Transcript Slide 1

Breakdown – Phase I
K. Paul, S. Veitzer, P. Stoltz, D. Smithe (Tech-X)
J. Norem (Argonne National Lab)
“The objective of this work is to improve modeling
of breakdown in devices relevant to muon cooling
by adding to PIC codes processes like plasma
radiation and multiple ionization.”
(i.e., We want to improve our PIC codes such that
they can thoroughly study breakdown in RF
cavities. We want to make our codes as “capable”
as possible.)
Tech-X Corporation
http://www.txcorp.com
August 22, 2007
Objectives
 Determine the best way to model radiation effects in
metallic breakdown processes
 Radiation is emitted from metallic plasma (line and
continuum radiation) that carries energy out of the system
 e.g., Coronal model (compute fluid quantities on grid from
particles, remove energy from fluid, and back…)
 Determine the best way to model high charge state ions
in metallic breakdown processes
 Multiple ionization for metallic gases
 e.g., Lotz model (Cun → Cun+1)
p. 2
Techniques
 Use 2 different Tech-X PIC codes:
 OOPIC Pro: Easy to use; Great for small scale problems
and exploratory runs
 VORPAL: More complex; Massively parallel (1000+ node
clusters); “Next Stage” simulation tool
 Add to Tech-X’s physics libraries (TxPhysics)
 Improved physics and modeling capabilities
 Already links to VORPAL, but needs to be linked to
OOPIC (OOPIC has it’s own models)
 Include “as much physics as possible”
p. 3
News…to come
 Peter Stoltz and Seth Veitzer can come early next year
to present results/work on this Phase I
 Direct all questions to them 
 New ideas can definitely go into a Phase II proposal
 I’ll give a small OOPIC demo
 Fowler-Nordheim emission
 Ionization
 Fully electromagnetic RF near surface
p. 4