Photoconductive x-ray detectors are becoming an important x-ray diagnostic as a result of their small size, fast response time, and high sensitivity. We are developing a discrete array of neutron- damaged GaAs detectors to be used in an imaging x-ray spectrometer, and we describe herein the techniques we use to fabricate and characterize them for an upcoming experiment. Using a 225-ps x-ray pulse from a laser-produced plasma, we measured the sensitivity and time response of the detectors to be 7.1 mA/W and on the order of 150 ps FWHM, respectively. The carrier mobility is 741 cm/sup 2//V/center dot/s at a bias of 2 /times/ 10/sup 4/V/cm. 6 figs.

We have developed a radiation-to-coherent light converter (RCLC) with a monolithically integrated semiconductor chip that consists of a chromium-doped GaAs photoconductor detector modulates the laser diode, which has been biased above the lasing threshold, thus converting a radiation pulse to an electric pulse and then to a light pulse. The laser pulse is then transmitted to a fast recorder through a high-bandwidth optical fiber. In the absence of a single-step x-ray pumped laser, our converter appears to be the first integrated device that can efficiently convert x-ray flux into coherent light. This device has been tested successfully with the 50-ps electron beams of a 17-MeV linear accelerator and with 50-ns x-ray pulses from a Z-pinch plasma source. 2 refs., 9 figs.

In the final design of the DO Detector, the three cryostats (CC and both EC's) will ride on a pair of hardened ways so as to move the EC's out and away from the CC cryostat to provide access between cryostats for repairs and such. Each of the cryostats sits on a carriage which has a pair of Tychoway rollers placed at each corner to roll on the hardened ways. When in position, the full weight of the cryostats is to be relieved from the rollers with the use of a pair of 90-ton jacks flanking the pair of rollers at each corner. Due to confined space, these jacks had to be custom made, triple cylinder, single block units. Five manufacturers were presented with the problem and three came back with proposals. All three satisfied the technical requirements but Ram-Pac International was easily the lowest priced.

In this paper we discuss the interaction of a continuous electron beam with wake-field generated plasma waves. Using a one-dimensional two fluid model, a fully nonlinear analytical description of the interaction is obtained. The phenomena of continuous beam modulation and wave period shortening are discussed. The relationship between these effects and the two-stream instability is also examined. 12 refs., 1 fig.

A number of recent developments in research on blood cell labeling techniques are presented. The discussion relates to three specific areas: (1) a new in vitro method for red blood cell labeling with /sup 99m/Tc; (2) a method for labeling leukocytes and platelets with /sup 99m/Tc; and (3) the use of monoclonal antibody technique for platelet labeling. The advantages and the pitfalls of these techniques are examined in the light of available mechanistic information. Problems that remain to be resolved are reviewed. An assessment is made of the progress as well as prospects in blood cell labeling methodology including that using the monoclonal antibody approach. 37 refs., 4 figs.

The basic physical processes associated with collisionless magnetic reconnection are investigated using the implicit PIC code AVANTI. The code is based on a 2.5-D fully electromagnetic direct implicit algorithm which has proven stable for arbitrary time step. This stability makes it possible to separate out the respective roles of the highly magnetized electrons and the un-magnetized ions for large ion-electron mass ratios. It is found that the inclusion of a guide magnetic field (magnetic shear) severely slows the initial stages of reconnection and damps out the electrostatic ringing if local values of the guide field are above a threshold determined by questions of electron mobility. 9 refs., 6 figs.

A fusion materials irradiation facility is required for the timely and cost-effective development of economical fusion power. Our conceptual machine provides sufficient neutron fluence for accelerated lifetime material tests in a time span of 1--2 y while producing less than 1 MW of fusion power. Neutral deuterium beams at 150 keV are injected into the center of a high-density warm tritium plasma housed in a 12-m-long cylindrical vessel. Superconducting magnets hold the plasma, which transfers the power to each end of the solenoid. The stainless steel end sections absorb the beam power and are externally cooled by high-pressure water to maintain the plasma-side wall temperature below 740 K. A service loop separates tritium from deuterium in the plasma effluent. Tritium is reinjected at each end. 9 refs., 2 figs., 2 tabs.

On April 26, 1986 the world's worst nuclear power plant accident occurred at the Unit 4 of the Chernobyl Nuclear Power Station in the USSR. This paper presents a discussion of the design of the Chernobyl Power Plant, the sequence of events that led to the accident and the damage caused by the resulting explosion. The structural design features that contributed to the accident and resulting damage will be highlighted. Photographs and sketches obtained from various worldwide news agencies will be shown to try and gain a perspective of the extent of the damage. The aftermath, clean-up, and current situation will be discussed and the important lessons learned for the structural engineer will be presented. 15 refs., 10 figs.

We made a minimal set of AC magnetic measurements of the engineering model of the ALS Booster Dipole Magnet as part of the process of qualifying its design for production. Magnetic induction integrals over paths approximating electron-beam trajectories were measured with long curved coils connected to an electronic integrator. Magnetic induction was measured with point coils and an integrator and independently with a Hall-effect Gaussmeter. These quantities, and magnet current, were displayed on a commercial digital storage oscilloscope as parametric functions of time. The displayed waveforms were stored, processed and redisplayed as representations of selected magnet parameters. A waveform representing the magnet's effective-length was created by dividing the integral waveform by the magnetic induction waveform. Waveforms of the transfer functions were produced by dividing both the integral waveform and the magnetic induction waveform by the current waveform. Pairs of matched coils, connected in series opposition, provided differential measurements of field uniformity. Quadrupole and sextupole coefficients were derived from the uniformity data. These magnet parameters were measured at 2 and 10 Hz frequencies. Together with measurements of the magnetic field at selected dc levels, the ac measurements demonstrated that the magnet design met specifications and qualified it for production. 7 refs., …

Two different acceleration schedules have been implemented in MBE-4 and the resulting longitudinal emittance measured in each case. The question arises, whether this measured longitudinal emittance is small enough so that when scaled up to a driver, using induction pulsers of the same quality, the stringent constraint on {Delta}p/p at the final focus can be met.

The maximum credible accident (MCA) approach to accident analysis places an upper bound on the potential adverse effects of a proposed action by using conservative but simplifying assumptions. It is often used when data are lacking to support a more realistic scenario or when MCA calculations result in acceptable consequences. The MCA approach can also be combined with realistic scenarios to assess potential adverse effects. This report presents a guide for the preparation of transportation accident analyses based on the use of the MCA concept. Rail transportation of contaminated wastes is used as an example. The example is the analysis of the environmental impact of the potential derailment of a train transporting a large shipment of wastes. The shipment is assumed to be contaminated with polychlorinated biphenyls and low-level radioactivities of uranium and technetium. The train is assumed to plunge into a river used as a source of drinking water. The conclusions from the example accident analysis are based on the calculation of the number of foreseeable premature cancer deaths the might result as a consequence of this accident. These calculations are presented, and the reference material forming the basis for all assumptions and calculations is also provided.

Added mass values for plates partially submerged in water are obtained from a series of experiments. Both solid and perforated plates are tested. Each plate is circular and is constrained to move as a piston in a horizontal cylindrical container. Water flow past the perimeter of a plate is controlled by the narrow gap between the container and the edges of the plate. The perforated plate has an equilateral triangular pitch pattern of circular holes. The plate vibrates as a rigid mass on a flexible suspension system. The plate excitation is produced with an impact hammer, although shaker excitation is used to confirm natural frequencies. The natural frequency of the plate is measured for seven water levels in the container ranging from empty to full. For each water level, added mass is computed using the ratio of the natural frequency in air to the natural frequency in water. The added mass for fully submerged plates is compared to published experimental and theoretical results.

This report is about an Alternative Injection Scheme for Heavy Ions into RHIC

A module has been designed that may be used to demodulate amplitude and phase information in radio frequency systems. This design has been used on PLT and is currently in use on TFTR. 8 figs.

Livermore will have an operational Accelerator Mass Spectrometer (AMS) by mid-1989 as part of its new Multi-user Tandem Laboratory. The spectrometer was designed primarily for applications in archaeology and the geosciences and was co-funded by the University of California Regents. Radiological control for personnel protection, ion sources and injection systems, the tandem and all beam handling hardware are operated with a distributed processor computer control system. The Tandem is the former University of Washington injector FN which has been upgraded with Dowlish tubes, pelletron charging and SF/sub 6/ gas. Design goals for the AMS system, computer aided operation, automated measurement capability, initial results and some of our intended applications will be presented. 5 refs., 2 figs.

The main thrust of the present study has been to (a) explore the thermal analysis potentials of the ANSYS program in solving thermal hydraulic problems in the APS beamline design, (b) compare the ANSYS results with those obtained by THTB for a specific test crystal, and (c) obtain some cost benchmarks for the ANSYS program. On the basis of a limited number of test runs for the silicon crystal problem, conclusions can be drawn that (a) except for conduction problems with simple boundary conditions the utility of ANSYS for solving a variety of three-dimensional thermal hydraulic problems is at best limited, (b) in comparison with THTB program, ANSYS requires a more detailed modeling (with increasing computation time) for comparably accurate results, and (c) no firm statement regarding the cost factor can be made at this time although the ANSYS program appears to be more expensive than any other code they have used so far.

Large solid angle position-sensitive phoswich detectors have been constructed to replace smaller units in an array for detecting medium mass fragments (Z less than or equal to 15) in nuclear experiments. The position information was obtained from a time analysis method. 5 refs., 9 figs.

The experimental evidence regarding a light Higgs boson is reviewed. It is shown that a light Higgs boson with almost any mass between 14 MeV/c/sup 2/ and 1 GeV/c/sup 2/ is still allowed by existing data. The only limit in this range comes from B decay data which, for sufficiently large values of the top quark mass, excludes a Higgs boson with a mass between 2m/sub ..mu../ and /approximately/700 MeV/c/sup 2/. Discussions of light Higgs boson emission in the decays of K, ..pi.., ..mu.., /tau/, /eta/', and GAMMA are also given. 29 refs., 2 figs.

A summary of several recent studies of electroweak e/sup +/e/sup /minus// physics is provided. The significance of upcoming SLC/LEP measurements of Z and W properties is discussed, with special emphasis placed on radiative corrections and polarization. New electroweak physics at a proposed TeV e/sup +/e/sup /minus// collider is presented as a natural outgrowth of the SLC/LEP programs. Precise tests of the trilinear gauge boson vertex through W pair production, searching for the disturbance of perturbative unitarity by radiative corrections, and of the gauge structure of a Z', through polarized e/sup /minus// beams, are presented. 19 refs.

This report summarizes the results of an independent assessment by Golder Associates, Inc. of the methods used by Westinghouse Hanford Company (Westinghouse Hanford) and its predecessors to estimate the annual offsite release of radionuclides from ground disposal of cooling and other process waters from the N Reactor at the Hanford Site. This assessment was performed by evaluating the present and past disposal practices and radionuclide migration data within the context of the hydrology, geology, and physical layout of the N Reactor disposal site. The conclusions and recommendations are based upon the available data and simple analytical calculations. Recommendations are provided for conducting more refined analyses and for continued field data collection in support of estimating annual offsite releases. Recommendations are also provided for simple operational and structural measures that should reduce the quantities of radionuclides leaving the site. 5 refs., 9 figs., 1 tab.

The expected large cross-section for e/sup +/e/sup -/ ..-->.. Z/sup 0/ and subsequent decay to b/bar b/ quarks makes the Z/sup 0/ an attractive place to pursue B meson physics. In addition, the big Electroweak asymmetries, thought to exist in Z/sup 0/ decays to b/bar b/ quarks with polarized electron beams, provide an outstanding handle for observation of such effects as B/sup 0/-/bar B//sup 0/ mixing. In this paper, the feasibility of such measurements is investigated and, with relatively small samples of Z/sup 0/'s (a few hundred thousand), both B/sub d/ and B/sub s/ meson mixing are shown to be measurable. The subject of CP violation in neutral B mesons is discussed last, but presently such measurements seem to be out of reach. 7 refs., 6 figs., 3 tabs.

Misalignments of magnetic quadrupoles and biases in beam position monitors (BPMs) in the Stanford Linear Collider (SLC) linac can lead to a situation in which the beam is off-center in the disk-loaded waveguide accelerator structure. The off-center beam produces wakefields which can limit SLC performance by causing unacceptably large emittance growth. We present a general method for determining quadrupole misalignments and BPM biases in the SLC linac by using beam trajectory measurements. The method utilizes both electron and positron beams on opposite rf cycles in the same linac lattice to determine simultaneously magnetic quadrupole misalignments and BPM biases. The two-beam trajectory data may be acquired without interrupting SLC colliding beam operations. 2 refs., 5 figs.

This report addresses the beam position monitor for RHIC.

Some aspects of SLC operation and running conditions in 1988 are discussed. 4 refs., 3 figs., 1 tab.