746 Matching Results

Search Results

Advanced search parameters have been applied.

Relativistic heavy ion physics

Description: In the fall of 1986, beams of heavy ions up to A = 40 at total energies up to E = 225 GeV/nucleon will become available for experiments at CERN (60 and 225 GeV/nucleon) and at Brookhaven (15.5 GeV/nucleon). Future experiments to look for quark confinement are discussed. 9 refs., 3 figs. (GHT)
Date: January 1, 1985
Creator: Hansen, O.
Partner: UNT Libraries Government Documents Department

Quasielastic reactions

Description: A brief review is presented of the experimental and theoretical situation regarding transfer reactions and inelastic scattering. In the first category there is little (very little) precision data for heavy projectiles and consequently almost no experience with quantitative theoretical analysis. For the inelastic scattering the rather extensive data strongly supports the coupled channels models with collective formfactors. At the most back angles, at intensities about 10/sup -5/ of Rutherford scattering, a second, compound-like mechanism becomes dominant. The description of the interplay of these two opposite mechanisms provides a new challenge for our understanding.
Date: January 1, 1983
Creator: Hansen, O.
Partner: UNT Libraries Government Documents Department

Trends in nuclear spectroscopy with (more or less) direct reactions

Description: Recent experiments on the Gamow-Teller giant resonance are discussed with special regard to the strength sum rules. Some ideas for further investigations of pairing collective modes are presented. The emphasis is on one fermion-two boson states and on two boson transfer reactions. Finally some new experimental results from heavy ion inelastic scattering are presented and the role of such processes in the energy ion mechanisms leading to deep inelastic collisions is discussed.
Date: January 1, 1981
Creator: Hansen, O.
Partner: UNT Libraries Government Documents Department

Strangeness production in Si + Au interactions at 14. 6 GeV/c per nucleon

Description: Production of strange particles in proton-proton interactions is systematically suppressed relative to the production of non-strange particles. A first order goal of experiments on strangeness production in nucleus-nucleus collisions is to find out if strangeness is suppressed in a way similar to the p-p interactions or whether the nuclear environment changes the behaviour. This paper investigates this possibility. 13 refs., 1 tab.
Date: January 1, 1989
Creator: Hansen, O.
Partner: UNT Libraries Government Documents Department

High sensitivity amplifier/discriminator for PWC's

Description: The facility support group at Fermilab is designing and building a general purpose beam chamber for use in several locations at the laboratory. This pwc has 128 wires per plane spaced 1 mm apart. An initial production of 25 signal planes is anticipated. In proportional chambers, the size of the signal depends exponentially on the charge stored per unit of length along the anode wire. As the wire spacing decreases, the capacitance per unit length decreases, thereby requiring increased applied voltage to restore the necessary charge per unit length. In practical terms, this phenomenon is responsible for difficulties in constructing chambers with less than 2 mm wire spacing. 1 mm chambers, therefore, are frequently operated very near to their breakdown point and/or a high gain gas containing organic compounds such as magic gas is used. This argon/iso-butane mixture has three drawbacks: it is explosive when exposed to the air, it leaves a residue on the wires after extended use and is costly. An amplifier with higher sensitivity would reduce the problems associated with operating chambers with small wire spacings and allow them to be run a safe margin below their breakdown voltage even with an inorganic gas mixture such as argon/CO2, this eliminating the need to use magic gas. Described here is a low cost amplifier with a usable threshold of less than 0.5 ..mu..A. Data on the performance of this amplifier/discriminator in operation on a prototype beam chamber are given. This data shows the advantages of the high sensitivity of this design.
Date: January 1, 1983
Creator: Hansen, S.
Partner: UNT Libraries Government Documents Department

Laboratory Directed Research and Development Program FY2004

Description: The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab or LBNL) is a multi-program national research facility operated by the University of California for the Department of Energy (DOE). As an integral element of DOE's National Laboratory System, Berkeley Lab supports DOE's missions in fundamental science, energy resources, and environmental quality. Berkeley Lab programs advance four distinct goals for DOE and the nation: (1) To perform leading multidisciplinary research in the computing sciences, physical sciences, energy sciences, biosciences, and general sciences in a manner that ensures employee and public safety and protection of the environment. (2) To develop and operate unique national experimental facilities for qualified investigators. (3) To educate and train future generations of scientists and engineers to promote national science and education goals. (4) To transfer knowledge and technological innovations and to foster productive relationships among Berkeley Lab's research programs, universities, and industry in order to promote national economic competitiveness. Berkeley Lab's research and the Laboratory Directed Research and Development (LDRD) program support DOE's Strategic Goals that are codified in DOE's September 2003 Strategic Plan, with a primary focus on Advancing Scientific Understanding. For that goal, the Fiscal Year (FY) 2004 LDRD projects support every one of the eight strategies described in the plan. In addition, LDRD efforts support the goals of Investing in America's Energy Future (six of the fourteen strategies), Resolving the Environmental Legacy (four of the eight strategies), and Meeting National Security Challenges (unclassified fundamental research that supports stockpile safety and nonproliferation programs). The LDRD supports Office of Science strategic plans, including the 20 year Scientific Facilities Plan and the draft Office of Science Strategic Plan. The research also supports the strategic directions periodically under review by the Office of Science Program Offices, such as strategic LDRD projects germane to new research facility concepts and ...
Date: March 22, 2005
Creator: Hansen, Todd C.
Partner: UNT Libraries Government Documents Department

MICROBAROGRAPH INSTRUMENTATION

Description: Microbarographs are used at the Nevada test site to measure acoustic energy at certain locations with respect to blasts. These data are used then to decide if weather conditions are favorable for a nuclear test. The microbarograph and its operation are described in detail. (T.R.H.)
Date: June 1, 1959
Creator: Hansen, H.E.
Partner: UNT Libraries Government Documents Department

GOTHIC MODEL OF BWR SECONDARY CONTAINMENT DRAWDOWN ANALYSES

Description: This article introduces a GOTHIC version 7.1 model of the Secondary Containment Reactor Building Post LOCA drawdown analysis for a BWR. GOTHIC is an EPRI sponsored thermal hydraulic code. This analysis is required by the Utility to demonstrate an ability to restore and maintain the Secondary Containment Reactor Building negative pressure condition. The technical and regulatory issues associated with this modeling are presented. The analysis includes the affect of wind, elevation and thermal impacts on pressure conditions. The model includes a multiple volume representation which includes the spent fuel pool. In addition, heat sources and sinks are modeled as one dimensional heat conductors. The leakage into the building is modeled to include both laminar as well as turbulent behavior as established by actual plant test data. The GOTHIC code provides components to model heat exchangers used to provide fuel pool cooling as well as area cooling via air coolers. The results of the evaluation are used to demonstrate the time that the Reactor Building is at a pressure that exceeds external conditions. This time period is established with the GOTHIC model based on the worst case pressure conditions on the building. For this time period the Utility must assume the primary containment leakage goes directly to the environment. Once the building pressure is restored below outside conditions the release to the environment can be credited as a filtered release.
Date: October 6, 2004
Creator: Hansen, P.N.
Partner: UNT Libraries Government Documents Department

Comparative study of the muon-catalyzed fusion in D-T and D-/sup 3/He systems

Description: The objective of this proposal is to carry out a comparative study of the muon-catalyzed reactions, D-T and D-/sup 3/He by measuring the number of neutrons/..mu.. and protons/..mu.. under equivalent experimental conditions. The comparison will be made as function of the T or /sup 3/He concentration in the systems, their densities and temperatures. Since some measurements of the D-T system are already available, the present study will concentrate on the D-/sup 3/He system and in that region of the parameter space (concentration-density-temperature) not covered by the existent neutron work, mainly, mixtures at very high pressures and temperatures. The experimental results will be compared with calculations of the neutron, and proton yields resulting from the mesomolecular processes taking place between the muon and the deuterium-tritium and deuterium-helium mixtures. 23 refs.
Date: September 1, 1985
Creator: Hansen, L.F.
Partner: UNT Libraries Government Documents Department

Acoustic absorption by the electron-hole liquid in germanium

Description: The absorption of ultrasonic acoustic waves by the electron-hole liquid that may be created in germanium at liquid helium temperatures by intense optical excitation was studied. This is a degenerate compensated Fermi liquid that exhibits the behavior of both classical dynamics in a force field, and quantum phenomena in a magnetic field. Results of theoretical and experimental studies of the interaction of the mobile liquid with a travelling acoustic wave force field, the attenuation of the wave due to energy-dissipative processes coupling the liquid to the crystal lattice, and the effect of a moderately strong magnetic field on the dynamic behavior of the system are presented. In unstrained germanium the electron-hole liquid (EHL) is known to be condensed into small droplets of radius approx. 5 ..mu..m; the creation of an EHL energy well by the application of an inhomogeneous stress causes the liquid to be aggregated into a macroscopically large volume.
Date: November 1, 1977
Creator: Hansen, A.D.A.
Partner: UNT Libraries Government Documents Department

ENCAPSULATED SURFACE-BARRIER PARTICLE DETECTORS SOME METHODS AND TECHNIQUES

Description: Techniques are described in detail that have been developed for the manufacture of encapsulated surface-barrier particle detectors. The devices manufactured to date have found use as counters and spectrometers for fission fragments, alpha particles, and low-energy electrons from radioactive nuclei. Devices, 50 mm/sup 2/ in area, have a resolution for 6.1-Mev alpha particles of 26 kev at room temperature and 18 kev at 78 deg K. Resolution for 1.1-Mev electrons has been measured as 7.5 kev at 78 deg K for devices 25 mm/sup 2/ in area. The silicon used has been n-type, grown with a 111 orientation, and purchased in the form of ingots about 2 cm in diameter; the resistivity has ranged from 100 to 3000 ohm-cm. (auth)
Date: March 1, 1962
Creator: Hansen, N.J.
Partner: UNT Libraries Government Documents Department