Timepix3 detector and Geant4-based simulations for gamma energy detection in Laser Produced Plasmas

Abstract

The particular physics of Laser Produced Plasmas (LPP) needs some diagnostic requirements. Specifically, the X-ray monitoring of the plasma is known to be difficult since typically X-ray emissions are concentrated in bursts from a few tens of ps to few ns, based on the power and pulse time width of the laser. Therefore, the energy measurement of the radiation coming from a single experimental run is basically unfeasible using conventional techniques. Additional particles can be produced from LPP experiments, especially high energy gamma photons and electrons. As a case study in recent experiments, carried out on VEGA-2 laser facility (CLPU, Salamanca, Spain), the aim was to produce neutrons through photonuclear reactions on different types of solid targets. We have used the Timepix3 chip, in a "side-on" configuration, in order to produce a quick estimate of the gamma photons energy involved in the reactions. This detector, based on silicon, is realized with a single chip of 256 × 256 pixels bump-bonded with a 14 mm × 14 mm × 300 µm silicon layer. Interaction of gammas with the detector in this configuration produces some characteristic clusters of pixels and, for each cluster, a variety of physical and morphological parameters can be defined. Based on some of these parameters, we have characterized the detector response using some known laboratory gamma sources and the related Geant4 simulations. This allows quick energy discrimination for the gamma photons coming from different experimental runs. K: Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc); Nuclear instruments and methods for hot plasma diagnostics; Plasma diagnostics -interferometry, spectroscopy and imaging; Simulation methods and programs 1Corresponding author.

Combined Spectroscopy System Utilizing Gas Electron Multiplier and Timepix3 Technology for Laser Plasma Experiments

“…The former is likely attributable to the high-energy tail of the thermal spectrum previously measured using the GEM camera. However, the TPX3 can also work in the side-on configuration and multi-photon regime to also detect the gamma rays, as was made previously in the occasion of the VEGA-2 experimental campaign, where gamma photons of 3 MeV have been identified [20].…”

Diagnostics for ultrashort X-ray pulses using silicon trackers

“…Therefore, a 2D pixel detector must be deployed as its pixel plane is parallel to the incident X-rays, i. e., the "side-on" configuration. The "side-on" configuration also allows the electron trajectories fully developed in the sensor body [28].…”

“…Recently, some new methods based on electron track detection have been proposed [26][27][21] [28] to diagnose the spectrum of ultrashort gamma pulses of 1 − 100 MeV with better efficiency and fast post-shot processing. These studies show the potential to diagnose high fluence rate X-ray pulses of a several hundred keV with electron track detection.…”