2025/08/06 by Kenichiro Tateishi, Tateishi, K., Yoji Saito +29
Chemistry · Engineering · Physics and Astronomy · #Advanced NMR Techniques and Applications #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Muon and positron interactions and applications #Nuclear Experiment (nucl-ex) #Nuclear physics research studies
paper · pdf · doi:10.48550/arxiv.2508.06549
openalex publication_date 2025/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Polarized targets evolved into indispensable tools in particle and nuclear physics. However, the polarized solid target is degraded by high-intense beam irradiation, known as radiation damage due to target heating and radical generation. We demonstrated a radiation-tolerant polarized solid target operating at room temperature. An annealing allows the spontaneous repair of the damage by reducing unwanted radicals. Using a single crystal of \it p-terphenyl doped with 0.01 mol% pentacene-\it d14, Dynamic Nuclear Polarization using photoexcited triplet electrons (Triplet-DNP) was applied to proton spins at room temperature and in 0.39 T. For the proof of concept, a deuteron beam with an energy of 135 MeV/u and the intensities of 107-109 counts per second (cps) was irradiated. The proton polarization was determined to be 3.0% ±0.2%\rm(stat.) ±0.1%\rm (sys.) from a scattering asymmetry. The polarization was almost not attenuated up to 109 cps, but the target crystal was yellowed. The visible-light absorption spectroscopy suggested irreversible radiation damage due to missing protons by the knock-out reaction. The room-temperature polarized solid target allows impractical experiments with the conventional target system, leading to a next-generation spin-dependent accelerator science.