After a long time on fusion shots, we're back to diagnostic work. We're measuring the x-ray spectrum emitted from the plasma, which is a way of measuring it's temperature. Using 6 channels per shot with different filters we can get the spectrum. (1/n) 🧵 @FLFusion #fusion 
The set here covers a range of photon energies from ~500 - 1500 eV. The Cu one stands out; each filter transmits a specific energy window. Unfortunately, nothing is easy. To get the x-rays out we have to put a hole in the target. (2/n)
The hole changes the dynamics, so we have to simulate the diagnostic version with the hole and check our results against that. The x-rays also interact with the hole. They can be absorbed in the walls and vapourise them, making them expand and making the hole close up. (3/n)
This can make a hotter target look colder, because the hole closed. Anyway, this image is the fully assembled target with detectors, gas fill connections, tilt adjustment and stuff. The important bit is inside the black tube, most of the vertical height is the amplifier. 🙂 (4/4)
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