Beam Diagnostics for Measurements of Antiproton Annihilation Cross Sections at Ultra-low Energy

• Main Authors: Todoroki K., Hori M., Aghai-Khozani H., Barna D., Corradini M., Kobayashi T., Leali M., Lodi-Rizzini E., Mascagna V., Prest M., Soter A., Vallazza E., Venturelli L., Zurlo N., Hayano R.
• Format: Article
• Language: English
• Published: EDP Sciences 2014-03-01
• Series: EPJ Web of Conferences
• Online Access: http://dx.doi.org/10.1051/epjconf/20146609020

The ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) collaboration of CERN is currently attempting to measure the antiproton-nucleus in-flight annihilation cross sections on thin target foils of C, Pd, and Pt at 130 keV of kinetic energy. The low-energy antiprotons were supplied by the Antiproton Decelerator (AD) and a radio-frequency quadrupole decelerator. For this measurement, a beam profile monitor based on secondary electron emission was developed. Data from this monitor was used to ensure that antiprotons were precisely tuned to the position of an 80-mm-diameter experimental target, by measuring the spatial profile of 200-ns-long beam pulses containing 105 − 106 antiprotons with an active area of 40 mm × 40 mm and a spatial resolution of 4 mm. By using this monitor, we succeeded in finely tuning antiproton beams on the target, and observed some annihilation events originating from the target.