February 21, 2005 The AGATA Week1 Overview of GRETINA Status I-Yang Lee Lawrence Berkeley National...
-
Upload
pearl-newman -
Category
Documents
-
view
223 -
download
5
Transcript of February 21, 2005 The AGATA Week1 Overview of GRETINA Status I-Yang Lee Lawrence Berkeley National...
February 21, 2005 The AGATA Week 1
Overview of GRETINA Status
I-Yang LeeLawrence Berkeley National Laboratory
The AGATA Week, 21-25th February 2005, GSI
February 21, 2005 The AGATA Week 2
Outline
• Physics opportunities
• High lights of recent achievements
• Plan for 2005
• Schedule and cost
• Management structure
February 21, 2005 The AGATA Week 3
Capabilities of a 4 -ray tracking detector
Resolving power: 107 vs. 104
– Cross sections down to ~1 nb• Most exotic nuclei• Heavy elements (e.g. 253,254No)• Drip-line physics• High level densities (e.g. chaos)
Efficiency (high energy) (15% vs. 0.5% at E=15 MeV)
– Shape of GDR– Studies of hypernuclei
Efficiency (slow beams) (48% vs. 8% at E =1.3 MeV)
– Fusion evaporation reactions
Efficiency (fast beams) (48% vs. 0.5% at E =1.3 MeV)
– Fast-beam spectroscopy with low rates -> RIA
Angular resolution (0.2º vs. 8º)– N-rich exotic beams
• Coulomb excitation
– Fragmentation-beam spectroscopy• Halos
• Evolution of shell structure
• Transfer reactions
Count rate per crystal (100 kHz vs. 10 kHz)– More efficient use of available beam
intensity
Linear polarization
Background rejection by direction
February 21, 2005 The AGATA Week 4
Advantages of - ray Tracking
• High position resolution
• High efficiency
• High P/T
• High counting rate
• Background rejection
• Large recoil velocity– Fragmentation– Inverse reaction
• Low beam intensity
• High background rate– Beam decay– Beam impurity
For Radioactive Beam Experiments
February 21, 2005 The AGATA Week 5
Important Features of GRETINA
• Better position Resolution – 2 mm vs. 20 mm– High recoil velocity experiments
• Higher efficiency for high energy gamma rays– Giant resonances studies
• Compactness – ¼ GRETA is comparable or better than Gammasphere– Use with auxiliary detectors, recoil separators etc.
GRETINA = ¼ GRETA
February 21, 2005 The AGATA Week 6
Physics Opportunities with GRETINA
• How does nuclear shell structure and collectivity evolve in exotic n-rich nuclei?
• What is the influence of increasing charge on the dynamics and structure for the heaviest nuclei?
• How do the collective degrees of freedom and shell structure evolve with the excitation energy and angular momentum?
• What are the characteristics of the Giant Dipole Resonances built on superdeformed states and loosely bound nuclei?
February 21, 2005 The AGATA Week 7
Recent Achievements
• Received CD1 approval – start design phase• Developed design concept for mechanical support• Received 3-crystal detector prototype III
– Extensive testing with sources and beam
• Analyzed in-beam test results of prototype II• Set up a data acquisition system• Finalized detector module design• Written requirement documents• MOU’s signed with collaborating institutions• Carried out safety and risk analysis
CD0: Approve mission needCD1: Approve preliminary baseline range CD2: Approve performance baseline rangeCD3: Approve start of construction CD4: Approve start of operation
February 21, 2005 The AGATA Week 8
Concept of Mechanical Support
• Two quarter-spheres• 17 detector mounting
positions• Allow translation and
rotation• Wedge plate for
detector alignment• Tool for detector
installation• Movable among
laboratories (e.g. ANL, LBNL, MSU, ORNL)
February 21, 2005 The AGATA Week 9
Three-crystal Prototype
Tests performed
• Mechanical dimension
• Temperature and LN
holding time
• Energy resolution
• Singles and preliminary
coincidence scan
• In-beam measurements
Tapered hexagon shape Highly segmented 6 6 = 36 Close packing of 3 crystals 111 channels of signal
Received June 4, 2004
8 cm
9 cm
10 deg.
February 21, 2005 The AGATA Week 10
Prototype Test Results
0
200
400
600
800
1000
1200
1400
0 10 20 30 40 50 60 70
Y (mm)
Co
un
ts 6
0k
eV
Am
(0,-50, )
FrontLeftRightBack
Crystal B, noise substracted
20
25
30
35
-90 -60 -30 0 30 60 90
Angle (degrees)
Dri
ft t
ime
(10
nse
c)
T90 - T10
T80 - T20
Crystal A segments 1 and 4
Segment boundary Electron drift velocity
In-beam measurementsSignal shapes
Under analysis
February 21, 2005 The AGATA Week 11
Detector Module Design
Design Choices
• 4 crystals per cryostat
• Warm FETs
Reasons Simpler geometry – 2 types of crystal, one cryostat Easier FET replacement – 1 day vs. 9 days Higher availability – near 100% vs. 85% Lower price – $400k cost difference, with one more crystal
February 21, 2005 The AGATA Week 12
Detector Geometry
• Packing scheme: 12 pentagons, 120 hexagons • Pentagon size: = 5.2%, fit a OD = 1.7” tube• Ge crystals: = 81.1%• Target-to-crystal distance: r = 185 mm
E = 1.3 MeV
46.4
46.8
47.2
47.6
48
48.4
15 17 19 21radius [cm]
Eff
i [%
]
33.5
33.9
34.3
34.7
35.1
35.5
35.9
36.3
36.7
37.1
37.5
14.5
14.9
15.3
15.7
16.1
16.5
16.9
17.3
17.7
18.1
18.5
Theta B
Th
eta
A
Sol id Angle
0.808-0.81
0.806-0.808
0.804-0.806
0.802-0.804
Packing scheme Optimization of shapes Optimization of distance
Geant4 program from Dino Bazzacco and Enrico Farnea
February 21, 2005 The AGATA Week 13
Crystal Shapes
Crystal A Corner angle Taper angle
124.84 9.70 117.71 9.64 117.45 9.33 115.18 9.86 119.98 9.70 124.84 9.59
Crystal B Corner angle Taper angle
118.29 9.72 121.46 9.64 119.41 9.86 123.51 10.15 118.94 10.15 118.39 9.34
February 21, 2005 The AGATA Week 14
Data Acquisition System
Signal digitizer Trigger/timing system Network switch Processing farm Data storage
Signal digitizer prototype
• 100 MHz, 12 bit• Energy
– trapezoidal filter– P/Z correction
• Leading edge time• Constant fraction time• Pulse shape
Data Acquisition System Schematic
Aux. Det. Trigger
Global TriggerModule
SignalDigitizers
Local TriggerModule
NetworkSwitch
Processing Farm
30 Crystals
Data Storage
2.2 MB/s
Aux. Det. Data
66 MB/s
75 dual Processors
Workstations, Servers
6.9 MB/s
2.3 MB/s + Aux. Det. Data
February 21, 2005 The AGATA Week 15
Electronics
• Produced twenty units of the 2nd version of the signal digitizer. Fifteen are in use.
• Added P/Z cancellation algorithm to FPGA.
• Studied the performance of Ge detector preamplifier
• Tested Ge signal cables and connectors
• Completed draft of requirement document
Before P/Z After P/Z
February 21, 2005 The AGATA Week 16
Detector Testing System
Use 15 prototype DSP boards in VME crate to acquire data from all 111 channels of prototype detector
Acquisition rate > 8 Mbytes/sec
Data stored to a redundant disk array (2 Tbytes) over Gigabit network
Three data processing computers
Online histogramming during in-beam test
Offline analysis programs
Setup for detector testing
February 21, 2005 The AGATA Week 17
Computing Requirements
Assumptions– Movable among labs, expandable to more detectors
Performance Requirements– Process 20,000 gamma/sec, store 10 Mbytes/sec
Data Processing Components– Readout, event building, signal decomposition, tracking
Services– Controls, configuration management, online
monitoring, data archiving
February 21, 2005 The AGATA Week 18
Pulse Shapes with n-damage
Pulse shapes from an undamaged detector (solid) and a neutron damaged detector after 1010 n/cm2 (dashed)
Neutrons cause:1) Reduction of
charge collection efficiency
2) Residual charge in neighboring segments
February 21, 2005 The AGATA Week 19
Neutron Damage effects
Degradation in E resolution
occurs for <100 cm, before
correction and for <30 cm, after
correction. But only for <17 cm position
resolution becomes worse than 1
mm.
A measurable effect of neutron
damage on position resolution is
never reached before annealing is
required for energy resolution!
February 21, 2005 The AGATA Week 20
Impurity Concentration
Impurity => Space Charge =>Electric Field => Drift velocity => Pulse shape
• Impurity concentration is not constant in the crystal.
From the manufacturer (z-variation) Vop = 5000 V
Crystal A: = (0.45 _ 1.5 ) x 1010 a/cm3 Vfd = 2500 V
Crystal B: = (0.76 _ 1.2 ) x 1010 a/cm3 Vfd = 2000 V
Crystal C: = (0.83 _ 1.8) x 1010 a/cm3 Vfd = 3750 V
• Impurity concentration from = 0 to = 1.4 x 1010 a/cm3.• Position resolution has been calculated.• The capability of reconstructing the interaction position is not affected, if the impurity concentration is known with accuracy of:
= 0.75 x 1010 atoms/cm3 => 1 mm
February 21, 2005 The AGATA Week 21
Improve Tracking Speed
Optimal permutation sequence– Track energy ordered
interactions (Learning mode)– Arrange permutation by success rate– Track with learned order of permutation (production mode)
0
10
20
30
40
50
60
70
0 200 400 600 800 1000
Energy Permutation
Even
ts
1.33 MeV, N=7
1.33 MeV, N = 7
7! = 5040
Permu. Event 3.4% 50% 5.0% 59% 7.0% 64% 8.4% 65%
0
10
20
30
40
50
60
70
0 100 200 300 400 500
Permutation
Eve
nts
SuccessOrdered
0
1000
2000
3000
4000
5000
0 100 200 300 400
Permutation
accu
mu
ltiv
e E
ven
ts
Success ordered
Random
1 2 3 5 6 7 4
1 2 3 7 5 6 4
1 2 3 5 7 6 4
1 3 2 5 6 7 4
1 2 3 6 5 7 4
1 2 4 5 7 6 3
1 2 6 5 7 4 3
1 2 5 4 6 7 3
1 2 6 4 5 7 3
1 2 5 7 4 6 3
February 21, 2005 The AGATA Week 22
Plan for 2005
Receive CD2A/3A approval for detector Receive and approve drawings of the 4-crystal detector
module and award contract Complete design of the Mechanical Support Structure Complete design of the Liquid Nitrogen System Complete analysis of in-beam data of prototype III Finalize Electronics Requirement Document Finish electronics R&D – preamp, trigger etc. Finalize Computing System Requirement Document Continue signal decomposition and tracking algorithm
developments
February 21, 2005 The AGATA Week 23
Schedule (Fiscal Years)
WBS Task Name
1 GRETINA
1.1 Mechanical
1.1.2 Design
1.1.3 Production
1.2 Detector Module
1.2.1 Purchasing
1.2.2 Test/Characterize Module 1
1.2.3 Test/Characterize Rest of Modules
1.3 Electronics
1.3.2 Prototype
1.3.3 Production
1.4 Computing Systems
1.4.2 Prototype
1.4.3 Production
1.5 System Assembly
1.5.1 Prototype
1.5.2 Production
1.6 Project Management
1.7 Environment and Safety
1.12 Level 1 Milestones: Critical Decisions CD1 CD2/3A CD2/3B CD4
Complete test proc. and apparatus Complete test/charac. module
1
Award module contract Exercise option last module
Complete design/draw. support structure
Complete mechanical subsystem
Complete test DSP module
Start production DSP module
Award computer farm contract
Ready for prototype assembly
Ready for final assembly
CD0
3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 42003 2004 2005 2006 2007 2008 2009 2010 2011
February 21, 2005 The AGATA Week 24
GRETINA Cost (Jan. 04)
Item Cost (M$)
• Mechanical 0.91 • Detector 6.95 • Electronics 1.52• Computer 1.15• Assembly 0.18 • Management 2.22• Safety 0.12
Sub total 13.05Contingency 2.85
(22%)Escalation 1.10
Total (TEC) 17.0
Includes overheadDoes not include R&D and scientific efforts
Gretina - MIE Labor & Matl Costs by Year
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
$k
Matl
Labor
Matl 280 1669 1717 2996 3272 939 7
Labor 720 831 1283 904 1128 1061 193
FY04 FY05 FY06 FY07 FY08 FY09 FY10
February 21, 2005 The AGATA Week 25
Management Structure
February 21, 2005 The AGATA Week 26
Collaborating Institutions
• Argonne National Laboratory– Trigger system– Calibration and online monitoring software
• Michigan State University– Detector testing
• Oak Ridge National Laboratory– Liquid nitrogen supply system– Data processing software
• Washington University– Target chamber
Role defined by MOU’s
February 21, 2005 The AGATA Week 27
Management Advisory Committee
• Don Geesaman, Argonne National Laboratory
• Konrad Gelbke, Michigan State University
• James Symons, (Chair) Lawrence Berkeley National Laboratory
• Glenn Young, Oak Ridge National Laboratory
February 21, 2005 The AGATA Week 28
Gretina Advisory Committee
• Con Beausang, Yale University• Doug Cline, University of Rochester• Thomas Glasmacher, Michigan State University• C. Kim Lister, Argonne National Laboratory• Augusto Macchiavelli, Lawrence Berkeley Laboratory• David Radford(Chair), Oak Ridge National Laboratory• Mark Riley, Florida State University• Demetrios Sarantites, Washington University• Kai Vetter, Lawrence Livermore National Laboratory
February 21, 2005 The AGATA Week 29
Working Groups
• Physics M. A. Riley
• Detector A. O. Macchiavelli
• Electronics D. C. Radford
• Software M. Cromaz
• Auxiliary Detectors D. G. Sarantites
ANL, LANL, LBNL, LLNL, NRL, ORNL, FSU, Georgia Tech, MSU, Miss. SU, Purdue, U. Mass. Lowell, Rochester, Notre Dame, Vanderbilt, Wash. U., Yale
ANU, CEA Saclay, Cologne, Daresbury, CNEA-UNSAM, CSNSM, Guelph,IFIC Valencia, INFN Podava, INFN Milano, Jyväskylä, Keele, KTH RIT, Liverpool, Lund, Manchester, Paisley, S. Paulo, Surry, TRIUMF, Tsinghua, TU Munich, Toronto, York, Uppsala, Warsaw
February 21, 2005 The AGATA Week 30
Working Group Meetings
• Detector– March 19-20, 2004, ORNL
• Software – June 22-23, 2004, LBNL
• Electronics– July 24-25, 2004, ANL
February 21, 2005 The AGATA Week 31
Summary
• Received CD1 – Started design phase
• No technical show stoppers
• Project on schedule and within cost so far
• Construction starts in 2007
• Completion in 2010
February 21, 2005 The AGATA Week 32
Summary
• Collaboration with AGATA has benefited GRETA/GRETINA
• We would like to continue and expand the collaboration
• Software working group meeting on signal decomposition ~ May 2005
• Postdoc position available at Berkeley