In the Plowshare Program many calculations of the effects of underground explosions are made. Usually these are done on high-speed digital computers. The effects are calculated for ranges up to hundreds of meters from the explosion; at these ranges pressures become less than one kilobar. In order to make these calculations, information about the properties of the materials involved is required. Benedick [13] has developed a low-pressure, plane-wave lens using nitroguanidine. It was decided to use a similar lens in the Plowshare Program. A number of lenses were built using Benedick's technique. This report is of a study of simultaneity and pressure uniformity of these lenses, with some attempts at development of a reflection pressure vs particle velocity curve for them.

Technical report. From Abstract : "Details are provided on the construction and operation of a two-stage diaphragm pump successfully used for the first time in liquid metal service. From the results of 5,376 hr. test of the pump it was concluded that it is well suited to the pumping of liquid metals at low flow rates where pulsating flow can be tolerated and also where remote operation is required. Operating temperatures and pressures are limited only by the availability of suitable materials of construction."

The rapid advances in many technologically important areas have not only served to accentuate the increased demands for high temperature metals and ceramics but have necessitated a more through knowledge of their physical properties when exposed to high temperature service. Toward this latter end, the use of X-ray diffraction has proved an invaluable tool in providing data of regions of thermal stability, expansion coefficients, solid solubility limits, and phase transformations by direct examination at temperature. Since this Laboratory has for some time now been engaged in the study of refractory nuclear materials, it was thought desirable to employ and possibly extend this technique to temperatures ranging up to 3000°C. This communication will describe the equipment developed for this purpose, with experimental results to be described in subsequent publications.

Cell proliferation on the actively growing periosteal surface of the femur of rabbits aged two weeks, has been investigated using autoradiographic techniques. Injections of tritiated glycine and tritiated thymidine were given simultaneously and the animals sacrificed at intervals from one hour to 5 days after injection. The glycine labelled the position of the bone surface at the time of injection and the thymidine labelled the cells which were synthesizing DNA . The rate of increase in the cell population was determined by counting the number of cells beyond the glycine label at different times after injection. The cell kinetics of the fibroblast--pre-osteoblast--osteoblast--osteocyte system has been studied. The fibroblasts are relatively unimportant from the point of view of increase in the cell population. The main site of cell proliferation is the layer of preosteoblasts on the periosteal surface. The rate of movement of cells from the pre-osteoblast to the osteoblast and osteocyte compartments has been measured. The incorporation of osteoblasts into the bone is not a random process, but it appears that the osteoblast must spend a certain time on the periosteal surface before becoming either an osteocyte or a relatively inactive osteoblast lining a haversian canal. During its most active …

A study of the cell kinetics on the actively growing periosteal surface of the femur of rabbits ages two weeks has been continues. A single injection of tritiated thymidine was given and the rabbits killed from one hour to four days after injection. The grain count spectra of the different cell types, pre-osteoblast, osteoblast and osteocyte, have been compared at different times after injection. The results showed evidence for the uptake of thymidine in nuclei which is not associated with cell division. A small percentage of osteoblasts was initially labelled at one hour and there was evidence that the majority of these had not divided by 3 or 4 days after injection. Some thymidine labelled cells had also become osteocytes without division. Furthermore, it appeared that a considerable fraction of the initially labelled pre-osteoblasts did not divide. The S-period for the pre-osteoblasts and osteoblasts was measured using a double-labelled thymidine technique.

Studies carried on since 1956 indicate that the prosaic breeding procedure of sibbing among the most perennial segregates in the hybrid of 4n maize x 4n perennial teosinte quickly restores perennialism to 50% maize tetraploids through increasing the expression of the rhizomatous habit under selection pressure. Similarly, only two generations of selection at the 75% maize level have resulted in a progressive recovery of the perennial expressive. A high degree of maize-likeness therefore appears to be compatible with the perennial expression at the 4n level.

Studies of linkage in polyploids have been exceedingly rare. Only three previous studies of linkage in autotetraploid maize have been reported. Murray (1944), in a limited analysis of crossing over among 4 linked markers in chromosome 2, found varying degree of difference in linkage values between 2n and 4n maize in the three interposed segments. Dempsey (1956) found linkage values wx - c region of chromosome 9 to correspond closely between autotetraploid and diploid maize. More recently Welch (1962), in a more extensive analysis of linkage among the same group of chromosome 2 markers studied earlier by Murray, concluded that although individual progenies varied, linkage values in diploid and tetraploid maize, with some exceptions, are similar. Limited data from one segment of the allotetraploid of perennial teosinte x maize (Emerson and Beadle 1932) probably represent the only reported linkage tabulation in this type of polyploid. A further study of linkage of Zea polyploids seemed worthwhile because of the increasing practical importance of polyploids, of the possibility of adding to fundamental knowledge of tetraploid cytology and genetics, and of the bearing such work may have upon the question of the taxonomic affinities of maize.

Initiation of reactions by intermittent irradiation is frequently encountered in physical, chemical, and biological systems. Mathematical expressions for transient and steady state concentrations of reactive species in these systems are useful for predicting performance and for research purposes. A general method of formulation of the intermittent irradiation problem is presented herein, and illustrative solutions are obtained for radioactive decay chains and for the rotating sector method.

The spectra of KHF2, KH2F3, NaH2F3, liquid and solid HF were measured between 1200 and 30 cm-1 by the inelastic scattering of "cold neutrons" (0.005e.v.). The spectrum of KHF2 is in agreement with previous infrared measurements and shows a peak at 147 mV corresponding to a deformation frequency v2 of the F-H-F group and a broad peak at 13 mV due to a libration of this group. The observed spectra for KH2F3, NaH2F3 solid and liquid HF were compared with that for KHF2 considering the known results that the F-F distance increases, the position of the H atom between the two fluorines becomes more asymmetrical, and the strength of the hydrogen bond decreases in going from the HF2- ion to H2F3- ion to HF. In this comparison the known structure of the H2F3- ion is considered as being intermediate between that of HF2- and the zig-zag hydrogen bonded chains in solid HF. As a result, the lines observed at 112 mV and 67 mV in the H2F3- spectra and in HF respectively are associated with the deformation frequency v2 of the H-F-H group in these compounds. In addition the spectra of H2F3- ions show a peak at a 15 mV …

The synthesis of several rare earth dodecaborides, isomorphous with UB12 and ZrB12, and crystallographic data for these phases were reported recently. The unit cells are face centered cubic with four formula weights of MeB12 per unit cell; the structures may be visualized in terms of boron atoms linked in a rigid three-dimensional network, with the metal atoms in large cubo-octahedral holes.

This is the third quarterly report on the work done under Contract AT(04-30-189, Project Agreement No.27, and covers the period August 12 to November 12, 1962.

Quarterly report describing the progress and development of improved zirconium alloys for service in superheated water and steam. This report covers the period between July 1 to September 30, 1962 and was conducted by the United States and the European Atomic Energy Community (EURATOM).

This is the second quarterly report on the work done under Contract AT(04-3)-189, Project Agreement No. 27. The results reported here have to do primarily with the loss in a rectangular (1/2" x 1-3/4") channel in the horizontal orientation, without contraction-expansion inserts.

"Short-range order coefficients were measured at 300 and 400°C for iron-aluminum alloys containing 14.8, 18.2, and 20.0 atomic per cent aluminum. These alloys exhibited a strong preference for unlike near neighbors. The short-range order was greater at the lower temperature and increased as the Fe 3Al composition was approached."

"Theoretical calculations have been carried our for the two ordering phases which occur in the FeAl system. The statistical treatment involves first and second neighbor interaction parameters as well as a magnetic interaction between first neighbor iron atoms. The phase diagram and the amount and type of long range order for slowly cooled alloys are calculated. Further calculations include short range order for the disordered phase at three compositions and two temperatures. As expected, the short range order increases as a critical temperature is approached either in composition of in temperature."

From abstract: "The preparation of pure molybdenum(IV) bromide was accomplished conveniently by the reaction between molybdenum(III) bromide and liquid bromine at ca. 55°. Molybdenum(IV) bromide was found to be soluble in liquid bromine, and this property was utilized to separate and purify the molybdenum(IV) bromide. The solution of MoBr4 in bromine was a poor electrical conductor. No evidence was found for the formation of MoBr4 from MoBr3 and bromine vapor at 2-4 atm. and temperatures from 180 to 400°. However, MoBr4 was completely decomposed at 110-130°, in vacuo, with formation of MoBr3 and bromine."

A code (RAPTURE) was programmed for the Philco TRANSAC 2000 computer to perform calculations needed for the evaluation of Doppler Coefficients in fast reactors with degraded neuron spectra. This code computes resonance integrals, averages them over resonance parameter distributions, and computes fission and capture cross sections as a function of fuel temperature and of potential scattering cross section per absorber isotope.

Abstract: This technical report summarizes the results of research and development tasks performed during Phase I of this contract and presents recommendations for future development work. Work is reported in the areas of plant assembly and relocation, housings and footings, waste heat dissipation, instrumentation, refueling systems, waste disposal, shielding, core nuclear thermal and hydraulic studies, gaseous waste processing (BWR), and critical experiments on a 5 x 5 array of Type 3 fuel elements.

Quarterly report describing the progress and development of improved zirconium alloys for service in superheated water and steam. This report covers the period between October 1 to December 31, 1961 and was conducted by the United States and the European Atomic Energy Community (EURATOM).

Antiproton-production and nucleon-interaction cross sections were investigated for antiprotons in the energy range 0.5 to 1.0 Bev. The antiprotons were distinguished from other particles produced at the Bevatron by a system of scintillation- and velocity-selecting Cerenkov counters. The excitation function and momentum distribution were recorded for antiproton production in carbon and compared with statistical model expectations.

A systematic study is made of the electromagnetic properties of charged vector mesons. The various formalisms used to describe charged particles of spin 1 are compared, and a new first-order formulation of the Stuckelberg theory is developed.

"A comparison of grafting to two thicknesses of polypropylene film is made using isotope and electron accelerator initiation. The results indicate that the grafting of methacrylic acid: styrene to polypropylene is mainly a surface reaction."

In the Communications of the ACM of April, 1960, p. 240, there appeared two Algol algorithms for the computation of In, the modified Bessel function of the first kind. One of these algorithms uses a convergent series and the other an asymptotic series. Their author, Dorothea S. Clarke, did not give any information with regard to which algorithm is more appropriate in a given situation (a given situation meaning the computation of In (x) for a definite pair of numbers n and x). Such information is necessary, however, if the algorithms are to be useful, particularly since the asymptotic series is in many cases not valid.

On 3/14/60 the Applied Physics Corporation was awarded a subcontract for the design and development of a high-temperature high-pressure spectrophotometer system based on the Cary Model 14pm Spectrophotometer insofar as possible, and consistent with our specifications, No. CTD-2, December 16, 1959.