Row data of laser induced (γ,p) production of 47-Sc and 67-Cu in CLAPA, Peking University

The data set includes four files. The text file contains nuclear data, representing the radioactive signals from a high-purity germanium detector. The remaining three files pertain to electron data, detailing the magnetic field distribution of the magnet used to get election spectrum, the electron distribution at the magnet entrance, and the electron distribution at the magnet exit, respectively. The experiment was carried out at the Compact Laser Plasma Accelerator (CLAPA) laboratory of Peking University, which had a 200 TW 5 Hz Ti: sapphire laser system, to validate the feasibility of this laser-induced photonuclear method and estimate its efficiency. Monochromatic electrons accelerated by laser wakefield acceleration(LWFA) flew past various detectors before reaching the converter, then subsequently generated bremsstrahlung photons underwent (γ, p) reactions with the target. During the experiment, the laser system ran at moderate energy(1.8 J on gas target), delivering laser pulses with a focused intensity of about 1.5 × 1019 W/cm2 and a full width at half maximum(FWHM) duration of 30 fs. The laser beam was focused to 21×23 μm FWHM at the nozzle. The gas jet emitted from the nozzle comprised 99.9% He2. After being expelled at a pressure of 30 bar, it underwent a supersonic expansion and would perform LWFA upon encountering a laser pulse. The electron charge was measured by a Turbo Integrating Current Transformer (Turbo-ICT). A 20×23 cm dipole magnet with 0.8 T peak magnetic field was settled 100 cm away from the gas target to measure the electron energy spectrum. At the entrance and the exit of the magnet, there was a scintillator( Gd_2O_2S:Tb) placed respectively. A CCD imaging system with two cameras recorded the divergences and the pointing angles of the beams at the entry[see the sample image in Fig.~\reffig:figure1(b)] and the energy spectrum at the exit. Because the decay signals of both isotopes are within the range of 150-200 keV and will undergo significant self-absorption within the target material, we chose our targets as 2 × 2 cm squares made from nat-Ti and nat-Zn with a thickness of 2 mm, which could also help to maintain radiation safety during experiments. A nat-Ta converter with the same shape as the target was put at the entrance of the magnet directly facing the target which was positioned at the exit of the magnet. Setting the laser repetition rate at 0.2 Hz to maintain the vacuum, we irradiated each target for 20 min, approximately 240 laser shots. Electron parameters were then analyzed, and it turned out that the electrons with energies exceeding 10 MeV typically carried charges ranging from 250 -350 pC while featuring a quasi-monoenergetic peak at around 220 MeV, and the charge within this peak was about 110 pC.