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When compared with the National Ignition Facility’s (NIF) original soft x-ray opacity spectrometer, which used a convex cylindrical design, an elliptically shaped design has helped to increase the signal-to-noise ratio and eliminated nearly all reflections from alternate crystal planes. The success of the elliptical geometry in the opacity experiments has driven a new elliptical geometry crystal with a spectral range covering 520–1100 eV. When coupled with the primary elliptical geometry, which spans 1000–2100 eV, the new sub-keV elliptical geometry helps to cover the full iron L-shell and major oxygen transitions important to solar opacity experimentation. The new design has been built and tested by using a Henke x-ray source and shows the desired spectral coverage. Additional plans are underway to expand these opacity measurements into a mode of time-resolved detection, ∼1 ns gated, but considerations for the detector size and photometrics mean a crystal geometry redesign. The new low-energy geometry, including preliminary results from the NIF opacity experiments, is presented along with the expansion plans into a time-resolved platform.

The Opacity Spectrometer (OpSpec) used in the National Ignition Facility’s opacity experiments measures x-ray spectra from 0.9 to 2.1 keV from the different experimental regions: the backlight source, emission source, and the absorption region with the transmission calculated from these regions. The OpSpec designs have gone through several iterations to help improve the signal-to-noise ratio, remove alternate crystal plane reflections, and improve spectral resolution, which helps to increase the validity of the opacity measurements. However, the source spans well outside the current working spectral range, and higher-order reflections are intrinsic to the crystal, which increases the overall signal seen in the data regions. The recorded data are the convolution of 1st order transmission, higher-order reflections, and the penumbra blurring. This work represents the details for deconvolving the 2nd and 3rd order spectral energy corrections with a penumbral de-blurring to correct the relative measurement of x-ray intensity of different spectral energies and further analysis of datasets relevant to the opacity experiments.

Perhaps the most serious ethical challenge to pacifism is the argument for the necessity of military action to protect civilians from violence. Whether articulated by IR scholars or armed rebels, ...

X-ray films remain a key asset for high-resolution x-ray spectral imaging in high-energy-density experiments conducted at the National Ignition Facility (NIF). The soft x-ray Opacity Spectrometer (OpSpec) fielded at the NIF has an elliptically shaped crystal design that measures x rays in the 900-2100 eV range and currently uses an image plate as the detecting medium. However, Agfa D4 and D3sc x-ray films' higher spatial resolution provides increased spectral resolution to the data over the IP-TR image plates, driving the desire for regular use of x-ray film as a detecting medium. The calibration of Agfa D4 x-ray film for use in the OpSpec is communicated here. These calibration efforts are vital to the accuracy of the NIF opacity measurements and are conducted in a previously un-studied x-ray energy range under a new film development protocol required by NIF. The absolute response of Agfa D4 x-ray film from 705 to 4620 eV has been measured using the Nevada National Security Site Manson x-ray source. A broader range of energies was selected to compare results with previously published data. The measurements were taken using selected anodes, filters, and applied voltages to produce well-defined energy lines.

The single-crystal spectropolarimeter envisioned by Baronova and Stepanenko splits an incident x-ray beam into two beams with mutually orthogonal linear polarizations by using simultaneous reflections at the perfectly polarizing 45° Bragg angle on certain pairs of internal planes in hexagonal or cubic crystals. These planes intersect along a threefold symmetry axis, making a 120° angle with each other, and are typically symmetric with respect to the crystal surface. In practice, the wavelength of the diagnostic x-ray lines does not exactly satisfy Bragg's law for the crystal in the ideal polarizing orientation, so the extinction of reflections is incomplete. Accepting this limitation, this paper shows that for cubic crystals, other pairs of internal planes exist that satisfy the polarization requirements approximately. Typically, they are accessible from the perfect polarization-splitting geometry by small rotations of the crystal. This paper includes examples of such planes for cubic crystals with {110} and {211} surface cuts.

The soft x-ray Opacity Spectrometer (OpSpec) used on the National Ignition Facility (NIF) has recently incorporated an elliptically shaped crystal. The original OpSpec used two convex cylindrical crystals for time-integrated measurements of point-projection spectra from 540 to 2100 eV. However, with the convex geometry, the low-energy portion of the spectrum suffered from high backgrounds due to scattered x-rays as well as reflections from alternate crystal planes. An elliptically shaped crystal allows an acceptance aperture at the crossover focus between the crystal and the detector, which reduces background and eliminates nearly all reflections from alternate crystal planes. The current elliptical design is an improvement from the convex cylindrical design but has a usable energy range from 900 to 2100 eV. In addition, OpSpec is currently used on 18 NIF shots/year, in which both crystals are typically damaged beyond reuse, so efficient production of 36 crystals/year is required. Design efforts to improve the existing system focus on mounting reliability, reducing crystal strain to increase survivability between mounting and shot time, and extending the energy range of the instrument down to 520 eV. The elliptical design, results, and future options are presented.

Hexagonal and cubic crystals contain paired sets of internal planes that reflect the linearly polarized components of certain x rays into two separate, perpendicular directions. For the cubic crystals, two distinct crystal orientations provide the same polarization-splitting geometry. One of the orientations may have advantages for plasma spectroscopy by suppressing unwanted reflections. This paper demonstrates the two orientations with a germanium crystal and K characteristic lines from copper and zirconium.

A recently developed single-crystal x-ray spectropolarimeter has been used to record paired sets of polarization-dependent and axially resolved x-ray spectra emitted by wire array z-pinches. In this measurement, two internal planes inside a suitable crystal diffract the x-rays into two perpendicular directions that are normal to each other, thereby separating incident x-rays into their linearly polarized components. This paper gives considerations for fielding the instrument on extended sources. Results from extended sources are difficult to interpret because generally the incident x-rays are not separated properly by the crystal. This difficulty is mitigated by using a series of collimating slits to select incident x-rays that propagate in a plane of symmetry between the polarization-splitting planes. The resulting instrument and some of the spatially resolved polarized x-ray spectra recorded for a 1-MA aluminum wire array z-pinch at the Nevada Terawatt Facility at the University of Nevada, Reno will be presented.

High-resolution reconstruction of reaction dynamics in nuclear-physics experiments with radioactive beams requires accurate knowledge of the beam-particle trajectories and the precise alignment of detectors with respect to the reaction target. In many cases, sub-millimeter position measurements of fragile beam-tracking and particle–detector systems are essential. We have constructed a laser-based alignment system (LBAS) which is a non-contact, high-precision alignment tool designed for applications where excellent spatial positioning must be achieved. The working principles and performance of the laser-based alignment system are presented.

Starting from violence's widely acknowledged status as a wrong, this article critically explores attempts to legitimate violence through appeals to moral frameworks that determine the ends for which violence may be employed. Recognizing that such frameworks exist on all sides of violent conflict, it argues that since there will never be complete agreement on their content or application, nor complete certainty about which moral framework is the ‘correct’ one, it becomes impossible to distinguish legitimate from illegitimate violence either non-controversially or with certainity. Two problems result: our own ‘legitimate’ violence may reproduce rather than limit violence by sparking ‘legitimate’ violence in return, and our own use of violence may actually be unjust, despite our intentions. If we wish to avoid these problems yet maintain our moral commitments – however contested or contingent – we must employ nonviolent means to wage our conflicts, as such means remain legitimate despite disagreement or uncertainty regarding ends.

A wide variety of z-pinches are host to energetic electron beams whose energies and origins have yet to be sufficiently characterized. Knowing the electron energies and currents of these electron beams can give insight into the mechanism responsible for the acceleration of the electrons to such high energies. Measurements with a magnetic analyzer have been carried out to determine the energy distribution of electron beams on a variety of aluminum wire array z-pinch geometries at the Nevada Terawatt Facility at the University of Nevada, Reno. These measurements show that as the geometry of the wire array is changed so that the initial angle of inclination, or necking shape, is enhanced, there is an increase in electron beam activity and electron energies. Measurements such as these can be useful to benchmark spectroscopic techniques used to characterize these energetic beams and give insight into the mechanisms responsible for the generation of such energetic beams in z-pinch plasmas.

The High Resolution Array (HiRA) is a large solid-angle array of silicon strip-detectors that has been developed for use in a variety of nuclear structure, nuclear astrophysics and nuclear reaction experiments with short lived beta-unstable beams. It consists of 20 identical telescopes each composed of a thin ( 65 μ m ) single-sided silicon strip-detector, a thick (1.5 mm) double-sided silicon strip-detector, and four CsI(Tl) crystals read out by photodiodes. The array can be easily configured to meet the detection requirements of specific experiments. To process the signals from the 1920 strips in the array, an Application Specific Integrated Circuit (ASIC) was developed. The design and performance characteristics of HiRA are described.

A systematic study of isotopic effects in the break-up of projectile spectators at relativistic energies has been performed with the ALADiN spectrometer at the GSI laboratory. Searching for signals of criticality in the fragment production we have applied the model independent universal fluctuations theory already proposed to track criticality signals in multifragmentation to our data. The fluctuation of the largest fragment charge and of the asymmetry of the two and three largest fragments and their bimodal distribution have also been analysed., Comment: 6 pages, 4 figures, IX International Conference on Nucleus-Nucleus Collisions, Rio de Janeiro, Brazil, August 28 - September 1, 2006

The dependencies of the light output response of CsI(Tl) crystals for various charged particle beams are investigated. Measurements were performed using5.5 MeV 241 Am alpha particles, 220 MeV alpha and 110 MeV deuteron beams from the K500 Cyclotron at Texas AM 29.90.+r

This talk will discuss the fragment yield measurements from the reaction of 58 Ni+ 9 Be and 58 Ni+ 181 Ta using the A1900 fragment separator at the National Superconducting Cyclotron Laboratory. In addition, the charge distributions for these two reactions as well as reactions using the 86 Kr beam will also be presented.

When energetic electrons inside a plasma have a preferred direction the x-rays emitted by the plasma can be polarized. Information about the electrons and the anisotropy of their velocity distribution can then be revealed by the x-ray spectrum's polarization. Polarization typically measured with two crystals at a 45 degrees Bragg, can now be determined in a new way using one crystal. This crystal utilizes two sets of planes that diffract the incident x-rays in two directions that are perpendicular to each other and to the incident beam1. These diffracted x-rays are then linearly polarized perpendicularly to each other. The polarization splitting properties of quartz crystals were confirmed with the linearly polarized x-rays from the Advanced Photon Source. A crystal with surface cut [10–10] that splits polarization with [11–20] planes at 7.15 keV was among those tested. Bragg reflections at 45 degrees from the crystal's [10–10] surface planes was then tested with x-rays from conical wire array z-pinches. These tests were aimed to verify the reflectivity of the planes intended for single crystal spectropolarimetric measurements in upcoming experiments.

2D X-ray imaging spectroscopic diagnostics is an advanced plasma diagnostics tool, providing a way to determine the spatial dependence of plasma temperature and density (Te and ne) in hot plasmas. This can be accomplished with the usual spectroscopic diagnostics methods by taking advantage of the spatial information contained in the broad energy range spectra recorded by convex crystal spectrometers. The sensitivity of these instruments to the size of the X-ray source has long been noted, mostly as a factor leading to the reduction of the resolving power. Spectra can be spatially resolved by using a slit to create an image of the source in the direction perpendicular to the spectral dispersion. In the case of such spectra recorded by convex crystal spectrometers, it is often noted that the shape of the lines themselves, as recorded on a medium, resembles the shape of the plasma source as obtained, for example, with pinhole imaging. This provides some crude resolution perpendicular to the spectral line. We propose to use this effect for a new diagnostics technique that allows 2D spatially resolved spectroscopy of the X-ray source. Modeling the plasma emission spectrum by the PrismSPECT code allowed the identification of suitable spectral features to determine ne and Te. For an Al-Mg wire array z-pinch, the optically thin Mg lines can be used. We applied the principles of this method to get a temperature distribution map for a z-pinch from the shape of the Mg K-shell lines recorded by a convex KAP sprectrometer. The spatial resolution can be improved by deconvolving the plasma broadened line profiles from the lineshapes recorded by the convex crystal spectrometer. To obtain lineshapes with minimum instrumental broadening, a concave cylindrically bent KAP crystal spectrometer was designed.2D X-ray imaging spectroscopic diagnostics is an advanced plasma diagnostics tool, providing a way to determine the spatial dependence of plasma temperature and density (Te and ne) in hot plasmas. This can be accomplished with the usual spectroscopic diagnostics methods by taking advantage of the spatial information contained in the broad energy range spectra recorded by convex crystal spectrometers. The sensitivity of these instruments to the size of the X-ray source has long been noted, mostly as a factor leading to the reduction of the resolving power. Spectra can be spatially resolved by using a slit to create an image of the source in the direction perpendicular to the spectral dispersion. In the case of such spectra recorded by convex crystal spectrometers, it is often noted that the shape of the lines themselves, as recorded on a medium, resembles the shape of the plasma source as obtained, for example, with pinhole imaging. This provides some crude resolution perpendicular to the spectral line. We propose to use this effect for a new diagnostics technique that allows 2D spatially resolved spectroscopy of the X-ray source. Modeling the plasma emission spectrum by the PrismSPECT code allowed the identification of suitable spectral features to determine ne and Te. For an Al-Mg wire array z-pinch, the optically thin Mg lines can be used. We applied the principles of this method to get a temperature distribution map for a z-pinch from the shape of the Mg K-shell lines recorded by a convex KAP sprectrometer. The spatial resolution can be improved by deconvolving the plasma broadened line profiles from the lineshapes recorded by the convex crystal spectrometer. To obtain lineshapes with minimum instrumental broadening, a concave cylindrically bent KAP crystal spectrometer was designed.

Summary form only given. It is well known that intense beams of energetic electrons are accelerated in z-pinches. Using magnetic deflection and Faraday cup detection we measured electron energies and the current of beams produced in conical wire array z-pinches and x-pinches. The variations in pointing and divergence of the beams reduced the accuracy of these measurements. However, the beam activity can be correlated with the x-ray emission of the z-pinches. We will present results of these measurements.

Summary form only given. A well-known feature in many otherwise thermal plasmas is an energetic electron component, whose origin and properties remain to be fully understood. When the energetic electrons have a preferred direction, the X-rays created by the beam can be polarized. In turn, information about the anisotropic electron energy distribution can be obtained from the X-ray spectrum's polarization, and a polarization-containing plasma radiation model. A promising way to perform the appropriate spectropolarimetry uses a crystal that contains two equivalent sets of planes under 120 degrees with each other. These diffract, for a given wavelength, an incident X-ray beam in two directions perpendicular to this beam and to each other.The diffracted X-rays are then linearly polarized perpendicular to each other. The polarization-splitting properties of a quartz crystal cut along the (10-10) plane and diffracting from two (11-20) planes were confirmed with synchrotron radiation from the Advanced Photon Source at the Argonne National Laboratory. The crystal characteristics and requirements for its use to diagnose electron beams in zpinch plasmas will be presented.

The ground state of Li-11 is the preeminent example of a two-neutron-halo nucleus and is part of an isobaric sextet. Another member of this sextet, the double isobaric analog of Li-11(g.s). in B-11, has been identified in the Be-12(p, 2n)B-11 reaction. The state was discovered through its two-proton decay branch. From detected 2p + Li-9 events, its excitation energy was determined to be 33.57(8) MeV using the invariant mass method. With the known masses of Li-11 and its isobaric analog state in Be-11, three members of the same sextet have measured masses for the first time, permitting the masses of the remaining members to be extrapolated using the isobaric multiplet mass equation. All members of this multiplet are expected to have a two-nucleon halo structure and this was found consistent with the evolution of the mass across the sextet. The momentum correlations of the detected protons were found to have both "diproton" and "cigar" components.

The performance of the LAND neutron detector is studied. Using an event-mixing technique based on one-neutron data obtained in the S107 experiment at the GSI laboratory, we test the efficiency of various analytic tools used to determine the multiplicity and kinematic properties of detected neutrons. A new algorithm developed recently for recognizing neutron showers from spectator decays in the ALADIN experiment S254 is described in detail. Its performance is assessed in comparison with other methods. The properties of the observed neutron events are used to estimate the detection efficiency of LAND in this experiment., 16 pages, 8 figures

The angular dependence of proton-proton correlation functions is studied in central $^{40}Ca+^{40}Ca$ and $^{48}Ca+^{48}Ca$ nuclear reactions at E=80 MeV/A. Measurements were performed with the HiRA detector complemented by the 4$\pi$ Array at NSCL. A striking angular dependence in the laboratory frame is found within p-p correlation functions for both systems that greatly exceeds the measured and expected isospin dependent difference between the neutron-rich and neutron-deficient systems. Sources measured at backward angles reflect the participant zone of the reaction, while much larger sources observed at forward angles reflect the expanding, fragmenting and evaporating projectile remnants. The decrease of the size of the source with increasing momentum is observed at backward angles while a weaker trend in the opposite direction is observed at forward angles. The results are compared to the theoretical calculations using the BUU transport model.

The N/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at the GSI Schwerionen Synchrotron (SIS). Stable and radioactive Sn and La beams with an incident energy of 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. For the interpretation of the data, calculations with the statistical multifragmentation model for a properly chosen ensemble of excited sources were performed. The parameters of the ensemble, representing the variety of excited spectator nuclei expected in a participant-spectator scenario, are determined empirically by searching for an optimum reproduction of the measured fragment-charge distributions and correlations. An overall very good agreement is obtained. The possible modification of the liquid-drop parameters of the fragment description in the hot freeze-out environment is studied, and a significant reduction of the symmetry-term coefficient is found necessary to reproduce the mean neutron-to-proton ratios /Z and the isoscaling parameters of Z, 23 pages, 29 figures, published in Physical Review C

The first direct measurement of the proton separation energy, Sp, for the proton-unbound nucleus 69Br is reported. Of interest is the exponential dependence of the 2p-capture rate on Sp which can bypass the 68Se waiting-point in the astrophysical rp process. An analysis of the observed proton decay spectrum is given in terms of the 69Se mirror nucleus and the influence of Sp is explored within the context of a single-zone X-ray burst model., 6 pages, 6 figures, INPC 2010 conference proceedings

We report the first detailed study of the relative importance of the stripping and diffraction mechanisms involved in nucleon knockout reactions, by the use of a coincidence measurement of the residue and fast proton following one-proton knockout reactions. The measurements used the S800 spectrograph in combination with the HiRA detector array at the NSCL. Results for the reactions 9 Beð 9 C; 8 B þ XÞY and 9 Beð 8 B; 7 Be þ XÞY are presented and compared with theoretical predictions for the two reaction mechanisms calculated using the eikonal model. The data show a clear distinction between the stripping and diffraction mechanisms and the measured relative proportions are very well reproduced by the reaction theory. This agreement adds support to the results of knockout reaction analyses and their applications to the spectroscopy of rare isotopes.

Resonance-decay spectroscopy is used to study particle-unbound excited states produced in interactions of E/A=50 MeV {sup 12}Be on polyethylene and carbon targets. The particle-unbound states are produced in a variety of reaction mechanisms, ranging from projectile fragmentation to proton pickup. New proton-decaying excited states are observed in {sup 9}Li(E*=14.1{+-}0.1 MeV, {gamma}=207{+-}49 keV) and {sup 10}Be(E*=20.4{+-}0.1 MeV, {gamma}=182{+-}74 keV). In addition a new {alpha}-decaying state is observed in {sup 13}B(E*=13.6{+-}0.1 MeV, {gamma}{ 2. A second T=2 state was confirmed in {sup 12}B at 14.82 MeV, which decays to the p+{sup 11}Be, {sup 3}H+{sup 9}Be, and {alpha}+{sup 8}Li channels. Its width was found to be {gamma}{

The GLAST Burst Monitor (GBM) is designed to provide wide field of view observations of gamma‐ray bursts and other fast transient sources in the energy range 10 keV to 30 MeV. The GBM is composed of several unshielded and uncollimated scintillation detectors (twelve NaI and two BGO) that are widely dispersed about the GLAST spacecraft. As a result, reconstructing source locations, energy spectra, and temporal properties from GBM data requires detailed knowledge of the detectors' response to both direct radiation as well as that scattered from the spacecraft and Earth's atmosphere. This full GBM instrument response will be captured in the form of a response function database that is derived from computer modeling and simulation. The simulation system is based on the GEANT4 Monte Carlo radiation transport simulation toolset.

The discriminant-analysis method has been applied to optimize the exotic-beam charge recognition in a projectile fragmentation experiment. The experiment was carried out at the GSI using the fragment separator (FRS) to produce and select the relativistic secondary beams, and the ALADIN setup to measure their fragmentation products following collisions with Sn target nuclei. The beams of neutron poor isotopes around 124La and 107Sn were selected to study the isospin dependence of the limiting temperature of heavy nuclei by comparing with results for stable 124Sn projectiles. A dedicated detector to measure the projectile charge upstream of the reaction target was not used, and alternative methods had to be developed. The presented method, based on the multivariate discriminant analysis, allowed to increase the efficacy of charge recognition up to about 90%, which was about 20% more than achieved with the simple scalar methods., Comment: 6 pages, 7 eps figures, elsart, submitted to Nucl. Instr. and Meth. A

The breakup of $E/A=50$ MeV $^{12}\mathrm{Be}$ fragments following inelastic scattering off of hydrogen and carbon target nuclei has been studied. The breakup channels $\ensuremath{\alpha}+$$^{8}\mathrm{He}$, $^{6}\mathrm{He}$$+$$^{6}\mathrm{He}$, $t+$$^{9}\mathrm{Li}$, and $p+$$^{11}\mathrm{Li}$ were observed. Two doublets at excitation energies of 12.8 and 15.5 MeV were found for the $\ensuremath{\alpha}+$$^{8}\mathrm{He}$ channel. A low-energy shoulder in the excitation-energy spectra at 10.2 MeV indicates one or more additional states. This work could not confirm the presence of $^{6}\mathrm{He}$$\text{\ensuremath{-}}$$^{6}\mathrm{He}$ rotational structure reported by Freer et al. [Phys. Rev. C 63, 034301 (2001)], although possible peaks at excitation energies of 13.5 and 14.5 MeV were found for $^{6}\mathrm{He}$$+$$^{6}\mathrm{He}$ decay. Significant structure is observed in the excitation-energy spectrum for $p+$$^{11}\mathrm{Li}$ at 25--30 MeV which maybe associated with $T=3$ analog states.

An exponential dependence of the fragmentation cross-section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross-sections. From the systematics of 75,77,78,79Cu isotope cross-sections have been extracted. They are 636.94 +/- 0.40 MeV, 647.1 +/- 0.4 MeV, 651.6 +/- 0.4 MeV and 657.8 +/- 0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of 75Cu is reduced from 980 keV (listed value in the 2003 mass table of Audi and Wapstra) to 400 keV. The predicted cross-sections of two near drip-line nuclei, 39Na and 40Mg, from the fragmentation of 48Ca are discussed., 12 pages, 3 figures

We measured fragmentation cross sections produced using the primary beam of $^{86}\mathrm{Kr}$ at 64 MeV/nucleon on $^{9}\mathrm{Be}$ and $^{181}\mathrm{Ta}$ targets. The cross sections were obtained by integrating the momentum distributions of isotopes with $25\ensuremath{\leqslant}Z\ensuremath{\leqslant}36$ measured using the RIPS fragment separator at RIKEN. The cross-section ratios obtained with the $^{181}\mathrm{Ta}$ and $^{9}\mathrm{Be}$ targets depend on the fragment masses, contrary to the simple geometrical models. We compared the extracted cross sections to EPAX; an empirical parametrization of fragmentation cross sections. Predictions from current EPAX parametrization severely overestimate the production cross sections of very neutron-rich isotopes. Attempts to obtain another set of EPAX parameters specific to the reaction studied here to extrapolate the neutron-rich nuclei more accurately have not been very successful, suggesting that accurate predictions of production cross sections of nuclei far from the valley of stability require information of nuclear properties that are not present in EPAX.

Using the measured fragmentation cross sections produced from the 48Ca and 64Ni beams at 140 MeV per nucleon on 9Be and 181Ta targets, we find that the cross sections of unmeasured neutron rich nuclei can be extrapolated using a systematic trend involving the average binding energy. The extrapolated cross-sections will be very useful in planning experiments with neutron rich isotopes produced from projectile fragmentation. The proposed method is general and could be applied to other fragmentation systems including those used in other radioactive ion beam facilities., accepted for publication in Europhysics Letters

The GLAST Burst Monitor (GBM) is designed to provide wide field of view observations of gamma‐ray bursts and other fast transient sources in the energy range 10 keV to 30 MeV. The GBM is composed of several unshielded and uncollimated scintillation detectors (twelve NaI and two BGO) that are widely dispersed about the GLAST spacecraft. As a result, reconstructing source locations, energy spectra, and temporal properties from GBM data requires detailed knowledge of the detectors’ response to both direct radiation as well as that scattered from the spacecraft and Earth’s atmosphere. This full GBM instrument response will be captured in the form of a response function database that is derived from computer modeling and simulation. The simulation system is based on the GEANT4 Monte Carlo radiation transport simulation toolset, and is being extensively validated against calibrated experimental GBM data. We discuss the architecture of the GBM simulation and modeling system and describe how its products will be used for analysis of observed GBM data. Companion papers describe the status of validating the system.

The N/Z dependence of projectile fragmentation at relativistic energies has been studied in a recent experiment at the GSI laboratory with the ALADiN forward spectrometer coupled to the LAND neutron detector. Besides a primary beam of 124Sn, also secondary beams of 124La and 107Sn delivered by the FRS fragment separator have been used in order to extend the range of isotopic compositions of the produced spectator sources. With the achieved mass resolution of \Delta A/A \approx 1.5%, lighter isotopes with atomic numbers Z \le 10 are individually resolved. The presently ongoing analyses of the measured isotope yields focus on isoscaling and its relation to the properties of hot fragments at freeze-out and on the derivation of chemical freeze-out temperatures which are found to be independent of the isotopic composition of the studied systems. The latter result is at variance with the predictions for limiting temperatures as obtained with finite-temperature Hartree-Fock calculations., Comment: 11 pages, 5 figures, Proceedings of International Workshop on Nuclear Dynamics in Heavy-Ion Reactions and Neutron Stars, Beijing, July 10-14, 2007, to appear in International Journal of Modern Physics E

The GLAST Burst Monitor (GBM) comprises 12 NaI and 2 BGO detectors dispersed about the GLAST spacecraft. The GBM instrument simulation software must generate an accurate response function database for all detectors in their flight configuration to optimize the mission science return. Before science analysis codes use the response database, we must confirm that our simulation codes and models can reproduce laboratory observations. To validate the simulation effort, Monte Carlo results are compared to calibrated laboratory measurements collected with a variety of radiation sources.

The GLAST Burst Monitor (GBM) consists of 12 NaI detectors and 2 BGO detectors mounted on two sides of the spacecraft. This provides detection capability for energies between 10 keV and 30 MeV, and sensitivity to all directions in the sky. Extensive measurements using radioactive sources have been performed on the isolated detectors. Simulations of these measurements using the GEANT4 Monte Carlo radiation transport simulations toolset have also been preformed. For gamma‐ray burst the spacecraft itself will have a significant impact on the detector response, therefore the final stage of validations involves measuring the detector response to radioactive sources after the spacecraft is fully assembled, and validating the results using simulation. Details of these simulations will be given in this paper.

In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species [Dryoxylon onoharaensum (Murayama), Euwallacea validus (Eichhoff), Pseudopityophthorus minutissimus (Zimmermann), Xyleborus atratus Eichhoff, and Xyleborus impressus Eichhoff]) were collected in South Carolina for the first time. Of four tree species in the plantation, eastern cottonwood, Populus deltoides Bartram, was the only one attacked, with nearly 40% of the trees sustaining ambrosia beetle damage. Clone ST66 sustained more damage than clone S7C15. ST66 trees receiving fertilization were attacked more frequently than trees receiving irrigation, irrigation + fertilization, or controls, although the number of S7C15 trees attacked did not differ among treatments. The study location is near major shipping ports; our results demonstrate the necessity for intensive monitoring programs to determine the arrival, spread, ecology, and impact of exotic scolytids.

A new experimental approach was developed that can reduce the uncertainties in astrophysical rapid proton capture ($rp$) process calculations due to nuclear data. This approach utilizes neutron removal from a radioactive ion beam to populate the nuclear states of interest. Excited states were deduced by the $\ensuremath{\gamma}$-decay spectra measured in a semiconductor Ge-detector array. In the first case studied, $^{33}\mathrm{Ar}$, excited states were measured with uncertainties of several keV. The 2 orders of magnitude improvement in the uncertainty of the level energies resulted in a 3 orders of magnitude improvement in the uncertainty of the calculated $^{32}\mathrm{Cl}(p,\ensuremath{\gamma})^{33}\mathrm{Ar}$ rate that is critical to the modeling of the $rp$ process. This approach has the potential to measure key properties of almost all interesting nuclei on the $rp$-process path.

A systematic study of isospin effects in the breakup of projectile spectators at relativistic energies has been performed with the ALADiN spectrometer at the GSI laboratory (Darmstadt). Four different projectiles 197Au, 124La, 124Sn and 107Sn, all with an incident energy of 600 AMeV, have been used, thus allowing a study of various combinations of masses and N/Z ratios in the entrance channel. The measurement of the momentum vector and of the charge of all projectile fragments with Z>1 entering the acceptance of the ALADiN magnet has been performed with the high efficiency and resolution achieved with the TP-MUSIC IV detector. The Rise and Fall behavior of the mean multiplicity of IMFs as a function of Zbound and its dependence on the isotopic composition has been determined for the studied systems. Other observables investigated so far include mean N/Z values of the emitted light fragments and neutron multiplicities. Qualitative agreement has been obtained between the observed gross properties and the predictions of the Statistical Multifragmentation Model., 10 pages,7 figure, 18th Nuclear Physics Division Conference of the EPS, Prague, submitted to Nucl. Phys. A

A search for $^{19}\mathrm{Mg}$ was performed using projectile fragmentation of a $150\phantom{\rule{0.3em}{0ex}}\text{MeV}∕\text{nucleon}$ $^{36}\mathrm{Ar}$ beam. No events of $^{19}\mathrm{Mg}$ were observed. From the time of flight through the fragment separator an upper limit of $22\phantom{\rule{0.3em}{0ex}}\text{ns}$ for the half-life of $^{19}\mathrm{Mg}$ was established.

The knockout of protons from ${}^{8}\mathrm{B}$ and ${}^{9}\mathrm{C}$ on a carbon target has been studied at average energies of 76 and 78 MeV/nucleon, respectively, with beams from the A1900 fragment separator incident on a stack of silicon detectors. The following cross sections were obtained: ${\ensuremath{\sigma}}_{\ensuremath{-}1\mathrm{p}}{(}^{8}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}}^{7}\mathrm{Be})=130(11)\mathrm{mb},$ ${\ensuremath{\sigma}}_{\ensuremath{-}1\mathrm{p}}{(}^{9}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{C}}}^{8}\mathrm{B})=54(4)\mathrm{mb},$ and ${\ensuremath{\sigma}}_{\ensuremath{-}2\mathrm{p}}{(}^{9}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{C}}}^{7}\mathrm{Be})=98(7)\mathrm{mb}.$ The results are discussed within the framework of an eikonal approach and compared with measurements performed at higher energies. From this analysis, a consistent picture emerges that gives evidence for the validity of the eikonal approach at energies below 100 MeV/nucleon. Knockout reactions at intermediate energy can thus be used to deduce absolute shell occupancies. We find the spectroscopic factors to be reduced by ${R}_{s}$ of 0.86(7) and 0.82(6) for ${}^{8}\mathrm{B}$ and ${}^{9}\mathrm{C},$ respectively, relative to shell-model predictions. The ${}^{9}\mathrm{C}$ result provides an accurate measurement of the asymptotic normalization coefficient of $1.27(10){\mathrm{fm}}^{\ensuremath{-}1}.$ A new technique is reported for determining separately the contributions from stripping and diffractive breakup.

A search for 19Mg was performed using projectile fragmentation of a 150 MeV/nucleon 36Ar beam. No events of 19Mg were observed. From the time-of-flight through the fragment separator an upper limit of 22 ns for the half-life of 19Mg was established.

Measuring magnetic field and current distribution in Z-pinch plasma systems is crucial to the validation of Z-pinch theory. In this letter, the demonstration of proton deflectometry to pulsed-power-driven loads at the mega-amp scale is presented, which is capable of making more detailed field maps in high-density regions of plasmas. In this method, a laser-driven, broad-spectrum, MeV-energy proton beam is directed through a pulsed-power-driven plasma system, and the resulting deflections are measured to examine configuration of magnetic fields and to infer the currents that support them. The technique was first demonstrated on simple short-circuit loads, and the results are in excellent agreement with numerical simulations providing reliable estimates of the field and current configurations. It was then applied to a more complex—radial foil—plasma load. The measurements show unexpected proton deflections that exhibit the complexity of the plasma load and that with further analysis will reveal details about the current and magnetic field topology in this complex configuration.

In hexagonal crystals such as quartz, an asymmetric Bragg reflection from two equivalent internal crystal planes can separate unpolarized x-rays into two linearly polarized components. The perfectly polarized and tunable x-rays from a synchrotron are ideal to evaluate polarization spitting in detail. One unanticipated feature is that additional reflections from the crystal affect the diffraction intensity of the two polarized components, an effect that is unlikely to matter in polarization spectroscopy of radiating plasmas for which the crystal is intended.

The expression and secretion of amyloid precursor protein (beta APP) is increased in rat cerebral cortices that have been denervated by subcortical lesions of the nucleus basalis of Meynert. The physiological role of the secreted beta APP in response to this injury has not been established. We have previously shown that secreted beta APP produced by alpha-secretase activity (sAPP(alpha)) potentiates the neuritogenic activity of nerve growth factor (NGF) in vitro on naive PC12 cells. In this investigation, we have further characterized the neurotrophic interaction of NGF and sAPP(alpha) using differentiated PC12 cells and rat primary cortical neurons. NGF required the expression of beta APP to maintain a neuronal phenotype. Reduction of endogenous beta APP expression by introduction of antisense oligonucleotides in the presence of NGF resulted in loss of neurites from differentiated PC12 cells but no apparent cell death. Addition of exogenous sAPP(alpha) (60--200 pM) potentiated the protective activity of NGF in serum-deprived differentiated PC12 cells as determined by retention of neurites and cell viability. In addition, exogenous sAPP(alpha) increased neuron viability in both short-term (3 days) cortical neuron cultures grown in the absence of serum and in long-term (9 days) cultures grown with serum. Disruption of the insulin signaling pathway by reduction of IRS-1 expression inhibited the ability of sAPP(alpha) to potentiate neurotrophic activity. These observations suggest that sAPP(alpha) acts as an injury-induced neurotrophic factor that interacts with NGF to enhance neuronal viability using the insulin signaling pathway.