AGATA; status, plans and

opportunities

John SimpsonNuclear Physics GroupDaresbury Laboratory

Dr Andy Bostonajboston@liv.ac.uk

Introduction: The AGATA project

Current status of the AGATA; towards the “demonstrator”

Exploitation of AGATA; demonstrator and beyond

AGATA The Advanced Gamma Ray Tracking Array

at Radioactive Ion Beam facilities

Next generation -ray spectrometer based on gamma-ray tracking

First “real” 4 germanium array no Compton suppression shields

Versatile spectrometer with very high efficiency and excellent spectrum quality for radioactive and high intensity stable beams

Experimental conditions and challenges

• Low intensity• High backgrounds• Large Doppler broadening• High counting rates• High -ray multiplicities

High efficiencyHigh sensitivityHigh throughputAncillary detectors

FAIRSPIRAL2SPESREX-ISOLDEEURISOLECOS

Need instrumentation

AGATAAGATA(Design and characteristics)

4 -array for Nuclear Physics Experiments at European accelerators providing radioactive and high-intensity stable

beams

Main features of AGATA

Efficiency: 43% (M =1) 28% (M =30)today’s arrays ~10% (gain ~4) 5% (gain ~1000)

Peak/Total: 58% (M=1) 49%

(M=30)today ~55% 40%

Angular Resolution: ~1º FWHM (1 MeV, v/c=50%) ~ 6 keV !!!today ~40 keV

Rates: 3 MHz (M=1) 300 kHz (M

=30)today 1 MHz 20 kHz

• 180 large volume 36-fold segmented Ge crystals in 60 triple-clusters • Digital electronics and sophisticated Pulse Shape Analysis algorithms allow• Operation of Ge detectors in position sensitive mode -ray tracking

The AGATA CollaborationMemorandum of Understanding 2003-07

Research and Development phaseBulgaria: Univ. Sofia

Denmark: NBI Copenhagen

Finland: Univ. Jyväskylä

France: GANIL Caen, IPN Lyon, CSNSM Orsay, IPN Orsay, CEA-DSM-DAPNIA Saclay, IreS Strasbourg

Germany: GSI Darmstadt, TU Darmstadt, Univ. zu Köln, LMU München, TU München

Hungary: Debrecen

Italy: INFN and Univ. Firenze, INFN and Univ. Genova, INFN Legnaro, INFN and Univ. Napoli, INFN and Univ. Padova, INFN and Univ. Milano, INFN Perugia and Univ. Camerino

Poland: IFJ PAN Krakow, SINS Swierk, HIL & IEP Warsaw

Romania: NIPNE & PU Bucharest

Sweden: Chalmers Univ. of Technology Göteborg, Lund Univ., Royal Institute of Technology Stockholm, Uppsala Univ.

UK: Univ. Brighton, STFC Daresbury, Univ. Liverpool, Univ. Manchester, Univ. Paisley, Univ. Surrey, Univ. York

Turkey: Univ. of Ankara, Istanbul University

 

The First Step:The AGATA Demonstrator

Objective of the final R&D phase 2003-2008

1 symmetric triple-cluster5 asymmetric triple-clusters

36-fold segmented crystals540 segments555 digital-channels

Eff. 3 – 8 % @ M = 1

Eff. 2 – 4 % @ M = 30

Full EDAQwith on line PSA and -ray trackingIn beam CommissioningTechnical proposal for full array

Cost ~ 6 M €

Ingredients ofIngredients of --TrackingTracking

Pulse Shape Analysisto decompose

recorded waves

Highly segmented

HPGe detectors

·

·

··

Identified interaction

points(x,y,z,E,t)i

Reconstruction of tracks

e.g. by evaluation of permutations

of interaction points

Digital electronicsto record and

process segment signals

1

2 3

4

reconstructed -rays

AGATA Detectors

Hexaconical Ge crystals90 mm long80 mm max diameter36 segmentsAl encapsulation

0.6 mm spacing0.8 mm thickness

37 vacuum feedthroughs

• Symmetric detectors– 3 delivered

• Asymmetric detectors– 15 ordered (4 accepted, 7 in 2007)

• Preamplifiers available– Core (Cologne); Segment (Ganil &

Milano)

• Test cryostats for characterisation– 3 delivered

– 2 ordered (1 delivered)

• Triple cryostats– 4 (soon 5) ordered

– 1st expected May 2007

AGATA triple-detector module

3 encapsulated Ge crystals in one cryostat

111 preamplifiers with cold FET~230 vacuum feedthroughs

LN2 dewar, 3 litre, cooling power ~8

watts

First prototype summer 2005

AGATA triple-detector module

3 encapsulated Ge crystals in one cryostat

111 preamplifiers with cold FET~230 vacuum feedthroughs

LN2 dewar, 3 litre, cooling power ~8

watts

Planning for 2007:

First asymmetric triple module in summer 2007

(In-beam) tests using “standard” digital electronics

AGATA Design and Construction

180 geometry definedConceptual design of 180 array doneDetails of HV etc. agreed, GSI testDesign of AGATA demonstrator for LNL final stagesFlanges manufacture startedAssembly in LNL, 2007

Characteristation and Scanning

Three symmetric capsules

scanned in Liverpool

Commissioning of further scanning systems

at Orsay and GSI

Scan of an asymmetric capsule in Liverpool

Scan of the 3rd symmetric capsule

662keV

374keV

288keV

Coincidence scan for 3D position determination

Comparison of real and calculated pulse shapes. Validate codes.

AGATA s002 & s003 comparison (prelim)

A

B

C

D

E

F

1 2 3 4 5 6

IGeometry

IIPotentialElec field

IIIDrift

velocities

IVWeighting

fields

AGATA symmetric crystal simulation

• Electric field simulations have been performed and details comparisons have been made with experimental pulse shape data.

Electric Field Simulations : MGS

Pulse-Shape Analysis: current status

Results from the analysis of an in-beam test with the first triple module, e.g. Doppler correction of gamma-rays using PSA results

Best resultγ detector, seg. mult. 1

Full dataset

Simulation

FWHM FWHM FWHM

Detector 32 keV 35 keV

Segment 11.1 keV 12 keV

PSA 4.8 keV 5.3 keV 5.0 keV

REACTION CHANNEL: (d,p)PsaSegDet

1382 keV

Results obtained with Grid Search PSA algorithm (R.Venturelli et al.)

Many different methods are under development

Segment level processing: energy, timeDetector level processing: trigger, time, PSAGlobal level processing: event building, tracking, software trigger, data storage

AGATA Digitiser Module 36+1 channels, 100 MhZ, 14 bits

(Strasbourg - Daresbury – Liverpool)

• Mounted close to the Detector 5-10 m

• Power Dissipation around400W

• Water Cooling required

• Testing in Liverpool

(December 2006)

• Production in progress

(for 18 modules)Prototype Segment Board

(2 boards per crystal)

• Demonstrator commissioning at LNL late 2008• First physics campaign at LNL in 2009

further proposals from GANIL, GSI • LoI for construction phase signed in 2005

to allow bids for new funds from 2006 (D, I)• MoU for AGATA construction from 2008• Start completion in 2008, 1 in possible in ~2011• Rate of construction depends on production

capability and financing• Stages of physics exploitation, facility

development

Status and Evolution

AGATA demonstrator at Legnaro

(2008-09)

5 triple clusters coupled to PRISMA Schematics of the mounting frame

holding (up to) 15 clusters

Peak efficiency3 – 8 % @ M = 1

2 – 4 % @ M = 30

AGATA demonstrator at Legnaro

Principal physics opportunities :

High-spin spectroscopy of moderately neutron-rich nuclei produced in deep-inelastic reactions

Good experience from CLARA + PrismaHeavy-ion beams from PIAVE + ALPIwith suitable intensities and energies

AGATA demonstrator at GANIL

(~2010/11)

Main physics opportunities:• Spectroscopy of heavy elements towards SHE• Gamma-ray spectroscopy of neutron-rich nuclei populated in

Deep Inelastic Reaction (with the GANIL specific aspects)• Gamma-ray spectroscopy with reactions at intermediate

energies (up to 50 A.MeV)• Classical high-spin physics and exotic shapes

Range of beams, fragmentation, SPIRAL, direct beam line

AGATA “post-demonstrator” array at GSI-FRS (~2010/11)

LYCCA

= 0 = 50 %

0

5

10

15

20

25

30

35

40

45

50

1 2

Effic

ien

cy (

%)

Solid Angle (%)

Efficiency M = 1

Efficiency M = 10

Efficiency M = 20

Efficiency M = 30

Forward Quadrant with 45 crystals in 15 triple-clusters

v/c = 0 v/c = 0.5

AGATA-15 at the GSI-FRSAGATA-15 at the GSI-FRS

AGATA “post-demonstrator” at GSI-FRS

“Test Bench” for HiSpec (~2011)

Main physics opportunities:

Gamma-ray spectroscopy with reactions • at relativistic energies (> 50 A.MeV)

Coulomb excitation, few nucleon removal etc.• with slowed-down beams (10-20 A.MeV)

direct reactions, inelastic scattering

AGATA web AGATA web pagepage

http://www.gsi.de/http://www.gsi.de/agata/agata/

Talks from last AGATA weekORSAY January 2007

http://www.csnsm.in2p3.fr/groupes/strucnuc/AGATAWEEK/agataweek.html

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