anode

dynode

Option 2- Partially digital (XIA)

BNC

BNC

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

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-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

20

1d5/2

2s1/2

1d3/2

1f7/2

20

1d5/2

2s1/2

1d3/2

1f7/2

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

34P19 (Simple) Nuclear Shell Model Configurations

20

1d5/2

2s1/2

1d3/2

1f7/2

20

1d5/2

2s1/2

1d3/2

1f7/2

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

34P19 (Simple) Nuclear Shell Model Configurations

20

1d5/2

2s1/2

1d3/2

1f7/2

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

•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.

M2 s.p. transition

20

1d5/2

2s1/2

1d3/2

1f7/2

20

1d5/2

2s1/2

1d3/2

1f7/2

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.

15 protons 19 neutrons 15 protons 19 neutrons

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

189Ir

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