A buncher and pre-accelerator for A-12 is described that has 360 degree acceptance and could handle a current of one ampere from a low voltage source.

Early in the design of the Mark I accelerator it was decided to install magnetic lenses in the drift tubes. A number of model magnets were constructed and tested to determine the best design for these lenses. This report includes only the results of the tests on the final models of the magnets that are designed for Mark I.

Isotopes of americium and curium with mass numbers less than 242 have been produced by cyclotron bombardment techniques, and several of their nuclear properties have been investigated. The partial alpha half-lives of Am(239), Cm(241), and Cm(240) and the partial half-life for spontaneous fission of Cm(240) were measured. The alpha decay daughter of Cm(238) was found and evidence for the discovery of Am(237) (an -1 hour electron capture activity) and Cm(239) (an -10 hour electron capture activity) has been presented. An Appendix indicating the conditions for separation of the plus three actinides by selective elution from ion exchange resin with citric acid has been included.

The free streaming of neutrons in a cylindrical cavity is investigated. Using experimental data for the flux distribution along the walls, the direct beam hole loss and leakage into the target from the lattice is estimated for the MTA system.

Quarterly summary report of studies conducted through the University of California Radiation Laboratory. Some results reported in the report may be of a preliminary or incomplete nature.

In the past it was felt that the easiest way to treat a three group equation for a MTA lattice was to solve it without certain terms. This iterative procedure converged rapidly for a medium with depleted uranium fuel, and in fact, a second iteration was not needed.

A quarterly summary of reports that have been published on research being conducted at the University of California Radiation Laboratory

An outline is given for mismatch and delay measurements methods on air dielectric transmission line components, and techniques for square wave testing are outlined. Equipment design of the needed pulsers, attenuation and delay sections, and high speed oscilloscopes is disclosed. The final section of this report is devoted to measurements and how to analyze results

Secondary charge effects from a 10 kilovolt proton beam and their effect upon beam current measurement are investigated. A collector is designed for beam current metering of a 60 kilovolt proton beam by means of charge measurement and energy measurement.

The proper roof thickness to correspond with a given side wall thickness has been estimated fro experience with the 184 feet cyclotron, which has indicated that a roof of about 1 1/2 feet should accompany a wall of 5 feet, and a roof of 4 feet should accompany a wall of 15 feet. For the roof area involved, this should bring about the condition that down-scattered neutrons in the working areas are but a small fraction of the neutrons coming through the side walls.

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 …

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.

The problem of photosynthesis is the problem of defining the way in which green plants are able to convert electromagnetic energy into chemical potential in the form of reduced carbon, usually as carbohydrate, and molecular oxygen. The use of tracer carbon, as carbon-14, has made possible considerable progress in the mapping of the routes taken by the carbon atom from CO2 into plant substances. The techniques of separation and identification that have made this progress possible lie largely in the region of chromatography and radioautography involving fractional-gamma amounts of material. A number of proposals have been made about the photochemical act itself. These proposals have led to the development of direct physical tests of their validity, and some results of these will be described.

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.

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.

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.

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.

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.

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.

Statistical methods were employed to measure relative values of electron loading and spark-over voltage for a large number of unoutgassed electrode materials. Test voltages up to 110 KV were employed in vacuum of the order of 10<sup>-7 mm Hg. All metals showed a square root dependence between spark-over voltage and spacing.

Quarterly progress on the metabolic properties of various materials, radiation chemistry, biological studies of radiation effects, health chemistry, health physics.

At high excitation energies, competition of proton and c-particle emission with neutron emission becomes important. For low excitation, the competition between Y-emission, neutron emission, and fission should be taken into account. To aid in the evaluation of this competition an experiment has been performed to measure the number and energy spectrum of the protons and c-particles emitted in the high energy bombardment of uranium with protons, deuterons, and c-particles.

This is an extension of the results reported in UCRL-2203, where bore diameter is determined in a linear accelerator.