Abstract. A series of paired explosions in a salt mine near Winnfield, Louisiana, has been conducted to test a theory by Dr. A. L. Latter concerning seismic decoupling by underground cavities. The theory predicted a decoupling of about 100. Free-field and surface measurements from an explosion in either a 6-ft- or a 15-ft-radius spherical cavity were compared with similar measurements from a completely tamped explosion. Shot sixes were from a 10 lb up to a few tons. Surface measurements were made out to 100 km and covered the frequency range from 0.05 to 100 cpa. The experiment confirmed that decoupling does occur. The actual decoupling factor as a function of frequency is presented and compared with the Latter theory.

The following report studies the interactions of K-mesons in nuclear track emulsions and measures range-energy.

An exact treatment of the structure of tracks in nuclear research emulsion recently was attempted with some success. Many of the proofs also appear to be generally valid for bubble tracks in Wilson chambers. This is a summary of the results that are applicable to tracks of charged particles in bubble chambers.

Abstract: "The problem of maintaining livable oxygen and carbon dioxide pressures in a closed space in which men must live leads to consideration of the possible use of the photosynthesis of green algae. A calculation based on the known respiratory rate of man and the photosynthetic rates of Chlorella indicates that it would be feasible to use algae for this purpose."

Abstract: "The quantities of interest in a confined plasma include the electric and magnetic fields, current density, diffusion velocity, temperature, pressure, and particle density. Equations governing the distribution of these seven variables are given in this report and special cases of a one-dimensional steady-state plasma are examined in detail. The solutions are given in graphical form."

The second and third law methods of thermodynamics are used to obtain the enthalpies of vaporization of the halides of Be, Mg, Ca, Sr, Ba, Zn, Cd, Hg, Sn, Pb, Ti, V, Cr, Mn, Fe, Co, Ni and Cu. Molecular and free energy data necessary for such calculations are presented. The structure of bonding in these molecules is briefly discussed.

The basic information about the path of carbon in photosynthesis is reviewed, together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From the combination of these, a structure for the grana lamella is suggested and a mode of function proposed. Experimental test for this mode of function is underway; one method is to examine photoproduced unpaired electrons. This is discussed.

The following report proposes a concept of a transient version of Astron thermonuclear reactor while describing the basic concepts of the reactor and the design criteria.

The vibrational eigenvalues belonging to the ground electronic state of the HD<sup>+ and HT<sup>+ ions have been calculated. These calculations have been done for the J = 0 rotational state and neglecting the dynamic corrections to the potential. For the HD<sup>+ ion we find twenty-two bound states, and for the HT<sup>+ ion twenty three bound states.

Abstract: "A magnetohydrodynamic model of a plasma-magnetic field instability, using liquid sodium, has been observed. The growth rate and wave length of the Taylor-type acceleration instability was observed to be in agreement with the theory of Kruskal and Schwarzschild."

Abstract: "A magnetohydrodynamic model of plasma-magnetic field instabilities, using liquid sodium, has been observed. The growth of flutes in the mirror geometry was observed for the case of [beta] = NKT/H²/8w = 1."

Report discussing "experimental results on the classical stabilized pinch," "the usefulness of the Levitron in Stellarator-type operation," and "practical details of the levitation process." A configuration is presented which involves a "toroidal pinch tube inside which a rigid toroidal conductor is levitated by means of an induced magnetic field." Additionally, "an alternative scheme is considered, where the toroidal core is suspended from current-carrying wires, but this approach does not appear promising."

Abstract: "From neutron-yield measurements made with a MnSO4 detecting solution, the average number of neutrons produced per inelastic event is determined for a series of elements from lithium to uranium for 340-Mev protons, 190-and 315-Mev deuterons, 490-Mev He3 ions, and 90- and 160-Mev neutrons. The results are analyzed in an attempt to understand the total yield measurements for thick targets and to explain the variation of yield with the atomic number of the target."

Report that summarizes unreported neutron-yield data for the MnSO₄ tank method. Other yield measurements had been reported in other quarterly reports prior to the completion of this one.

Summary of research progress conducted on subjects such heavy element energy cycles and scattering.

In this paper, a theoretical solution is developed for the transient thermal stress distribution in a reactor fuel tube of circular cross sections with spatially uniform internal power generation and forced convective heat transfer at the inner surface of the tube. Solution of the equation of heat conduction is done my means of a Laplace transform with subsequent application of the inversion integral to arrive at a final expression for the transient temperature distribution. The solution is of interest in the analysis of transients in reactors which use either a gas or liquid heat transfer medium. The work was initiated in conjunction with the quench testing of ceramic fuel elements for a gas-cooled reactor. Expressions for the component stresses are given explicitly and examples of application of these formulas to startup of a gas cooled reactor and the flow quenching of a fuel tube are given.

From abstract: "Within the framework of age theory an expression is developed which represents the probability of a neutron being reflected with an energy loss corresponding to age, v, as a function of reflector thickness."

From abstract: "The relative differential neutron-proton scattering cross section has been measured in the range of center-of-mass angles from 5.1° to 36.0° for approximately 90-Mev neutrons and from 10.7° to 37.8° for approximately 290-Mev neutrons."

Summary of the research progress meeting of June 12, 1952

Abstract: "Theoretical and experimental results of the effect of gamma moderation are described. A 6.7-fold enhancement factor was obtained with a 1/8-in. - thick sodium-iodide crystal when using gamma moderation and a Co-60 gamma source. A counter was designed and built to make the most use of gamma source. A counter was designed and built to make the most use of gamma moderation. The results indicate that this counter can be made energy independent over a wide region. Though the cost of the counter is about 1/3 that of a 1-in, -diam, 1-in. -thick sodium-iodide crystal plus photomultiplier, the counting efficiency for gammas such as Na-24 is over two times greater."

Report discussing low and high acceleration flight mechanics for interplanetary missions, as well as the energy limitation for electric propulsion systems powered by a nuclear energy source. From abstract: "An optimization procedure for low acceleration systems is given which leads to a simple relationship between mission requirements, payload fraction, power plant specific power, and exhaust velocity."

The use of threshold detector foils to measure the external neutron spectrum of two reactors is described. The foils employed are Pu236 to measure the total fast flux, U238 for the region above 1.5 Mev, S32 above 2.5 Mev, and Au197 for thermal neutrons. Scintillation counters ae used to determine the activity induce din the detectors. The foil-counting system is calibrated by used a Cockcroft-Walton accelerator as a fast neutron source. The results indicate a fission type spectrum at each reactor.

Abstract: "A particularly conventional modified form of Maxwell distribution is chosen. The modified expressions for (a) the energy transfer from the ions to the electrons in a plasma and (b) the brehmestrahlung from the electrons are calculated. Using the expressions some possible steady-state conditions for the ion and electron gases are derived and compared with those for the usual Maxwell distributions."

Report discussing the heating of a plasma which passes through a series of magnetic pumping cells by applying the second-order theory of transit-time heating developed by Berger and Newcomb. From abstract: "Transit-time magnetic pumping in single-transit systems seems to be a feasible method of increasing plasma energy by amounts of the order of a factor of 10."