Time-Of-Flight methodologies with large-area diamond detectors for the effectively characterization of tens of MeV protons

TL;DR

This paper presents a novel diamond-based Time-Of-Flight detector optimized for high-energy ion characterization in challenging laser-matter interaction environments, demonstrating effective proton spectrum measurement amidst intense electromagnetic pulses.

Contribution

Introduction of a new polycrystalline diamond detector and advanced TOF methodology for accurate ion characterization under high electromagnetic interference.

Findings

Successful measurement of tens of MeV protons using the detector.

Effective discrimination of proton signals in high-EMP environments.

Calibration procedure for the high-energy portion of the proton spectrum.

Abstract

A novel detector based on a polycrystalline diamond sensor is here employed in an advanced Time-Of-Flight scheme for the characterization of energetic ions accelerated during laser-matter interactions. The optimization of the detector and of the advanced TOF methodology allow to obtain signals characterized by high signal-to-noise ratio and high dynamic range even in the most challenging experimental environments, where the interaction of high-intensity laser pulses with matter leads to effective ion acceleration, but also to the generation of strong Electromagnetic Pulses (EMPs) with intensities up to the MV/m order. These are known to be a serious threat for the fielded diagnostic systems. In this paper we report on the measurement performed with the PW-class laser system Vega 3 at CLPU (30 J energy, 10^21 W/cm2 intensity, 30 fs pulses) irradiating solid targets, where both tens of MeV ions and intense EMP fields were generated. The data were analyzed to retrieve a calibrated proton spectrum and in particular we focus on the analysis of the most energetic portion (E > 5.8 MeV) of the spectrum showing a procedure to deal with the intrinsic lower sensitivity of the detector in the mentioned spectral-range.