William A. Peters

The ¹⁵O(α,γ)¹⁹Ne reaction is an important trigger reaction leading to the rapid proton (rp) capture process in X-ray bursts. The primary uncertainty in determining its astrophysical rate is the uncertain α branching ratios of levels near E_x = 4.1 MeV in ¹⁹Ne. These states have been populated in a study of the ²⁰Ne(p, d)¹⁹Ne reaction, and α branching ratios are reported in this manuscript.

5573 Background: We established the olaparib tablet maximum tolerated dose, dose limiting toxicities (DLT’s) and response to therapy of carboplatin, paclitaxel and olaparib tablet given simultaneously, reported at ASCO 2014. This abstract will include data from both the phase 1b and the phase 2 expansion. Methods: A total of 54 subjects were evaluated in this trial, 14 in phase 1b and 40 in phase 2. Eligibility required measurable disease, adequate organ function and ECOG performance status of ≤ 2. Subjects had to have failed first line platinum containing chemotherapy. BRCA testing was conducted as available. Subjects received the metronomic therapy of paclitaxel 60mg/m2 IV and carboplatin AUC 2 IV weekly, 3 weeks out of 4, and olaparib tablets at the MTD of 150 mg bid administered orally for 3 consecutive days (D1-D3), every week for each cycle. Subjects were assessed for toxicity and response according to the protocol. Subjects that reached a confirmed complete remission were transitioned to olaparib t...

The goal of this proposal is to enable neutron detection for precision Non-Destructive Assays (NDAs) of actinide-fluoride samples. Neutrons are continuously generated from a UFx matrix in a container or sample as a result of the interaction of alpha particles from uranium-decay α particles with fluorine nuclei in the matrix. Neutrons from 19F(α,n)22Na were once considered a poorly characterized background for assays of UFx samples via 238U spontaneous fission neutron detection [SMI2010B]. However, the yield of decay-α-driven neutrons is critical for 234,235U LEU and HEU assays, as it can used to determine both the total amount of uranium and the enrichment [BER2010]. This approach can be extremely valuable in a variety of safeguard applications, such as cylinder monitoring in underground uranium storage facilities, nuclear criticality safety studies, nuclear materials accounting, and other nonproliferation applications. The success of neutron-based assays critically depends on an accurate knowledge of the cross section of the (α,n) reaction that generates the neutrons. The 40% uncertainty in the 19F(α,n)22Na cross section currently limits the precision of such assays, and has been identified as a key factor in preventing accurate enrichment determinations [CRO2003]. The need for higher quality cross section data for (α,n) reactions has been amore » recurring conclusion in reviews of the nuclear data needs to support safeguards. The overarching goal of this project is to enable neutron detection to be used for precision Non- Destructive Assays (NDAs) of actinide-fluoride samples. This will significantly advance safeguards verification at existing declared facilities, nuclear materials accounting, process control, nuclear criticality safety monitoring, and a variety of other nonproliferation applications. To reach this goal, Idaho National Laboratory (INL), in partnership with Oak Ridge National Laboratory (ORNL), Rutgers University (RU), and the University of Notre Dame (UND), will focus on three specific items: (1) making a precision (better than 10 %) determination of the absolute cross section of the 19F(α,n)22Na reaction as a function of energy; (2) determining the spectrum of neutrons and γ-rays emitted from 19F(α,n)22Na over an energy range pertinent to NDA; and (3) performing simulations with this new cross section to extract the neutron yield (neutrons/gram/second) and resulting neutron- and gamma ray-spectra when α particles interact with fluorine nuclei in actinide samples, to aid in the design and reduce uncertainty of future NDA measurements and simulations.« less

Galactic 26Al is the first radioactive nucleus to be positively identified by $\gamma${}-ray astronomy with detection of the 1.809~MeV $\gamma${} ray associated with its decay. This nucleus is destroyed in astrophysical environments in the 26Al(p,$\gamma${})27Si and inelastic 26Al+p scattering reactions where properties of 27Si levels determine reaction rates. To investigate these properties, elastic and inelastic 26Al+p scattering reactions were measured between Ec.m.~= 0.5\char21{}1.5~MeV at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). A candidate for a new resonance in the 26Al(p,$\gamma${})27Si reaction was identified. Upper limits were also set on the strengths of postulated resonances and on the cross section of the inelastic reaction, but there is little effect on current reaction rate calculations.