A report is given of the activities of the 1977 ISABELLE Summer Workshop, held from July 18 to 29, 1977 at the Brookhaven National Laboratory. An abstract was prepared for each of the seventy-four separate presentations for inclusion in DOE Energy Research Abstracts (ERA). (PMA)

A study was made to examine the effects which raising the ISA from 200 x 200 GeV to 400 x 400 GeV would have on the ''canonical'' experiments. These were ''canonical'' in the sense that they span the full range of foreseeable physics and have served as topics in previous Summer Studies and Workshops which resulted in quite explicit hardware designs and experimental goals. The study results indicate that all of the ''canonical'' experiments survive. Some are actually improved, some are unaffected, and some require changes which are suggested. In general, the 90/sup 0/ experiments are relatively unaffected. The single arm small angle spectrometer, the wide aperture (FATS-WASP) spectrometer and the Coulomb interference experiment have the largest number of modifications suggested. No uniqueness to these solutions are claimed, and there may be more desirable radical approaches. It is, however, felt that the 400 x 400 GeV ISA not only permits the work on conceptual experiments from previous Summer Studies to be taken over entirely, but indicates areas of improvement in many of them. Specifics of the individual experiments are discussed.

Preliminary design and performance test results for fast optical shutters intended for use in the Nova high power fusion laser system are briefly described. Both an opening shutter to protect the pellet target from amplified spontaneous emission (ASE), and a closing shutter to protect the laser from light reflected back from the target are discussed. Faraday rotators, synchronized by a 400 Hz oscillator, provide an opening shutter mechanism with an opening time of approximately 10 ..mu..s. A plasma closing shutter, employing electrical sublimation of a foil, provide a shutter closing time of 70 ns +- 20 ns. Energy for foil sublimation is provided by discharge of a 42 J capacitor bank. Implementation of these shutter techniques in the Nova system is anticipated to improve laser output power and efficiency. (RME)

A 25 megajoule, 20 kV capacitive energy storage and delivery system has been built and tested for Shiva--a 20 arm, 10 kJ, 20 TW neodymium glass fusion research laser. This system supplies over 3.5 megamperes to xenon flashlamps for optical pumping of the laser amplifier. About 15% of the energy is used to establish magnetic fields within Faraday rotator glass. A digital based control and diagnostics scheme is employed through the entire pulse power system. This scheme utilizes a distributed digital data bus that addresses every element through two levels of optical isolation. The interfacing of low level digital circuitry to a pulse power environment is discussed, as well as the design and performance of the total system. Cost and manufacturing details are important in a project of this size. The projected cost goal of 27 cents/joule, installed and operating, has been met. The general approach to the design, transient analysis, manufacture, and activation of this large power conditioning system is also discussed.

The absorption of intense laser light is found to be reduced when targets are irradiated by 1.06 ..mu..m light with long pulse widths (150-400 psec) and large focal spots (100-250 ..mu..m). Estimates of Brillouin scatter which account for the finite heat capacity of the underdense plasma predict this reduction. Spectra of the back reflected light show red shifts indicative of Brillouin scattering.

There are many experimental elementary particle objectives which are uniquely achievable with polarized proton beams. These objectives require both higher beam energies and intensities than are presently available. The polarized ion source working group concluded that it looks quite practical to produce polarized H sources with output currents of several mA. The significance of this is best demonstrated by the fact that the ZGS operates at its space charge limit using a 6 mA H/sup -/ impolarized ion source and charge exchanger injection. Thus, polarized H/sup -/ ions offer the possibility of operating high energy synchrotrons at their ''normal'' intensity. With interesting physics to be done and the high probability of adequate intensities for both fixed target and colliding beam machines, the question to be answered is whether or not it is possible to accelerate polarized protons and/or deuterons to energies above the presently available 12 GeV/c of the ZGS and to store beams in a colliding beam machine such as the ISR or ISABELLE. This question was considered by the accelerator physics working group, and the conclusions reached are discussed.

To meet neutral-beam source requirements, a combination series switch/regulator system has been developed that can provide up to 40-kV at 80A output for 10-ms from the continuously decaying voltage of a charged capacitor bank. The system uses 100% feedback control of a series hard tube regulator. This feedback regulator is able to maintain a 40-kV output level for 100% load variations while the source voltage for the capacitor bank is drained from an initial 55-kV down to as low as 43-kV during a 10-ms pulse. In addition to controlling the output voltage, the series regulator tube also serves the dual role of a disconnect or interrupt switch at the end of each pulse and during the frequent occurrence of a neutral-beam source fault. In the interrupt mode, complete disconnect is achieved in less than 2-..mu..s after first observance of a fault condition; recovery times to normal operation of less than 10-..mu..s after fault clearance can be attained if desired.

LEED theory has developed to the point where the diffraction beam intensities can be computed using the locations of the surface atoms as the only adjustable parameters. The position of atoms in many clean monatomic solid surfaces and the surface structures of ordered monolayers of adsorbed atoms have been determined this way. Surface crystallography studies are now extended to small hydrocarbon molecules that are adsorbed on metal surfaces. These studies are reviewed. (GHT)

When the plasma outflow velocity relative to the critical surface is supersonic, compressional density profiles can form in the critical region. These compressions involve dissipative processes like those in collisionless shocks; associated plasma instabilities and reflected ions may inhibit energy transport and enhance laser light absorption.

A calculation is presented for the final bunching of a particle beam in a synchrotron or storage ring. The voltage per turn, the harmonic number, and the bunching time are obtained. (PMA)

This paper discusses the current status of reactor design for heavy ion fusion.

It is shown that recently published observations of angle- and polarization-dependent absorption of intense laser light are consistent with computer simulations of resonance absorption in a steepened plasma profile, with the additional assumption of a modestly rippled critical surface. About 10% absorption seems to be due to mechanisms not addressed in the simulations.

The continuum ..gamma..-ray spectrum following neutron emission in a (HI,xn) reaction consists of a high-energy tail, the statistical cascade, and a lower-energy bump, the yrast cascade, which contains most of the intensity and consists mostly of stretched E2 transitions. Thus, a good approximation to the average angular momentum carried by the ..gamma..-rays is 2N/sub ..gamma../-bar. Under favourable conditions, effective moments of inertia can be deduced for states up to the top of the ..gamma..-ray cascade. The maximum angular momentum in the cascades is probably limited by ..cap alpha..-emission for nuclei with A < 150 and by fission for those with A > 150. 17 figures.

Numerical methods are capable of solving very difficult problems in solid mechanics and gas dynamics. In the design of engineering structures, critical decisions are possible if the behavior of materials is correctly described in the calculation. Problems of current interest require accurate analysis of stress-strain fields that range from very small elastic displacement to very large plastic deformation. A finite difference program is described that solves problems over this range and in two and three space-dimensions and time. A series of experiments and calculations serve to establish confidence in the plasticity formulation. The program can be used to design high pressure systems where plastic flow occurs. The purpose is to identify material properties, strength and elongation, that meet the operating requirements. An objective is to be able to perform destructive testing on a computer rather than on the engineering structure. Examples of topical interest are given.

The techniques of stepwise laser excitation were applied to obtain Ryberg series in the lanthanides and in uranium. The methods employed circumvent many of the experimental difficulties inherent in conventional absorption spectrosopy of these heavy atoms with very complex spectra. The Rydberg series observed have allowed the determination of accurate ionization limits. The values in eV are: Ce, 5.5387(4);Nd, 5.5250(6); Sm, 5.6437(10); Eu, 5.6704(3); Gd, 6.1502(6); Tb, 5.8639(6); Dy, 5.9390(6); Ho, 6.0216(6); Er 6.1077(6); U, 6.1941(5). A comparison of the f/sup n/s/sup 2/-f/sup n/s ionization limits as a function of n with theoretical calculations is made.

There is a great deal of experimental evidence associating selective bond breaking ability with low coordination number surface sites on transition metal surfaces. Atomic steps break H-H and C-H bonds efficiently while kinks in the steps are required for additional C-C and C=O bond scissions. The blockage of some of the ''active sites'' yields the reaction selectivity commonly observed as a result of alloying or upon introduction of certain promoters. Another important parameter in controlling transition metal catalytic activity is the formal oxidation state of the surface metal atom. Oxidation of the surface atoms by oxygen or halogens or their reduction by electron donors (carbon, alkali metals, etc.) changes markedly the catalytic surface chemistry. H/sub 2/-D/sub 2/ exchange, hydrocarbon conversion reactions and the hydrogenation of CO are examples to demonstrate the importance of low coordination number sites and surface oxidation state in controlling catalytic activity and selectivity.

Two types of MOS detector arrays were used to sense directly patterns of soft x-rays, in the Lawrence Livermore Laboratory experimental laser-fusion program. A linear self-scanning photodiode array (SSPA) is used in a wave-length-dispersive spectrometer. A frame transfer charge-coupled device (CCD) facilitates the use of an x-ray microscope. Measurements and calculations of the x-ray sensitivity of these devices are presented. Their linearity and dynamic range are discussed, as well as data recovery systems for each detector. Experiences in using these devices to detect pulses of x-rays in laser-fusion experiments are described.

In an exposure of the Fermilab 15' neon (64 atomic %)--H/sub 2/ bubble chamber to a broad band anti ..nu.. beam, 3 ..mu../sup +/e/sup -/X and 6 ..mu../sup -/e/sup +/X events (with estimated backgrounds 1.1 and 0.6 events, respectively) were found with the ..mu../sup +-/ identified in the EMI. The fractions of ..mu../sup +/e/sup -/ and ..mu../sup -/e/sup +/ production relative to anti ..nu../sub ..mu../ and ..nu../sub ..mu../ charged current interactions are respectively anti f = (0.10 +- /sub 0.07//sup 0.13/)% and f = (0.34 +- /sub 0.13//sup 0.23/)%, giving anti f/f = 0.3 +- /sub 0.2//sup 0.5/.

This paper describes the Fiber Optic Telemetry System designed to operate in the hostile particle and electromagnetic radiation environment of the High Voltage Test Stand. It discusses system criteria, components, packaging, and performance. In all tests to date, the system exceeds its design goals with very comfortable margins. It is well advanced into the fabrication stages with all crucial components tested and only straightforward TTL (Transistor Transistor Logic) circuitry to be completed.