The desired neutron spectrum for the High Flux Beam Reactor under construction at BNL requires use of U-Al fuel elements with more then 30 wt% U235 in the meat. The operating cycle of this reactor requires a minimum burn-up of 20%, and preferably 40% of the uranium in the element.

One of the major, as well as first, decisions which must be taken on a large chamber is to decide on the direction of the magnetic field, i.e., vertical or horizontal. Either alternative has advantages and disadvantages ad it is the intention of this note to discuss these features.

Mammalian bone marrow contains a considerable number of small lymphoid cells (small lymphocytes and small lymphocyte-like cells). The total number of these cells (50,000 to 500,000 per mm3) depends on species, age and other factors. The origin, function and fate of these cells remain obscure in many respects. In particular, it has not been shown beyond doubt, if and to what extent small lymphoid cells enter the bone marrow via the blood stream or if their origin is in part or entirely within the bone marrow. In addition it has not been clearly shown whether or not these cells may function as multipotential hemopoietic stem cells. Results obtained from experiments with irradiated parabiotic animals and animals given regional fractioned doses of X-irradiation, and transplantation of leukocytes from peripheral blood into lethally irradiated recipients afford indirect evidence that peripheral blood of mice and rats may contain stem cells capable of DNA synthesis and division.

The vacuum system for the bubble chamber must evacuate rapidly a volume of approximately 500 cubic feet and eliminate the outgassing of a surface area of approximately 50,000 square inches. The backstreaming of oil from the diffusion pump must be kept to an absolute minimum to prevent oil films forming on the window. The vacuum system must also provide the protection against liquid nitrogen and hydrogen/leaks to prevent pressure buildup.

Speed limits of decimal counting schemes based on binary-to-decimal conversion are considered. A simple "1-2-4-8" decimal logic is described, which is inherently as fast as the basic bistable. A decade for counting in 100-200 Mc/sec range, based on this logic and the tunnel diode-transistor bistable, is presented.

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.

It has been well established that even small doses of radiation will shorten life expectancy of animals, and that in general the causes of death are the same for the irradiated as for the normal animals. When x or γ rays are compared with neutrons in their ability to shorten the life span, some interesting differences appear. All available data from different laboratories on the shortening of the life span by x or γ on the one hand and neutrons on the other, have been compared. In spite of the obvious difficulties in comparing such data, if one expresses dose in terms of the LD 50/30 dose required for acute survival, one can pool the data from other laboratories and plot them on a single graph without excessive error. Results of such a compilation for single acute exposures are shown for x or γ rays in Figure 1 and for neutrons in Figure 2.

The Brookhaven proton synchrotron (Cosmotron) is capable of accelerating protons to energies as high as 3.0 BeV. The biologic effects of particle bombardment at these energies have not been investigated but are of considerable radiobiologic interest. In addition, particle beams have long been discussed with regard to their potential usefulness in medical therapy, and actual clinical applications have been made, although at lower particle energies. Recent rapid advances in space technology have raised serious questions regarding the dosimetry of cosmic and solar radiations, the spectra of which contain energies in excess of those which have been investigated experimentally. For all of these reasons, we have recently begun a study of the effects of protons at 2.0-2.2 BeV, using the external beam of the Cosmotron.

It has been previously reported that within twenty days following bombardment of mice 10 MeV protons (as well as with 20 MeV deuterons and 40 MeV alpha particles) that atypical epithelial hyperplasia developed without underlying recognizable vascular or collagen alterations as predisposing factors. The source of these monoenergetic accelerator-produced heavy ionizing particles was the 60-inch cyclotron of the Brookhaven National Laboratory. The technique employed utilized a variable-thickness filter in the beam in order to deliver multiple Bragg peaks in depth in the path of the charged particles in the tissue being irradiated. In this way a cylinder of skin was bombarded with essentially uniform ionization limited to a depth of 1-2 mm. In some instances the epidermal lesions resulting from an exposure of 2000 to 5000 rad resembled the type of lesion considered in the skin of man to be carcinoma in situ. The eventual fate of such lesions then constituted a question of importance in the possible relationship atypical hyperplasia in the pathogenesis of carcinoma in situ and of invasive carcinoma in skin. It is with this problem that the currently reported study is concerned.

Many workers have recently attempted to evaluate the P-wave strength function from a measurement of average capture cross sections or average total cross sections in the kiloelectron volt region. The primary interest of these measurements has been to determine the strength of the spin-orbit potential in the optical model. In view of the interest in determining the size of the spin-orbit coupling and in view of the considerable disagreement group has undertaken to measure the average total neutron cross sections from 10 to 100 keV in the region of the P-wave giant resonance. The following elements were studied: Nb, Mo, Rh, Ag, Cd, and In. The wok was carried out at the BNL-AECL fast chopper facility at Chalk River, using an 88-meter flight path and a nominal resolution of 15 nsec/meter.

Recent studies suggest that the primary action of insulin is on the permeability of cell membranes. This idea may account for the effects of the hormone in broken cell preparations as well as in tissue preparations with intact cells if the concept of the cell membrane is broadened to include endoplasmic reticular extensions and the membranes of subcellular organelles. Following on the initial demonstration that insulin was bound to muscle and the elucidation of the structure of insulin, evidence was presented that this binding involves a sulfur-sulfur linkage between hormone and target tissue. In the present work, skeletal muscle cell ghosts were prepared for use in studying the chemical nature of the attachment of insulin to a relatively pure cell membrane preparation.

The angle by which a magnet deflects the trajectory of a particle in the x-z plane is proportional to the integral [integral not transcribed] taken over the trajectory wherever B≠0. Alternating gradient focusing is achieved by designing magnets so that I=I(x) varies linearly with x over a suitable x interval. Usually this is done by shaping the poles to give a linear variation of By with x while keeping the length of the magnet constant for different x. Certain advantaged may be gained by varying the effective length of the magnet with x and keeping By constant so that the integral varies properly with x. Figure 1 shows several such poles for which the trajectory length, and hence the integral (1), varies approximately from 2/3 to 4/3 of the mean value.

Technique used in deriving values of the linac ball tuner settings to produce various fields is discussed briefly, and tables showing ball tuner change numbers and values used in making up the ball tuner change numbers are given.

Abstract: "The purpose of this investigation is to determine the extent to which zirconium exhibits delayed failure (static fatigue) as caused by a combination of absorbed hydrogen and applied stress. Both notched and unnotched specimens of unalloyed zirconium and Zircaloy-2 are being initially hydrogenated to 200 ppm by means of a modified Sieverts apparatus, and delayed failure studies are proceeding at room-temperature. Thus far only preliminary data on unnotched, unalloyed zirconium are available; at the 200 ppm hydrogen level, this material appears to be relatively insensitive to delayed failure at room-temperature."

The spin of neodymium-141 was measured by the method of atomic beams and found to be 3/2. A lower limit placed on the hyperfine separation of the states with total angular momentum [formula] by second-order perturbation theory shows [formula]. A prerequisite for the determination of the nuclear spin from hyperfine-structure measurements is the knowledge of the electronic structure. The ground-state configuration of neodymium is known and the value is used throughout this work.

Studies are being made on the recovery of thorium (and uranium) from granitic rock, since this source represents a very large potential thorium reserve for the nuclear power industry. In preliminary leaching studies on 16 granite samples (containing 8-95 ppm thorium and 1.5-16 ppm uranium), maximum recoveries of thorium and uranium ranged 30-85% and 15-65% respectively, and sulfuric acid consumption was high (30-120 lbs H2SO4 per ton of granite). A relatively high acidity was needed to obtain rapid and efficient dissolution of the soluble thorium fraction. The cost of treating granite was estimated at $3.50-5.20 per ton, variations within this range being dependent primarily on differences in acid consumption for different granites. Estimated costs per pound of thorium plus uranium recovered ranged $30-500.

A reference design of a large high power density core has been established representing the available technology as of August, 1960. Reference core performance and cost should improve considerably after incorporation of improvements now under study.

"Evacuated electrical oscillating cavities frequently are found to exhibit a strong loading due to electron (or iron) multiplications, the so-called multipactor effect. This effect tends to prevent the buildup of dee voltage in cyclotrons. In conventional cyclotrons driven from external oscillators having their own resonant tank circuits the difficulties are usually slight, but in cyclotrons using a simple dee system as the tank circuit difficulties are encountered in getting the oscillator to break into full oscillation."

This partially annotated bibliography contains references on boiling heat transfer of liquid metals. Emphasis is place on boiling heat transfer of liquid sodium, liquid potassium, and liquid rubidium. The period covered is 1950 to date. References are arranged alphabetically by title. Sources used in compiling this bibliography are: Abstracts of Classified Reports, Nuclear Science Abstracts.

The attached memo by G. N. Krouse of Sturm-Krouse, Inc. gives results of a preliminary analysis of the deflections of beam holes due to thermal expansion and internal pressure in the vessel. A partial solution of the problem is suggested. Based on preliminary pressure-temperature data the following deflections were derived: Movement of horizontal beam tubes = 0.046 in. Movement of Engineering facility tubes = 0.117 in. Vertical motion of the vessel at the horizontal beam tubes due to thermal expansion may be eliminated by locating the supports in that plane. That also will reduce the expansion at the point where the slant tubes pierce the vessel wall.

Abstract. The Tory II-A reactor is a small, air cooled, high power-density reactor which is to operate at quite high temperatures. Design of the reactor is essentially complete. First operation is scheduled for late 1960 at the Nevada Test Site of the Atomic Energy Commission. Since the reactor is unshielded, the control room which houses the recording and indicting equipment is located approximately two miles from the test bunker. Signals from reactor and facility transducers are amplified in the test bunker and transmitted by cable to the control point. The kinds of quantities measures include neutron flux level, temperatures, pressures, vibration amplitudes, strain and air mass flow rate. The recording and indicating system is centered around 258 channels of 1.5 cycle per second, pulse-width modulation tape recording equipment and 72 channels of 120 cps, analogue strip-chart records. In addition, there is a number of the usual meters, scalers and slow-response strip-chart recorders.