Paper 13093-29
Paper 13093-29
Low-temperature proton irradiation with DEPFETs for Athena’s wide field imager
On demand | Presented live 17 June 2024 
Abstract
The Wide Field Imager (WFI), one of two instruments on ESA’s next large X-ray mission Athena, is designed for imaging spectroscopy of X-rays in the range of 0.2 to 15 keV with a large field of view and high count rate capability. The focal plane consists of back-illuminated DEPFET (Depleted p-channel field effect transistor) sensors that have a high radiation tolerance and provide a near Fano-limited energy resolution. To achieve this, a very low noise readout is required, ∼3 electrons ENC at beginning of life is foreseen. This makes the device very susceptible to any radiation induced worsening of the readout noise. The main mechanism of degradation will be the increase of dark current due to displacement damage caused primarily by high energy protons.
To study the expected performance degradation, a prototype detector module with fully representative pixel layout and fabrication technology was irradiated with 62.4 MeV protons at the accelerator facility MedAustron in Wiener Neustadt. A total dose equivalent to 3.3 · 109 10-MeV protons/cm2 was applied in two steps. During, in-between and after the irradiations the detector remained at the operating temperature of 213 K and was fully biased and operated. Data was recorded to analyze the signal of all incident particles.
We report on the increase of dark current after the irradiation and present the current related damage rate at 213 K. The effect of low temperature annealing at 213 , 236 K, 253 K, 273 K, and 289K is presented.
To study the expected performance degradation, a prototype detector module with fully representative pixel layout and fabrication technology was irradiated with 62.4 MeV protons at the accelerator facility MedAustron in Wiener Neustadt. A total dose equivalent to 3.3 · 109 10-MeV protons/cm2 was applied in two steps. During, in-between and after the irradiations the detector remained at the operating temperature of 213 K and was fully biased and operated. Data was recorded to analyze the signal of all incident particles.
We report on the increase of dark current after the irradiation and present the current related damage rate at 213 K. The effect of low temperature annealing at 213 , 236 K, 253 K, 273 K, and 289K is presented.
Presenter
Valentin Emberger
Max-Planck-Institut für extraterrestrische Physik (Germany)
Valentin Emberger graduated in physics at the Humboldt-University of Berlin in 2011 about III-V semiconductor heterostructures. His professional experience includes a research stay at the University of Basel, Switzerland dealing with thin-film deposition and a short-term position for science communication and outreach at DESY. Since 2012 he is working at the Max-Planck-Institute for extraterrestrial physics on the development, test and qualification of spectroscopic single photon X-ray detectors for space telescopes, i.e. eROSITA and ATHENA.