12 research outputs found
HARPO: a TPC as a gamma-ray telescope and polarimeter
A gas Time Projection Chamber can be used for gamma-ray astronomy with
excellent angular-precision and sensitivity to faint sources, and for
polarimetry, through the measurement of photon conversion to pairs. We
present the expected performance in simulations and the recent development of a
demonstrator for tests in a polarized photon beam.Comment: SPIE Astronomical Telescopes + Instrumentation, Ultraviolet to gamma
ray, Montr\'eal, Canada 2014. v2: note added in proof. Copyright 2014 SPIE.
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Performance Analysis of UHF RFID Tags Dedicated to Power Supply Cords
International audienc
ILD silicon tungsten electromagnetic calorimeter first full scale electronic prototype
International audienceThe “long slab” is a new prototype for the SiW-Ecal, a silicon tungsten electromagnetic calorimeter for the International Large Detector (ILD) at the future International Linear Collider (ILC). The new prototype has been evaluated with cosmics, radioactive sources and with 3 GeV electrons in beam tests at the DESY facility, Hamburg. A channel-wise calibration has been achieved, at different angles of incidence of the beam on the sensors. Using data collected at non-normal incidence, the signal of particles traversing adjacent pixels were used to estimate the absolute value of the trigger threshold in units of mips. This new prototype provides us many hints on how to improve the design of the front-end electronics. It is also a convenient tool to estimate the critical characteristics of ILD SiW-Ecal (like power consumption, cooling, readout time, etc.) and to optimise the future design of the detector
First measurement of the polarisation asymmetry of a gamma-ray beam between 1.7 to 74 MeV with the HARPO TPC
International audienc
Electronics for HARPO: Design, development and validation of electronics for a high performance polarised-Gamma-ray detector
International audienceWe designed and built an experimental apparatus based on a time projection chamber, a novel scheme for high performance γ-ray astronomy and polarimetry in the γ → e+e- regime. This presentation focuses on the electronics aspect of the detector and, in particular, on the versatile dedicated trigger system that we have developed which allowed us to take data on beam with a high γ-conversion signal efficiency and a high rejection factor for single tracks and upstream conversion background events. Our scheme allows for the selective collection of γ conversions in a high-background-rate environment, such as that which is present in orbit, with a fine 3D imaging of the events and very low (in particular electronics) background, at a mild cost in terms of the number of electronics channels and therefore of electrical power consumption