Quarterly updates on nuclear chemistry, bio-organic chemistry, general chemistry, chemical engineering (process chemistry).

Our aerosol program employing monkeys has been initiated. A plutonium oxilate solution was introduced into the trachea. Preliminary results of the fecal and urinary determinations appear here.

Progress report on biological studies of radiation effects, metabolic properties of various materials, health chemistry, health physics.

Certain isotopes in the region of the heaviest elements have been produced by cyclotron and pile bombardment techniques, and their nuclear decay properties have been investigated. The orbital electron capture decay of At210, At211, Np234, Np235, Pu234, Pu237, and Am242m has been studied and decay schemes have been proposed. In addition, the alpha spectra of Po211, At210, and At211 have been observed.

One of the oldest properties of electrons is their emission of x-rays (discrete and continuous spectra) when impinging on matter. Cloud-chamber tracks show light ionization, and considerable multiple scattering, except for fast electrons. Tracks are long and range indefinite.

Diffusion equations for a cascade shower which include an energy cutoff and energy parameters for each particle have not previously been studied. In this paper it is found that an inclusion of both permits collision loss to be represented as a discrete process by modifying the differential radiation cross section.

An empirical relation is presented which represents a boundary between no vacuum sparking and possible vacuum sparking. Metal electrodes and r.f. or d.c. voltages are used. The criterion fits several orders of surface gradient, voltage, gap, and frequency. Current due to field emission is considered necessary for sparking but in addition, energetic particles are required to initiate a cascade process which increases the field emission currents to the point of sparking. An elementary cascade process is outlined, but the data upon which it is based is not fully stated.

A preliminary study of positive pion production from proton-nucleus collisions revealed that positive pion production cross sections agree more favorably with a Z 2/3 variation than with a variation proportional to the atomic number. A similar study on negative pion production has shown that negative pion yields from proton-nucleus collisions tend to vary in proportion to the number of neutrons in the nucleus. As a result an experiment was performed to investigate if there is a significant change in positive pion production with changing atomic number at two lower pion energies.

Physics Division quarterly report - general physics research projects and accelerator operation and development.

Summary of the research progress meeting of June 12, 1952

The geometry of the magnetic pole structure in the cloverleaf cyclotron suggests the use of three dees excited by three phase rf placed in the valleys out of the way of the beam. Experience with the model machines indicates that it is desirable to be able to vary the phase angles between the three dee voltages through 30 or 40 degrees and to be able to maintain them at any given value within plus or minus one degree. It is desirable, also, to be able to vary the phase angle independently of the amplitude of the dee voltages. There are several possible ways of meeting these requirements. The one which was chosen appears to be the most flexible and to best meet the problems presented by the center geometry of the machine.

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 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.

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.

Ever since the existence of a bound state of Hydrogen was discovered, it has been uncertain whether any other bound states existed. In addition to its importance in astrophysics this question has also come up in discussions of the scattering of electrons from hydrogen. To settle this problem it is necessary to calculate lower bounds for the eigenvalues of the Schrodinger equation. A simple calculation has been carried out for the problem of the negative hydrogen ion.

An incident is described concerning a curium accelerator target aerolized by explosion. Management of the spill, sampling, particle sizing, and medical findings are presented. Seven of the 27 persons present showed low levels of curium excretion. The data from this incident were compared with those from three other inhalation exposures to curium compounds at Lawrence Laboratory.

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.

This is an attempt to summarize and relate at least some of the material presented in four talks during a symposium on radiobiological studies on yeast, and in addition discuss some related experimental results. The discussion will be divided into two sections: I) a discussion of the various manifestations of radiation damage in yeast; and II) a consideration of modification of these damages by variations of physico-chemical and biological parameters.

A quarterly report consisting of reports published on Transuranic Elements from the University of California Radiation Laboratory. Each report is a brief one to two page summaries of the article submitted for publication during the months of September-November, 1948.

The electrostatically deflected beam of the 184-inch cyclotron has been used with the stacked foil and absorber technique to determine the excitation functions. The data are presented graphically and discussed individually for each of the reactions. The results are discussed in terms of compound nucleus formation, transparency effects, and other factors in order to arrive at a qualitative picture for the mechanism of high energy nuclear reactions with heavy nuclei.

Research at the University of California Radiation Laboratory has been directed toward the development of processes designed to recover plutonium and uranium from neutron-irradiated uranium. This report has been prepared in answer to requests for information by interested workers in the Atomic Energy programs. The material discussed herein represents the efforts of a sizable research group over several years, and summarizes both the current status of the investigation and the future program now contemplated.

Quarterly progress report on various research projects conducted at the University of California Radiation Laboratory.

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