학술논문
Characterization of iLGADs using soft X-rays
Document Type
Working Paper
Author
Liguori, Antonio; Barten, Rebecca; Baruffaldi, Filippo; Bergamaschi, Anna; Borghi, Giacomo; Boscardin, Maurizio; Brückner, Martin; Butcher, Tim Alexander; Carulla, Maria; Vignali, Matteo Centis; Dinapoli, Roberto; Ebner, Simon; Ficorella, Francesco; Fröjdh, Erik; Greiffenberg, Dominic; Ali, Omar Hammad; Hasanaj, Shqipe; Heymes, Julian; Hinger, Viktoria; King, Thomas; Kozlowski, Pawel; Lopez-Cuenca, Carlos; Mezza, Davide; Moustakas, Konstantinos; Mozzanica, Aldo; Paternoster, Giovanni; Paton, Kirsty A.; Ronchin, Sabina; Ruder, Christian; Schmitt, Bernd; Thattil, Dhanya; Xie, Xiangyu; Zhang, Jiaguo
Source
Journal of Instrumentation 18, P12006 (2023)
Subject
Language
Abstract
Experiments at synchrotron radiation sources and X-ray Free-Electron Lasers in the soft X-ray energy range ($250$eV--$2$keV) stand to benefit from the adaptation of the hybrid silicon detector technology for low energy photons. Inverse Low Gain Avalanche Diode (iLGAD) sensors provide an internal gain, enhancing the signal-to-noise ratio and allowing single photon detection below $1$keV using hybrid detectors. In addition, an optimization of the entrance window of these sensors enhances their quantum efficiency (QE). In this work, the QE and the gain of a batch of different iLGAD diodes with optimized entrance windows were characterized using soft X-rays at the Surface/Interface:Microscopy beamline of the Swiss Light Source synchrotron. Above $250$eV, the QE is larger than $55\%$ for all sensor variations, while the charge collection efficiency is close to $100\%$. The average gain depends on the gain layer design of the iLGADs and increases with photon energy. A fitting procedure is introduced to extract the multiplication factor as a function of the absorption depth of X-ray photons inside the sensors. In particular, the multiplication factors for electron- and hole-triggered avalanches are estimated, corresponding to photon absorption beyond or before the gain layer, respectively.
Comment: 16 pages, 8 figures
Comment: 16 pages, 8 figures