exp(-mu*thickness of material)
In addition to the attenuation due to the Dewar walls, I did two more calculations to get a ball park figure for how much attenuation I should expect from the superconducting solenoid magnet that will surround the sample and that is made from copper clad niobium alloy wire that is .045 cm thick. The first graph is for copper of this thickness and the second graph is for Niobium, (pictures 3 and 4).
The theory predicts x-rays of about 382 keV energy. If x-rays are produced at a much lower energy, say around 50 keV, it's conceivable that they could be missed with the detector outside the liquid helium Dewar.
Any thoughts, pointers, or questions are always welcome!
1. Aluminum attenuation
2. Copper attenuation
3. Niobium attenuation
4. x-ray attenuation documentation