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ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.

Description: This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linear accelerator (Linac). The highly successful development of an EBIS at Brookhaven National Laboratory (BNL) now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based preinjectors are presently used at most accelerator and collider facilities with the exception of RHIC, where the required gold beam intensities could only be met with a Tandem until the recent EBIS development. EBIS produces high charge state ions directly, eliminating the need for the two stripping foils presently used with the Tandem. Unstable stripping efficiencies of these foils are a significant source of luminosity degradation in RHIC. The high reliability and flexibility of the new Linac-based pre-injector will lead to increased integrated luminosity at RHIC and is an essential component for the long-term success of the RHIC facility. This new pre-injector, based on an EBIS, also has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium beams and, as part of a future upgrade, might also be used to produce polarized {sup 3}He beams. These capabilities will be critical to the future luminosity upgrades and electron-ion collisions in RHIC. The proposed pre-injector system would also provide for a major enhancement in capability for the NASA Space Radiation Laboratory (NSRL), which utilizes heavy-ion beams from the RHIC complex. EBIS would allow for the acceleration of all important ion species for the NASA radiobiology program, such as, helium, argon, and neon which are unavailable with the present Tandem injector. In addition, the new system would allow for very ...
Date: September 1, 2005
Creator: ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D.; GRANDINETTI, R.; HSEUH, H. et al.
Partner: UNT Libraries Government Documents Department

Demonstration of Key Elements of a Dual Phase Argon Detection System Suitable for Measurement of Coherent Neutrino-Nucleus Scattering

Description: This feasibility study sought to demonstrate several necessary steps in a research program whose ultimate goal is to detect coherent scattering of reactor antineutrinos in dual-phase noble liquid detectors. By constructing and operating a Argon gas-phase drift and scintillation test-bed, the study confirmed important expectations about sensitivity of these detectors, and thereby met the goals set forth in our original proposal. This work has resulted in a successful Lab-Wide LDRD for design and deployment of a coherent scatter detector at a nuclear reactor, and strong interest by DOE Office of Science. In recent years, researchers at LLNL and elsewhere have converged on a design approach for a new generation of very low noise, low background particle detectors known as two-phase noble liquid/noble gas ionization detectors. This versatile class of detector can be used to detect coherent neutrino scattering-an as yet unmeasured prediction of the Standard Model of particle physics. Using the dual phase technology, our group would be the first to verify the existence of this process. Its (non)detection would (refute)validate central tenets of the Standard Model. The existence of this process is also important in astrophysics, where coherent neutrino scattering is assumed to play an important role in energy transport within nascent neutron stars. The potential scientific impact after discovery of coherent neutrino-nuclear scattering is large. This phenomenon is flavor-blind (equal cross-sections of interaction for all three neutrino types), raising the possibility that coherent scatter detectors could be used as total flux monitors in future neutrino oscillation experiments. Such a detector could also be used to measure the flavor-blind neutrino spectrum from the next nearby (d {approx} 10kpc) type Ia supernova explosion. The predicted number of events [integrated over explosion time] for a proposed dual-phase argon coherent neutrino scattering detector is 10000 nuclear recoils/kton, compared to the estimated rate ...
Date: April 16, 2007
Creator: Adam, B.; Celeste, W.; Christian, H.; Wolfgang, S. & Norman, M.
Partner: UNT Libraries Government Documents Department

General computational spectroscopic framework applied to Z-pinch dynamic hohlraum K-shell argon spectra

Description: We describe a general computational spectroscopic framework for interpreting observed spectra. The framework compares synthetic spectra with measured spectra, then optimizes the agreement using the Dakota toolkit to minimize a merit function that incorporates established spectroscopic techniques. We generate synthetic spectra using the self-consistent nonlocal thermodynamic equilibrium atomic kinetics and radiative transfer code Cretin, relativistic atomic structure and cross section data from Hullac, and detailed spectral line shapes from Totalb. We test the capabilities of both our synthetic spectra model and general spectroscopic framework by analyzing a K-shell argon spectrum from a Z-pinch dynamic hohlraum inertial confinement fusion capsule implosion experiment. The framework obtains close agreement between an experimental spectrum measured by a time integrated focusing spectrometer and the optimal synthetic spectrum. The synthetic spectra show that considering the spatial extent of the capsule and including the effects of optically thick resonance lines significantly affects the interpretation of measured spectra.
Date: January 10, 2005
Creator: Adams, M L; Sinars, D B & Scott, H A
Partner: UNT Libraries Government Documents Department

Computational Modeling of K-shell Argon Spectra from Z-pinch Dynamic Hohlraum Experiments

Description: Z-pinch dynamic hohlraum experiments on the Z-Machine at Sandia National Laboratories measured K-shell argon spectra using a focusing spectrometer with spatial resolution. The spectra are modeled using Hullac atomic data input, Cretin nonlocal thermodynamic equilibrium (nlte) atomic kinetics and radiative transfer calculations, and Dakota optimization capabilities. Hullac provides atomic structure and cross section data for Ar XIX, Ar XXVIII (n=1 (illegible) 5), Ar XXVII (n=1 (illegible) 10), and Ar XXVI (n=1 (illegible) 5), where n is the principal quantum number. Cretin calculates the area-integrated spectral intensity escaping an argon doped Dcapsule as a function of electron density, electron temperature, and capsule radius. Dakota optimizes the plasma properties for the best to the measured spectrum by minimizing an objective function comprise of argon spectral line ratios and full-width at half-maximums (fwhms). We highlight the framework of this general spectroscopic capability and discuss the extension to magnetized plasmas using Totalb spectral line shapes.
Date: October 27, 2004
Creator: Adams, M L; Sinars, D B; Scott, H A; Brandon, S T; Chung, H K & Lee, R W
Partner: UNT Libraries Government Documents Department

The Mark III vertex chamber

Description: The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 ..mu..m at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 ..mu..m using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin.
Date: July 1, 1987
Creator: Adler, J.; Bolton, T.; Bunnell, K.; Cassell, R.; Cheu, E.; Freese, T. et al.
Partner: UNT Libraries Government Documents Department

Current and future directions in the study of light nuclei employing an on-line mass separator

Description: Recent work on isospin quintets utilizing the on-line mass analysis system RAMA is described. Possibilities for future studies of both proton-rich and neutron-rich light nuclides towards the limits of nuclear stability are discussed. 4 figures.
Date: September 1, 1979
Creator: Aeystoe, J. & Cerny, J.
Partner: UNT Libraries Government Documents Department

Design Considerations for Large Mass Ultra-Low Background Experiments

Description: Summary The objective of this document is to present the designers of the next generation of large-mass, ultra-low background experiments with lessons learned and design strategies from previous experimental work. Design issues divided by topic into mechanical, thermal and electrical requirements are addressed. Large mass low-background experiments have been recognized by the scientific community as appropriate tools to aid in the refinement of the standard model. The design of these experiments is very costly and a rigorous engineering review is required for their success. The extreme conditions that the components of the experiment must withstand (heavy shielding, vacuum/pressure and temperature gradients), in combination with unprecedented noise levels, necessitate engineering guidance to support quality construction and safe operating conditions. Physical properties and analytical results of typical construction materials are presented. Design considerations for achieving ultra-low-noise data acquisition systems are addressed. Five large-mass, low-background conceptual designs for the one-tonne scale germanium experiment are proposed and analyzed. The result is a series of recommendations for future experiments engineering and for the Majorana simulation task group to evaluate the different design approaches.
Date: July 1, 2011
Creator: Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E. & Orrell, John L.
Partner: UNT Libraries Government Documents Department

RF gas plasma source development for heavy ion fusion

Description: Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx}100 ns) for the extracted beam pulse must also be achieved. Progress on these experiments will be presented.
Date: February 22, 2002
Creator: Ahle, L.E.; Hall, R.P. & Molvik, A.W.
Partner: UNT Libraries Government Documents Department

RF Gas Plasma Source Development for Heavy Ion Fusion

Description: Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx} 100 ns) for the extracted beam pulse must also be achieved. Progress on these experiments will be presented.
Date: September 4, 2001
Creator: Ahle, L; Hall, R P; Molvik, A W; Kwan, J W & Leung, K N
Partner: UNT Libraries Government Documents Department

Report to users of ATLAS

Description: This report contains discussing in the following areas: Status of the Atlas accelerator; highlights of recent research at Atlas; concept for an advanced exotic beam facility based on Atlas; program advisory committee; Atlas executive committee; and Atlas and ANL physics division on the world wide web.
Date: May 1, 1995
Creator: Ahmad, I. & Glagola, B.
Partner: UNT Libraries Government Documents Department

Heavy residue properties in intermediate energy nuclear collisions with gold

Description: We have measured the target fragment production cross sections and angular distributions for the interaction of 32, 44 and 93 MeV/nucleon argon, 35 and 43 MeV/nucleon krypton with gold. The fragment isobaric yield distributions, moving frame angular distributions and velocities have been deduced from these data. This fission cross section decreases with increasing projectile energy and the heavy residue cross section increases. The ratio v{sub {parallel}}/v{sub cn} increases approximately linearly with mass removed from the target. 21 refs., 8 figs.
Date: October 1, 1990
Creator: Aleklett, K.; Sihver, L. (Uppsala Univ., Nykoeping (Sweden). Studsvik Neutron Research Lab.); Loveland, W. (Oregon State Univ., Corvallis, OR (USA)); Liljenzin, J.O. (Chalmers Univ. of Tech., Goeteborg (Sweden)) & Seaborg, G.T. (Lawrence Berkeley Lab., CA (USA). Nuclear Science Div.)
Partner: UNT Libraries Government Documents Department

Progress on an EBIS for RHIC

Description: Work is continuing on the development of an Electron Beam Ion source (EBIS) which could be used as part of a new heavy ion injector for RHIC. On a test EBIS, the authors have operated with an electron beam current of up to 1.14A, and have extracted ions such as Tl{sup 41+}, Xe{sup 26+}, Ar{sup 14+}, N{sup 7+}, and Na{sup 7+}. Recent experimental results are reported. In addition, they discuss plans for a new electron beam test stand that is now being built. This will allow operation with electron currents of 10 A, as well as testing of a warm-bore superconducting magnet system, methods for fast extraction of ions, and possible off-axis collection of the electron beam.
Date: July 1, 1997
Creator: Alessi, J.; Beebe, E.; Hershcovitch, A.; Kponou, A.; Lockey, R.; Pikin, A. et al.
Partner: UNT Libraries Government Documents Department

Nuclear reaction studies

Description: Research focused on the statistical and dynamical properties of ``hot`` nuclei formed in symmetric heavy-ion reactions. Theses included ``flow`` measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study {sup 40}Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs.
Date: November 1, 1994
Creator: Alexander, J.M. & Lacey, R.A.
Partner: UNT Libraries Government Documents Department

Computational investigation of noble gas adsorption and separation by nanoporous materials.

Description: Molecular simulations are used to assess the ability of metal-organic framework (MOF) materials to store and separate noble gases. Specifically, grand canonical Monte Carlo simulation techniques are used to predict noble gas adsorption isotherms at room temperature. Experimental trends of noble gas inflation curves of a Zn-based material (IRMOF-1) are matched by the simulation results. The simulations also predict that IRMOF-1 selectively adsorbs Xe atoms in Xe/Kr and Xe/Ar mixtures at total feed gas pressures of 1 bar (14.7 psia) and 10 bar (147 psia). Finally, simulations of a copper-based MOF (Cu-BTC) predict this material's ability to selectively adsorb Xe and Kr atoms when present in trace amounts in atmospheric air samples. These preliminary results suggest that Cu-BTC may be an ideal candidate for the pre-concentration of noble gases from air samples. Additional simulations and experiments are needed to determine the saturation limit of Cu-BTC for xenon, and whether any krypton atoms would remain in the Cu-BTC pores upon saturation.
Date: October 1, 2008
Creator: Allendorf, Mark D. (Sandia National Laboratories, Livermore, CA); Sanders, Joseph C. & Greathouse, Jeffery A.
Partner: UNT Libraries Government Documents Department

Operations Experience at the Bevalac Radiotherapy Facility

Description: During the first years of Bevalac operation the biomedical effort concentrated on radiobiology work, laying the foundation for patient radiotherapy. A dedicated radiotherapy area was created in 1978, and in 1979 full-scale patient treatment was begun. As of now over 500 treatments with carbon, neon and argon beams have been delivered to about 50 patients, some as boosts from other modalities and some as complete heavy ion treatments. Up to 12 patients per day have been treated in this facility. Continuing efforts in refining techniques and operating procedures are increasing efficiency and accuracy of treatments, and are contributing to the alleviation of scheduling difficulties caused by the unique requirements of radiotherapy with human patients.
Date: March 1, 1981
Creator: Alonso, J. R.; Criswell, T. L.; Howard, J.; Chu, W. T.; Singh, R. P.; Geller, D. et al.
Partner: UNT Libraries Government Documents Department

Charge changing cross sections for heavy ions at energies to 8. 5 MeV/amu. [Preliminary cross sections, electron pickup and loss, 3. 4 to 8. 5 MeV/amu]

Description: Preliminary cross sections for single electron pickup and loss are presented for Fe, Kr and Xe ions at 8.5 MeV/amu and for Ar ions at energies from 3.4 MeV/amu to 8.5 MeV/amu passing through nitrogen gas.
Date: March 1, 1979
Creator: Alonso, J.; Dietrich, D. & Gould, H.
Partner: UNT Libraries Government Documents Department

Acceleration of Partially Stripped Ions at the Bevalac

Description: We present results of the first attempts to accelerate partially stripped heavy ions in the Bevatron. Experiments were performed for hydrogen-like argon and neon ions, and, although the survival time of these ions in the 10{sup -7} torr Bevatron vacuum was not sufficient to achieve full energy, valuable charge-changing cross section information was obtained.
Date: October 1, 1977
Creator: Alonso, J.; Force, R.; Tekawa, M. & Grunder, H.
Partner: UNT Libraries Government Documents Department

Acceleration of partially stripped ions at the Bevalac

Description: Results are presented of the first attempts to accelerate partially stripped heavy ions in the Bevatron. Experiments were performed for hydrogen-like argon and neon ions, and, although the survival time of these ions in the 10/sup -7/ torr Bevatron vacuum was not sufficient to achieve full energy, valuable charge-changing cross section information was obtained.
Date: March 1, 1977
Creator: Alonso, J.; Force, R.; Tekawa, M. & Grunder, H.
Partner: UNT Libraries Government Documents Department

Monte Carlo simulation of turbulent atmospheric transport and comparisons with experimental data. [/sup 41/Ar continuously emitted from BNL reactor to atmosphere]

Description: In a previous paper Peterson presented measurements on the /sup 41/Ar emitted continuously into the atmosphere from a reactor at the Brookhaven National Laboratory. Here, calculated results obtained with the Monte Carlo atmospheric transport model of Watson and Barr are presented and compared with the experimental data. The measured quantities with which comparisons are made are: the position north of Brookhaven where the maximum /sup 41/Ar concentration occurred for specific values of x (east of Brookhaven) and t, time; the standard deviation, sigma/sub y/, of the /sup 41/Ar concentration about the position of maximum concentration for specific values of x and t; and a quantity that is proportional to the maximum /sup 41/Ar concentration for specific values of x and t. The calculated results are in moderately good agreement with the experimental data at most distances (less than or equal to 300 km) and most times for which data are available.
Date: March 1, 1978
Creator: Alsmiller, F. S.; Alsmiller, Jr., R. G.; Bertini, H. W. & Begovich, C. L.
Partner: UNT Libraries Government Documents Department

Heavy-Ion Elastic Scattering

Description: The elastic scattering of C/sup 12/ ions from Ar, Fe, Ni, Ag/sup 107/ In, and Ta was measured as a function of angle, at a laboratory-system energy of 124.5 Mev with the Berkeley heavy-ion linear accelerator. The experimental equipment and techniques are discussed. The angular distributions show the same general behavior as previous heavy-ion elastic scattering experiments. The experimental data were analyzed with the semiclassical Blair model as modified by McIntyre. Very good agreement with experiment was obtained. The measurements were taken with 1% statistics in order to study the structure of the angular distributions in greater detail, because only by fitting the details in the structure was it possible to obtdin unambiguous sets of parameters. The parameters indicated a nuclear radius of 1.45A/sup 1/3/ x 10/sup -13/ cm, and a nearly constant surface thick ness of 1.6 x 10/sup -13/ cm. Total reaction cross sections were obtained. A rainbow-model analysis by Goldman of the data is given. Existing alpha - and heavy-ion scattering data were analyzed with the McIntyre model and compared with previous optical-model analyses of the same data. It was found that, by independent analysis, the two models give the same imaginary phase shifts for all partial waves. The real phase shifts are identical above a certain lth partial wave, but differ widely below this 1 value. It is shown that in the region of disagreement the real part of the phase shifts is irrelevant to the calculation of the cross section. (auth)
Date: April 17, 1961
Creator: Alster, Jonas
Partner: UNT Libraries Government Documents Department

Single and multiple electron loss processes in MeV heavy ion-target collisions

Description: Experimental data, derived from the study of interactions between MeV heavy ions and gaseous targets are presented which illustrate important physical aspects such as the dependence of cross sections on projectile velocity, and projectile and target atomic numbers. Included are data which reflect the importance of the electron binding energy, the existence of shell effects, the possibility of target polarizability, and the presence of non-additivity and density effects in electron loss processes. Charge state yield versus scattering angle, a prescription for relating total single electron loss cross section per atom atomic and molecular target data and formulas which predict electron loss cross sections with reasonable accuracy are also given.
Date: January 1, 1980
Creator: Alton, G.D.
Partner: UNT Libraries Government Documents Department