Inspection with an electron microscope II
Contents
Stone kapton straw
Pristine
The relative X-ray analysis of a normal area gave three peaks C, Al, and O. The magnitude of the peaks compared as C > Al > O. White spots are Ca = C = O > Al > P
Under source (irradiated)
The relative X-ray analysis of a normal area gave three peaks C, Al, and O. The magnitude of the peaks compared as C > Al > O . The X-ray analysis of a dark spot gave C = 0 > Al. Also the darker the spot the more O present.
3 years under voltage (big prototype)
The relative X-ray analysis of a normal area gave three peaks C, Al, and O. The magnitude of the peaks compared as C > Al > O, also the darker areas gave the same relative C > Al > O.
Lamina thin straw
The relative X-ray analysis of a normal area (light gray) gave three peaks C, Al, and O. The magnitude of the peaks compared as Al > C > O. The dark spots showed O > Al > C or O = Al > C . White spots are Ca = C = O > Al > P
Lamina thick straw
The relative X-ray analysis of a normal area gave one peak: Al. The white dots are Fe
Conclusion at 2am
It might be that the dark gray areas seen on the kapton and Lamina-thin straws after radiation are due to the same process. They appear to be a higher concentration of (Al?)O indirectly induced by radiation. This process takes time and it looks that after 3 years of normal (low radiation) operation of a stone kapton straw a difference (darker gray areas) can be observed with the EM but not with the X-ray analysis. As after an equivalent of 44 years of radiation the straw (Lamina-thin and kapton) shows a big increase in dark areas or "black pits" the straw is still operational. It hints that although the aLuminum layer of the Lamina-thin straw "degrades" after being exposed to radiation, this process is too slow to harm operation during the running period of GlueX. The Lamina-thick straw does not show any effect at all.