Charge-state distribution of Li ions from the β\beta decay of laser-trapped 6^{6}He atoms

Background: The accurate determination of atomic final states following nuclear $\beta$ decay plays an important role in many experiments. In particular, the charge state distributions of ions following nuclear $\beta$ decay are important for determinations of the $\beta-\nu$ angular correlation with improved precision. Purpose: Our measurement aims at providing benchmarks to test theoretical calculations. Method: The kinematics of Li$^{n+}$ ions produced following the $\beta$ decay of $^6{\rm He}$ within an electric field were measured using $^6{\rm He}$ atoms in the metastable $(1s2s,~{^3S_1})$ and in the $(1s2p,~{^3P_2})$ states confined by a magneto-optical trap. The electron shake-off probabilities were deduced including their dependence on ion energy. Results: We find significant discrepancies on the fractions of Li ions in the different charge states with respect to a recent calculation and discuss a plausible explanation. We also point out that there is no explanation for a large discrepancy between the same calculation and a previous measurement of the Li-ion energy dependence of the charge distribution from decays of the electronic ground state

Novel Investigation of Iron Cross Sections via Spherical Shell Transmission Measurements and Particle Transport Calculations for Material Embrittlement Studies. Quarterly Status Report 5

Previously, measurements were made of the transmission of 14 MeV neutrons through various spherical shell thicknesses of iron in a comprehensive investigation at Lawrence Livermore National Laboratory (LLNL) about 30 years ago. Two of these spheres, composed of hemispherical sections, have appropriate dimensions for the lower energy neutron measurements that we propose to make. Due to their interest in our experimental results, LLNL has agreed to make these hemispheres available for our work. Those hemispheres have been shipped. In addition, a spherical iron shell, composed of two hemispherical sections with an annular thickness of approximately 1 inch, was fabricated at NEST. However, since we will need additional hemispheres for our experiments, we purchased a radius cutter that will allow us to fabricate hemispheres as large as 5 inches in radius at the Ohio University Machine Shop. This will give us maximum flexibility to adapt to the needs of the spherical shell transmission experiments. High purity (99.94% iron) Armco iron has been obtained which can be used to make the smaller hemispheres. Larger hemispheres will be made using ASTM designation steel with high iron content. In all cases compositional analyses will be made of the hemispheres

The children's brain tumor network (CBTN) - Accelerating research in pediatric central nervous system tumors through collaboration and open science

Pediatric brain tumors are the leading cause of cancer-related death in children in the United States and contribute a disproportionate number of potential years of life lost compared to adult cancers. Moreover, survivors frequently suffer long-term side effects, including secondary cancers. The Children's Brain Tumor Network (CBTN) is a multi-institutional international clinical research consortium created to advance therapeutic development through the collection and rapid distribution of biospecimens and data via open-science research platforms for real-time access and use by the global research community. The CBTN's 32 member institutions utilize a shared regulatory governance architecture at the Children's Hospital of Philadelphia to accelerate and maximize the use of biospecimens and data. As of August 2022, CBTN has enrolled over 4700 subjects, over 1500 parents, and collected over 65,000 biospecimen aliquots for research. Additionally, over 80 preclinical models have been developed from collected tumors. Multi-omic data for over 1000 tumors and germline material are currently available with data generation for > 5000 samples underway. To our knowledge, CBTN provides the largest open-access pediatric brain tumor multi-omic dataset annotated with longitudinal clinical and outcome data, imaging, associated biospecimens, child-parent genomic pedigrees, and in vivo and in vitro preclinical models. Empowered by NIH-supported platforms such as the Kids First Data Resource and the Childhood Cancer Data Initiative, the CBTN continues to expand the resources needed for scientists to accelerate translational impact for improved outcomes and quality of life for children with brain and spinal cord tumors