New developments for the investigation of hard X-rays emitted by peeling adhesive tapes

We realized an advanced apparatus for the investigation of emitted X-rays produced by peeling adhesive tape rolls under vacuum conditions. Two stepper motors can unwind and rewind a tape roll, and an additional roller with an optical encoder provides measurement and control of the tape speed. This way reproducible and consecutive experiments are feasible without having to change the tape or break the vacuum. The dependence of the X-ray emission on tape speed, gas pressure, type of adhesive tape, and detector angle has been investigated. The resulting spectra are continuous and span an X-ray energy range of typically 2-60 keV with high intensity. Furthermore, the new apparatus allows the in situ metalization of adhesive tape rolls by a gold sputter source. A significantly increased X-ray emission was observed for adhesive tapes with a metal coating. Thin metal foils have been placed between the tape and the detector, different K- and L-absorption edges could be measured. A considerable enhancement of the emission was achieved under the influence of the magnetic field of an NdFeB permanent magnet.