1. Can we control PMI to reduce erosion or deposition? Effects of excited particles Reflection of excited neutrals, on deposition and erosion Excited molecules Influence of electrons, Any effects of magnetic field, are there any other ? Transport of eroded materials Mostly local transport repetitive processes of erosion and prompt redepsotiond How important flow is? How high neutral pressure? Is it important at the first wall? Can we know where deposition go ? Effects of ELM Delay of particle reemission Effect of reflected particles and energy Where eroded materials goes?

2. In situ measurements of redeposited materials and tritium retention Spectroscopy? (Elipsometery,IR, Raman etc. ) Confocal microscopy Laser ablation Dust How important (Tritium safety) Diagonstics, Spectroscopy, Laser probe measurements (reflection scattering) How to correct? Remote house keeping seems the best Tritium Removal Laser, Temperature (Out gassing, how high temperature? ) Oxygen (question to HTO production) Isotope exchange

3. Tritium permeation to cooling water Ferritic and V steel is very bad Hydrogen embrittlement?