With the rapid development of advanced manufacturing industries, there is a great demand for high-resolution imaging methods applicable for metal materials in the field of nondestructive testing (NDT). Due to the large focal spot and broad spectrum characteristics of a bremsstrahlung-based gamma-ray source, the resolution of the traditional absorption-based gamma-ray imaging method is limited...
A flat distribution in the energy spectrum and a spatial distribution with a small beam size, Flat-Laser Compton Scattering Gamma-ray (F-LCS) beam, has been generated by exciting a circular motion of an electron beam for a multi-isotope CT Imaging application through Nuclear Resonance Fluorescence (NRF) method. A proof-of-principle experiment to generate F-LCS beam has been carried out at the...
Photon-induced fission product yield (FPY) studies were conducted on 238 U. Fission was induced at the Triangle Universities Nuclear Laboratory’s High Intensity γ-ray Source using monoenergetic γ-rays of Eγ = 8.0, 9.8, 11.2, 13.0, and 15.5 MeV. The FPYs of short-lived isotopes were measured using a RApid Belt-driven Irradiated Target Transfer System (RABITTS). The RABITTS is a fully automated...
The electric and magnetic polarizabilities ( 𝛼$_{𝐸1}$ and 𝛽$_{𝑀1}$ ) are fundamental quantities encoding the internal structure of nucleons. They characterize the response of the nucleon to an external electromagnetic field and can be probed using Compton scattering processes. From chiral effective field theories ( 𝜒 EFTs) [1,2], the angular distributions of the Compton differential cross...
Since they have been proposed, laser-plasma accelerators have interested the scientific community for their ability to generate electric fields exceeding the ones of Linacs and RF cavities. Several efforts have been made in order to produce monochromatic electron beams and to increase their maximum energy, often at the expense of the charge. However, some applications like femtosecond...
Neutron resonance diagnosis technology has been developed worldwide for several decades. Most previous studies have used neutrons provided by large-scale particle accelerators. As a new approach to neutron generation, the Laser-Driven Neutron Source (LDNS) has been studied to obtain neutron pulses with the ultra-short pulse duration and high flux[1]. By setting a converter at downstream of the...
The interaction between photons and electrons is a well-studied phenomenon known as Compton scattering. Based on this mechanism, Compton light sources operating in the x-ray and gamma-ray regions have been developed by colliding a laser beam with an electron beam. One such example is the High-Intensity Gamma Source (HI$\gamma$S) at Triangle Universities Nuclear Laboratory (TUNL). Resonant...
The polarization of the gamma-ray beam plays a critical role in experimental photonuclear research by probing angular momentum. For example, the $^{80}$Se(g,n)$^{79}$Se differential reaction cross-section can be measured as a function of the azimuthal angle relative to the plane of polarization. This provides information about the electromagnetic multipolarities involved in the reaction. [1]...
Frequencies are the physical quantity that can be measured with highest precision with applications ranging from clock transitions over search for dark matter to high precision measurements and tests of fundamental constants. Currently, the most precise clock transitions are optical transitions [1]. However, there are also a few nuclear transitions featuring Q-factors on a similar level or...
For the N=50 isotones $^{90}$Zr and $^{92}$Mo, additional isovector spin-flip M1 (IVSM1) strength could be expected for $^{92}$Mo in comparison to $^{90}$Zr because of the two additional protons in the proton g$_{9/2}$ orbital above the closed pf shell. In addition, the IVSM1 resonance is closely related to Gamow-Teller strengths and can serve to constrain the calculation of electron-capture...
Nuclear resonance fluorescence has significant potential in the identification and measurement of isotopes due to its specificity for different nuclei. This study explored the NRF pinhole imaging technique through Monte Carlo simulations in the detection of $^{239}$Pu samples. By designing and optimizing key parameters of the pinhole imaging system, including the direction of incident photons,...
Energy spectra for prompt neutrons emitted from actinide targets irradiated with $\gamma$-ray beams have been measured near the ($\gamma$, n) reaction threshold by Mueller et al. [1]. Examples of measurements of the total cross sections for prompt neutron emission from photofission and neutron multiplicities as a function of the incident $\gamma$-ray beam energy are reported by [2, 3]. The...
The time distribution and energy spectra of the delayed neutrons emitted from fission
provide information about the excitation energies of the fission fragments and reveal structure properties of the fragments. In addition, detection of delayed neutrons and γ-rays provide clean signatures for identifying fissile materials in γ-ray beam-based cargo scanners. Accurate prompt and delayed...
The giant dipole resonance (GDR) is a fundamental nuclear excitation that dominates the dipole response of all nuclei. The present work aims at quantifying the branching ratio of the decay of the GDR of $^{154}$Sm and $^{140}$Ce, via emission of γ-rays or neutrons as a function of excitation energy. Simultaneously to a nuclear resonance fluorescence (NRF) measurement an activation measurement...
