There is but little known about the thermal process involving the dynamics and thermodynamics of the cycling liquid H2 in the chamber and those of the H2 fluid flow in the cooling coil as well as the geometrical characteristics of the chamber body. This the physical equations governing this process are involving so many variables that this analysis becomes rather complex even if simplifying assumptions are made. To those difficulties is added the ignorance even of an approximative expression for some physical quantities such as film heat transfer coefficients entering as major parameters the process equation.

Boron-10 has a high thermal neutron capture cross section (3880 barns). Following neutron capture, the subsequent nuclear disintegration produces an alpha particle and a lithium-7 nucleus with the release of an average of 2.34 MeV for the particle irradiation, and in 93% of the reactions there is also the emission of an 0.48 MeV gamma ray: [equation not transcribed]. The kinetic energy is divided between the lithium-7 nucleus and the alpha particle giving the equal and opposite momentums with a range in tissue of about 8-14μ or approximately 1 cell diameter (1). This fact and the reported favorable partition of boron between tumor and the normal brain suggested a possible therapeutic usefulness which has been investigated clinically. The object of our study is to document the biological effects of the B10 (n,α) Li7 reaction on the brain of dogs injected with boron-10 30 minutes prior to irradiation with thermal neutrons. For this, we felt it desirable to estimate a dose for the boron-10 reaction which if exceeded, produces destruction of normal tissue. This dose could then be a reference dose to be utilized as a maximal limit for the irradiation of normal tissue. We have assured that the largest fluence …

The biological evaluation of the thermal neutron capture reaction of boron-10, B10 (n,α)Li7 + 2.786 MeV, has previously been studied, using different particles from the boron-10 thermal neutron capture reaction compared with 250 kvp x-rays has been reported as 1.05 for spleen-thymic weight reduction (1), as 1.5 to 2.0 for skin lesions in pigs (2), and 1.87 for skin lesions of the rabbit's ear (3). The significance of such a calculation is felt to be unreliable for the boron-10 reaction in animals because of the vagaries of dose determination resulting from irregular boron distribution, and by the presence of an adventitious irradiation from fast neutrons and capture gammas that is inadequately determined at present. Our present experiment attempts to circumvent the difficulties attendent to studies of the boron-10 reaction in animals by comparing the effect of this reaction on the proliferative capacity of HeLa cells with those produced with 250 kvp x-ray.

The purpose of this report is to determine the amount of refrigeration capacity required to cool down the 80" bubble chamber from ambient temperature to liquid hydrogen temperature.

Reliability of individual components and the ability to produce refrigeration even if one or two of these components should be in operable are the prime design parameters of this cycle. Each component was looked at with these two parameters in mind and any item that had obvious objections was either rejected or backed up with another piece of equipment. Along this line, you will notice (refer to line schematic) two hydrogen compressors and two nitrogen compressors; for full capacity all are required. However, in the event of the loss of use of one of these compressors, it will still be possible to produce at least 50% of the rated capacity. To eliminate outside influences, the cycle was designed around what may be called a closed cycle cascade system; with the assumption that there is no loss of power, cooling water, the equipment can run indefinitely. The nitrogen and hydrogen cycles are of the Simple Linde type with pre-cooling making use of the Joule-Thompson Effect for the refrigeration produced. The low-temperature components of the cycle have no moving parts other than valves, consisting entirely of counter-flow heat exchangers to lower the temperature of the incoming high-pressure gas to a level where …

When the design of the refrigerator was begun, one of the important parameters was refrigeration capacity required. In order to estimate the required hydrogen refrigeration load the following had to be considered: 1. Dynamic Load due to pulsing of the chamber. Although this has been determined some two years ago through test work, it has not been published as of this date and will be presented here. 2. Static losses due to conduction, radiation, and convection. This is covered by Eng. Note BC-03-0-B. 3. Cool-down requirements. This is covered by Eng. Note BC-03-0-C.

The subject which I will discuss is the distorted - waves theory of direct reactions and its application to the study of nuclei. I shall mainly be concerned with a study of the reaction theory, its range of validity, and its ability to give quantitative information about nuclear structure.

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.

Technical report. From Introduction : "In a recent study by Spedding, et al. on some rare earth alloy systems, an intermediate phase was found to form when a light rare earth (ABAC stacking) was alloyed with a heavy rare earth (ABAC stacking). This intermediate phase was found to have the structure of samarium metal with the stacking ABABCBCAC and was designated "delta". Since the cause of this rather unusual structure occurring in either samarium metal or these alloys is not known the study of these phases as some of their properties is continuing in the Ames Laboratory. It was the purpose of the present study to extend our knowledge of the composition and more of formation of these phases."

The blue-green algae, classed as primitive monerans, represent the lowest level of organization known to possess a higher plant type of photosynthesis. The role in photosynthesis of the phycocyanin in these organisms is particularly interesting from the point of view of ultrastructural biochemistry. It has been shown repeatedly that despite the primacy normally assigned to chlorophyll, the light absorbed by phycocyanin is used more efficiently for photosynthesis (equated with photosynthetic oxygen evolution). This property is all the more intriguing since Hill activity is very labile in these organisms; the loss being correlated with the release of phycocyanin. Then too, it has been observed that fluorescence at about 685 mμ, attributed to chlorophyll, is proportionately greater for wavelengths absorbed by phycocyanin. French and Young attributed the differential to inactive absorption by carotenoids in the "Soret" region of chlorophyll, but Duysens concluded that the magnitude of the difference observed by him was too great to be explained by screening. Duysens proposed the existence of two pools of chlorophyll of about equal size; one containing fluorescent, photosynthetically active chlorophyll in proximity to phycocyanin, the other nonfluorescent, photosynthetically inactive and remote from phycocyanin.

We consider the kinetic isotope effect in three center reactions of the type of A+BC→AB+C. Such model calculations are a good approximation to primary hydrogen isotope effects. For abstraction or transfer reactions, B becomes H, D, or T. The dynamics of the three storm system are calculated for a general quadratic potential, with the assumption that the potential energy is constant along the reaction coordinate (flat top barrier). This model system can be calculated in detail and serves to illustrate the relationship between kinetic isotope effect and chemical bonding in the transition state. The statistical mechanical part of the calculation can be carried out exactly within the framework transition state theory or in any one of a number of approximations. The γ bar method gives particularly good insight into the chemistry of the problem with a minimum of arithmetic.

In these lectures we will discuss some examples of information about magnetic properties of solids which can be obtained by neutron scattering. We consider a scattering process in which a neutron with wave vector k and spin σ is incident upon a solid in state q>. (Here q stands for all of the quantum numbers which describe the state of the solid, such as spin and orbital electronic states, phonon numbers, etc.) After interacting with the solid, the neutron goes off with wave-vector k' and spin σ', leaving the solid in state q'>. In performing an experiment of this sort one does not usually observe the initial and final spin states of the neutron or the initial and final states of the solid. We must then sum over all possible final states and average over all initial states.

Recent underground nuclear tests conducted by the U.S. Atomic Energy Commission have yielded data on the effects of contained nuclear explosions in four rock mediums: tuff, alluvium, rock salt, and granite. This report presents and compares data obtained primarily through exploratory mining and drilling into the postshot environment of 35 such events.

First paragraph of report: M. Neumann and H. Sherrard reported the development of a wire spark chamber experiment toward receiving digitized spark information. Since late 1962 our effort has been directed toward a wire-chamber with a core memory, using standard ferrite cores, and toward an on-line operation between spark chamber and computer.

Abstract: A materials exposure program has been established in the Garigliano Nuclear Power Plant to measure the effect of neutron irradiation and time at temperate on the mechanical properties of the reactor pressure vessel steel. Base metal specimens were made from portions of the pressure vessel steel, and weld heat-affected zone and weld metal samples were taken from a weldment made from the pressure vessel steel and simulating a pressure vessel circumferential weld since there are no longitudinal welds in the forged ring shell. The specimens were sealed in helium-filled capsules and placed in the reactor vessel at locations where they will be exposed to a variety of conditions. Tensile property changes will be measured by pre- and post-irradiation tests on small tensile specimens. Fracture characteristic changes will be measured in similar fashion by Charpy V-notch impact tests. The program is planned to cover a 32-year period, with specimens to be removed for test at intervals of 1, 2, 4, 8, 16, and 32 years.

Quarterly report discussing progress on the Fast Ceramic Reactor Development Program. Information is reported on vented fuel production, transient testing of fuel, fuel performance evaluation, fast-flux irradiation of fuel, and reactor physics and core analysis.

Technical report. From Introduction : "The nuclear volume dependent isotope shift of optical spectral lines has long been a very useful means for studying the changes in the nuclear size or shape for different isotopes of heavy elements."

The purpose of this report is to compare multi-layer insulation and liquid nitrogen shielding as methods of insulating the 80-inch Liquid Hydrogen Bubble Chamber.

The angle errors of a rotary table can be accurately measured by stepping off the angles with an optical caliper and computing table error from (1) the error readings at each angle measured and (2) the cumulative caliper error that will be evident when the circle is closed at 360', eliminating the necessity of adjusting the caliper to the exact setting.

In any underground nuclear explosion, the shock front that propagates from the shot point carries with it energy from the explosion, and distributes this energy by doing work on the surrounding material. In the process, the material undergoes changes in both its physical and mechanical states. If enough energy is deposited in the material, it will vaporize or melt thus changing its physical state, or cause it to crush or crack. During the past few years, special computer codes have been developed for predicting the close-in phenomena of underground nuclear explosions using the laws of physics, and the knowledge of the properties of the materials in which the detonations occur. As a consequence, a better understanding of experimental observations and measurements has evolved.

Summary: An analytical study of the stability of the Big Rock Nuclear Reactor has been performed for the plant as built, and supplements a previous design stability study. The plant has been determined by this analysis to be very stable under every mode of operation anticipated during Phase I of the development program testing. Even under conservative assumptions of system parameters the minimum calculated gain and phase margins do not go below 13.0 db and 46 degrees, respectively. (Nor are these both reached simultaneously for the same operating condition.) These are characteristics of a very stable, well-behaved system. In addition to this analysis, a second, less conservative series of computations was performed to provide expected realistic closed loop data for comparison with Phase I test results. The most responsive test thus predicted occurs at 60 percent power, 1500 psia, minimum flow, and maximum subcooling. For this case the closed loop peak response of power to reactivity occurs at a frequency of 0.90 cycles per second with an amplitude of 3.90 db. This corresponds to an expected open loop gain margin of 16.5 db and a phase margin of 63 degrees. Although knowledge of reactor transfer function is to be determined …

This report presents the results of an analysis which was undertaken to investigate the power stability of the Consumers Big Rock Point Nuclear Power Reactor.

Programs are under way at Brookhaven National Laboratory to study the behavior of fission products released from reactor fuel materials. Major emphasis has been placed on fission product iodine because of the physiological hazard associated with the I131 isotope. A complete reactor safety analysis, considering either a slow or rapid release of fission products, requires a knowledge of the chemical and physical states of the fission products during release, the extent of their release, and an understanding of their chemical interactions with the reactor environment.

The effects of explosion-induced ground motion must be evaluated in planning and executing any nuclear excavation project. For some projects ground use intensity may dictate the use of less-than-optimum yields to minimize damaging effects. In remote areas, weighing the alternatives of outright purchase of some property or use of smaller yields may be required. The cost of indemnifying owners against damage must be considered in any case. Discussions of the effects of ground motion on three broad types of facilities - engineered structures, residential buildings, and equipment required for the support of nuclear excavation operations - are presented. A method of predicting the response of single- and multi-storied buildings, the response spectrum technique, is discussed, with emphasis on the application of explosion-induced spectra.