Response functions of imaging plates to photons, electrons and 4He particles

Abstract

Imaging plates from Fuji (BAS-SR, MS, and TR types) are phosphor films routinely used in ultra high intensity laser experiments. However, few data are available on the absolute IP response functions to ionizing particles. We have previously measured and modeled the IP response functions to protons. We focus here on the determination of the responses to photons, electrons, and (4)He particles. The response functions are obtained on an energy range going from a few tens of keV to a few tens of MeV and are compared to available data. The IP sensitivities to the different ionizing particles demonstrate a quenching effect depending on the particle stopping power.

High-Brightness High-Energy Electron Beams from a Laser Wakefield Accelerator via Energy Chirp Control

“…The laser-accelerated e-beams were deflected by a 90-cm-long tunable dipole electromagnet with a maximum magnetic field of 1.1 Tesla, and measured by a Lanex phosphor screen imaged onto an intensified chargecoupled device (ICCD) camera in a single shot, which was cross-calibrated by using a calibrated imaging plate and an integrating current transformer (ICT) to measure the charge of the e-beams [19]. The uncertainty of the measured e-beam charge was estimated to be within ±12%.…”

Interaction of relativistically intense laser pulses with long-scale near critical plasmas for optimization of laser based sources of MeV electrons and gamma-rays

“…The dispersion curve that accounts for this gradient dynamics was used to simulate electron trajectories. The response of BASF MS IPs to an electron impact accounting for the electron energy and angle of incidence was taken from [41,42].…”

“…A rather poor dispersion of the end-on IP, where signals from electrons with energies between 12 and 100 MeV are accumulated, still allowed for the registration of the pronounced effect of the effective laser energy coupling into electrons in NCD-plasmas and their acceleration up to tens of MeVs (see raw electron spectra measured by ES1 end-on IP for shots 31,34,38,44). Data from the absolute calibration of the image plates for relativistic electrons with energies up to 10 MeV and the dependence of the absolute signal on the electron angle of incidence onto the IP [41,42] were used to evaluate the number of electrons in different energy ranges. Additionally, the IP-signal was corrected for energies above 10 MeV where the stopping power increases by a factor of 2 between 10 and 100 MeV due to radiation losses.…”

Recent developments in the Thomson Parabola Spectrometer diagnostic for laser-driven multi-species ion sources

“…Since the response of the detectors for different charged particles depends heavily on the ion species and energy, calibration functions for the most common types of TPS detectors and particles have been obtained experimentally by different groups. Some of the relevant works include calibration of Image Plates [30] for protons [31][32][33], deuterons [34,35], alpha particles [35,36] and carbon ions [37], and the calibration of MultiChannel Plates for protons [23,38] and carbon ions [39].…”