Discussion on Electron Cloud Progress and US-LARP Activities 
on the Occasion of Miguel Furman's and Ji Qiang's visit to CERN
22.03.2005
 
Gianluigi Arduini, Vincent Baglin, Elena Benedetto, Miguel Furman,
Miguel Jimenez, Ji Qiang, Francesco Ruggiero, Daniel Schulte, 
Frank Zimmermann

Some notes:

WARP/POSINST first simulation for LHC FODO cell (absorption efficiency
1, no secondary emission yet). 3-D fully self-consistent tool is in hands.
Magnetic field of the beam not fully included. But longitudinal electric
field is included.

Review of HIF efforts since 2002.

Items of interest for POSINST simulations:
Measurements of e- energy spectra
Sensitivity to material
Benchmarking against ECLOUD

Two RHIC e-cloud detectors installedi n warm regions
(cold not of interest to LHC and difficult), 1 normal
and 1 NEG coated. Dipole field available, 0.2-0.4 T
maximum strength. D. Hseuh will be visiting CERN for 
April vacuum workshop. Detectors will be shipped in 
July.

Main difference to SPS, possibility to fill RHIC ring
completely (no large gap), study of long term build up,
also 2 beams. 

Application of maps approach to LHC (Ubaldo no longer
available). 

LHC IR4 diagnostice bench. ECR within 2 months. Measure
heat load to cold magnets with high sensitivity.

Gas desorption was discussed at ILHC meeting.

Vincent commented that HIF tilted target measurements may
be wrong. 

COLDEX data show SEY Decreasing but constant heat load,
no evidence for gas diffucion from the arcs as source.

Daniel's presentation on SPS benchmarking:

Spacing scans, intensity scans.

Are low-energy e- measured by strip detector or not?

Possible experiment: increase vacuum pressure on purpose.

Elena's presentation (comments from Ji): 

Handle collisionality. Increase number of macro-p and
macro-el at the same time. Higher-order interpolation 
instead of linear. Or cut in Fourier space.
Calculate electric fields in beam rest frame and then
apply Lorentz transform. Apply filters. 
References: Birdsall, Struckmeier.