Collimator for H+, E>100MeV

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• 1Keenan
Drilling a 100 micron hole in a 2 inch plate will not work, you need to find a smaller hole. The smaller the hole, the more precise the measurement.

1Keenan

Hello,

I would need to use a 0.1mm pinhole upstream a spectrometer. I need it so small because of the energy resolution.
Now, the point is that this small hole should be in a 50mm thick plate (or thicker if the plate is not stainless steal). In general the minimum hole diameter that can be drilled on a plate is 0.1*thickness so how to solve the problem?
The simplest way would be stacking together several plates of 1mm, but I'm not sure it could be very precise.
I was thinking about using injector for fuel, like those used in scooters. They are calibrated, so it might work, but I cannot find the tech drawings and I would like to see them first.
Any other suggestion?

Thanks
F.

Why the solid 50 mm ? Two 1 mm plates 50 mm apart should do the trick.

no really, I need to stop 100 MeV protons and maybe higher energy, they would pass 1mm plate...

1Keenan said:
The simplest way would be stacking together several plates of 1mm, but I'm not sure it could be very precise

Why would this be worse than trying to drill a 100 micron hole in a 2 inch plate?

because of the alignment: machining and tolerances should be very strict and there is always and error.
BTW it is not possible to drill 0.1 hole in a 2inch plante, i need to find a better idea to do it

Do you have enough space for two sets of collimators, one vertical one horizontal? Both can be pairs of 5 cm plates 0.1 mm apart. That would be the usual approach in accelerators.

If that doesn't work, just two plates fit together with some of the surface material scratched off to make a gap?

Yet another approach: Calculate how much the protons scatter in a 1 mm plate. Make one or two 1mm plates with a tiny hole, then make thicker plates with larger hole diameters behind it. Most particles that don't hit the small hole will get scattered and then end up in the plates even with the larger holes.

berkeman
I should have enough space for 100mm long pair of slits, I think this approach is the most affective, thank you!
Very simple idea, very robust solution!

berkeman