Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles

Abstract

A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6–3.2 MeV

“…Although previous work [6][7][8] has been carried out to determine the response function of Fuji TR IPs to laser accelerated protons, response values extrapolated from the different response functions vary by at least one order of magnitude. Therefore, we have conducted an experiment based on a new technique with a 3.5 MV proton accelerator.…”

“…4,5 Imaging plates (IPs) are ionizing particle sensitive detectors well suited for the characterization of laser-accelerated proton beams. [6][7][8] They are used in experiments where a spatial resolution of tens of μm, 8 a sensitivity to a few protons or a detector insensitive to the electromagnetic fields accompanying a laser shot, are needed. However IPs were originally developed for imaging techniques 9 only and quantitative experimental data are still needed to determine absolute proton fluxes.…”

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].…”

A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and ρR are determined in thin-shell inertial-confinement-fusion implosions

“…In particular, the charged particle spectrometers (CPS) 5,7 operated at the OMEGA laser facility 10 are positioned at fixed locations and are limited to proton yields above 10 8 . The wedge range filter (WRF) proton spectrometers 7,11 are compact and portable, and can be fielded simultaneously at multiple positions around implosions at OMEGA and the National Ignition Facility (NIF), 12 but their energy range for proton detection is limited to [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] MeV. The operating parameters of exista) Electronic mail: mrosenbe@mit.edu ing proton spectrometers used at OMEGA and NIF, in comparison to the step range filter (SRF) proton spectrometer presented in this work, are summarized in Table I.…”

“…[1][2][3][4] Several diagnostic techniques have been used, including magnet-based spectrometers 1,5,6 and ranging filters, 7 with detection substrates consisting of image plates 8 or the solid-state nuclear track detector CR-39. 7 Though the existing suite of charged-particle spectrometers is able to detect protons over a wide range of energies, from ∼0.1 to ∼30 MeV, and at a variety of incident particle fluences, 9 there are limitations to their usage that render them unavailable for certain applications.…”