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.

From abstract: "The adsorption of ethane, ethylene and acetylene on clean iridium in a field emission microscope has been found to cause characteristic changes in the work function of the iridium surface. Further changes, which are time and temperature dependent, result when such surfaces are heated. Flash filament experiments have shown that the changes in work function upon heating are due to desorption reactions and that the desorbed product consists principally of hydrogen. By assuming a linear relationship between surface coverage and work function, it has been possible to determine the desorption kinetics from the observed rates of work function change at various temperatures. The results are consistent with a mechanism involving stepwise surface dehydrogenation in which a pair of hydrogen atoms is removed from the hydrocarbon molecule in each step, followed by desoption of the adsorbed hydrogen. At very high temperatures the remaining carbon atoms are removed, presumably by evaporation."

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 following report analyzes the characteristics of eight chelated uranium complexes and seven uranium ammines, prepared from the reaction of organic solutions of uranium salts with complexing agents and organic bases.

For an experiment to measure the magnetic moment of the Λ hyperon, it was necessary to extract the external beam of the Cosmotron with maximum efficiency and with minimum time duration. To accomplish this end, the standard external beam of the machine was supplemented with the Rapid Beam Ejector. It was found that, unfortunately, the ejection efficiency of the beam was less than normal when the RBE was used. Measurements of the ejection efficiency were made by irradiating polyethylene foils at the second focus of Beam 1 with 3 BeV protons. The external beam was tuned up and optimized in a standard manner. It was found that the ratio of the number of protons ejected with the RBE to the number ejected without the RBE was 0.3 in one run and 0.22 in another try. It was also observed that the RBE did not shift the position of the external proton beam focus to within ± 1/8 in.

A preliminary study of dispersing agents for thorium oxide has been completed and several of the dispersants have possible uses. Also many of the industrial dispersing agents tested are not usable with thorium oxide due to induced behavior causing balling and caking. The effects of nitric acid concentration have been observed to also effect each dispersing agent.

The following report follows the studies of electroplating on uranium and concurrent metallurgical clodding.

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.

The proposed ORNL Research Reactor is designed to serve as a general purpose research tool delivering a maximum thermal flux of 8x10^13 n/cm2-sec at the initial power level of five megawatts. Operation at power levels up to ten megawatts is proposed for such items as sufficient cooling capacity is available to handle the increased heat load. The reactor will use MTR-type fuel elements and beryllium reflector pieces in a 7 x 9 grid with moderation and cooling provided by forced circulation of demineralized water. The reactor tanks are submerged in a barytes concrete pool, filled with water, which serves as a biological shield. Experimental facilities include two 18" diameter "Engineering Test Facilities" and six 6" diameter beam holes. In addition, access to the core is available through the water of the pool. The result on the surrounding population of release to the atmosphere of a large fraction of the radioactive material in the core has been computed by two methods. It is shown that under certain conditions off-area personnel could be subjected to greater than the maximum permissible exposure. An analysis of the maximum hazard caused by the release of the entire contents of the core to the local watershed …

This memorandum sets forth a recommended uniform basis for designing the ORN shield.This includes design values for power level and emergent radiation, standards values for various material properties, and basic radiation intensities.

Abstract. An analysis is made of a proposal to obtain neutrons of 15-25 Kev energy by moderating fast neutrons in aluminum and then reflecting off titanium. The fluxes calculated do not significantly exceed those obtainable from a standard antimony-beryllium photoneutron source. Two appendices treat aspects of the transport of neutrons through a slab of finite thickness.

Despite similar atomic arrangement, Brucite (Mg(OH)2) and phlogopite (KMg3(OH)2(Al,Si3)O10) present striking difference in their infrared spectra. A single absorption band is observed in phlogopite whence brucite possesses a total of 15 bands on both sides of the fundamental. A comparison of the hydroxides with micas provides supporting evidence that the complexity of the hydroxide spectra is due to interactions between neighboring hydroxyl groups. Each mineral contains a layer of magnesium ions possessing trigonal symmetry. Both minerals contain hydroxyl ion is located in such a way that it is in contract with three magnesium ions.

The wrist badge provides a dosimeter that is useful in estimating the radiation dose to the hands and forearms. Its new shield system gives good gamma and slow neutron dose discrimination with duPont 552 film packets. The film can be evaluated using the present technique and equipment. Several attempts to develop hand dosimeters have been made. Finger rings using film have been used routinely but have not been entirely satisfactory for all situations. The wrist badge was developed to provide improved gamma and slow neutron dose measurement of the upper extremities under certain appropriate conditions. The wrist badge dosimeter is not a substitute or alternate for finger ring dosimeters but is a necessary dosimeter for some extremity exposure situations.

This quarterly progress discusses the ongoing work at the Oak Ridge National Laboratory for the quarter ending in March 10, 1952. Topics discussed include reactor theory and design, shielding research, materials research, and includes appendixes with supplemental information.

The angular distribution of fission fragments from the neutron-induced fission of several isotopes has been studied. Distributions were observed for thermal neutrons on U233 and U235, Lady Godiva leakage neutrons on U235 and U238, and 14 Mev neutrons on U233, U235, U238, Th232, and Np237. No anisotropy was observed for thermal neutron fission, whereas for Lady Godiva neutrons and 14 Mev neutrons the probability of fission along the axis of the neutron beam was determined to be higher than for fission in the orthogonal direction. Experimental results are given on pages 10 and ll.

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 following document is a note describing the building process of an improved nuclear density gauge in comparison to previous gauges, within the interval of July 1 to August 1, 1959.

Introduction: This report is principally concerned with analysis of measurements taken on the APPR-1 core during the course of the extended Zero Power Experiments (ZPE-2). The bulk of these measurements are reported in APAE No. 21. There are some additional measurements reported in APAE Memo 115. In addition to the analysis of the ZPE-2 data some re-evaluation has been made of a few of the results obtained from the first set of Zero Power Experiments (ZPE-1). The ZPE-1 measurements are reported in APAE No. 8. During the course of analysis work it became apparent that a considerable amount of basic experimental data had been taken on the APPR-1 core. It seemed worthwhile to organize this report in such a fashion that other investigators could make maximum use of this data. It provides excellent opportunity for individuals and groups interested in basic reactor reactor analysis problems to check calculational techniques. An attempt has been made to include all of the fundamental information concerning the material content and geometry of the APPR-1. This material is in included in the Appendices. In addition, cross-section files and group constants have been listed rather extensively in order that other investigators could compare results presented in …

This report follows a study that was undertaken to evaluate the practicality if removing the heat from the reactor cooling water by means of a "flash cooler" and to compare its economics with that of the conventional heat exchange system.

From introduction: "The present investigation of the properties of boron stainless steel is an outgrowth of a project started in 1947. The problem is to replace the present steel used for drop rods in the Hanford piles with a material much less subject to corrosive attack from the humid atmosphere existing at the location of the rods."

Several plates of 98.7% Th - 1.2% U 235 (clad in aluminum) were irradiated in the MTR for an integrated flux of 2.6 x 10 21 neutrons/cm2. Although these samples represent an early development in bonding of aluminum to thorium and there are better methods at present, the bond proved to be quite strong and both clad and core were dimensionally stable under irradiation. The production of uranium 233 was as much as theory would indicate and the total amount of fissionable material material after irradiation and after decay of the protactinium 233 was greater than before irradiation. A fuel element of this nature appears to offer excellent potentialities from the standpoint of radiation stability.

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.