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Collisional processes of interest in MFE plasma research. Annual report, October 1, 1980-September 30, 1981

Description: Research on this contract can be divided into two general topics: (1) D/sup -/ formation collision processes, and (2) the determination of scattering cross sections used to diagnose properties of magnetically-confined plasmas. For topic (1) during last year, we completed theoretical calculations on the differential (angular) scattering of H/sup 0/ and D/sup 0/ on Cs, and determined the mechanisms and trends in the electron detachment cross sections for collisions of H/sup -/ and D/sup -/ on He, Ne, and the alkali and heavy alkaline earth atom systems. On topic (2) a major accomplishment was the determination of the electron capture and ionization cross sections for the C/sup 5 +/, N/sup 5 +/, and O/sup 6 +/ + H systems in the energy range from 13 eV/amu to 2.1 MeV/amu.
Date: October 15, 1981
Creator: Olson, R.E.
Partner: UNT Libraries Government Documents Department

Confinement requirements for ohmic-compressive ignition of a Spheromak plasma

Description: The Moving Plasmoid Reactor (MPR) is an attractive alternative magnetic fusion scheme in which Spheromak plasmoids are envisioned to be formed, compressed, burned, and expanded as the plasmoids translate through a series of linear reactor modules. Although auxiliary heating of the plasmoids may be possible, the MPR scenario would be especially interesting if ohmic decay and compression alone is sufficient to heat the plasmoids to an ignition temperature. In the present work, we examine the transport conditions under which a Spheromak plasmoid can be expected to reach ignition via a combination of ohmic and compression heating.
Date: January 1, 1981
Creator: Olson, R.E. & Miley, G.H.
Partner: UNT Libraries Government Documents Department

Computational simulation of spheromak plasma heating

Description: The examination of spheromak plasma heating provides a logical bridge between the present-day experimental studies of compact torus formation and the futuristic conceptual studies of the spheromak and moving ring reactors. In the near term, the work helps in understanding the temperature clamping in experiments and provides some insight into how to overcome this obstacle (e.g., via impurity cleanup). In the longer term, the work also provides some insight into other possible temperature clamping problems (i.e., soft beta limit and resistive interchange) and allows us to propose and study methods for overcoming them.
Date: January 1, 1982
Creator: Olson, R.E. & Miley, G.H.
Partner: UNT Libraries Government Documents Department

Recovery of magnetic energy in an MPR expansion chamber

Description: The technique of magnetic coupling for measurements of charged particles from Moving Plasmoid Reactors is described. A model is developed to calculate the magnitude of and the recovery efficiency of magnetic energy leftover in the MPR. Some estimates and observations are also made concerning the possible plasmoid velocities and power output in the expansion chamber system. (MOW)
Date: January 1, 1981
Creator: Olson, R.E. & Miley, G.H.
Partner: UNT Libraries Government Documents Department

Cometary X-ray emission: theoretical cross sections following charge exchange by multiply charged ions of astrophysical interest

Description: The CTMC method is used to calculate emission cross sections following charge exchange collisions involving highly charged ions of astrophysical interest and typical cometary targets. Comparison is made to experimental data obtained on the EBIT machine at Lawrence Livermore National Laboratory (LLNL) for O{sup 8+} projectiles impinging on different targets at a collision energy of 10 eV/amu. The theoretical cross sections are used together with ion abundances measured by the Advanced Composition Explorer as well as those obtained by a fitting procedure using laboratory emission cross sections in order to reproduce the x-ray spectrum of comet C/LINEAR S4 measured on July 14th 2001.
Date: February 13, 2007
Creator: Otranto, S; Olson, R E & Beiersdorfer, P
Partner: UNT Libraries Government Documents Department

Cometary X-Rays: Line Emission Cross Sections for Multiply Charged Solar Wind Ion Charge Exchange

Description: Absolute line emission cross sections are presented for 1 keV/amu charge exchange collisions of multiply charged solar wind ions with H{sub 2}O, H, O, CO{sub 2}, and CO cometary targets. The present calculations are contrasted with available laboratory data. A parameter-free model is used to successfully predict the recently observed x-ray spectra of comet C/LINEAR 1999 S4. We show that the resulting spectrum is extremely sensitive to the time variations of the solar wind composition. Our results suggest that orbiting x-ray satellites may be a viable way to predict the solar wind intensities and composition on the Earth many hours before the ions reach the earth.
Date: December 22, 2006
Creator: Otranto, S; Olson, R E & Beiersdorfer, P
Partner: UNT Libraries Government Documents Department

X-Ray Emission Cross Sections following Charge Exchange by Multiply-Charged Ions of Astrophysical Interest

Description: State selective nl-electron capture cross sections are presented for highly charged ions with Z = 6-10 colliding with atoms and molecules. The energy range investigated was from 1 eV/amu (v = 0.006 a.u.) to 100 keV/amu (v =2.0 a.u.). The energy dependence of the l-level populations is investigated. The K-shell x-ray emission cross sections are determined by using the calculated state-selective electron capture results as input and then applying hydrogenic branching and cascading values for the photon emission. A major shift in the line emission from being almost solely Lyman-{alpha} transitions at the highest collisions energies to strong high-n to 1s transitions at the lowest energies is observed. The calculated cross sections are in reasonable accord with measurements made by Greenwood et al, Phys. Rev. A 63, 062707 (2001), using O{sup 8+} and Ne{sup 10+} on various targets at 3 keV/amu. The calculations are also in accord with x-ray emission cross section data obtained on the EBIT machine at LLNL where O{sup 8+} and Ne{sup 10+} high resolution measurements were made at a temperature of 10 eV/amu for a series of targets with varying ionization potentials. The Ne{sup 10+} data clearly shows the contribution from multiple capture followed by Auger autoionization in the line emission spectra. Our calculated line emission cross sections are used to provide an ab initio determination of the soft x-ray spectrum of comet C/Linear 1999 S4 that was observed on the Chandra X-ray Observatory. The calculations show that the spectrum is due to charge exchange of the neutral gases in the comet's coma with the ions of the slow solar wind.
Date: September 19, 2005
Creator: Otranto, S; Olson, R E & Beiersdorfer, P
Partner: UNT Libraries Government Documents Department

X-Ray Emission Cross Sections following Charge Exchange by Multiply-Charged Ions of Astrophysical Interest

Description: The CTMC method is used to calculate emission cross sections following charge exchange processes involving highly charged ions of astrophysical interest and typical cometary targets. Comparison is made to experimental data obtained on the EBIT-I machine at Lawrence Livermore National Laboratory LLNL for O{sup 8+} projectiles impinging on different targets at a collision energy of 10 eV/amu. The theoretical cross sections are used together with ion abundances measured by the Advanced Composition Explorer to reproduce cometary spectra. Discrepancies due to different estimated delays of solar wind events between the comet and the Earth-orbiting satellite are discussed.
Date: March 12, 2007
Creator: Otranto, S; Olson, R E & Beiersdorfer, P
Partner: UNT Libraries Government Documents Department

The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Date: April 29, 1940
Creator: Olson, R. E. & Allison, J. M.
Partner: UNT Libraries Government Documents Department

The Calculated Effect of Various Hydrodynamic and Aerodynamic Factors on the Take-Off of a Large Flying Boat

Description: Present designs for large flying boats are characterized by high wing loading, high aspect ratio, and low parasite drag. The high wing loading results in the universal use of flaps for reducing the takeoff and landing speeds. These factors have an effect on takeoff performance and influence to a certain extent the design of the hull. An investigation was made of the influence of various factors and design parameters on the takeoff performance of a hypothetical large flying boat by means of takeoff calculations. The parameters varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The takeoff times and distances were calculated to the stalling speeds and the performance above these speeds was studied separately to determine piloting technique for optimum takeoff. The advantage of quick deflection of the flap at high water speeds is shown.
Date: April 28, 1939
Creator: Olson, R. E. & Allison, J. M.
Partner: UNT Libraries Government Documents Department

Collisional processes of interest in MFE plasma research

Description: Research on this grant is devoted to the calculation of heavy particle collision cross sections needed for diagnostic studies of magnetic fusion plasmas. This work requires the development and testing of new theoretical methods, with the implementation of benchmarked techniques to collisions pertinent to fusion reactors. Within the last context, we have provided charge-exchange-recombination cross sections to specific n,1-levels for diagnostic studies on TFTR and for a major compilation for IAEA. We have also completed a cross section study related to the planned neutral beam current drive for ITER. In addition, calculations were completed to assess the use of He neutral atom angular scattering measurements for JT-60. Also, new theoretical methods have been developed to more accurately calculate cross sections involving either He or H{sub 2} targets and partially stripped multiply-charged ions.
Date: May 24, 1990
Creator: Olson, R.E.
Partner: UNT Libraries Government Documents Department

Charge exchange produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral beam injection

Description: High-resolution spectroscopy of hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain the first high-resolution K-shell x-ray spectrum formed solely by charge exchange. The observed K-shell emission of Ar{sup 16+} is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge exchange cross sections.
Date: December 27, 2004
Creator: Beiersdorfer, P; Bitter, M; Marion, M & Olson, R E
Partner: UNT Libraries Government Documents Department

Inertial fusion power for space applications

Description: More than thirty-seven design concepts have been proposed for terrestrial ICF power plants. The design space is large because of the many allowable driver and reaction chamber combinations. These design studies have illustrated advantages of ICF power plants over other sources in lower impact on the environment, high safety, and almost no dependence on consumables like fuel. The fact that, once built, a 1000 MW/sub e/ ICF power plant would require only 240 kg of deuterium and from 770 to 9260 kg of lithium to run for five years (at 70% capacity factor) makes it potentially attractive for space power also. However, the designs proposed to date have emphasized features that would make the plant attractive for terrestrial applications, where economics, efficiency, and environmental considerations dominate. The resulting plants are large and contain many very heavy components that would not be at attractive for space applications. In this paper, we evaluate alternative ICF driver and reactor technologies using space application criteria and also discuss how some of those technologies can be altered to produce smaller, lighter fusion power sources for space.
Date: May 19, 1986
Creator: Meier, W.R.; Hogan, W.J.; Hoffman, N.J.; Murray, K.A. & Olson, R.E.
Partner: UNT Libraries Government Documents Department

Analytic Models of High-Temperature Hohlraums

Description: A unified set of high-temperature-hohlraum models has been developed. For a simple hohlraum, P{sub s} = [A{sub s}+(1{minus}{alpha}{sub W})A{sub W}+A{sub H}]{sigma}T{sub R}{sup 4} + (4V{sigma}/c)(dT{sub R}{sup r}/dt) where P{sub S} is the total power radiated by the source, A{sub s} is the source area, A{sub W} is the area of the cavity wall excluding the source and holes in the wall, A{sub H} is the area of the holes, {sigma} is the Stefan-Boltzmann constant, T{sub R} is the radiation brightness temperature, V is the hohlraum volume, and c is the speed of light. The wall albedo {alpha}{sub W} {triple_bond} (T{sub W}/T{sub R}){sup 4} where T{sub W} is the brightness temperature of area A{sub W}. The net power radiated by the source P{sub N} = P{sub S}-A{sub S}{sigma}T{sub R}{sup 4}, which suggests that for laser-driven hohlraums the conversion efficiency {eta}{sub CE} be defined as P{sub N}/P{sub LASER}. The characteristic time required to change T{sub R}{sup 4} in response to a change in P{sub N} is 4V/C[(l{minus}{alpha}{sub W})A{sub W}+A{sub H}]. Using this model, T{sub R}, {alpha}{sub W}, and {eta}{sub CE} can be expressed in terms of quantities directly measurable in a hohlraum experiment. For a steady-state hohlraum that encloses a convex capsule, P{sub N} = {l_brace}(1{minus}{alpha}{sub W})A{sub W}+A{sub H}+[(1{minus}{alpha}{sub C})(A{sub S}+A{sub W}{alpha}{sub W})A{sub C}/A{sub T}]{r_brace}{sigma}T{sub RC}{sup 4} where {alpha}{sub C} is the capsule albedo, A{sub C} is the capsule area, A{sub T} {triple_bond} (A{sub S}+A{sub W}+A{sub H}), and T{sub RC} is the brightness temperature of the radiation that drives the capsule. According to this relation, the capsule-coupling efficiency of the baseline National-Ignition-Facility (NIF) hohlraum is 15% higher than predicted by previous analytic expressions. A model of a hohlraum that encloses a z pinch is also presented.
Date: November 29, 2000
Creator: Stygar, W.A.; Olson, R.E.; Spielman, R.B. & Leeper, R.J.
Partner: UNT Libraries Government Documents Department

Transfer ionization in 0. 5-1. 5 MeV/u O/sup 5 -8 +/ + He collisions

Description: Transfer ionization (TI), in which electron capture is accompanied by loss of the other electron from the target, been measured for 0.5 to 1.5 MeV/u 0/sup q//sup +/ ions (q = 5-8+) colliding with helium. These new measurements, in conjunction with previous measurements at lower energies, are used to formulate a scaling rule to describe the projectile energy and charge state dependences of TI for collisions involving helium targets. 10 refs., 2 figs.
Date: January 1, 1986
Creator: Tanis, J.A.; Clark, M.W.; Price, R.; Ferguson, S.M. & Olson, R.E.
Partner: UNT Libraries Government Documents Department

High Pu-240-content plutonium Chemical Processing cost estimates

Description: In response to an inquiry by Euratom, estimates of the costs for the production of 85 kg of 15% Pu-240 metal and for the production of 15 kg of 25% Pu-240 oxide at HAPO were recently requested by the Atomic Energy Commission. In connection with this inquiry, comments were requested regarding the possibility of establishing and measuring product plutonium oxide ``sinterability`` parameters. This report presents estimates of the costs for separations processing by the Chemical Processing Department for the cases of interest. Process ground rules and any necessary assumptions are explained. In addition, the problems of measuring oxide ``sinterability`` are briefly discussed. Highlights of this study were previously transmitted to the Irradiation Processing Department for incorporation in a formal reply to the original Commission request. Subsequently, some adjustments in ground rules have caused cost changes which are included in this report.
Date: September 26, 1963
Creator: McDonald, J. E.; Olson, R. E. & Rathvon, H. C.
Partner: UNT Libraries Government Documents Department

Charge Exchange Spectra of Hydrogenic and He-like Iron

Description: We present H-like Fe XXVI and He-like Fe XXV charge-exchange spectra resulting from collisions of highly charged iron with N{sub 2} gas at an energy of {approx}10 eV amu{sup -1} in an electron beam ion trap. Although high-n emission lines are not resolved in our measurements, we observe that the most likely level for Fe{sup 25+} {yields} Fe{sup 24+} electron capture is n{sub max} {approx} 9, in line with expectations, while the most likely value for Fe{sup 26+} {yields} Fe{sup 25+} charge exchange is significantly higher. In the Fe XXV spectrum, the K{alpha} emission feature dominates, whether produced via charge exchange or collisional excitation. The K{alpha} energy centroid is lower in the former case than the latter (6666 versus 6685 eV, respectively), as expected because of the strong enhancement of emission from the forbidden and intercombination lines, relative to the resonance line, in charge-exchange spectra. In contrast, the Fe XXVI high-n Lyman lines have a summed intensity greater than that of Ly{alpha}, and are substantially stronger than predicted from theoretical calculations of charge exchange with atomic H. A discussion is presented of the relevance of our results to studies of diffuse Fe emission in the Galactic Center and Galactic Ridge, particularly with ASTRO-E2.
Date: April 27, 2005
Creator: Wargelin, B J; Beiersdorfer, P; Neill, P A; Olson, R E & Scofield, J H
Partner: UNT Libraries Government Documents Department

The light ion pulsed power induction accelerator for ETF

Description: Our Engineering Test Facility (ETF) driver concept is based on HERMES III and RHEPP technologies. Actually, it is a scaled-down version of the LMF design incorporating repetition rate capabilities of up to 10 Hz CW. The preconceptual design presented here provides 200-TW peak power to the ETF target during 10 ns, equal to 2-MJ total ion beam energy. Linear inductive voltage addition driving a self-magnetically insulated transmission line (MITL) is utilized to generate the 36-MV peak voltage needed for lithium ion beams. The {approximately} 3-MA ion current is achieved by utilizing many accelerating modules in parallel. Since the current per module is relatively modest ({approximately}300 kA), two-stage or one-stage extraction diodes can be utilized for the generation of singly charged lithium ions. The accelerating modules are arranged symmetrically around the fusion chamber in order to provide uniform irradiation onto the ETF target. In addition, the modules are fired in a programmed sequence in order to generate the optimum power pulse shape onto the target. This design utilizes RHEPP accelerator modules as the principal power source.
Date: December 31, 1994
Creator: Mazarakis, M.G.; Olson, R.E.; Olson, C.L.; Smith, D.L. & Bennett, L.F.
Partner: UNT Libraries Government Documents Department

Design data for calculating neutral beam penetration into Z/sub eff/ > 1 plasmas

Description: Impurities such as C, N, O, Fe, and Mo in a confined plasma reduce the penetration of the energetic neutral deuterium or hydrogen beam injected for heating or fueling the plasma, thus affecting the energy- and fuel-deposition profiles. New calculations, confirmed by recent experimental results, show that previous estimates of the reduction of neutral beam penetration due to impurities in the plasma were overly pessimistic. Until recently, the cross sections used to calculate beam attenuation had been assumed to be q/sup 2/times the cross section for H/sup +/ + H obtained from the Born approximation, where q is the charge state of the ion. This led to very large cross sections for large values of q, and thus to very stringent requirements on the acceptable level of impurity ions in the plasma.
Date: January 1, 1978
Creator: Olson, R.E.; Berkner, K.H.; Graham, W.G.; Pyle, R.V.; Schlachter, A.S. & Stearns, J.W.
Partner: UNT Libraries Government Documents Department

Feasibility studies for an ECR-generated plasma stripper: Preliminary

Description: Computational studies of the principal electron capture and loss processes which take place during interactions between a multi-electron projectile and a target in various degrees of ionization have been initiated. These studies are designed to determine the feasibility of a plasma stripper as a possible alternative to the gaseous and foil strippers which are commonly used to enhance the charge states of energetic ion beams. The idea is based on the knowledge that the stopping powers (energy loss per unit path length) are greater for a plasma than a gaseous stripper at equivalent line densities, and the number of electron channels available for capture by the projectile are reduced when the target is highly ionized. Preliminary results of attempts to evaluate the merits of a plasma for this applications are given in this report. 11 refs., 3 figs.
Date: January 1, 1990
Creator: Alton, G.D. (Oak Ridge National Lab., TN (USA)); Sparrow, R.A. & Olson, R.E. (Missouri Univ., Rolla, MO (USA))
Partner: UNT Libraries Government Documents Department

The light ion LMF and its relevance to IFE

Description: The inertial confinement fusion (ICF) program at Sandia National Laboratories (SNL) is directed toward validating light ions as an efficient driver for ICF defense and energy applications. The light ion laboratory microfusion facility (LMF) is envisioned as a facility in which high gain ICF targets could be developed and utilized in defense-related experiments. The relevance of LMF technology to eventual inertial fusion energy (IFE) applications is assessed via a comparison of LMF technologies with those projected in the Light Ion Beam Reactor Assessment (LIBRA) conceptual reactor design study.
Date: December 1, 1993
Creator: Olson, R. E.; Allshouse, G. O.; Cook, D. L.; Lockner, T. R.; Mazarakis, M. G.; Olson, C. L. et al.
Partner: UNT Libraries Government Documents Department