Enhanced production of 99Mo in inverse kinematics heavy ion reactions

The reaction of a 100Mo beam at 12 MeV/nucleon impinging on a 4He gas-cell target was performed. The 99Mo alongside other coproduced isotopes were collected after the gas target on an aluminum catcher foil and their respective radioactivities were measured by offline γ-ray analysis. In this contribution, preliminary experimental results which are used to discuss the possibility of optimal large-scale production conditions of the produced radioisotopes are presented.

Pump-Probe Delay Controlled by Laser-dressed Ionization with Isolated Attosecond Pulses

In a recent work [1], we demonstrated how laser-dressed ionization can be harnessed to control with attosecond accuracy the time delay between an extreme-ultraviolet (XUV) attosecond pulse train and an infrared (IR) femtosecond pulse. In this case, the comb-like photoelectron spectrum obtained by ionizing a gas target with the two superimposed beams exhibits peaks oscillating with the delay. Two of them can be found to oscillate in phase quadrature, allowing an optimal measurement and stabilization of the delay over a large range. Here we expand this technique to isolated attosecond pulses, by taking advantage of the delay-modulation of attosecond streaking traces. Although the photoelectron spectrum contains no peaks in that case, it is possible to reconstruct the pump-probe delay by simply monitoring the mean energy of the spectrum and the amplitude at this energy. In general, we find that active delay stabilization based on laser-dressed ionization is possible as long as the XUV pulses are chirped.

A novel approach to medical radioisotope production using inverse kinematics

The inverse kinematics methodology using a gas target has been applied to produce medically important radionuclides at the Cyclotron Institute at Texas A&M University. The production of the theranostic radionuclide 67Cu (T1/2 = 62 h) through the reaction of a 70Zn beam at 15 MeV/nucleon with a hydrogen gas target was performed. The activities at end of irradiation and the thick target yield were obtained for 67Cu. A test using the forward-focused neutrons from the primary reaction to irradiate natZn to produce 67Cu is also presented.

Reconsideration of the Adsorption/Desorption Characteristics with the Influences of Water in Unconventional Gas Systems

The exploration and development of unconventional resources have been of growing interest in the industry in recent years. It is widely known that the adsorption and desorption mechanisms of unconventional gas have great significance for gas accumulation and exploration. However, major researches based on the mechanism of solid-gas interface have failed to reveal it completely, which introduce large discrepancies between actual and predicted production. In this paper, the mechanism of solid-liquid-gas adsorption and desorption interface is enlightened to describe the characteristics of unconventional gas. The validity of the proposal was verified preliminarily by building a conceptual model which redefines the gas-water distribution. Furthermore, the possibility of production of gas trapped in micropores was first investigated. The findings of this study can help for better understanding of the adsorption, desorption, and production mechanisms and in unconventional gas system. Accordingly, the explanation of variation between experiment result and actual production rate even with physical parameters was reasonable in theory. Therefore, this work should provide a basis for improving the accuracy of production predictions in actual reservoirs and should assist analysts in determining reasonable unconventional gas target.

The Study of the 22Ne(α,γ)26Mg Reaction at LUNA

The 22Ne(α,γ)26Mg reaction is the competitor of the 22Ne(α,γ)25Mg reaction, an effective neutron source for element synthesis through s-process in massive and AGB stars. Currently the ratio between the rates of these two reactions is poorly constrained because of the high uncertainty affecting the 22Ne(α,γ)26Mg reaction rate. Indeed a wide range of values for the 395 keV resonance strength (10−15 - 10−9 eV) is reported in literature, all of them from indirect measurements. The present study represents the first direct measurement which was performed at the ultra-low background LUNA laboratory. An high efficiency detector was installed at the gas target beamline of LUNA 400kV accelerator and the 99% enriched in 22Ne neon gas was irradiated with a 399.9 keV α-beam. No significant signal was detected in the 22Ne(α,γ)26Mg region of interest, thus an upper limit for the 395 keV resonance strength was estimated. A new campaign was completed in August 2019 with an improved setup and some details are reported here.

Laser wakefield accelerated electron beams and betatron radiation from multijet gas targets

Laser Plasma Wakefield Accelerated (LWFA) electron beams and efficiency of betatron X-ray sources is studied using laser micromachined supersonic gas jet nozzle arrays. Separate sections of the target are used for the injection, acceleration and enhancement of electron oscillation. In this report, we present the results of LWFA and X-ray generation using dynamic gas density grid built by shock-waves of colliding jets. The experiment was done with the 40 TW, 35 fs laser at the Lund Laser Centre. Electron energies of 30–150 MeV and 1.0 × 108–5.5 × 108 photons per shot of betatron radiation have been measured. The implementation of the betatron source with separate regions of LWFA and plasma density grid raised the efficiency of X-ray generation and increased the number of photons per shot by a factor of 2–3 relative to a single-jet gas target source.