Performance of the Ultraheavy Collector of the Trek experiment

Abstract

We report on the performance of the trek ultraheavy cosmic ray collector, an array of track-etch detectors which was deployed on the Russian space station Mir. Trek is the first space-based cosmic ray experiment to exploit the unique properties of the track-recording glass BP-1. We describe the systematic analysis of the Trek experiment, with emphasis on the calibration and verification of the Trek detectors, the automated scanning system used to locate and measure cosmic ray tracks, and the sources of dispersion in the measurement of cosmic ray charge. We find that the resolution for measurement of charge of ultraheavy galactic cosmic rays in Mir orbit will be 0.39–0.45 e in the absence of strong thermal variations or episodes of significantly elevated temperature. We also will discuss the extremely heavy cosmic ray composition observer (ECCO), a planned second generation BP-1 experiment, which would measure the age of galactic cosmic ray nuclei using the actinides as radioactive clocks.