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FAST BEAM CHOPPERS FOR THE ELECTRON-RING ACCELERATOR

Description: Two beam choppers were constructed which produce an approximately square, 20-ns pulse of 3+-MeV electrons out of the best portion of the 300-ns Astron beam or an 8-{micro}s microwave electron linac beam for injection into the electron-ring accelerator (ERA) compressor. The choppers are impedance-matched traveling-wave devices which deflect the beam with equal strength electric and magnetic forces, and are powered with either three-electrode spark gaps or thyratrons and a 20-ns pulse line. The electron beam is biased out of the beam-transport system with a dc magnetic field, and switched into it with the chopper.
Date: February 7, 1969
Creator: Faltens, Andris & Kerns, Cordon.
Item Type: Article

A Reliability Improvement Program Planning Report for the SNAP 10A Space Nuclear Power Unit

Description: The estimated achieved reliability of SNAP 10A space nuclear power units will be relatively low at the timeof the first SNAPSHOT flight test in April 1963 and the existing R&D program does not provide a significant reliabiity growth thereafter. The total costs of an 8-satellite network using SNAP 10A units over a 5-year period has been approximated for the case where the total cost of a single satellite launched is 8 million dollars.
Date: March 14, 1961
Creator: Coombs, M.G.; C.K., Smith & Wilson, L.A.
Item Type: Report

Thermal Cycling of Uranium Dioxide - Tungsten Cermet Fuel Specimens

Description: In phase I tungsten clad cermet fuel specimens were thermal cycled, to study the effects of fuel loading, fuel particle size, stablized fuel, duplex coatings, and fabrication techniques on dimensional stability during thermal cycling. In phase II the best combination of the factors studies in phase I were combined in one specimen for evaluation.
Date: December 8, 1969
Creator: Gripshover, P.J. & Peterson, J.H.
Item Type: Report

PLUTONIUM HANDLING AND CONTROL PRACTICES AT PACIFIC NORTHWEST LABORATORY

Description: One of two major facilities used for plutonium fuels research and development studies at Battelle-Northwest is the Plutonium Fuels Laboratory (PFL). This facility was specifically designed and equipped for research and development studies involving multikilogram quantities of plutonium and its mixtures, compounds, and alloys. As at other sites, the design and operation philosophy of the PFL is one of complete plutonium containment. Primary plutonium containment is provided by glove boxes, secondary containment is provided by individual laboratories, and tertiary containment is supplied by the building proper. Air samples, taken throughout the facility, are constantly being monitored for free contamination. Personnel exposure caused by X, gamma, and neutron radiation has been primarily omitted by inspiring good work habits and housekeeping practices in personnel (i.e., uncontrolled accumulations of plutonium are avoided, plutonium is confined as much as possible, exposure times are limited, and shielding equipment is used whenever necessary). Rules for the prevention of an inadvertent criticality in the PFL are based upon the criteria that at least two control conditions must fail before criticality is imminent.
Date: October 1, 1966
Creator: Gulley, RL
Item Type: Report

LAWRENCE RADIATION LABORATORY COUNTING HANDBOOK

Description: The Counting Handbook is a compilation of operational techniques and performance specifications on counting equipment in use at the Lawrence Radiation Laboratory, Berkeley. Counting notes have been written from the viewpoint of the user rather than that of the designer or maintenance man. The only maintenance instructions that have been included are those that can easily be performed by the experimenter to assure that the equipment is operating properly.
Date: October 1, 1966
Creator: Group, Nuclear Instrumentation
Item Type: Report

NOTE ON TRANSISTORS FOR AVALANCHE-MODE OPERATION

Description: We have found that selected Motorola transistors of the MM-486, MM-487, and MM-488 type are quite useful for avalanche-mode operation. Figure 1 shows a circuit used in conjunction with a traveling-wave oscilloscope for selecting avalanche units. The output of the line-type pulse generator is 40 to 60 volts (either polarity of output pulse is available), and the rise time is less than 0.5 nsec. Figure Z shows a plot of the static V-I characteristics of the collector-to-emitter junction for various units, avalanching and nonavalanching. A transistor that avalanches will do 80 over the entire flat portion of the V-I characteristic. One can expect that 10 to 30% of the transistors will avalanche. There is some indication that the low-beta type (MM-486) give the best yield. There is a time delay of a few nanoseconds between application of a trigger pulse and the rise of the main avalanche current. Figures 3 and 4 shows this delay, measured between the 50% point of the trigger-voltage waveform and the 50% point of the avalanche output waveform, as a function of trigger-voltage amplitude (Fig. 3) and static-collector current (Fig. 4). The negative-resistance region (such as that in Fig. 2) should be avoided if time and amplitude jitter of the output pulse are to be minimized. A temperature change from 70 to 150 F has negligible effect on time delay, but raises the breakdown knee (Fig. 2) to higher current (e. g., from 2 x 10{sup -3} to 8 x 10{sup -3} {micro}a).
Date: March 1, 1962
Creator: Miller, Harold W. & Kerns, Quentin A.
Item Type: Report

SOME THOUGHTS ON STABILITY IN NONLINEAR PERIODIC FOCUSING SYSTEMS

Description: A brief discussion is given of the long-term stability of particle motions through periodic focusing structures containing lumped nonlinear elements. A method is presented whereby one can specify the nonlinear elements in such a way as to generate a variety of structures in which the motion has long-term stability.
Date: September 5, 1967
Creator: McMillan, Edwin M.
Item Type: Report

SPARK-GAP-TRIGGER AMPLIFIER

Description: Short over-all time delay, low time jitter, and excellent long-term reliability are among the desirable features designed into a pulse generator that produces a 2-MW output pulse 30 nsec after the application of a 1-V signal at its 50-ohm input connector. The 10-kV output pulse can be used to trigger simultaneously several spark gaps of the type used in spark-chamber pulse modulators. The 10{sup 8} power gain of the spark-gap-trigger amplifier is achieved by four stages of amplification packaged in a 5-1/4 inch rack-mount chassis that operates directly from a 117-V line. The individual stages, each selected to give minimum time delay for a given power gain at their respective power levels are: avalanche transistors, planar triode, grounded-grid planar triode, and a triggered-spark gap. The techniques used for the last stage, a spark gap triggered by a corona light, are of particular interest since the same techniques are applicable to obtaining short time delays and long-term reliability from the larger spark gaps that the amplifier was designed to trigger. During 10 months of operation, there have been no failures and no adjustments necessary in any of the seven spark-gap trigger amplifiers used in various spark-chamber experiments at the Lawrence Radiation Laboratory of the University of California (UCLRL) in Berkeley.
Date: October 20, 1964
Creator: Kerns, Q.A. & Miller, H.W.
Item Type: Report

A SPARK-GAP TRIGGER SYSTEM

Description: The construction and operation of a trigger system designed to fire a 30-kV 5000 A spark gap with a minimum delay following the arrival of a small signal pulse is described. In this particular experiment a 150-MeV/c muon is detected with scintillators on three 6199 phototubes, and the output pulse of the attached tunnel-diode triple-coincidence circuit is amplified and used to trigger the gap. Approximately 32 nanoseconds are needed from passage of the muon to the coincidence output, and approximately 25 nanoseconds are required from the coincidence output to the time of complete breakdown of the gap. These delays represent the shortest times that we could achieve with the particular boundary conditions under which the circuit had to operate. Sufficient detail is given to show how additional savings of nanoseconds could be made under different operating conditions.
Date: August 6, 1963
Creator: Schrank, Glen E.; Henry, George R.; Kerns, Quentin A. & Swanson, Robert A.
Item Type: Report

Tungsten Cladding of Tungsten-Uranium Dioxide (W-UO2) Composites by Deposition from Tungsten Hexafluoride (WF6)

Description: A program is being conducted to develop a process for cladding tungsten and tungsten cermet fuels with tungsten deposited from the vapor state by the hydrogen reduction of tungsten hexafluoride. Early work was performed using recrystallized, high purity, commercial tungsten as the substrate material. Temperatures in the range 660 to 12950F (350 to 1700°C) and pressures from 10 to 350 mm Hg were investigated. Hydrogen to WF 6 ratios of 10: 1 to 150: 1 were utilized. Efforts were directed toward optimizing deposition process parameters to attain control of qualities such as coating thickness, uniformity, density, impurity content, and surface quality. Substrate penetration methods have been investigated in the interest of completely eliminating the interface between the fueled substrate and cladding. In addition, the effects of process parameters and post-cladding heat treatments on the fuel retention properties of clad composites at 4500 degrees F (2480 degrees C) in hydrogen for 2 hours have been evaluated. As a result of work performed during the first phase of the program it has been shown that the rate of deposition of tungsten from WF 6 and the uniformity of the deposit can be varied in a predictable and reproducible manner by exercising control over the temperature, pressure, and gas flow rates at which the deposits are produced. A significant result of the study is the discovery that substrate nucleation and epitaxial growth in deposits made on both unfueled tungsten and fueled substrates may be effected by pretreating the substrates in hydrogen. High temperature fuel retention testing of tungsten clad W-U02 at 45000F (2480 degrees C) in hydrogen for 2 hours has demonstrated that the vapor deposited layer effectively and consistently restricts fuel loss.
Date: February 15, 1965
Creator: Lamartine, J.T. & Hoppe, A.W.
Item Type: Report

Trip Report, Solar aircraft, May 26, 1960

Description: Discussions held with A. S. Stetson, General George Gordes and W. Compton going over technical aspects of Contract NO-S-935 for the research and development studies on coating materials for SNAP reactors.
Date: June 10, 1960
Creator: Henry, D.L.
Item Type: Report

Mound Laboratory Progress Report for December, 1964

Description: This monthly report has the following sections: (1) Radioelements - Uranium-234, Hydrolytic Separations of Protactinium, Polonium-208 and Polonium-209; (2) Isotope Separation and Purification - Carbon-13, Helium, Neon, Argon, Krypton, Xenon, Thermal Diffusion Research, and Helium Research; (3) Analytical and Instrumentation - Neptunium Analysis, Cobalt Analysis, Analysis of Enriched Uranium-234 for Comparison Purposes, Analysis of Stearic Acid in Silver Powder, Nuclear Magnetic Resonance Studies, Semiconductor Radiation Detectors, and Calorimetry.
Date: December 21, 1964
Creator: EIchelberger, J.F.; Grove, G.R. & Jones, L.V.
Item Type: Report