The transient aerothermodynamic processes in a gas-cooled reactor are described in a simplified manner to illustrate some of the fundamental physical phenomena involved, to provide some approximate but useful methods of analysis, and to aid in the understanding and use of more complex computer solutions. The transient heat balance equation for an element of a single reactor channel is derived in terms of aerothermodynamic time constants, and typical analytic solutions for transients are presented. This equation is used in generating the time-dependent equation for the channel exhaust gas temperature. The single-channel analysis is extended to multiple channels. A method for determining the approximate transient temperature envelopes for various reactor components is presented. The effects of aerodynamic and thermal coupling between different reactor channels are illustrated. Some of the simplifying assumptions are investigated with respect to the conditions under which they are valid.

This scaler was designed to replace an obsolescent tube design that was in general use at Lawrence Radiation Laboratory in Livermore. The new design, using solid state devices and printed circuit modules, allows two complete scalers in one frame to occupy the same rack space as the tube design. Switches in the input circuits of the new scaler change input impedance and sensitivity for operation with either tube or transistor circuits. The use of transistors has greatly increased reliability, and has also reduced power by a factor of fifteen. Modular construction of all circuits, including the power supply, minimizes down time since all modules are replaceable without removing the scaler from its rack. Reliability, then cost, were the criteria dictating choice of components and circuits in the scaler design.

The theory of the hydrodynamic origin of cosmic rays proposed by Johnson and the author (Colgate) has developed to the point where the final evolution of a star to the supernova instability and subsequent explosion can be described with sufficient detail such that cosmic rays with appropriate intensity, composition, and spectrum to account for observations are a logical and necessary result. In the first publication it was pointed out that nuclei in the surface of the star may acquire many orders or magnitude more than the average energy per particle released in the explosion because of the large ratio of matter density between the core and the outer mantle. A shock from a sudden pressure increase in the core intensifies as it advances into lower-density material, thereby imparting extreme relativistic energies to the outermost layers. The shock wave was assumed on the basis that the observed explosion occurred in a time short compared to the traversal time of sound across the dimensions of the star. It was argued without proof that an adiabatic process would be inconsistent with the accepted gravitational instability as the trigger mechanism. In an attempt to confirm this supposition we extend the hydrodynamic calculations to describe …

Project Sherwood is a nation-wide attempt to produce a controlled thermo-nuclear fusion reaction. The Astron experiment, conceived by Nicholas Christofilos, will utilize the effects of a cylindrical layer of relativistic electrons to contain and heat the plasma. A high quality, 200-ampere, 5-Me V electron beam is required to form the electron layer. The electron beam is produced by a linear induction electron accelerator. Three hundred and thirty-three toroidal cores of magnetic material surround an evacuated ceramic accelerating column. The electrons are accelerated by the transverse electric field produced by the changing flux. The magnetic cores are tape-wound toroids of .001", 50% Ni - 50% Fe. Two hundred eighty-eight cores are 24" o.d. x 8-1/2" i. d. x 1/2" thick and the remaining forty-five are 33" o. d. x 18" i. d. x 1/2" thick. Each core is required to support 16 kG for 0.4 psec. The choice of magnetic material was made by testing all available material for the required parameters. Results of these tests are presented.

FLOSS III is a third-generation version of a digital computer program which solves a one-dimensional difference representation of the momentum, energy, continuity, and state equations for turbulent, compressible gas flow in equivalent hydraulic channels. Extensive use of this program has been employed in the design and performance analyses of Pluto-type nuclear heat exchangers, and in the specific case of the Tory II-A test series, agreement was obtained to better than 5% for all experimentally measured parameters. The NOMAC and DASH-N programs combine the effects of up to thirty varieties of channels with the dependent boundary conditions imposed by a common inlet diffuser and exit nozzle. The resulting calculations yield performance information for blow-down facility and ramjet flight condition application of the heat exchanger.

Calculations of the photonuclear giant resonance according to the Wilkinson model are presented in this report. In this model the giant resonance in the cross section for absorption of gamma rays by nuclei is ascribed to the excitation of large numbers of nucleons in closed shells. The model generally predicts correctly the integrated cross section for the giant resonance, bu the resonance energy is too low. Results are presented in a series of tables and formulas so that the integrated cross section may be calculated for any given nucleus.

It has been observed that energetic gaseous ions mark their region of impingement on certain metals in color. Under identical conditions of bombardment, multicharged ions of the same gas mark their impact areas with different colors. The colors are sensitive to the type and energy of the ion as well as to the metal bombarded. These colors may result from reflections from thin films formed by reactions at the target. Because the colors indicate that thicker films are produced with increased ion energy, ion penetration depth as predicted by theory is compared with the depth indicated by the colors observed.

Presented herein is a philosophy for designing wideband multistage transistor amplifiers. The amplifier is visualized as an integral unit, the interstage networks constituting the elements of the amplifier unit. By designing the amplifier as a unit and adjusting the overall response (gain and bandwidth) with the interstage time constants, an increase in gain-bandwidth product is realized over the iteratively designed amplifiers. The resulting increase in gain-bandwidth product results from absence of the bandwidth shrinkage factor for multistage amplifiers. Formulas are derived for both a two- and three-transistor integrally designed wideband amplifier, in which shunt peaking networks are used for coupling. Experimental amplifiers were constructed following these formulas, and the observed performance agreed quite well with the calculations.

The problem of crystal structure of the martensitic B1 phase of the eutectic alloy in the Cu-Al system still requires a more accurate clarification (Hun ger and Dienst 1960, Tarora 1949). Martensitic phases in general are formed through small thrust (shear) deformations of the original lattice. On this basis the results of Hunger and Dienst (1960) are doubtful, since the lattice constants found by them have required a considerable reclassification. From the known lattice constants of the B1 phase (Tarora, 1949) and the orientation relationships of the B1 phase (Wassermann, 1934) one has expected a hexagonal lattice for the martensitic phase with [formula].

The validity of the nuclear track emulsion technique for fast-neutron dosimetry is examined in the exposure of a human phantom to PuBe neutrons, Semiautomatic track scanning and high-speed data analysis obviate the major disadvantages of emulsion dosimetry, and allow the absolute differential proton track energy spectrum at various locations in the phantom to be obtained without a serious cost in time. From this are calculated the total absorbed local tissue dose due to proton recoils and the local thermal neutron intensity during irradiation.

This revised version contains material published in the two years since the original report was issued in January 1960. The report covers the history of the discovery of fission, fission theory, and the probability of fission. It discusses the distribution of mass in fission, the distribution of nuclear charge in fission, kinetic energy of fission fragments, and the role of neutrons and gamma rays in fission.

The instrument (polychromator) described observes time-dependent spectral-line profiles by simultaneous measurement at nine different wavelengths of light intensity as a function of time. A cylindrical lens magnifies the dispersion of a Jarrell-Ash Model S2000 Ebert Monochromator and forms an image on a light-pipe solder. Light pipes transfer light from various sections of the image--i.e., different wavelengths--to photomultiplier tubes, and the responses are displayed on oscilloscopes. The instrument has been used to look at total wavelength spans of 15 A and 20 A.

Females heterozygous for a wildtype X chromosome from a Samarkand stock and an chromosome of the composition [formula] were tested for the frequency of X-chromosomal non-disjunction and segregation of the X's when Y chromosomes of different types were present in the females. The Y chromosomes used were 1) a normal unmarked Y, 2) [formula], 3) [formula] and 4) [formula] (a chromosome which arose in one of our experiments and has not yet been analyzed). Since this was only a preliminary test no attempt was made to isogenize the stocks. Larger scale experiments are planned in which these and other Y's will be used and the genetic background will be strictly controlled.

A model is proposed to directly relate observed tidal action with orbital movements of the moon and the earth. The basic model consists of a unit mass acting as a free point on the rotating earth's surface and being carried into a field gradient. The field is such as to cause the free point to "fall" along the surface, gain a velocity with respect to the earth's surface, and thus produce a tidal interaction at coastal barriers. Gyroscopic and resonant oscillatory current effects are not treated.

The absolute differential cross sections for elastic scattering of 31-Mev He3 ions on Be, Al, Cu, Sn(nat), Sn120, and Bi have been measured in the angular range of approximately 10 to 120 deg in the center-of-mass system. Thin self-supporting foil targets were chosen to span the parameter A 1/3, where A is the target mass number. The first excited states of the isotopes of the above elements had sufficient energy separation from the ground state to enable elastic scattering to be resolved from inelastic scattering. The detection system, consisting of Cal(Tl) scintillation crystals, was capable of 3%pulse-height resolution and 1 degree angular resolution. Characteristically, the light-element angular distributions show strong diffraction effects. The differential cross section divided by the Rutherford cross section decreases exponentially at large angles for the heavy elements, and the differential cross sections break away from Rutherford behavior at angles which increase almost linearly with increase of atomic number of the target nucleus. A comparison of the results for natural tin, and tin enriched to 85% in Sn120, indicated that within the experimental uncertainties over the measured angular interval, there were no pronounced isotopic effects. The data are presented both in tabular and graphical form to allow …

One of the techniques by which highly ionized plasmas can be generated in the laboratory makes use of strong, electromagnetically driven shock waves propagating into a cold gas. In this paper the phenomenon is analyzed as a one-dimensional single-fluid hydromagnetic problem, neglecting dissipation behind the wave.

Use of that portion of the characteristic curve of photographic film in which transmission is linear with log exposure eliminates the distributional error and thus makes possible the assessment of total mass of an inhomogeneously distributed cell consistent without scanning or measuring the cell's projected area. Measurement consists of obtaining the difference in output of a photocell receiving the total light transmitted by a photomicrograph of the cell, and a photomicrograph of the microscope field illumination against which the cell was photographed. A method of making such measurements is given, and its basis is described.

The effect of temperature on the yield strength of the polycrystalline hexagonal Ag-Al intermetallic phase was investigated over the temperature range 77 to 775 K. It was found that the curve for yield stress vs temperature for both polycrystalline Ag-33 at .% Al specimens that were heavily cold worked prior to deformation and those that were recrystallized prior to deformation was parallel to that for prismatic slip in single crystals.

One of the techniques by which highly ionized plasmas can be generated in the laboratory makes use of strong, electromagnetically driven shock waves propagating into a cold gas. In this paper the phenomenon is analyzed as a one-dimensional single-fluid hydromagnetic problem, neglecting dissipation behind the wave. We hypothesize that the rarefaction wave remains attached to the front. In the limit of essentially complete ionization behind the front the problem can be solved analytically as long as the transverse magnetic field there remains small compared with the longitudinal field.

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.

The neutron-deficient yttrium isotopes Y82, Y83, and Y84 have been produced by irradiations with the Berkeley heavy-ion linear accelerator. Where possible, identifications were made by establishing genetic relationships with known daughter or granddaughter activities. The half-life of Y84 determined by direct decay is 39+-1 min. By a series of timed chemical separations, the following half-lives have been established: Y82, 9+-3 min; Y83, 8+-2 min. No information pertaining to the radiations emitted in the decay of three yttrium isotopes, other than Y84, has been obtained. The gamma-ray spectra of Y84 and Sr83 are shown.

Two types of apparatus are described for measuring the absorption spectra of metal-ammonia solutions with the Gary Model 14 Spectrophotometer. One apparatus was used for dilute solutions at -70'; the other was used for more concentrated solutions and had provision for holding the solutions at any temperature between their boiling points and -70'.

The power of nuclear track research emulsion as a fast neutron dosimeter is examined in the exposure of a human phantom to PuBe neutrons. Semiautomatic track scanning and high-speed data analysis obviate the major disadvantages of this dosimeter, and allow the following basic information to be obtained without a serious cost in time: the rulative proton recoil energy spectrum, the absolute differential proton track den sity spectrum, and the average proton recoil energy at various locations in the phantom. From this are calculated the total absorbed local tissue doze due is proton recoils, the local thermal neutron intensity, and that portion of the tissue doze due to thermal [formula] tracks.

Recoil ranges of C11 from the reaction C12(p,pn)C11 are presented for incident proton energies from 0.25 to 6.2 Gev. From these data it is concluded that a neutron evaporation mechanism cannot be the major mechanism. The result for incident energies of 3 and 6.2 Gev are consistent with a fast reaction consisting of a single inelastic nucleon-nucleon collision. Assuming this mechanism, an average kinetic energy of 19 Mev can be deduced for the struck neutron (before the collision) in the C12 nucleus.