1. 8/12/2002 Bob/RolAbsorber Review/GH2 status1 Gaseous H 2 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

2. 8/12/2002 Bob/RolAbsorber Review/GH2 status2 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)

3. 8/12/2002 Bob/RolAbsorber Review/GH2 status3 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.

4. 8/12/2002 Bob/RolAbsorber Review/GH2 status4 H2 Paschen Data exist up to P=25 Atm,V=28 MV/m

5. 8/12/2002 Bob/RolAbsorber Review/GH2 status5 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.

6. 8/12/2002 Bob/RolAbsorber Review/GH2 status6 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

7. 8/12/2002 Bob/RolAbsorber Review/GH2 status7 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. 8/12/2002 Bob/RolAbsorber Review/GH2 status8 RF test cell assembly

9. 8/12/2002 Bob/RolAbsorber Review/GH2 status9 RF test cell plan view

10. 8/12/2002 Bob/RolAbsorber Review/GH2 status10 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)