Thomson parabola ion spectrograph with the microchannel plate image converter in investigations of high-Z laser plasma ion sources

Abstract

The results of experimental investigations on ion production from tantalum targets, made with the application of the Thomson parabola ion spectrograph (TP) to an image converter equipped with a microchannel plate of the size of 70×90 mm2, are presented. In the experiments, the iodine photodissociation laser system PERUN (λ=1.315 μm, EL≤50 J, τ∼350–650 ps. I≤1015 W/cm2) was used for ion generation. The TP can give useful information about physical processes, ion species, their energies, and charge states from a single laser shot. The results obtained are compared with the results of measurements made with an electrostatic ion energy analyzer and charge collectors and they are used to estimate the Ta ion yield with an average charge state of 40+. The obtained values are N∼2.6×1011 sr−1.

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

“…This device has found applications in studying the acceleration of ions by ultra-intense lasers. [1][2][3][4] Similar devices have been used in magnetic fusion research. 5 The device described in this paper was designed for the Multiterawatt (MTW) laser facility [6][7][8] at the Laboratory for Laser Energetics (LLE).…”

“…(3) The sensitivity of Fujifilm imaging plates (IP), used as a detector in the device, was measured as a function of energy for protons, deuterons, and alpha particles from the SUNY Geneseo Pelletron accelerator. (4) The device was used to measure the energy spectrum of laser-produced protons at the MTW facility.…”

Development and calibration of a Thomson parabola with microchannel plate for the detection of laser-accelerated MeV ions

“…Barabash et al, 17 Olsen et al, 18 and W. Mróz et al 19 presented TP data about ions accelerated by microsecond, nanosecond, and picosecond lasers, respectively. The most striking publication was the detection of quasimonoenergetic ions produced by the interaction of a high-intensity laser with structured thin titanium foils by Schwoerer et al 20 Section II describes the working principle and the setup of the TP and gives a comparison to other detectors often used.…”

A pixel detector system for laser-accelerated ion detection

“…To determine the total detection efficiency of such a combined diagnostic system, collection efficiencies of the camera lens, the quantum efficiency of the CCD camera at the phosphor emission wavelength and sensitive area of the MCP have also to be considered. A detection efficiency of only 0.7% has, thus, been reported for a proton energy of 13 MeV which increases to about 10% for 2 MeV for a typical MCP-based system [25]. The typical dead time of a single MCP channel of 10 ms when operated in pulsed mode, exceeds the duration of a laser-accelerated ion pulse by several orders of magnitude.…”

“…A directly competing detector system for the detection of laser-accelerated ion spectra behind a spectrometer are MCPs coupled to a phosphor screen whose light output is detected by a CCD camera [9][10][11]25]. The single ion sensitivity of a MCP-based detector system depends on the secondary electron emission (SEM) probability which scales with the energy loss of incident particles.…”