The Commissioning of a Pixelated Charge-particle Detector : for High-sensitivity Measurements of Hydrogen

Abstract: The Tandem Laboratory at Uppsala University, a national research infrastructure forworld-leading materials analysis, has a long history of performing hydrogen measurementusing NRA (Nuclear Reaction Analysis). This project intents to diversify the infras-tructure for hydrogen measurement by investigating the feasibility of an advanced ERCS(Elastic Recoil Coincidence Scattering) system, enabling finer detection limits. The sys-tem, based on a DSSD (Double-sided Silicon Strip Detector) and a 64 channel dataacquisition system, is set up, tested and calibrated using both single- and triple peakα-radiation sources. Results indicate that all but 14 front segments work correctly. Thestatus of three segments could not be determined due to faulty pre-amplifier channels.Two of the segment faults were found to be caused by snapped electrode connections onthe DSSD. The status of half the backside rings could not be determined due to a faultypre-amplifier. Despite this, the energy spectrum of a 241Am α-particle source was mea-sured with good resolution, showing a clear energy peak corresponding to the 5486 keVα-particles with FWHM equaling 270 keV. Calculations indicate an average dead timefor the working channels of 1.37 %. Measurements on a 239Pu-241Am-244Cm α-particlesource resulted in three main peaks with energies at 5155 keV, 5486 keV and 5805 keV,corresponding to the three peaks of the α-source. Results indicated FWHMs of 208 keV,190 keV and 169 keV respectively, with an average dead time of 32.8 %. These resultsdemonstrate that the detector is in working condition. Furthermore, the pre-amplifiershave been examined and any dead channels are accounted for.