X-Ray Anode
Posted: Tue Jun 14, 2011 8:56 pm
Not sure if this is really the right posting category, didn't see anything chemistry (maybe something should be added).
Been working with an x-ray source, and recently we've been making various anodes to calibrate some instruments. Tried coating an aluminum anode in sodium chloride today by dissolving it in water, putting a drop on the tip of the anode, then heat drying the anode. This stuck fairly well, and then it was run in the source for a few minutes at 6kV 1mA beam current, and came out blown off in the center, and purple where it remained. Just out of curiosity, we were wondering what it is but couldn't seem to figure out. Only remotely reasonable purple substance of aluminum or sodium we seemed to come up with would be sodium permanganate, but that doesn't make much sense really, possibly some manganese in the aluminum alloy but I wouldn't think it would this easily react with the salt coating. Any thoughts what this is or what happened to it (pics attached)? This was scientific grade sodium chloride, not table salt.
Also, any tips on anode coating with salt so that it won't burn off or become chemically altered? We also used milk of manganese on another anode and interestingly that one worked great and didn't seem to burn off.
Been working with an x-ray source, and recently we've been making various anodes to calibrate some instruments. Tried coating an aluminum anode in sodium chloride today by dissolving it in water, putting a drop on the tip of the anode, then heat drying the anode. This stuck fairly well, and then it was run in the source for a few minutes at 6kV 1mA beam current, and came out blown off in the center, and purple where it remained. Just out of curiosity, we were wondering what it is but couldn't seem to figure out. Only remotely reasonable purple substance of aluminum or sodium we seemed to come up with would be sodium permanganate, but that doesn't make much sense really, possibly some manganese in the aluminum alloy but I wouldn't think it would this easily react with the salt coating. Any thoughts what this is or what happened to it (pics attached)? This was scientific grade sodium chloride, not table salt.
Also, any tips on anode coating with salt so that it won't burn off or become chemically altered? We also used milk of manganese on another anode and interestingly that one worked great and didn't seem to burn off.