Gallium oxide (Ga2O3) energy dependent scintillation response to fast neutrons and flash gamma-rays.

Gallium oxide is a newly emerged ultrawide bandgap (4.9 eV) semiconductor that is suitable as a combined electronics and radiation detection platform. We have experimentally demonstrated fast neutron and gamma-ray scintillation from Czochralski-grown ß-Ga2O3 in a recent series (October 2023) of experiments at the unmoderated pulsed neutron spallation source located at the Los Alamos Neutron Science Center. Using the neutron time-of-flight (TOF) technique and a fast-gated intensified CCD camera, we observed energy-dependent neutron scintillation for neutron energies ranging from 1 to 400 MeV, including the 14.1 MeV neutron energy relevant to D-T fusion. Neutron flux is quantified and calibrated by cascading the scintillator after the fission chamber, enabling a detailed analysis of temporal and energy-dependent characteristics of the scintillation events. A pronounced scintillation signal from the spallation gamma flash with a temporal full width of half maximum of ∼4 ns is indicative of the material's rapid response. Neutron energy dependent scintillation is observed using the TOF method at a 22.6-m distance from the neutron source. These results highlight the possibility of developing a Ga2O3 based fusion neutron diagnostic platform integrated with both scintillation and electronics functions on the integrated chip scale.

Direct Measurement of Resonances in

We have performed the first direct measurement of two resonances of the ^{7}Be(α,γ)^{11}C reaction with unknown strengths using an intense radioactive ^{7}Be beam and the DRAGON recoil separator. We report on the first measurement of the 1155 and 1110 keV resonance strengths of 1.73±0.25(stat)±0.40(syst) eV and 125_{-25}^{+27}(stat)±15(syst) meV, respectively. The present results have reduced the uncertainty in the ^{7}Be(α,γ)^{11}C reaction rate to ∼9.4%-10.7% over T=1.5-3 GK, which is relevant for nucleosynthesis in the neutrino-driven outflows of core-collapse supernovae (νp process). We find no effect of the new, constrained reaction rate on νp-process nucleosynthesis.

Evidence of a Near-Threshold Resonance in

A narrow near-threshold proton-emitting resonance (E_{x}=11.4 MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4 keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the ß-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11 keV) emission channels.

Neutron-upscattering enhancement of the triple-alpha process.

The neutron inelastic scattering of carbon-12, populating the Hoyle state, is a reaction of interest for the triple-alpha process. The inverse process (neutron upscattering) can enhance the Hoyle state's decay rate to the bound states of 12C, effectively increasing the overall triple-alpha reaction rate. The cross section of this reaction is impossible to measure experimentally but has been determined here at astrophysically-relevant energies using detailed balance. Using a highly-collimated monoenergetic beam, here we measure neutrons incident on the Texas Active Target Time Projection Chamber (TexAT TPC) filled with CO2 gas, we measure the 3α-particles (arising from the decay of the Hoyle state following inelastic scattering) and a cross section is extracted. Here we show the neutron-upscattering enhancement is observed to be much smaller than previously expected. The importance of the neutron-upscattering enhancement may therefore not be significant aside from in very particular astrophysical sites (e.g. neutron star mergers).

Randomized controlled trial comparing above- and below-elbow plaster casts for distal forearm fractures in children.

PURPOSE: Long arm cast is the method of immobilization after closed reduction of the fracture of the distal third of the forearm, although short arm cast has been used to immobilize the forearm by some orthopedic surgeons. We conducted this study to evaluate the rate of displacement, union time, complication, and cost of treatment between the above-elbow and below-elbow plaster cast groups. METHODS: We designed a prospective randomized controlled trial to compare above- and below-elbow casts for patients of distal forearm fracture aged 4-12 years. One hundred and one patients were presented to our institution during the period from 1st June 2007 to 31st May 2008. Twelve patients were excluded from the study. Eighty-nine patients were randomized into two groups. Four patients were lost to follow up. Hence, 85 patients, 42 in the above-elbow group and 43 in the below-elbow group, were analyzed. Informed consent was obtained prior to participation in the trial. The parameters to be studied were defined before treatment and noted in the pilot-tested pro forma and follow up was done. RESULTS: Among the 85 patients analyzed, randomization was successful. Pain and swelling on the next day and at one week following cast application was significantly higher (P = 0.000) in the above-elbow group. Three cases in the above-elbow group needed slitting of the plaster cast. Remanipulation was needed more often in the above-elbow group (9.5%). Although the cast index was not statistically significant (P = 0.054) between the groups, those who needed remanipulation had a larger cast index (0.80). The total cost of the treatment and the number of school days lost was significantly higher (P = 0.000) in the above-elbow group. CONCLUSION: Below-elbow cast treatment was comparable in terms of redisplacement, union time, and movement of the wrist to the above-elbow treatment. The complications rate and total cost was higher in the above-elbow plaster group, which could be a cost benefit if a below-elbow cast is used.