[Tpe] radiation damage of mylar and kevlar

[David Kashy]

Larry,
These are good finds and give some confidence that the window should 
survive the TPE exposure. I still think it might be worth thinking about 
a small raster across the width of the gap of the tagger to increase the 
exposed area and reduce the peak dose. Can we do this using the standard 
raster magnet if we put the radiator upstream of it? Or are we really 
confident that we are not close to the dose where mylar starts to 
degrade. Someone should make an estimate of the dose received so far .

Thanks
Dave


Larry Weinstein wrote:
> Dear Dave and Eugene,
>
> These are the two articles I found concerning radiation damage of 
> mylar and kevlar.
> Kevlar was tested up to 200 MRad with no loss of strength.  Mylar was 
> tested up to 1000 MRad with significant loss of strength above 500 MRad.
>
> This indicates that the window should be safe with our projected does 
> rates that are 10-20 MRad.  However, on this topic I would much prefer 
> to defer to an expert.
>