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Recent advances in Inertial Confinement Fusion (ICF) experiments at Lawrence Livermore National Laboratory's National Ignition Facility (NIF) have underscored the need for accurate total yield measurements of DT neutrons because yield measurements provide a measure of the predicted performance of the experiments. Future gas-puff DT experiments at Sandia National Laboratory's Z facility will also require similar measurements. For ICF DT experiments, the standard technique for measuring the neutron (14.1 MeV) yield, counts the activity (counts/minute) induced in irradiated copper samples. This activity occurs by the 63Cu(n, 2n)62Cu reaction where 62Cu decays by positrons (β+) with a half-life of 9.67 minutes. The calibrations discussed here employ the associated-particle method (APM), where the α(4He) particles from the T(d,n)4He reaction are measured to infer neutron fluxes on a copper sample. The flux induces 62Cu activity, measured in a coincidence counting system. The method leads to a relationship between a DT neutron yield and copper activity known as the F-factor. The goal in future experiments is to apply this calibration to measure the yield at NIF with a combined uncertainty approaching 5%. [ABSTRACT FROM AUTHOR]

The development of a new radiation effects microscopy (REM) technique is crucial as emerging semiconductor technologies demonstrate smaller feature sizes and thicker back end of line (BEOL) layers. To penetrate these materials and still deposit sufficient energy into the device to induce single event effects, high energy heavy ions are required. Ion photon emission microscopy (IPEM) is a technique that utilizes coincident photons, which are emitted from the location of each ion impact to map out regions of radiation sensitivity in integrated circuits and devices, circumventing the obstacle of focusing high-energy heavy ions. Several versions of the IPEM have been developed and implemented at Sandia National Laboratories (SNL). One such instrument has been utilized on the microbeam line of the 6 MV tandem accelerator at SNL. Another IPEM was designed for ex-vacu use at the 88″ cyclotron at Lawrence Berkeley National Laboratory (LBNL). Extensive engineering is involved in the development of these IPEM systems, including resolving issues with electronics, event timing, optics, phosphor selection, and mechanics. The various versions of the IPEM and the obstacles, as well as benefits associated with each will be presented. In addition, the current stage of IPEM development as a user instrument will be discussed in the context of recent results. [ABSTRACT FROM AUTHOR]

Nuclear microscopy is usually associated with the use of highly focused MeV ions to measure microscopically the composition of solids. Another use of such focused ions emerged 10 years ago with the introduction of radiation effects microscopy or REM. With REM one exploits the charge deposited by each ion, or the effect of this charge. The power of this new technique stems from the reproducible, and very well understood, linear charge density produced by ions in semiconductors, coupled with the capability of a nuclear microprobe to provide individual ions to a specimen with high spatial resolution. Several techniques form the bases for REM, and these can be categorized under the headings: ion beam induced charge collection (IBICC) and single event effects (SEE) imaging, this paper reviews these techniques, and gives examples of their use in studying charge transport, and the effects of this transport, in semiconductors and integrated circuits. [ABSTRACT FROM AUTHOR]

Ion Beam Induced Luminescence (IBIL) and Ion Beam Induced Charge Collection (IBICC) have been used to study the efficiency and the homogeneity of the luminescence emission in phosphors. The IBIL imaging was made by using sharply focused ion beams or broad/partially-focused ion beams. Samples were examined to reveal possible distributed crystal-defects that may lead to the inhomogeneity of the luminescence emission. The purpose of the study is to search for suitable thin films that have high homogeneity of luminescence emission and large IBIL efficiency under heavy ion excitation. These films may be placed as a thin layer on the top of microelectronic devices to be analyzed with Ion Photon Emission Microscopy (IPEM). The emission yields were found to be low for organic materials, due to saturation of the light output dependence on the energy deposition of heavy ions. The emission yield of a typical Bicron plastic scintillator is about 70 photons/ion/micron. Inorganic materials may have higher IBIL yields under high-energy and heavy-ion excitation, but the challenging problem is the inhomogeneity of the IBIL emissions. The IBIL image techniques are applied in the investigation of the homogeneity of a GaN epitaxial thin film, a zircon single crystal and a thin layer coated by Thiogallate (EuII) ceramic. [ABSTRACT FROM AUTHOR]

The knowledge of (diffusion, drift, and funneling assisted) charge collection within electronic devices is essential to design radiation hardened Integrated Circuits (ICs). In the present work, diffusion time resolved charge collection studies were performed on stripe-like junctions using 12 MeV carbon and 28 MeV silicon microbeams and MEDICI simulation calculations. The relative average arrival time of the diffused charge on the junctions was measured along with the amount of charge collection by the junctions. The average arrival time of the diffused charge is related to the first moment (or the average time) of the arrival carrier density on the junction. The experimental results and MEDICI (a 2D-device simulator) calculations support this interpretation. These results show the importance of the diffusive charge collection by junctions, which is especially significant in accounting for Single Event Upsets (SEUs) and Multiple Bit Upset (MBUs) in digital devices. [ABSTRACT FROM AUTHOR]