Initial rough measurements of the quality of the gamma radiation from Co-60 in air indicated agreement with the theoretical calculations of Spencer and Fano for an infinite water medium. Further experiments were performed, duplicating the conditions assumed in the calculations. Since the spectral region between 100 kev and 1 mev has already been examined by Hayward, it was decided to investigate in detail the region below 100 kev and above 1.0 mev. Total radiation dosage measurements were made in water using Victoreen ion chambers. The build-up factor was measured as a function of distance. Good agreement was obtained with the results of White. The spectrum below 150 kev was examined with a small NaI(Tl) scintillation counter and both the shape of the spectrum and the attenuation as a function of distance was in good agreement with the calculations. At distance less than 30 cm from the source the spectral shape changed, gradually broadening with the peak shifting to higher energies. The primary region above 1.0 mev was examined using a large NaI(Tl) crystal, and the gradual loss of resolution in the two primaries as a function of distance with an increase in lower energy events was shown. The measurements to …

This report is a summary of the neutron attenuation data which have been obtained at the Brookhaven shielding facility on a mock-up of the fuel-rod-unloading plug used in the KAPL Reactor. Before this program was initiated, a number of small scale tests had been made in the ORNL lid tank on carbon steel mock-ups of components of the rotating plug. The results of the tests indicated considerable neutron streaming through the vertical steel and air members of the plug. However, the lid tank source strength and dimensions did not permit the tests to be extended to the full plug height. In view of the concern aroused by the ORNL tests and the absence of fundamental information on the transmission of neutrons through steel and the addition height (12') available here resulted in a request for BNL to construct and test a mock-up of a sector of the SIR top plug in accordance with KAPL specifications.

This report is the culmination of a year of progress and planning in the high-energy particle field. During this year the Brookhaven Cosmotron has been successfully completed and brought into operation for research at 2.3 Bev. Preliminary experimental results with the copious output of π-mesons are in process of publication. Multiple production of mesons has been observed, a few V-particles detected, and the interactions of π-mesons in hydrogen have been studied. Yet it already appears that higher energies will be needed to produce and study the several new heavy particles detected in cosmic ray observations.

A number of questions have arisen in regard to the interpretation of personnel monitoring results reported to users of the Brookhaven neutron monitoring service. The original announcement was rather brief and did not contain most of the technical characteristics upon which an evaluation of results must be based. The following paragraphs have been composed with the hope that they will clarify the meaning of the exposure reports.

Report issued by the Brookhaven National Laboratory discussing non-overload amplifiers, including features, performance, and improvements of amplifiers. This report includes illustrations, and photographs, as well as errata at the end of the report.

In recent months, experiments investigating the total, non-elastic, transport, etc., cross-sections of U-238 have been performed. It is the purpose of this memo to examine these data and to obtain from them information which will be of use in refinements pile calculations. In cases, e.g. transport cross-sections, where experimental data do not suffice, the theory developed pertaining to the continuum model of the nucleus has been depended upon. One of the fundamental requirements of this model is that the spacings of the energy levels in the compound nucleus are small compared to their widths and that consequently many levels are excited by the incoming particles. As a result there are many more modes of decay and the continuum model is an average over these levels.

The following report concerns the application of a relaxation mesh method for the determination of the average flux within the moderator of a light water moderated, 1.027 per cent U-235, hexagonal lattice with a volume ratio (V_H2O + V_Al)/V_Uranium of 4:1. It was hoped that the calculation would enable one to determine any differences in flux which might result from the fact that the unit cell is a hexagon instead of a cylinder. Because we were primarily interested in the effect due to geometry we applied the same theory, diffusion theory, to the hexagon by means of the mesh method and to the equivalent cylinder.

The method of spherical harmonic tensors developed Mark for solving the Boltzmann transport equation in isotropic media is herein extended to anisotropic media for cylindrical geometry. A formal solution is given for the case of two concentric cylindrical media, A and B, but no numerical work has yet been done. The following treatment differs from a similar one by the H. K. Ferguson Co. in that the external medium B is assumed to be both a neutron absorber and finite in extent rather than a non-absorber and infinite in extent.

This memorandum clarifies the present status of ξ measurements in the uranium-water lattices.

We consider here the accuracy of relaxation lengths measured during the water-uranium lattice experiments. Since such an analysis for all measurements would take a great deal of time, we have applied it to just one lattice. This one (2:1 water-to-metal ratio) was chosen completely at random.

A study has been made of entrainment generation in a submerged coil evaporator and a vertical-tube natural circulation evaporator. Both evaporators generated about the same amount of entrainment at comparable boil-up rates. The decontamination efficiency of a submerged coil evaporator is correlated to the boil-up rate. The efficiency of a bubble-cap column, a Raschig ring packed tower, and a glass wool packed tower as de-entrainment devices was studied, the glass wool packed tower proving to be the most effective.

The proton beam in the Cosmotron is accelerated to an energy of 2.3 billion electron volts by a radio frequency voltage which is impressed across an insulated gap in the ferrite loaded accelerating cavity of the vacuum chamber. To maintain a constant orbit radius as the beam is accelerated, the frequency of the accelerating voltage must increase from the initial value of 370 kc/sec to 4200 kc/sec during the one second magnet pulse. Over the entire 11:1 frequency range, a minimum gap voltage of 2000 volts rms must be maintained. At every instant throughout the magnet pulse, the frequency of this voltage must be a predetermined function of the magnet field to a high degree of accuracy. Frequency errors greater than about .2 percent result in loss of beam due to excessive radius changes. Smaller errors than this however, can excite fatal phase oscillations in the beam if they occur rapidly. As little as .005 percent frequency modulation can result in total beam loss if it occurs at a rate of several kc/sec, where the beam is most sensitive to such disturbances.

Radiation damage to graphite has several consequences of practical importance. The growth of graphite under radiation (Wigner's disease) in production reactors has always been a serious concern. The thermal conductivity of graphite decreases greatly with time of irradiation and is important in long range studies of reactor temperature problems.

The rotary rain indicator, an electrical device for recording the time of beginning and ending of periods of precipitation, was developed at the Brookhaven National Laboratory Meteorology Group and has operated successfully for eight months. Its sensitive element consists of a rotating grid whose circuit may be completed by a drop of water.

In the memorandum entitled "Stored Energy in BNL Reactor Graphite", dated February 25, 1953, there is described an experiment conducted by Gurinsky's group to determine the energy per gram of irradiated graphite released in a 200°C anneal. Similar experiments were subsequently conducted by W. Kosiba, differing from the original in two particulars: a) Instead of two graphite samples, one normal, and one irradiated, Kosiba used only an irradiated sample which he heated first to release the stored energy, and then again after the energy was released. In this way, he obtained time against temperature curves for both normal and irradiated graphite from the same sample. (These curves are graphed for each run in Figs. 1 thru 5.) b) The vycor tubing used in the original experiment was not used by Kosiba. Five runs of this experiment were selected, Runs 4P, 13, 36, and 40 at furnace temperatures of 200°C, and Run 45 at a furnace temperature of 400°C.

A series of measurements of ε in slightly enriched uranium, light water lattices is presently under way at Brookhaven. Figure 1 shows ε as a function of water-to-metal ratio for .600" diameter rods, of 1.3% enrichment. Because of interaction between neighboring groups of rods, ε increases rapidly as the water-to-metal ratio decreases.

A series of measurements was performed to investigate the gamma ray spectra, in the region from about 100 kev to about 3 Mev, resulting from the capture of thermal neutrons in a number of elements. The purpose of the experiment was to supplement the high energy capture gamma ray data in order to remove some of the ambiguities from the proposed energy level schemes and to obtain information for the Shielding Group of Brookhaven National Laboratory on elements normally found in reactors.

Selective incorporation of radioactivity from proteins of labeled chorio-allantoic grafts of adult chicken tissues into proteins of homologous tissues of host chick embryos.

By heating the normally cool areas of graphite to temperatures of 200°C or higher, it is evident that a substantial portion of the energy stored will be released. The physical dimension change which is associated with the radiation damage of graphite has been noted to partially recover under laboratory conditions when this amount of stored energy is released. This latter phenomenon is of prime interest in this operation. If a dimension recovery is noted on the gross structure, a solution to certain formidable operating problems may have been achieved.