Charged particles produced in neutron reactions on nuclei from beryllium to gold

Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound reactions are clearly seen in the data. The data are compared with data from the literature where available, with evaluated nuclear data libraries, and with calculations where the selection of the nuclear level density prescription is of great importance. Calculations normalized at En = 14 MeV can differ from the present data by a factor of 2 for neutron energies between 5 and 10 MeV

Status report to DOE Nuclear Data Committee

This status report from Lawrence Livermore Laboratory covers work in the areas of nuclear data applications - measurements, nuclear data application - calculations, nuclear data for reactor safety, fission physics, and data evaluation and compilation. Separate abstracts were prepared for seven of the contributions to this report. 7 figures, 3 tables. (RWR

The 14C(n,g) cross section between 10 keV and 1 MeV

The neutron capture cross section of 14C is of relevance for several nucleosynthesis scenarios such as inhomogeneous Big Bang models, neutron induced CNO cycles, and neutrino driven wind models for the r process. The 14C(n,g) reaction is also important for the validation of the Coulomb dissociation method, where the (n,g) cross section can be indirectly obtained via the time-reversed process. So far, the example of 14C is the only case with neutrons where both, direct measurement and indirect Coulomb dissociation, have been applied. Unfortunately, the interpretation is obscured by discrepancies between several experiments and theory. Therefore, we report on new direct measurements of the 14C(n,g) reaction with neutron energies ranging from 20 to 800 keV

Testing T Invariance in the Interaction of Slow Neutrons with Aligned Nuclei

The study of five-fold (P even, T odd) correlation in the interaction of slow polarized neutrons with aligned nuclei is a possible way of testing the time reversal invariance due to the expected enhancement of T violating effects in compound resonances. Possible nuclear targets are discussed which can be aligned both dynamically as well as by the "brute force" method at low temperature. A statistical estimation is performed of the five-fold correlation for low lying p wave compound resonances of the $^{121}$Sb, $^{123}$Sb and $^{127}$I nuclei. It is shown that a significant improvement can be achieved for the bound on the intensity of the fundamental parity conserving time violating (PCTV) interaction.Comment: 22 pages, 5 figures, published versio

Poverty and Service Delivery in Suburban America Framing Paper

In the United States today, contrary to popular belief, living in the suburbs is not synonymous with living the American dream. An unprecedented number of people in the suburbs are living on household incomes of less than $20,000, many on much less. Increasingly, individuals and their families need to rely on services and public benefits to meet their basic needs (Kneebone & Berube, 2013). Over the past 30 years, poverty in the suburbs has grown due to multiple factors, including job decentralization, shifts in the location of affordable and subsidized housing, and the relocation to the suburbs of lower income immigrants and minorities (Covington, Freeman, & Stoll, 2011; Frey, 2011a). The rate of growth in suburban poverty has been particularly high in the past decade, outpacing growth in both urban and rural areas. During the Great Recession (2007-2009), high rates of unemployment and underemployment and the home foreclosure crisis brought the number of people living in poverty in the suburbs to an all-time high. Today, suburban areas are home to about 40 percent of all poor people in the country, an increase from 25 percent in 1980. Furthermore, in the 100 largest metropolitan areas, more people are living in poverty in the suburbs than in urban areas (Frey, 2011b). Suburbs are now facing a range of challenges traditionally associated with cities, such as high rates of unemployment and underemployment, lower educational attainment, food insecurity, and lack of access to health care. The increase in the suburban poverty rate is straining social service providers and local governments at a time when resources are shrinking (Allard & Roth, 2010). The Office of the Assistant Secretary for Planning and Evaluation (ASPE) of the U.S. Department of Health and Human Services (HHS) seeks to better understand poverty and service delivery in suburban America, including how the dynamics of suburban poverty may differ from those in rural and urban communities and whether service models may need to be tailored to meet these differences. To that end, ASPE commissioned this framing paper to review and synthesize existing research, analyze the characteristics and service needs of those living in poverty in the suburbs, and identify information and research needed to more fully understand and guide efforts to address suburban poverty. To prepare this review, we used three types of information sources: existing literature, both published and unpublished; a select number of key informant interviews; and two sources of extant U.S. Census Bureau household survey data: the Annual Social and Economic Supplement to the Current Population Survey (CPS), which provides an annual count of the number of people living below 100 percent of the federal poverty level from 1959 to 2011, and the 2009-2011 American Community Survey (ACS) Weighted 3-Year Restricted-Use Files, a household survey of a nationally representative sample of individuals. These data provide information about all suburbs, including but not limited to, the 100 largest metropolitan areas (see Appendix 1). This paper will serve to frame the discussion during the Poverty and Service Delivery in Suburban America Roundtable, to be convened in 2014. The roundtable will bring together researchers, policy 5 experts, practitioners, and federal staff to discuss the issues raised in this paper and gaps in the research, formulate new research questions, consider the implications of the research for service delivery and public benefits, and assess opportunities for HHS and broader federal engagement

Poverty and Service Delivery in Suburban America Framing Paper

In the United States today, contrary to popular belief, living in the suburbs is not synonymous with living the American dream. An unprecedented number of people in the suburbs are living on household incomes of less than $20,000, many on much less. Increasingly, individuals and their families need to rely on services and public benefits to meet their basic needs (Kneebone & Berube, 2013). Over the past 30 years, poverty in the suburbs has grown due to multiple factors, including job decentralization, shifts in the location of affordable and subsidized housing, and the relocation to the suburbs of lower income immigrants and minorities (Covington, Freeman, & Stoll, 2011; Frey, 2011a). The rate of growth in suburban poverty has been particularly high in the past decade, outpacing growth in both urban and rural areas. During the Great Recession (2007-2009), high rates of unemployment and underemployment and the home foreclosure crisis brought the number of people living in poverty in the suburbs to an all-time high. Today, suburban areas are home to about 40 percent of all poor people in the country, an increase from 25 percent in 1980. Furthermore, in the 100 largest metropolitan areas, more people are living in poverty in the suburbs than in urban areas (Frey, 2011b). Suburbs are now facing a range of challenges traditionally associated with cities, such as high rates of unemployment and underemployment, lower educational attainment, food insecurity, and lack of access to health care. The increase in the suburban poverty rate is straining social service providers and local governments at a time when resources are shrinking (Allard & Roth, 2010). The Office of the Assistant Secretary for Planning and Evaluation (ASPE) of the U.S. Department of Health and Human Services (HHS) seeks to better understand poverty and service delivery in suburban America, including how the dynamics of suburban poverty may differ from those in rural and urban communities and whether service models may need to be tailored to meet these differences. To that end, ASPE commissioned this framing paper to review and synthesize existing research, analyze the characteristics and service needs of those living in poverty in the suburbs, and identify information and research needed to more fully understand and guide efforts to address suburban poverty. To prepare this review, we used three types of information sources: existing literature, both published and unpublished; a select number of key informant interviews; and two sources of extant U.S. Census Bureau household survey data: the Annual Social and Economic Supplement to the Current Population Survey (CPS), which provides an annual count of the number of people living below 100 percent of the federal poverty level from 1959 to 2011, and the 2009-2011 American Community Survey (ACS) Weighted 3-Year Restricted-Use Files, a household survey of a nationally representative sample of individuals. These data provide information about all suburbs, including but not limited to, the 100 largest metropolitan areas (see Appendix 1). This paper will serve to frame the discussion during the Poverty and Service Delivery in Suburban America Roundtable, to be convened in 2014. The roundtable will bring together researchers, policy 5 experts, practitioners, and federal staff to discuss the issues raised in this paper and gaps in the research, formulate new research questions, consider the implications of the research for service delivery and public benefits, and assess opportunities for HHS and broader federal engagement

Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

Prompt fission neutron spectra in the neutron-induced fission of 239Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Preliminary results are discussed and compared to theoretical model calculation