A few of 1.5" pumping holes on the MST chamber can be used to install our primary beam detectors. From a priliminary calculation, we can find those pumping holes are located around toroidal 130 ~ 135 degrees, and poloidal -57 ~ -110 degrees. Please look at the following plot to see the distribution of our primary ions ending points on the chamber, with those pumping holes that can be possiblely covered by the ion beam.
From the results of the calculation and the availablity of the holes, I plan to use 3 type of detection rods: SINGLE RODs, TRAVERSE ROD, and ROTARY ROD.
I want to put at least four single detection rods at the following pumping holes (shown blue in the plot above):
A traverse rod will be installed across the following two pumping holes (shown red in the above plot):
and
I want to put one rotary wire at the following 2" port (shown green in the plot above):
SINGLE ROD: just a simple rod structure. They can tell where the beam is. They can also tell the sweep angle when changing the sweep voltages. (you can click each part to see its drawing)
TRASVERSE ROD: can be looked as two single rod connected together. They can tell when the beam walks across this rod by sweeping the beam or during the discharge. (you can click each part to see its drawing)
ROTARY ROD: Basically it gives the same information as a traverse rod. But as I design it to be rotatable and movable, which can give us much more flexibility. (you can click each part to see its drawing)
Teflon wedge Back
No need to design and machine a new major part of the rotary probe. This can be a recycled one in MST.