ORIGAMIX, a CdTe-based spectro-imager development for nuclear applications

S. Dubos (1) , Hermine Lemaire (2) , S. Schanne (1) , O. Limousin (1) , Frédérick Carrel (2) , Vincent Schoepff (2) , C. Blondel (1)

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 LCAE - Laboratoire Capteurs et Architectures Electroniques

The Astrophysics Division of CEA Saclay has a long history in the development of alTe based pixelaled detection planes for X and gamma-ray astronomy, with time-resolved imaging and spectrometric capabilities. The last generation, named Caliste HD, is an all-in-one modular instrument that fulfills requirements for space applications, Its full-custom front-end electronics is designed to work over a large energy range from 2 keV to 1 MeV with excellent spectroscopic performances, in particular between 10 and 100 keV (0.56 keV FVVHM and 0.67 keV FVVHM at 13.9 and 59.5 keV). In the frame of the ORIGAMIX project, a consortium based on research laboratories and industrials has been settled in order to develop a new generation of gamma camera. The aim is to develop a system based on the Caliste architecture for post-accidental interventions or homeland security, but integrating new properties (advanced spectrometry, hybrid working mode) and suitable for industry. A first prototype was designed and tested to acquire feedback for further developments. The main difference between astronomy and nuclear applications is the radiation flux and energy-ranges involved. In this study, we particularly focused on spectrometric performances with high energies and high fluxes. Therefore, our device was exposed to energies up to 700 key (Ba-133, Cs-137) and we measured the evolution of energy resolution (0.96 keV at 80 keV, 2.18 key at 356 key, 3.33 keV at 662 key), Detection efficiency decreases after 150 key, as Compton effect becomes dominant. However, CALISTE is also designed to handle multiple events, enabling Compton scattering reconstruction, which can drastically improve detection efficiencies and dynamic range for higher energies up to 1408 keV (Na-22, Co-60, Eu-152) within a 1-mm thick detector. In particular, such spectrometric performances obtained with Eu-152 and Co-60 were never measured before with this kind of detector

Keywords: CdTe; Spectrometry; Charge-sharing; Nuclear instrumentation; Gamma-rays; X-rays; IMAGING SPECTROMETER; GAMMA CAMERA; PITCH; HD; instrumentation; gamma spectrometry; gamma imaging

Domains: Physics [physics]; Nuclear Experiment [nucl-ex]; Physics [physics]; High Energy Physics - Experiment [hep-ex]; Physics [physics]; Physics [physics]; Instrumentation and Detectors [physics.ins-det]

S. Dubos, Hermine Lemaire, S. Schanne, O. Limousin, Frédérick Carrel, et al.. ORIGAMIX, a CdTe-based spectro-imager development for nuclear applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2015, 787, pp.302 - 307. ⟨10.1016/j.nima.2014.12.111⟩. ⟨hal-01864078⟩