The design of the interior portions of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility incorporated shielding and controls from the beginning of the installation of the Accelerators. The purpose of the design and analysis was to demonstrate the adequacy of shielding or to determine the need for additional shielding or controls. Two classes of events were considered: (1) routine operation defined as the annual production of 10,000 2000-ns pulses of electrons at a nominal energy of 20 MeV, some of which are converted to the x-ray imaging beam consisting of four nominal 60-ns pulses over the 2000-ns time frame, and (2) accident case defined as up to 100 2000-ns pulses of electrons accidentally impinging on some metallic surface, thereby producing x rays. Several locations for both classes of events were considered inside and outside of the accelerator hall buildings. The analysis method consisted of the definition of a source term for each case studied and the definition of a model of the shielding and equipment present between the source and the dose areas. A minimal model of the fixed existing or proposed shielding and equipment structures was used for a first approximation. If the resulting dose from the first approximation was below the design goal (1 rem/yr for routine operations, 5 rem for accident cases), then no further investigations were performed. If the result of the first approximation was above our design goals, the model was refined to include existing or proposed shielding and equipment. In some cases existing shielding and equipment were adequate to meet our goals and in some cases additional shielding was added or administrative controls were imposed to protect the workers. It is expected that the radiation shielding design, exclusion area designations, and access control features, will result in low doses to personnel at the DARHT Facility.

This document describes the results of consensus agreements reached by the DARHT Safety Planning Team during the development of the update of the DARHT Safety Analysis Document (SAD). The SAD is one of the Authorization Basis (AB) Documents required by the Department prior to granting approval to operate the DARHT Facility. The DARHT Safety Planning Team is lead by Mr. Joel A. Baca of the Department of Energy Albuquerque Operations Office (DOE/AL). Team membership is drawn from the Department of Energy Albuquerque Operations Office, the Department of Energy Los Alamos Area Office (DOE/LAAO), and several divisions of the Los Alamos National Laboratory. Revision 1 of the DARHT SAD had been written as part of the process for gaining approval to operate the Phase 1 (First Axis) Accelerator. Early in the planning stage for the required update of the SAD for the approval to operate both Phase 1 and Phase 2 (First Axis and Second Axis) DARHT Accelerator, it was discovered that a conflict existed between the Laboratory approach to describing the management of facility and worker safety.

We have measured cross sections for the (pi (+), pi (+/-)p) reactions on H-3, He-4, Li-6 and Li-7 in quasi-free kinematics at incident pion beam energy 500 MeV. An enhancement of the (pi (+), pi (-)p) cross section in this kinematics is observed. If this is interpreted as due to quasi-free scattering from preexisting Delta components of the nuclear wave function, the extracted probabilities are in agreement with theoretical expectations. (C) 2001 Elsevier Science B.V. All rights reserved.

High quality analyzing powers for the {Pi}{sup -}p{yields}{yields}{Pi}{sup 0}n reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing {Pi}N single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the {Delta}(1232) resonance. They will also be helpful for constraining the evaluation of the pion-nucleon {sigma} term from the scattering amplitudes.

Asymmetries for the (pi(-), pi(0)) reaction on polarized He-3 were measured using a 200-MeV pion beam at LAMPF. The pi(0)'s were detected with the neutral meson spectrometer in coincidence with the recoiling tritons. A recoil triton detector, consisting of scintillation-counter telescopes and a wire chamber, was used to measure the time-of-flight, energy loss, and direction of the tritons. The polarized gaseous He-3 target, developed at TRIUMF, was modified to run with two diode lasers; the polarization reached 65%. The asymmetries between theta(lab)=60 degrees and 105 degrees were found to be strongly angle dependent. The results are compared with theoretical calculations. [S0556-2813(99)02208-6].

High quality analyzing powers for the ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$ reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing $\ensuremath{\pi}N$ single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the $\ensuremath{\Delta}(1232)$ resonance. They will also be helpful for constraining the evaluation of the pion-nucleon $\ensuremath{\sigma}$ term from the scattering amplitudes.

High quality analyzing powers for the ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$ reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing $\ensuremath{\pi}N$ single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the $\ensuremath{\Delta}(1232)$ resonance. They will also be helpful for constraining the evaluation of the pion-nucleon $\ensuremath{\sigma}$ term from the scattering amplitudes.

High quality analyzing powers for the pi(-) (p) over right arrow --> pi(0)n reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing pi N single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing Powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the Delta(1232) resonance. They will also be helpful for constraining the evaluation of the pion-nucleon sigma term from the scattering amplitudes. [3S0556-2813(99)02408-5].