Under the stimulus of electronic materials development - particularly thin-film studies - and the need for space environmental simulation chambers, a very rapid increase in the availability of industrial-sized vacuum components and systems operable in the ultrahigh vacuum range has taken place in the last three years. It is the purpose of this paper to explore the design considerations of ultrahigh vacuum systems for metallurgical applications.

To properly assess the "sensitivity" of explosives systems under impact conditions we must obtain detailed information on these mechanisms by which explosives are ignited by impact. It is necessary to know which impact conditions represent the greatest hazard to explosive materials, as well as to know for a given impact condition the relative responses of explosives of interest. I should like to describe to you a program sponsored jointly by the Department of Defense and the Atomic Energy Commission to attain this type of information. A wide variety of impact experiments have been conducted using geometrical arrangements of explosive, plastic, and metal which are relatively simple compared to complete ordnance systems. All of these tests have employed billets of explosive fabricated by standard production techniques, and the billets have been sufficiently large that ignition, once started, has something of the same opportunity to grow or decay as in full scale ordnance assemblies. From these relatively simple tests there has accrued much new useful information on the behavior of explosives under impact. With this new information providing a base from which to work, it is hoped that theoretical calculations on impact phenomena will in the future make a bigger contribution to …

In the course of modern physics research, the need frequently arises for storage of large quantities of electrical energy which can be periodically discharged at high peak power into a load. Until recently, the homopolar machine has been an intriguing device having considerable academic interest but little practical value. In recent years, successful machines have been developed to utilize liquid-metal brush systems. The liquid-metal brush overcomes all the problems associated with current collection power loss, frictional loss, and limiting peripheral velocity. Consequently, these machines are now worth serious consideration where high-current dc generation is required. The main purpose in setting up a homopolar generator test program was to establish the limits to which an essentially standard commercially available generator of this type could be pushed.

It has been observed that energetic gaseous ions mark their region of impingement on certain metals in color. Under identical conditions of bombardment, multicharged ions of the same gas mark their impact areas with different colors. The colors are sensitive to the type and energy of the ion as well as to the metal bombarded. These colors may result from reflections from thin films formed by reactions at the target. Because the colors indicate that thicker films are produced with increased ion energy, ion penetration depth as predicted by theory is compared with the depth indicated by the colors observed.

The following document describes the usage and results of sending pulsed beams of electrically charged particles with electrically wide range of pulse lengths and pulse repetition rates.

The most important component required for the Astron experimental facility is a high energy, high current, pulsed electron accelerator. A thin cylindrical layer of high energy electrons trapped within an axially symmetric magnetic field is the key feature of the Astron thermonuclear device. The trapping magnetic field is constant in time. Therefore, it is not possible to inject electrons and trap the electrons in this field unless during the injection phase a part of the electron energy is absorbed by some friction process. This is accomplished by means of eddy currents generated on suitable passive circuits by the current of the injected electron bunch. This method has ben described elsewhere. However, in order to achieve an effective loss mechanism the current of the injected electron beam must be over one hundred amps. Such high current beams are difficult to handle except if the electron energy is high enough so that the electrostatic repulsive force is compensated to great extent by attractive magnetive forces. Hence the electron energy required is 5 Mev or higher. Other requirements on the electron layer yield the same result.

Individual Samarkand wildtype D. melanogaster males were permitted to choose between either two white-eyed or two red-eyed females or between a red-eyed and a white-eyed female. Observations of the flies were made over a period of about two hours and premating periods, intermating periods and the durations of copulations were recorded.

Tory 11-A, the first experimental reactor in the Pluto nuclear ramjet program, will be tested in late 1960 at the Nevada Test Site of the Atomic Energy Commission. The fundamental objective of Tory II-A is to demonstrate that a high power density, high-temperature, air-cooled reactor can be successfully designed, constructed, and operated. This application places requirements on the reactor control system which are considerably more stringent than those found in previous reactor systems, both from the standpoint of radiation environment and system performance. To fulfill the system requirements a high-performance reactor control system has been designed and built; control actuation hardware has been developed which can withstand the high-radiation environment of Tory LI-A. This actuation system features radiation-tolerant electrohydraulic components: actuators, servo-valves, solenoid valves, feedback transducers, accumulators and associated hydraulic components. To provide high reliability against undesired shutdowns while carrying out high power level transients, the Tory 11-A control philosophy includes a new concept in reactor safety: reliance on a nonlocking, fast-reset safety system during accident situations. The fast-reset system acts so as to hold the programmed power level rather than initiating an irreversible "scram" action. A reactor "scram", if tolerated, could produce thermal shocks which would seriously damage the …

The Astron, a thermo-nuclear fusion research machine, requires the injection of high-energy electron at 5 MEV emery level +- 1/2 %, 200 amperes, 60 pulses per second, 0.3 usec pulse width. The accelerator will work by the induction principle with approximately 500 magnetic cores, each 1/2 inch thick lined up on centers. Each core will be pulsed by a single primary turn and the electrons forming the secondary will experience a voltage acceleration equivalent to the primary voltage upon passing by each core. The coupling in this arrangement has been tested and it is very nearly unity.

The development of high-energy charged particle accelerators such as the Bevatron and of improved nuclear-event detection devices such as the Berkeley 72-in. hydrogen bubble chamber has greatly increased the need for high-speed data reduction of nuclear events. Full exploitation of the potential of the 72-in. bubble chamber demands a very high-speed analysis system. This paper describes an approach to such a system.

Abstract: "Microwaves have been used for several years at Lawrence Radiation Laboratory to study conditions in the magnetically contained plasmas of controlled fusion research. There are two basic microwave techniques. One gives information on electron density and distribution in the plasma, the other provides data on electron temperature. This paper briefly summarizes the established techniques, discusses engineering requirements and limitations, and describes some further applications of microwaves presently being considered."

Introduction. The von Neumann stability criterion is used to analyze the stability of three types of difference schemes for partial differential equations. It is shown that, contrary to the usual rule of thumb, there exist symmetric implicit schemes for a class of equations which are unstable for every mesh-ratio but that this cannot occur if (a) there are fewer than three "space" variables or (b) the difference expression is used to approximate the mixed derivative.

The statistical behavior of measured track quantities, gap density, gap length coefficient, and lacunarity is studied. The transformations which give the expectation values of track quantities on inclined tracks are then found.

The following report describes the workings and development of the nuclear ramjet propulsion systems.

Abstract: "The cross section for the Be-9(n, t')Li-7*-->Li-7 + Y(0.477 Mev) reaction has been measured in the vicinity of 14 Mev by detecting the gamma-rays at scattering angles from 30 to 150 degrees. A time-of-flight technique was used to distinguish the gamma-rays from the high neutron background. The cross section drops from 20 mb at 13.6 Mev to 10 mb at 14.1 Mev and then rises to 30 mb at 14.7 Mev."

From Introduction: "This report is intended as a handbook for the users of the Satellite code which was developed as a general purpose satellite and space probe program. The components of acceleration, in a three-dimensional rectangular coordinate system, are integrated to produce the velocities and coordinates. These may be transformed into elliptical elements at each time step. The output, therefore, may resemble an integration in the coordinates as well as in the parameters."

Abstract: "Classical electromagnetic theory indicates that a conducting metallic shield can reduce the magnetic-radiation loss from a hot plasma (centrally located) undergoing D-D burn to less than 1%, or two orders of magnitude."

"This report presents some of the theory of operation of the Mirror Machine, and summarizes the experimental work which has been carried out...The modus operandi of the Mirror Machine is to create, heat and control a high temperature plasma by means of externally generating magnetic fields."

Apparent [Sigma] hyperon decay events in a large emulsion stack of 240 9" x 12" pellicles have been classified into those judged to have occurred at rest and those in flight. Of 36 decay events at rest, 21 secondaries were observed to be protons of about 1675 microns range. Of the events decaying in flight, 23 were decays into protons and 46 were decays into near-minimum secondaries. Attempts have been made to trace the tracks of 35 of the lightly ionizing secondaries; the results of this effort are summarized in a table.

Abstract: "The dependence on mean electron kinetic energy of the ratio of intensities of [lambda]5015[HeI] and [lambda]4686[HeII] has been calculated. A low-density plasma is considered, the principal assumptions being that the reaction processes are governed by electron collisions and the electron energy distribution is Maxwellian. The results show a fairly large variation of the intensity ratio within the range of 3 to 7 ev."

The following document presents an analysis on a phase-shift of p-p scattering with various measurements in Mev.

Abstract: "Fast neutron effects on a widely used x-ray film have been investigated. The neutron flux was provided by the (d, t) reaction of a Cockcroft-Walton accelerator. Integrated exposures to 10-10 n/cm-2 were given the film. It was found that perturbations on film that were pre-exposed to Co-60 gamma rays from 10 to 2000 r were negligible. Simultaneous exposure of neutrons plus gammas also indicated negligible effect on the film insofar as the gamma dose was concerned."

From abstract: "This progress report describes four IBM 704 codes developed and used by UCRL, Livermore, to investigate the motion of any object in the force fields of the sun and any or all of the planets and their satellites."

Abstract: "Components for switching large stored energies have been under development at the University of California Radiation Laboratory at Livermore. Applications and problems are discussed. Work has been done on a low inductance ignitron. A test and development program of 5550 type 2" ignitrons has led to a tube good at 10 kv for pulses of 30 ka with a decay time of 500 μs. Times for transfer of the arc to the wall have been measured for several types of ignitrons. A 4"-insulated cathode ignitron has been developed for pulses of 10 ka for 20 ms. The firing delay and jitter of 2" ignitrons has been found to be as low as 0.25 μs and 0.06 μs, respectively."