1. Ion Issues
Goal: define R&D plan producing a viable specification of machine settings within the next 2 (3?) years.
Modeling / Simulations
Experiments / Modeling-validation
Remedies / Machine, beam parameters specifications

2. Talking points Modeling/Simulations
Is the model/physics of FII well understood, adequate?
e.g. photo-ions could be important, in particular in the wigglers where significant portion of radiation is emitted along the beam?
…and the action item goes to … Oleg?
Do the available codes capture all the relevant physics?
Clarify issue on single-bunch vs. multi-bunch instabilities
Strong-strong vs. weak-strong
Feedback-modeling integrated in simulations?
Survey of available simulations codes and simulators:
Ohmi, KEK, (?)
E-S Kim, (KNU), (?)
Tor R, SLAC, (strong-strong)
Lanfa Wang, SLAC, (weak-strong, strong-strong)
Gouxing Xia, DESY (weak strong)
Werner Bruns, CERN, (?)
We should make an effort (short term action item) to
document codes to ease communication
test codes against each other (as well against measurements). E.g. investigate further convergence against numerics (how robust are results against choice of no. of kick stations?, etc)

3. Experiments / Validation of models
The main value for experiments/measurements for us in validation of modeling/simulations
Experimental demonstration that a ILC DR like beam can be made immune to FII, desirable but less likely
An experiment with a non ILC-DR beam is useful only if it is accompanied by a robust simulation effort
We should try to match measurement plans with simulators (e.g. proposal of simulations for ATF).
There may be specific aspects that can be studied at certain facilities and not others (experiment proposals
Facilities with programs to do FI experiments
ATF  2007 only, 22 shifts * 8hrs available
Proposal for experiments/simulations in place. Need to produce a detailed version Simulators involved: Lanfa, Guoxing (both at 50% FTE level) + in-house simulation capabilities Ohmi
PLS
No simulation program in place – not clear their commitment for further studies
ALS
Hopefully some measurements in 2007; plans to develop some in-house simulation capabilities; collaboration with L. Wang
CESR(TA)
>2008; can pick-up the torch from ATF; would make it possible to look at conditions closer to DR beam specifications.

4. Remedies/Machine settings
Ion problem is coupled with, has implication for:
vacuum,
Depending on the choice of vacuum technology, vacuum composition may be different with possibly different implications for ions.
Eg. In NEG coated chamber CO will be negligible, methane likely to be dominant
feedback specifications
Perhaps we can live with a feedback system that doesn’t have to kill the instability completely (Lanfa talk)
design of bunch filling patterns, timing
....
More invasive remedies:
Clearing electrodes for “conventional” ions?