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a) Dieter recommends using another tungsten type materials, like W-26Re, or W-Ta alloys that are machinable and still have a Z that is about the same as W. Dieter has the material and can ship it to you. It may be easier to machine the 3mm and 2 mm slits out of one piece (say 3cm by 2.5cm - 1 cm thick) than use three separate pieces.
2 May 2014
Here is the response from our engineer. It looks like our machine shop
has a piece HD17 that we can use. It seems HD12 is very close to what
Dieter has, first material. If this will work for the collimator we will go
a head with the design and fabrication, otherwise, we should get the
piece from Dieter.
Stepan
b) Do we need a slit collimator in front of the thin gold foil?
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