Transcript Document

Gaseous H2 Absorber Status
IIT and Muons, Inc.
Chuck Ankenbrandt, Ed Black, Kevin
Cassel, Bob Hartline, Rol Johnson,
Dan Kaplan, Moises Kuchnir, Al
Moretti, Milorad Popovic
2 SBIR/STTR proposals
(phase I $100k, phase II $750k/$500k)
submitted on 1/15/2002
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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Bad News, Good News
20b. Gaseous Energy Absorber
Conceptual Design----Rejected,
but
21a. High Pressure RF Cavities
Funded for $100k as an STTR
phase 1 for 9 months starting 7/22/02.
(MUCOOL note 247 is the proposal)
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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21a Project Goal
Unlike any previous particle accelerator, muon
beams in an ionization cooling channel are not only
allowed but are required to be accelerated through
an energy absorbing material. This proposal is to
develop very high voltage RF cavities by filling
them with cold, pressurized helium or hydrogen
gas, which also acts as the energy absorber, to
suppress high-voltage breakdown.
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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H2 Paschen Data exist up to
P=25 Atm,V=28 MV/m
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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21a Phase I Goal
To build an RF test cell for testing breakdown
characteristics of gases for ionization cooling.
The test cell will allow the exploration of Paschen’s
Law, relating breakdown voltages to gas
density, over a range of temperatures, pressures,
external magnetic fields, and ionizing particle
radiation at Lab G and the Linac Test Area.
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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Measures of Phase 1 Success
• Paschen curve measurements for Helium
– 805 MHz breakdown vs. gas density
– At 300K and 80K (LN2)
– Pressures up to 100 Atmospheres
• Be ready to do the same for Hydrogen
• This should increase probability for phase 2
– Also for resubmission of rejected phase 1
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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Test Cell Requirements
• Safe (pressure, ODH, x-rays, HV)
• Robust and Versatile
– open many times
– change electrodes
– good for H2
• Instrumented
– T, P, spark, RF parameters
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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RF test cell assembly
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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RF test cell plan view
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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Present Status
• Basic test-cell system designed
– Conflat blanks, keg cryostat, simple Cu cylinder
• Designing/Testing RF, HP seals
– Copper or Indium seals, knife-edge or groove
• Designing/Testing RF feedthrough designs
– ceramic or epoxy, parallel or conical
(hydrostatic, pneumatic, cryo tests soon)
• Defining procedures
– safety, construction, measurements (may start 10/1/02)
8/12/2002 Bob/Rol
Absorber Review/GH2 status
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