Teng Jian

Time-Resolved Radiography using Chirp-Pulse Proton Beams

Protons accelerated by the target normal sheath acceleration (TNSA) mechanism have a wide energy spectrum and are called chirp-pulse protons. The numerical simulation of chirp-pulse proton radiography in an implosion process with single shot is carried out using the Monte Carlo method. Two different methods are proposed. The first method, proton framing radiography, uses a stack of radiochromic film layers as the detector. Each layer deposits protons with energy corresponding to the Bragg peak, which can record the transient state of the implosion process. The second method, proton streak radiography, uses an external magnetic field to deflect protons. Different energies correspond to different times. By using a slit before the magnetic field, one-dimensional spatial resolution and temporal resolution can be obtained. This method is more suitable for the diagnosis of the implosion process.

DD proton spectrum for diagnosing the areal density of imploded capsules on Shenguang III prototype laser facility

The primary DD proton spectrum is used for diagnosing the fuel-shell areal density ρR of imploded capsules on Shenguang III (SG-III) prototype laser facility for the first time. A charged particle spectrometer (CPS) with a CR39 nuclear track detector is used to measure the DD proton spectrum. The proton spectrum is determined from both the proton track and its size. A typical proton energy peak shift from 3.02 MeV to 2.6 MeV is observed in our experiment, which yields a maximum ρR larger than 6 mg/cm2.