Performance of silicon-drift detectors in kaonic atom X-ray measurements

Large-area silicon drift detectors (SDDs) were used for the first time in the background condition of a collider for precision spectroscopy of the kaonic atom X-rays in the SIDDHARTA experiment for the study of the strong interaction in a low-energy regime. The measurements were performed at the DA Phi NE electron-positron collider (LNF, Italy), using gas targets of hydrogen, deuterium, helium-3, and helium-4. A test measurement using the kaonic He-4 X-rays showed an excellent performance of the SDD devices under the beam conditions, and a good background suppression capability using the time correlation between the kaonic atom X-rays and the back-to-back correlated K+ K- pairs produced by phi decays. (C) 2010 Elsevier B.V. All rights reserved.