1. |
- Correa, J., et al.
(author)
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On the Charge Collection Efficiency of the PERCIVAL Detector
- 2016
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In: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:12
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Journal article (peer-reviewed)abstract
- The PERCIVAL soft X-ray imager is being developed by DESY, RAL, Elettra, DLS, and PAL to address the challenges at high brilliance Light Sources such as new-generation Synchrotrons and Free Electron Lasers. Typical requirements for detector systems at these sources are high frame rates, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency, and (multi)-mega-pixel arrangements. PERCIVAL is a monolithic active pixel sensor, based on CMOS technology. It is designed for the soft X-ray regime and, therefore, it is post-processed in order to achieve high quantum efficiency in its primary energy range (250 eV to 1 keV) . This work will report on the latest experimental results on charge collection efficiency obtained for multiple back-side-illuminated test sensors during two campaigns, at the P04 beam-line at PETRA III, and the CiPo beam-line at Elettra, spanning most of the primary energy range as well as testing the performance for photon-energies below 250 eV . In addition, XPS surface analysis was used to cross-check the obtained results.
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2. |
- Khromova, A., et al.
(author)
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Report on recent results of the PERCIVAL soft X-ray imager
- 2016
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In: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:November
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Journal article (peer-reviewed)abstract
- The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125–1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10–120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10–120 Hz range an average noise floor of 14e− has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 centerdot 106 e− or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.
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3. |
- Marras, Alessandro, et al.
(author)
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Characterization of the Percival detector with soft X-rays
- 2021
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In: Journal of Synchrotron Radiation. - 0909-0495 .- 1600-5775. ; 28, s. 131-145
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Journal article (peer-reviewed)abstract
- In this paper the back-side-illuminated Percival 2-Megapixel (P2M) detector is presented, along with its characterization by means of optical and X-ray photons. For the first time, the response of the system to soft X-rays (250 eV to 1 keV) is presented. The main performance parameters of the first detector are measured, assessing the capabilities in terms of noise, dynamic range and single-photon discrimination capability. Present limitations and coming improvements are discussed.
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4. |
- Nooripour, Roghieh, et al.
(author)
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Psychometric properties of persian version of escapism scale among Iranian adolescents
- 2023
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In: BMC psychology. - 2050-7283. ; 11
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Journal article (peer-reviewed)abstract
- The aim of this study was to assess the psychometric properties of the Persian version of the Escapism Scale among Iranian adolescents aged 14-18. Between January 2021 and August 2021, cross-sectional study was conducted using a convenience sampling method to select 566 participants (340 girls and 226 boys) to investigate the relationship between physical activity and mental health in adolescents. The participants completed several questionnaires, including the Escapism Scale, Erikson Psychosocial Stage Inventory (EPSI), Satisfaction with Life Scale (SWLS), Hope Scale (AHS), Smartphone Addiction Scale-Short Version (SAS-SV), and General Self-efficacy (GSE). Construct validity, reliability using Cronbach's alpha, and concurrent validity were used to evaluate the Escapism Scale's validity and reliability. Results of the Confirmatory Factor Analysis (CFA) indicated that a two-factor model provided a good fit for the data: sbX2 = 179.99 (p < 0.01); SRMR = 0.07; RMR = 0.56, CFI = 0.91; NFI = 0.89; IFI = 0.91; NFI = 0.89; GFI = 0.93; AGFI = 0.90, RMSEA = 0.076). The Cronbach's alpha coefficient for escapism was 0.73. The study found a significant positive relationship between escapism and smartphone addiction (r = 0.19). Additionally, a significant negative relationship was observed between escapism and hope (r=-0.31), satisfaction with life (r=-0.34), and general self-efficacy (r=-0.33). Furthermore, a significant relationship was found between escapism and gender. Lastly, the study found a significant relationship between escapism and identity confusion (r = 0.164, P < 0.01) and identity coherence (P < 0.01, r = 29). In conclusion, the Escapism Scale is a valid and reliable tool for assessing escapism and psychological evaluations in Iranian adolescents. These results may inform future research and suggest re-testing in clinical populations.
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