E166 Background Test Plans SLAC, October 31, 2003 J. C. Sheppard

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E166 Background Test Plans SLAC, October 31,
2003J. C. Sheppard
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E-166 Background Tests

• Review and Advisory Committee
• Robert Noble (chair), C. Field, H. Lynch, and M.
  Ross
• Review design of test in the FFTB to validate
  that the backgrounds in E-166 are acceptable
• Review results and recommend to Dorfan and
  Paterson to proceed with E-166
• E-166 to be run in early calendar 2005
• Background results early in calendar 2004

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E-166 Activities
EPAC/SLAC Approval in June, 2003 Formation of
Background Test Review Committee, June
2003 Mini-Workshop on E166 Backgrounds July,
2003 E166 Collaboration Meeting October 24-27,
2003 Background Test Review October 31,
2003 SLAC Tech. Div. Schedule Discussion Week of
November 3, 2003 EPAC Status Report November
14-15, 2003
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E-166 Activities, contd
T467 Detector and DAQ Development in FFTB since
April, 2003 Installation of Background Test
equipment February, 2004 Background Tests
February-July, 2004, tbd E166 Polarized Positron
Production January, 2005
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E-166 Beamline Schematic
50 GeV, low emittance electron beam 2.4 mm
period, K0.17 helical undulator 0-10 MeV
polarized photons 0.5 rad. len. converter
target 51-54 positron polarization
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E166 Polarimeter Overview

g Polarimeter
4 x 109 ? ? 4 x 107?
1 x 1010 e- ? 4 x 109 ?
4 x 109 ? ? 2 x 107 e
4 x 105 e ? 1 x 103 ?
2 x 107 e ? 4 x 105 e
and Polarimeter
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E-166 Background Tests

• There are three sources of E-166 background
• Streaming from up-beam of the undulator
• Interception at the undulator
• Secondaries produced in the spectrometer
• Background studies test the first two sources
• First meeting of RA committee June 26, 2003

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E-166 Background Test, June 2003
Shielding to be added as indicated by modeling
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E-166 Background Test, now
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E-166 Background Test Background Detectors and
Shielding overlayed on the E166 Pol. E Prod.
Detector package
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E166 Background Test Goals
The goals of the E166 Background Test are to
transport a low emittance beam through a small
aperture tube located at IP1 in the FFTB and to
measure the background levels at the locations of
the E166 detectors. Success for this test is
demonstrated by being able to keep the beam on
with the small aperture tube in place (loss
levels below the FFTB radiation limits) and by
measuring the background levels at each of 5
detectors to be less than 5 of the signal levels
anticipated for E166 proper.
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E-166 Background Test
For the background tests, a beam energy of 28 GeV
is sufficient. A 1.2 mm id1, 1 meter long, thin
walled SS tube and a protection collimator will
be installed at IP1. Six detectors two
Cerenkov-aerogel flux counters, a Si-W
calorimeter, a Si-Counter calorimeter, and a
CsI/PMT and a CsI/Diode-Pair calorimeters will be
located about 35 m downstream of IP1. Figure 1
shows the approximate layout of the required
equipment in the FFTB enclosure. Shielding for
the detectors, including Fe blocks representing
the E166 magnetized absorbers, for the background
tests is commensurate the full E166 experiment.
Table 1 lists the expected E-166 signal strengths
and 5 background levels
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E-166 Background Tests
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1. The 0.9 mm aperture of the E-166 undulator is
scaled inversely with the square root of the beam
energy from the 50 GeV of E-166 proper to the 28
GeV of the background test. Thus
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E-166 Background Tests Detectors
2 Cerenkov aerogel/PMT flux counters (Princeton
U.) 1 Si-G10 flux counter (U. Tenn) 1 Si-W
calorimeter (U. Tenn) 1 CsI/PMT calorimeter (DESY
Zeuthen/Humblodt Univ) 1 CsI/Diode-Pair
calorimeter (DESY Zeuthen/Humblodt Univ)
.
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T467 Detectors
2 Cerenkov aerogel/PMT flux counters (Princeton
U.), at SLAC, not installed 1 Si-G10 flux counter
(U. Tenn), installed 1 Si-W calorimeter (U.
Tenn), installed-replaced for Background Test 1
CsI/PMT calorimeter (SLAC/ U. So. Carolina) T467
Labview and CAMAC installation in B407,
10/31/03 Previously observing signal using a
scope and pulse height analyzer
.
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E166 Background Test Responsibilities
See Portrait Slides Also Analytical Calculation
.
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E166 Background Tests, Simulations

• Questions for the Simulations
• How much lead
• How much Boron-Polyethylene
• How much blasts thru the 3 mm hole
• Do we need floor, ceiling, side wall shielding
• What is expected change from 28 GeV to 50 GeV
• We are concentrating on beam splat on the
  undulator tube and collimator, ignoring
  essentially everything else (upstream sources,
  synchrotron radiation, ). Are we fooling
  ourselves?

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E166 Background Tests, Simulations

• Status
• Analytical calulation indicates about 80 r.l. of
  Pb
• GEANT3 undulator interception model indicates
  higher flux on-axis, consistent with analytical
  calculation off axis
• GEANT4 Pb shielding consistent w/ analytical no
  neutrons
• FLUKA neutrons, gammas, muons (maybe) Pb and
  B-Poly full geometry, consistent w/ analytical
  calc. at location of CsI to be checked w/ Fasso
• Need to add 6 m of Fe dumpline magnets

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E166 Background TestMagnets/Beamline
Equipment/InstrumentationJ. C. Sheppard
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E-166 Background Test Equipment
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E164/166 Sliding Table
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E164/166 Sliding Table
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E166 Background Test Equip/Instrmnt
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E-166 Background Tests Detectors
2 Cerenkov aerogel/PMT flux counters (Princeton
U.) 1 Si-G10 flux counter (U. Tenn) 1 Si-W
calorimeter (U. Tenn) 1 CsI/PMT calorimeter (DESY
Zeuthen/Humblodt Univ) 1 CsI/Diode-Pair
calorimeter (DESY Zeuthen/Humblodt Univ)
.
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E-166 Background Tests Equipment

• Beamline equipment is standard equipment, most of
  which exists.
• Engineering for sliding table has been done
  (E164). Fine control stage are T4 stages many
  copies exist
• Detectors are in good shape, essentially have on
  site a full set will use somewhat different set
  than for T467
• DAQ is in development extreme fallback is to use
  a calibrated scope
• Need permission to use SLC FFS hardware (bpms)
• Need to settle on how to ensure 1.2 mm tube
  straightness

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E166 Background TestBeamtime RequestJ. C.
Sheppard
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E166 Background Test Beam Requirements
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E166 Background Test Run Script, 1
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E166 Background Test Run Script, 2
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E166 Background Test Run Script, 3
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E166 Background Test Run Summary

• Time early for installation February 1, 2004
• Time required for installation and non-beam
  check-out 2 weeks ( Note this needs to be
  shortened)
• Time required to conduct measurements 9-18
  shifts (?)
• Wild card is accelerator tune-up time will be
  able to accurately plan, schedule, and execute
  hardware switch over.

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E166 Background Test Concerns
Run Time Schedule Early rather than Late in
2004 Accelerator Tune up need to understand
whats going on at present Time early for
Installation February 1, 2004 Duration of
Installation Minimize vacuum incursion, stretch
out controls hook up and equipment check out
(later is by-in-large parasitic) Compatibility w/
SPPS, E164, E165 E166 Bckgrnd equipment is
compatible with everyone else need to remove
some E164, E165 down beam equipment and install
spool pieces, reinstall after E166 dedicated
running