GRETINA at BGS: Capabilities, plans and status

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GRETINA at BGSCapabilities, plans and status

• I-Yang Lee
• Lawrence Berkeley National Laboratory
• GRETINA Science Workshop
• Lawrence Berkeley National Laboratory,
  Berkeley, CA
• April 23rd - April 24th, 2009

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Outline

• Deliverables and performance
• Important features for BGS experiments
• Schedule and plans
• Status

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Deliverables and performance

• WBS 1.1 Mechanical System (1,120 k)
• Support structure
• Liquid nitrogen filling system
• Target chamber

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Deliverables and performance

• WBS 1.2 Detector Modules (8,170 k)
• Detector modules

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Deliverables and performance

• WBS 1.3 Electronics (1,860 k)
• DSP Modules
• Trigger and Timing System
• Power Supplies
• Cables

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Deliverables and performance

• WBS 1.4 Computing system (1,280 k)
• Data storage system
• Network switching system
• Data Processing computer cluster
• Signal decomposition software
• Tracking software
• Slow control software

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Important features

• Compactness- center of GRETINA is at the designed
  target position of BGS.
• Efficiency comparable to current generation of
  4p array
• Position resolution ? 1-2 mm RMS
• Counting rate 36 segments

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GRETINA efficiency

• Simulated single-g efficiency ? 14 at 0.4 MeV

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Efficiency of tracking
Tracking efficiency depends on position
resolution and gamma-ray multiplicity
Mg 25, a 10?
Eg 1.33 MeV, Dr 1 mm
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GRETINA count rate

• Segment rate is lt 10 of that of crystal rate
• Run segment at 10 kHz, ? 100 kHz crystal rate

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Transfermium spectroscopy

• Assumptions for simulation
• sTOT 1 barn
• Target 0.5 mg/cm2
• Beam Current 50 pnA
• eg / crystal 0.0067
• Mg 10
• ? 30.3 kHz/crystal
• ? 3 kHz/segment (max)

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GRETINA schedule
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GRETINA at the 88-Inch
At completion (2/14/2011), GRETINA will be at
CAVE 4C
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Engineering runs
From the CD2B/3B review and the Richmond Meeting
- Oct. 14-15, 2007

• Source and In-Beam tests of GRETINA
• Further tests, debugging and characterization in
  battle conditions
• Initial Optimization
• 3-4 months following CD4 ( March June 2011)
• Strong participation from the community
• (3-4 FTEs of redirected scientific effort)

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Commissioning Runs
From the Richmond Meeting - Oct. 14-15,
2007 GRETINA at BGS Structure of heavy elements

• Move to Cave 1 - July 2011 (1 month)
• Community and GAC will help develop the
  experimental program - August - November 2011 (4
  months)
• Move to NSCL/MSU - December 2011

These are all tentative dates uncertainties in
project schedule DOE has not blessed this plan
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GRETINA at BGS
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Detector modules
Two received
A-type
B-type
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Mechanical structure
Quarter sphere shell
Axle bearings Rotation Axle gear set
Flange Wedge plate - under and
attached to detector flange
All parts ready
Preamp housing
Detector module Cap LN dewar
Railroad car
Hexapod
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Electronics production
All modules produced
Trigger Timing Control module (ANL) Fast
trigger (lt300 nsec) Trigger conditions
Multiplicity Sum energy Hit pattern
Digitizer module (LBNL) 14bit, 100
MHz Energy Leading edge time Constant fraction
time Pulse shape
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Pencil beam results
Using the latest decomposition program and
basis, we have achieved lt2 mm (RMS) resolution
Pencil beam of 662 keV, 1 mm diameter
Module Q1 crystal A1
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System Assembly

• Infrastructure available at the 88 Cyclotron to
  start assembly
• Staff experienced in the assembly of similar
  systems (GAMMASPHERE).
• Site preparation in Cave 4C already underway.

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Technical issues

• High rate operation refine P/Z correction
• Sum segment energies non-linear energy
  calibration at low energy
• Optimize tracking for low energy gamma-rays
• Full performance simulation use improved
  decomposition and tracking results
• No Show stoppers two years before we start to
  do experiment

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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

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Collaborators

• Mechanical Steve Virostek,
• Tim Loew, Derek Shuman, David C. Radford,
  Demetrios Sarantites
• Detector - Augusto Macchiavelli
• Sebastien Gros, Thomas Glasmacher, Stefanos
  Paschalis, Dirk Weisshaar
• Electronics- Sergio Zimmermann
• Dionisio Doering, John Joseph, Kim Lister, John
  Anderson
• Computing - Carl Lionberger
• Mario Cromaz, Paul Fallon, David C. Radford,
  Karin Lagergren, Torben Lauritsen

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Summary

• GRETINA at BGS will have major impacts on nuclear
  physics.
• GRETINA construction is on time and within budget
  with completion date of 2/14/2011
• A tentative schedule for engineering runs and
  commissioning runs is in place