Technical report with short reports from the (A) Crystal Structure Section ; (B) Mass Spectroscopy Section ; and (C) Metallurgy Section.

With discussion under way concerning power production by chain reacting piles, it becomes pertinent to consider the ration of the temperature of the hottest spot in the pile to the average exit temperature of the cooling stream. This is important because the temperature of the hottest spot in the pile is one of the limiting factors in determining the maximum power at which a pile can be operated. However, the higher the temperature of the emerging cooling stream, the more efficient can be the thermal engine operated by it. Thus the ideal situation is to have the average exit temperature of the cooling stream as near as possible to the hottest temperature of the hottest spot in the pile.

Abstract. In investigating stability of a homogeneous pile it has been customary to assume that the production of bubbles follows the production of power instantaneously. Here we investigate the implications of introduction of an intermediate dissolved gas stage under two hypotheses on the formation of bubbles from this dissolved gas. It is seen that this additional stage tends to make the pile unstable.

Abstract. the Laplacian of a beryllium metal lattice with 3.3 kg of uranium metal per cell and a volume ratio of 17.2 was measured in the removable region of the CP-2 machine. the sandwich effect with different moderators made interpretation of the observations very uncertain. The best result found was Be = 407 x 10(-6) cm(-2).

Summary. The effect of the conduction electrons on the stopping power of metals has been considered from two essentially different points of view. No numerical calculations have been carried out, because we have found no completely satisfactory was of computing Z'e, the effective charge on the moving ion. A rather crude estimate made on the basis of the Thomas-Fermi atomic model indicates that Z'2/E is roughly constant. Using this relation one finds that the stopping power of the conduction electrons is of the same order of magnitude as the stopping power due to bound electron excitation, and is important for the greater part of the range of the particle.

Abstract. Irradiated Whiting graphite possesses a small negative or a positive Hall constant, depending upon the dosage. Annealing at 500 degrees C for 1 hour in helium results in a Hall constant which is large in magnitude and negative in sign. The properties of the annealed graphite are presumably close to those of the original unirradiated material. Unirradiated AGOT-K graphite has a large, negative Hall constant. A mechanism is suggested which accounts for the change in sign of the Hall constant as a result of neutron bombardment.

Abstract. the fluctuation in pile intensity caused by an oscillating point absorber is calculation. It is found that the nature of the response depends on the frequency of the impressed oscillation. If the frequency is high compared to the decay rate of the high harmonics, the response consists of a wave which is propagated away from the oscillator. If the frequency is low, the propagated wave character of the response disappears and the intensity of the whole pile tends to oscillate with the same phase. The amplitude of the response decreases with increasing frequency.

The solubility constants are presented for He , Kr , Xe , O2 , N2 , and air in H20 . Inter-diffusion constants for gases and the diffusion of gases in water are given.

Abstract. Measurements were made to determine the effect of thermal cycling on heat transfer from slug to jack using a slug with a sand blasted surface. The value of the transfer coefficient h decreased from initial values ranging from 10 to [formula], to values and [formula] after 1700 cycles, and to a range of 0.15 to 0.45 [formula] after 3200 cycles. Comparisons are made with the results found for slugs with different surfaces.

Technical report with short reports from the (1) Physics Section I; (2) Physics Section II ; and (3) Physics Section III.

Experiments wee performed to evaluate the feasibility of detecting swelled slug elements in Hanford reactors by measuring the force necessary to push the slug column in its tube. These experiments are described. The results indicate the method presents no unsolvable problems.

Abstract. Some idealized calculations (CP-807) relating to the design of heat exchangers for minimum holdup of pile liquid are presented in compact form to facilitate quick estimates. Their use is illustrated by application to a falling film type exchanger.

Abstract. Some rather idealized considerations are given regarding the depth a warped rod presses into the ribs at the places of contact. It appears that this distance may, under some conditions, be of the order of 70 times greater than for a straight rod resting uniformly on the ribs.

Abstract. The probability of exceeding assigned values of displacements or forces in simple rod models assembled from slugs picked at random is discussed, and some estimate for the statistical gain resulting from use of shorter slugs is obtained. The probability that a rod with self-warping will touch the top of the tube appears great enough to justify a recommendation of the use of top ribs.

Technical report with short reports from the (1) Physics Section I; (2) Physics Section II ; and (3) Physics Section III.

Technical report with short reports from the (1) Physics Section I; (2) Physics Section II ; and (3) Physics Section III.

When a slug has been displaced from its normal position the thickness of the water film is decreased over part of the surface, and higher temperatures may be expected where the film is thin. The experimental data necessary for an exact calculation is incomplete, but some approximate estimates ae made here with special assumption concerning the heat transfer coefficient h as a function of the angle p from the point where the water film is thinnest. Variation in water bulk temperature around the annulus due to poor mixing is not considered here.

Abstract. Successive approximations ae obtained from transport theory for the neutron distribution around a black sphere surrounded by a spherical gap and a non-absorbing medium extending to infinity. Six cases are calculated numerically to show the difference between this treatment and simple diffusion theory. The extrapolation distance and a quantity that is essentially the thermal utilization are calculated in different approximations. It is found that the neutron density in the gap, instead of being a constant as predicted by the simple theory, may vary by a factor of one-third in cases of practical interest.

Abstract. The effect of the neutron flux on the relative importance of different fission product poisons is discussed. The general expression for the poising of a fission product is given with the various equations for special cases of interest. The formulae are applied to the problem of finding the poisoning due to fission products at the end of one day in a pile operating with a flux of 4 x 10(14) neutrons/cm(2)/soc. These results are summarized in the table on page 12. Appendix I contains a revised list of cross sections x yields for all stable isotopes. Such a list was first given by Wheeler in CP-889. Appendix II contains a list of radioactive fission products with half lives greater than one day with data about yields, parents, gaseous ancestors, and numbers of neutrons.

Prior to operating a chain reacting, graphite moderated, water cooled uranium pile at Hanford, the corrosive action of water on uranium was studied. It was necessary to enclose the uranium cylinders in Al jackets. Preliminary data were available which indicated Al jacket corrosion might be influenced by the water temperature. Therefore, in order to specify safe operating conditions, it was desirable to know the temperature at any position on the Al jacket of a slug in the tube. Because of the experimental difficulties encountered in the measurement of the correct surface temperature, the problem has been attacked primarily from a mathematical standpoint. Mathematical formulae have been developed for most of the proposed Hanford designs. The purpose of this report was to evaluate and summarize the theoretical and experimental information for calculation of Al jackets surface temperatures for the design now installed at Hanford. Also, the summarized results were to be put into a form suitable for use in routine calculations. As a result of this survey, the Al surface temperature for the Hanford tube and slug design may be calculated with 15 degrees C by employing routine methods and certain simple factors and equations contained in this report. The factors …

Abstract. An apparatus for measuring the thermal conductivities materials which are moderately good conductors of heat is described. Results obtained with a sample of pure Th are given on p. 10, 12, and 13.

The problem of lining a hollow aluminum sphere, 10 inches i.d., with lunes of heavy metal foil, was assigned to this group by Dr. E. Creutz. The work was carried out under the direct supervision of Dr. D.H. Gurinsky. the problem was divided naturally into tow parts: first, forming fitting the lunes, and second, cementing hem to the inside of the sphere.

Abstract. A method for calculating jacket temperatures in a region of varying heat transfer coefficients is given Some applications are made for temperatures above a supporting rib.

Abstract. The thermal conductivity of uranium as a function of temperature is measured by comparing its conductivity with that of a sample of brass. An absolute measurement is then made of the conductivity of the brass sample. The thermal conductivities as a function of temperature of two samples of extruded uranium rod are given.