Measurement of the Li8 half-life

We report a new measurement of the Li8 half-life using a plastic scintillator and an ultrafast waveform digitizing module. The result, T1/2=(838.40±0.36)ms, improves by a factor of 2.5 the most precise result obtained so far and is furthermore deduced with negligible corrections due to dead time.Ministerio de Ciencia e Innovación FPA2008-0468

Espadon, an R package for automation, exploitation and processing of DICOM files in medical physics and clinical research

International audienceIntroduction: One of the main issues in the field of clinical research is to enhance clinical databases with information from imaging (CT, MR, PET-scan), contouring (RTstruct), or produced by TPS such as dose distribution (RTdose) or treatment plans (RTplan). To perform these analyses automatically, we propose the new open-source package “espadon”, developed in R environment. This package also opens up numerous perspectives for TPS-independant calculation, automation and processing of DICOM data. Results: The espadon package converts DICOM objects into espadon objects. Several tools have been developed to manipulate these objects and extract the desired information. In addition to decode DICOM files and pseudonomize them, the great advantage of espadon is that it presents the links between patient data (images, structures, treatment plans) in a didactic way, respecting the dates of the examinations. It can visualize volumes or structures in 2D or 3D, resample volumes, segment them, and change geometric frames of reference. It integrates dose-volume histogram functions on a selection, with Monte Carlo calculations of random shifts of contours. It offers the automatic calculation of several usual radiotherapy indices, as well as the calculation of Gamma and Chi indices. Conclusions: Espadon is a toolkit designed to be easily used by radiotherapists, medical physicists or students. Espadon's functions are implemented in an R script, and allow the automatic extraction or calculation of data from DICOM files, which can be used for statistical modelling or machine-learning in the R environment. This package is available on the Comprehensive R Archive Network (CRAN) repository

Low noise optimization of an electron beam current transformer for conventional radiotherapy up to ultra high dose rate irradiations

International audienceUltra high dose rate electron beams also known as FLASH radiotherapy is becoming of importance in several preclinial cancer treatment studies. However, due to the dose rate used during the irradiation sessions, no real time dose monitoring device exists to date. In this work, we present the development of a beam current transformer (BCT), from the choice of the ferromagnetic component and the realisation of the shielding to the design of a front-end electronics based on a trans-impedance circuit in order to perform a low noise optimization of the detector. The BCT prototype is able to monitor a beam current range from 1.2 μA to 200 mA with a rise time constant better than 20 ns and a droop rate of the signal below 0.05% · μs$^{-1}$. Preliminary in-situ measurements are also presented. The goal is to combine the BCT system which measure in real time the beam current, to an ionisation chamber monitoring the beam shape and position in order to provide a reliable dose monitoring system

A Comprehensive Analysis of the Relationship Between Dose Rate and Biological Effects in Preclinical and Clinical Studies, From Brachytherapy to Flattening Filter Free Radiation Therapy and FLASH Irradiation

International audiencePurposeFor many years, the effect of dose rate (DR) was considered negligible in external beam radiation therapy (EBRT) until very-high DR (>10 Gy/min) became possible and ultrahigh DR (>40 Gy/s) showed dramatic protection of normal tissues in preclinical experiments. We propose a critical review of preclinical and clinical studies to investigate the biological and clinical effects of DR variation in the range covering brachytherapy to flattening filter free EBRT and FLASH.Methods and MaterialsPreclinical and clinical studies investigating biological and clinical DR effects were reviewed extensively. We also conducted an in silico study to assess the effect of pulse DR (DRp), taking into account the mean time between 2 tracks during the pulse.ResultsPreclinical studies have shown that an increase in DR in the range of 0.01 to 20 Gy/min (not including ultralow or ultrahigh DR) resulted in decreased survival of both normal and tumor cells. This effect was attributed primarily to increasingly unrepaired “sublethal” DNA damage with increasing the DR. However, the models and irradiation conditions have often been very different from one radiobiological study to another. Moreover, the physical parameters on the spatial and temporal microstructure of the beam were not considered systematically. In particular, the DRp was rarely mentioned. The in silico studies showed that for the same average DR, increasing DRp induced an increase of mean track rates. These results could explain the presence of more complex damage when the DRp was increased within the range of DR considered, in relation to the time-dependent probability of accumulating unrepaired, “sublethal” DNA lesions in close proximity.ConclusionsKnowledge of the beam microstructure is critical to understanding the biological impact and the clinical outcomes of radiation at the DR commonly used in radiation therapy

Detection of recoil ion in the beta decay of laser oriented trapped radioactive isotopes for the MORA Project

International audienceThe Matter’s Origin from RAdioActivity (mora) project focuses on ion manipulation in traps and laser orientation methods for the searches of New Physics (np) in nuclear beta decay by precisely measuring the D correlation parameter. We predominantly have focussed here on the detection configuration of mora and alongside talked in detail about the Recoil Ion DEtection system (ride) and its characterization focusing mainly on the methods applied to achieve high order position correction

Les catégories religieuses et séculières de la martialité

Le dossier sur « les catégories religieuses et séculières de la martialité » s’organise autour de quatre enquêtes historiques et anthropologiques, conduites en Inde, en Chine, au Japon et en Indonésie. La martialité y apparaît comme une notion englobante qui permet d’inclure des termes plus spécifiques, la « guerre », le « militaire », les « arts martiaux », par une approche comparée au sein des mondes sociaux différents dans lesquels ils se déploient. Il s’agit aussi de décrire les processus sociaux de longue durée par lesquels les sphères du religieux et du politique s’autonomisent l’une à l’égard de l’autre, au prix du développement de traitements en apparence paradoxaux du registre guerrier qu’elles ont en commun. À ce premier ensemble s’ajoutent deux articles consacrés à des approches quantitatives du fait religieux au Portugal et en Argentine, ainsi qu’une réflexion sur les usages du mot « hérésie » dans la sociologie de Pierre Bourdieu. Enfin, la revue a demandé à trois auteurs de croiser leurs lectures sur la récente traduction en français du livre majeur d’Ernesto De Martino Morts et pleurs rituels

Gas scintillation chamber for superheavy elements detection at GANIL

In the paper we present scintillation-ionization detector (SID) - a new device for support of the superheavy elements (SHE) identification in the standard, complete fusion methods. We highlight problems with background effects in SHE production and their minimization by introducing SID to the detection set-up at GANIL. We also point possible application of this detector in alternative approach for superheavy elements production.SCOPUS: ar.jinfo:eu-repo/semantics/publishe