XEMIS2 Liquid Xenon Compton Camera for Small Animal 3γ Medical Imaging: Scintillation Light Measurement

International audienceAn innovative XEnon Medical Imaging System, named XEMIS2, consisting of a liquid xenon (LXe) Compton camera, is developed to image small animal with 3γ imaging technique. The main objective of XEMIS2 involves the 3D localization of a radiopharmaceutical labeled with a specific radionuclide 44 Sc and the lessening of the administered radiotracer activity while preserving the image quality in oncology diagnosis. XEMIS2 is a monolithic single-phase detector with a large axial Field Of View (FOV), handling up to nearly 200 kg of ultra-high-purity liquid xenon. The XEMIS2 facility has been successfully conceived and developed at the SUBATECH laboratory. In XEMIS2, the scintillation signals provide the γ-rays interaction time. Furthermore, it is possible to pre-localize the γ-rays interactions spatially and then achieve the virtual fiducialization of the active volume by matching the scintillation signals with the ionization signals. In order to measure scintillation light, we distribute a set of PhotoMultiplier Tubes (PMTs) around the surface of the active area. Besides, a self-triggered scintillation light detection chain has been specially developed for XEMIS2 to carry out continuous data taking with negligible electronics dead-time. It is currently calibrated in the prototype XEMIS1. The calibration results indicate that the dedicated detection chain has a good performance in scintillation light measurement. XEMIS2 is recently under construction in a small animal medical imaging center CIMA, for further preclinical studies. I. INTRODUCTION OR the past few decades, nuclear medical imaging has extended from organ imaging for tumor localization of a variety of diseases and proven remarkable value in oncology Manuscript receive

Direct Measurement of Ionization Charges in Single-phase Liquid Xenon Compton Telescope for 3γ Medical Imaging

International audienceWe report the study of direct measurement of ionization charges in an innovative liquid xenon Compton camera of small animal imaging, named XEMIS2. It was combined with a novel 3γ medical imaging modality, showing a "TOF-like" PET performance, targeted to reduce the administered activity diametrically while preserving the image quality in oncology diagnosis. For the Compton cones reconstruction, the sequential low energy electronic recoils from Compton scattering of third γray (∼ 1 MeV) are measured directly from ionization signals under a high electric field of 2 kV/cm. The Geant4/NEST simulations studies reveal that the intrinsic energy and spatial resolutions of charges carriers measuring in liquid xenon are dominated respectively by the electron-ion recombination and the abstruse trajectory of recoil electrons. Besides, a novel ASIC front-end electronic, XTRACT, and data acquisition chain were developed, dedicated to optimizing the accuracy and efficiency of ionization signals measurement in XEMIS2. It allows a continuous read-out with ultra-low charges threshold and negligible deadtime per individual channel. The performing characteristics were calibrated in the prototype XEMIS1 under the XEMIS2 operation condition, showing a good homogeneous charge linearity response. Meanwhile, the data processing and analysis were developed, where the charge measurement has been optimized through Monte Carlo simulations. I. INTRODUCTION T HE personalized medicine as the heart of healthcare priorities of the 21 st century requires molecular imag-Manuscrip

30th Franco-Belgian conference of Pharmacochemistry

International audienc

SEIS first year: nm/s^2 (and less) broadband seismology on Mars and first steps in Mars-Earth-Moon comparative seismology. (Invited)

AGU Fall Meeting 2019 in San Francisco , 9-13 December 2019EIS/InSIght teamInSight is the first planetary mission with a seismometer package, SEIS, since the Apollo Lunar Surface Experiments Package. SEIS is complimented by APSS, which has as a goal to document the atmospheric source of seismic noise and signals. Since June 2019, SEIS has been delivering 6 axis 20 sps continuous seismic data, a rate one order of magnitude larger originally planned. More than 50 events have been detected by the end of July 2019 but only three have amplitudes significantly above the SEIS instrument requirement. Two have clear and coherent arrivals of P and S waves, enabling location, diffusion/attenuation characterization and receiver function analysis. The event¿s magnitudes are likely ¿ 3 and no clear surface waves nor deep interior phases have been identified. This suggests deep events with scattering along their final propagation paths and with large propagation differences as compared to Earth and Moon quakes. Most of the event¿s detections are made possible due to the very low noise achieved by the instrument installation strategy and the very low VBB self-noise. Most of the SEIS signals have amplitudes of spectral densities in the 0.03-5Hz frequency bandwidth ranging from 10-10 m/s2/Hz1/2 to 5 10-9 m/s2/Hz1/2. The smallest noise levels occurs during the early night, with angstrom displacements or nano-radian tilts. This monitors the elastic and seismic interaction of a planetary surface with its atmosphere, illustrated not only by a wide range of SEIS signals correlated with pressure vortexes, dust devils or wind activity but also by modulation of resonances above 1 Hz, amplified by ultra-low velocity surface layers. After about one half of a Martian year, clear seasonal changes appear also in the noise, which will be discussed. One year after landing, the seismic noise is therefore better and better understood, and noise correction techniques begun to be implemented, either thanks to the APSS wind and pressure sensors, or by SEIS only data processing techniques. These data processing techniques open not only the possibility of better signal to noise ratio of the events, but are also used for various noise auto-correlation techniques as well as searches of long period signals. Noise and seismic signals on Mars are therefore completely different from what seismology encountered previously on Earth and Moon

Performance of the ALICE Electromagnetic Calorimeter

International audienceThe performance of the electromagnetic calorimeter of theALICE experiment during operation in 2010–2018 at the Large HadronCollider is presented. After a short introduction into the design,readout, and trigger capabilities of the detector, the proceduresfor data taking, reconstruction, and validation are explained. Themethods used for the calibration and various derived corrections arepresented in detail. Subsequently, the capabilities of thecalorimeter to reconstruct and measure photons, light mesons,electrons and jets are discussed. The performance of thecalorimeter is illustrated mainly with data obtained with test beamsat the Proton Synchrotron and Super Proton Synchrotron or inproton-proton collisions at √s = 13 TeV, and compared tosimulations