User profiles for Heishun Zen

Heishun Zen

Associate Professor, Institute of Advanced Energy, Kyoto University
Verified email at iae.kyoto-u.ac.jp
Cited by 1295

[HTML][HTML] Full characterization of superradiant pulses generated from a free-electron laser oscillator

H Zen, R Hajima, H Ohgaki - Scientific Reports, 2023 - nature.com
The detailed structure of superradiant pulses generated from a free-electron laser (FEL)
oscillator was experimentally revealed for the first time. Owing to the phase retrieval with a …

High-extraction-efficiency operation of a midinfrared free electron laser enabled by dynamic cavity desynchronization

H Zen, H Ohgaki, R Hajima - Physical Review Accelerators and Beams, 2020 - APS
The extraction efficiency is one of the key parameters of an oscillator-type free electron laser
(FEL). An extraction efficiency higher than 5% was observed with the midinfrared (MIR) FEL …

Present status and perspectives of long wavelength free electron lasers at Kyoto University

H Zen, S Suphakul, T Kii, K Masuda, H Ohgaki - Physics Procedia, 2016 - Elsevier
A mid-infrared Free Electron Laser (FEL) named as Kyoto University FEL (KU-FEL) has been
developed for energy-related research at Institute of Advanced Energy, Kyoto University. …

Record high extraction efficiency of free electron laser oscillator

H Zen, H Ohgaki, R Hajima - Applied Physics Express, 2020 - iopscience.iop.org
The highest extraction efficiency (9.4%) of a free electron laser (FEL) oscillator has been
achieved at the midinfrared FEL facility of Kyoto University. Because of the interaction between …

Generation of high energy gamma-ray by laser Compton scattering of 1.94-μm fiber laser in UVSOR-III electron storage ring

H Zen, Y Taira, T Konomi, T Hayakawa, T Shizuma… - Energy Procedia, 2016 - Elsevier
Abstract Development of a laser Compton scattering (LCS) gamma-ray source in the
UVSOR-III storage ring has been proposed to perform basic research on non-destructive three …

[HTML][HTML] Dissociation process of polyalanine aggregates by free electron laser irradiation

H Okumura, SG Itoh, H Zen, K Nakamura - PLoS One, 2023 - journals.plos.org
Polyalanine (polyA) disease-causative proteins with an expansion of alanine repeats can be
aggregated. Although curative treatments for polyA diseases have not been explored, the …

Lasing at 12 µm mid-infrared free-electron laser in kyoto university

H Ohgaki, T Kii, K Masuda, H Zen… - Japanese Journal of …, 2008 - iopscience.iop.org
Laser amplification using a 12 µm mid-infrared free-electron laser (MIR-FEL) was observed
at the Institute of Advanced Energy (IAE), Kyoto University. A 25 MeV electron beam of 17 A …

[HTML][HTML] Demonstration of tomographic imaging of isotope distribution by nuclear resonance fluorescence

H Zen, H Ohgaki, Y Taira, T Hayakawa, T Shizuma… - AIP Advances, 2019 - pubs.aip.org
Computed Tomography (CT) using X-ray attenuation by atomic effects is now widely used
for medical diagnosis and industrial non-destructive inspection. In this study, we performed a …

Measurement of the spatial polarization distribution of circularly polarized gamma rays produced by inverse Compton scattering

…, T Nambu, M Okuizumi, T Shizuma, M Omer, H Zen… - Physical Review A, 2023 - APS
Inverse Compton scattering of polarized laser photons by energetic electrons is an excellent
method to generate polarized gamma rays. A 100% polarized laser can generate 100% …

Demonstration of a high-field short-period undulator using bulk high-temperature superconductor

R Kinjo, M Shibata, T Kii, H Zen, K Masuda… - Applied Physics …, 2013 - iopscience.iop.org
The first ever practical-level field generation for an undulator consisting of bulk high-temperature
superconductors is reported and described. A high-field short-period undulator enables …