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Production Of Cl⁻·Hcl Cluster Ions In Hcl-N2 Mixtures, R. J. Corbin, Kaare J. Nygaard, William R. Snow, Laird D. Schearer Jan 1978

Production Of Cl⁻·Hcl Cluster Ions In Hcl-N2 Mixtures, R. J. Corbin, Kaare J. Nygaard, William R. Snow, Laird D. Schearer

Physics Faculty Research & Creative Works

A drift-tube-mass-spectrometer apparatus has been used to study the production of Cl-·HCl cluster molecules in HCl-N2 mixtures. The concentration of HCl was 730 ppm and the total pressure ranged from 0.1-5 Torr. The primary ion Cl- is produced mainly by dissociative attachment of HCl and is converted to a cluster ion in a three-body collision. The rate of formation of the cluster ion is k2≃ 10-25 cm6/sec at E/N=12 Td. © 1978 American Institute of Physics.

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Proton Spin-Lattice Relaxation And Methyl Group Rotation, Peter A. Beckmann, C. I. Ratcliffe, B. A. Dunell Jan 1978

Proton Spin-Lattice Relaxation And Methyl Group Rotation, Peter A. Beckmann, C. I. Ratcliffe, B. A. Dunell

Physics Faculty Research and Scholarship

Proton spin-lattice relaxation times have been measured at 16, 31, and 59 MHz in 4-methyl-2,6-ditertiarybutyl phenol between 80 K and its melting point, 340 K. The variation of T1 with temperature shows too distinct minima. The lower-temperature minimum has been analyzed in terms of relaxation by reorientation of four of the six t-butyl methyl groups with an average apparent activation energy of about 2.4 kcal mole−1 (104 meV molecule−1). The higher-temperature minimum has been analyzed in terms of relaxation by reorientation of the t-butyl groups about their C3 axes with four of the six t-butyl methyl groups reorienting …

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Electron Spin Relaxation And Tunnelling Methyl Groups, Peter A. Beckmann, S. Clough Jan 1978

Electron Spin Relaxation And Tunnelling Methyl Groups, Peter A. Beckmann, S. Clough

Physics Faculty Research and Scholarship

The energy transfer has been studied between free radicals and nearby tunnelling methyl groups near the resonant condition that the electron Larmor frequency and the methyl tunnelling frequency are equal. The measurements were made in a gamma -irradiated single crystal of 4-methyl-2,6-ditertiarybutylphenol (MDBP) at 4.2K and consisted of saturating the ESR signal and observing its return to equilibrium. This has been done at eleven ESR frequencies in the range 8.97< nu s<0.63 GHz and for saturation times of 5, 50 and 200 s. A theoretical model has been developed for the non-exponential recovery which assumes that all the 4-methyl groups of the molecules surrounding a free radical have the same tunnelling rotation frequency nu t and that the only coupling between the electrons and the methyl groups is the intermolecular dipole-dipole interaction.

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The Coma/A1367 Supercluster And Its Environs, Stephen A. Gregory, Laird A. Thompson Jan 1978

The Coma/A1367 Supercluster And Its Environs, Stephen A. Gregory, Laird A. Thompson

Department of Physics and Astronomy: Faculty Publications

The three-dimensional galaxy distribution in the region of space surrounding the two rich clusters Coma and A1367 is analyzed by using a nearly complete redshift sample of 238 galaxies with mp < 15.0 in a 260 degree2 region of the sky; 44 of these redshifts are reported here for the first time. We find that the two clusters are enveloped in a common supercluster which also contains four groups and a population of isolated galaxies. The least dense portions of the Coma/A1367 supercluster have a density which is approximately 6 times that of the Local Supercluster in the regions of our own Galaxy. In …

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Precipitation Phenomena In Antimony-Implanted Aluminium, Richard Allen Kant Dec 1977

Precipitation Phenomena In Antimony-Implanted Aluminium, Richard Allen Kant

Physics & Astronomy ETDs

An experimental and theoretical study of the influence of temperature flux, and fluence on the formation and evolution of compounds formed by ion implantation has been conducted. Transmission electron microscopy was used to determine the size distribution of AJSb precipitates resulting from implanting single crystal A1 with Sb. In addition, the role of ion damage was investigated using both Ar and Al bombardment. These experiments show that for samples which initially contain no Sb, the number density of pre• cipitates decreases with increasing fluence and temperature, and with decreasing flux.

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Impurity Photomagnetoelectric Effect: Application To Semi-Insulating Gaas, David C. Look Dec 1977

Impurity Photomagnetoelectric Effect: Application To Semi-Insulating Gaas, David C. Look

Physics Faculty Publications

The theories of the photomagnetoelectric (PME) and photoconductivity (PC) effects in semiconductors are extended to include unequal excitation rates of holes and electrons, as might be expected from impurity photo-excitation. The results are applied to two semi-insulating Cr-doped GaAs crystals, which exhibit mixed conductivity. It is seen that the PC and PME effects give complementary information on the holes and electrons. In the impurity excitation region the PME current responds strongly to changes in the absorption coefficient, and provides a convenient way to study this quantity.

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The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson Aug 1977

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson

Faculty Publications

Depth profiles for hydrogen in amorphous silicon have been determined by the use of resonant nuclear reactions [1H(15N,αγ)12C and 1H(19F,αγ)16O] and by secondary ion mass spectroscopy (SIMS). Independent calibration procedures were used for the two techniques. Measurements were made on the same amorphous silicon film to provide a direct comparison of the two hydrogen analysis techniques. The hydrogen concentration in the bulk of the film was determined to be about 9 at % H. The SIMS results agree with the resonant nuclear reaction results to within 10%, which demonstrates that quantitative hydrogen depth profiles can be obtained by SIMS analysis …

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19th Annual Conference On Analytical Chemistry Aug 1977

19th Annual Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 19th annual meeting of the Conference on Analytical Chemistry, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 1-3, 1977.

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Erratum: Excitation Of The N=2 State Of Atomic Hydrogen By Electron Impact In The Distorted-Wave Approximation (Physical Review A (1977) 16, 2), Ralph V. Calhoun, Don H. Madison, W. Neil Shelton Aug 1977

Erratum: Excitation Of The N=2 State Of Atomic Hydrogen By Electron Impact In The Distorted-Wave Approximation (Physical Review A (1977) 16, 2), Ralph V. Calhoun, Don H. Madison, W. Neil Shelton

Physics Faculty Research & Creative Works

No abstract provided.

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Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom Jul 1977

Static Temperature Measurements In Supersonic Flow Using Lasar Raman Spectroscopy, Paul A. Nystrom

Mechanical & Aerospace Engineering Theses & Dissertations

Laser Raman spectroscopy is a nonintrusive technique which can generate mean static temperature (MST) data within flow fields. By ratioing two simultaneously gathered portions of the Raman scattered spectrum, absolute intensity measurements were not needed. This method was applied to a supersonic cold air jet, where the NST ranged from 160'K to 300'K. Accurate measurements were not realized due to the presence of flow contaminates, especially water vapor.

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X-Ray Investigation Of The Critical Exponent Η In Argon, Harold D. Bale, J. S. Lin, Duane A. Dolejsi, James L. Casteel, Oran Allan Pringle, Paul W. Schmidt Jul 1977

X-Ray Investigation Of The Critical Exponent Η In Argon, Harold D. Bale, J. S. Lin, Duane A. Dolejsi, James L. Casteel, Oran Allan Pringle, Paul W. Schmidt

Physics Faculty Research & Creative Works

Measurements were made of the small-angle x-ray scattering intensity from argon near the critical point. After the scattering curves are corrected for all known effects except those resulting from irrelevant variables, a value of the critical exponent η=0.09±0.02 is obtained, while if a correction for the estimated effect of irrelevant variables is also made, η=0.03±0.03. The scattering data for argon therefore show that if irrelevant variables can be neglected, the critical exponent η for argon is in good agreement with the value obtained by Warkulwiz, Mozer, and Green from small-angle neutron scattering data for neon. These values of η, however, …

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Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott L. Whittenburg, C. H. Wang Jun 1977

Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott L. Whittenburg, C. H. Wang

Chemistry and Biochemistry Faculty Publications

The zero‐frequency shear wave dip appearing in the depolarized Rayleigh spectrum in benzonitrile has been studied as a function of concentration and temperature. The solution study was carried out at constant viscosity equal to the viscosity of liquid benzonitrile at each temperature. The result indicates that the presence of shear wave fine structure does not depend on the collective orientational fluctuations. The orientational and vibrational relaxation times of benzonitrile were measured at various concentrations and temperatures. The orientational relaxation times show no concentration dependence at any temperature, suggesting that the pair correlation is negligible at all concentrations. The orientational relaxation …

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Measurement Of The Difference Between The Dynamic Nmr And Static Susceptibilites Of Superfluid 3he-B Using An Rf-Biased Superconducting Quantum-Interference Device, Richard A. Webb May 1977

Measurement Of The Difference Between The Dynamic Nmr And Static Susceptibilites Of Superfluid 3he-B Using An Rf-Biased Superconducting Quantum-Interference Device, Richard A. Webb

Faculty Publications

The temperature-dependent susceptiblity of superfluid 3He-B has been measured both statically and via a pulse technique in a field of 309 G using an rf-biased superconducting quantum-interference device (SQUID). In the pressure range 26.5 to 18 bar, the dynamic NMR susceptiblity agrees qualitatively with the theoretical weak-coupling predictions for the Balian-Werthamer state. However, the static susceptiblity, measured using the same rf-biased SQUID and detection system, is significantly smaller thatn the dynamic susceptibility.

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Light Scattering Studies Of Rotational And Vibrational Relaxations Of Acetonitrile In Carbon Tetrachloride, Scott L. Whittenburg, C. H. Wang May 1977

Light Scattering Studies Of Rotational And Vibrational Relaxations Of Acetonitrile In Carbon Tetrachloride, Scott L. Whittenburg, C. H. Wang

Chemistry and Biochemistry Faculty Publications

The rotational and vibrational relaxation times of acetonitrile–carbon tetrachloride solutions were investigated as a function of concentration, viscosity, and temperature using depolarized Rayleigh and Raman scattering. Using a Fabry‐Perot interferometer and single frequency laser source, we have shown that reliable results for the single particle orientational correlation times (τs) for CH3CN can be obtained by carrying out a concentration dependent depolarized Rayleigh scattering study. Raman scattering was shown to yield inconsistent results for τs in CH3CN. At constant viscosity, it was found that the Rayleigh scatteringrelaxation time (τRay) of CH3 …

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Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert May 1977

Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert

Physics & Astronomy ETDs

In Chapter 1, I outline the methods of making ground-based infrared observations. I concentrate on the observational procedures rather than the instrumental design. Near-infrared observations of S 156A, _S 158A, S 159A, S 162A1, S 228, and G 45. 5 + 0 .1 (#2) made with a beam size of ̴1 are used to estimate the total near infrared flux. After correcting for the line of sight extinction the near infrared luminosities are greater than the Lyman-α luminosities inferred from radio observations. A strong double peaked infrared source was discovered near the region of G 25.3-0.1. The infrared …

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Measurement Of The Xenon Σ3/2:Σ1/2 Branching Ratio Within The Xe 5s5p66p(1P1) Resonance, Peter C. Kemeny, James A. R. Samson, Anthony F. Starace Apr 1977

Measurement Of The Xenon Σ3/2:Σ1/2 Branching Ratio Within The Xe 5s5p66p(1P1) Resonance, Peter C. Kemeny, James A. R. Samson, Anthony F. Starace

Anthony F. Starace Publications

Photoionization of the 5p6 shell in xenon leaves the ion in either the 5p5(2P3/2) or np5(2P1/2) state. Measurements of the 2P3/2 : 2P1/2 branching ratio are reported within the Xe 5s5p66p(1P1) resonance and fitted to a new theoretical expression. The maximum value of the ratio as determined by a two-parameter fit of theory to experiment is 8.8 ± 0.5 within the resonance, almost six times the nearly constant value of 1.55 found outside any resonance.

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Can Physics Develop Reasoning?, Robert Fuller, Robert Karplus, Anton E. Lawson Feb 1977

Can Physics Develop Reasoning?, Robert Fuller, Robert Karplus, Anton E. Lawson

Robert G. Fuller Publications

The life of every physicist is punctuated by events that lead him to discover that the way physicists see natural phenomena is different from the way non-physicists see them. Certain patterns of reasoning appear to be more common among physicists than in other groups. These include:
• focusing on the important variables (such as the force that accelerates the apple, rather than the lump it makes on your head);
• propositional logic ("if heat were a liquid it would occupy space and a cannon barrel could only contain a limited amount of heat, but this is contrary to my observations, …

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Differential Energy-Loss Cross Sections For Ionization Of Atomic Hydrogen By 25-200-Kev Protons, John T. Park, John E. Aldag, Jacob M. George, Jerry Peacher, Jim H. Mcguire Feb 1977

Differential Energy-Loss Cross Sections For Ionization Of Atomic Hydrogen By 25-200-Kev Protons, John T. Park, John E. Aldag, Jacob M. George, Jerry Peacher, Jim H. Mcguire

Physics Faculty Research & Creative Works

Ionization continuum cross sections, differential in energy loss, have been determined from the energy-loss spectra of 25-, 50-, 75-, 145-, and 200-keV protons scattered from atomic hydrogen. The theoretical differential cross sections in the Glauber and Born approximations that are presented show that the theory and the experimental results for 200-keV proton impact agree very well, but below 200 keV there are differences. These differences, which are more pronounced at the lower projectile energies, may be explained in terms of charge transfer to the continuum, which is not treated in our Born and Glauber calculations of direct Coulomb ionization. The …

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Compton's 'Crucial Test' - Theoretical Preconceptions And Experimental Interpretation, Roger H. Stuewer Jan 1977

Compton's 'Crucial Test' - Theoretical Preconceptions And Experimental Interpretation, Roger H. Stuewer

Journal of the Minnesota Academy of Science

Arthur Holly Compton, as a result of his own research and confidence in the validity of classical electrodynamics, was convinced in 1921 that homogeneous x-rays and gamma rays could be affected in only two possible ways when passing through matter: either they gave rise to "truly scattered" radiation of the same wavelength as that of the incident rays, or they excited "fluorescent" radiation of a longer wavelength. When Compton was led to carry out experiments using homogeneous x-rays and actually found secondary radiation of longer wavelength, he regarded his result as a crucial test between the "truly scattered" and the …

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Atomic Numbers Revalued, Frank H. Meyer Jan 1977

Atomic Numbers Revalued, Frank H. Meyer

Journal of the Minnesota Academy of Science

As a general physical theory, the Reciprocal System of D.B. Larson covers all physical fields, including atomic physics . Inasmuch as all of the conclusions reached in the theoretical development are derived entirely by deduction from the basic postulates of this system, the conclusions provide information that is completely independent of observation. The theoretical development indicates that the Mosely atomic number mathematical formula is quite right, and the Rutherford-Bohr-Mosely nuclear atom physical interpretation of atomic number is seriously wrong. The discrete units constituting atoms evidently are not neutrons and electrically charged particles. Nor are atoms made up of parts, a …

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Four-Color And Hβ Photometry Of Stars In Ngc 7654 And M25, Edward G. Schmidt Jan 1977

Four-Color And Hβ Photometry Of Stars In Ngc 7654 And M25, Edward G. Schmidt

Edward Schmidt Publications

Four-color and Hβ photometry has been obtained of stars in the galactic clusters NGC 7654 and M25. An analysis of these data shows variable extinction in both clusters. The distance modnlus of NGC 7654 is found to be 10m.99 ± 0.2 and that of M25 is 8m.68 ± 0.1.

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Eclipsing Systems In Star Structures. Iii. Early-Type Contact System Bh Centauri, Kam-Ching Leung, Donald P. Schneider Jan 1977

Eclipsing Systems In Star Structures. Iii. Early-Type Contact System Bh Centauri, Kam-Ching Leung, Donald P. Schneider

Department of Physics and Astronomy: Faculty Publications

Close to 1000 photoelectric observations of BH Cen in the yellow, blue, and ultraviolet regions were analyzed. The period found was 0.791616 days. The depths of minima were about equal, and were more than 1 magnitude! A photometric solution was derived with the Wilson and Devinney model. The binary is an overcontact system with primary and secondary masses equal to 10 M?. Based on its membership in IC 2944 and the size of the primary radius, BH Cen may be another example of a zero-age contact system.

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Electron And Ion Temperatures—A Comparison Of Ground-Based Incoherent Scatter And Ae-C Satellite Measurements, R F. Benson, P Bauer, L H. Brace, Herbert C. Carlson, J Hagen, W B. Hanson, W R. Hoegy, M R. Torr, R H. Wand, Vincent B. Wickwar Jan 1977

Electron And Ion Temperatures—A Comparison Of Ground-Based Incoherent Scatter And Ae-C Satellite Measurements, R F. Benson, P Bauer, L H. Brace, Herbert C. Carlson, J Hagen, W B. Hanson, W R. Hoegy, M R. Torr, R H. Wand, Vincent B. Wickwar

All Physics Faculty Publications

The Atmosphere Explorer-C satellite (AE-C) is uniquely suited for correlative studies with ground-based stations because its on-board propulsion system enables a desired ground station overflight condition to be maintained for a period of several weeks. It also provides the first low-altitude (below 260 km) comparison of satellite and incoherent scatter electron and ion temperatures. More than 40 comparisons of remote and in situ measurements were made by using data from AE-C and four incoherent scatter stations (Arecibo, Chatanika, Millstone Hill, and St. Santin). The results indicate very good agreement between satellite and ground measurements of the ion temperature, the average …

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A Geomagnetic Survey Of Greene County, Ohio, V. E. D. Obot, Paul J. Wolfe Jan 1977

A Geomagnetic Survey Of Greene County, Ohio, V. E. D. Obot, Paul J. Wolfe

Physics Faculty Publications

No abstract provided.

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The Nitrogen Dayglow On Mars, Jane L. Fox, Alexander Dalgarno, E. R. Constantinides, G. A. Victor Jan 1977

The Nitrogen Dayglow On Mars, Jane L. Fox, Alexander Dalgarno, E. R. Constantinides, G. A. Victor

Physics Faculty Publications

The ultraviolet dayglow spectrum arising from emission of N2 in the Mars atmosphere is predicted. The intensities are such that a high-resolution spectrum should readily reveal the presence of N2 at the abundances suggested by the Viking experiments.

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Radiative Transition Probabilities Of The 1S2P22P And 1S2P22D States Of The Lithium Isoelectronic Sequence, Jane L. Fox, Alexander Dalgarno Jan 1977

Radiative Transition Probabilities Of The 1S2P22P And 1S2P22D States Of The Lithium Isoelectronic Sequence, Jane L. Fox, Alexander Dalgarno

Physics Faculty Publications

A Z-expansion procedure is used to obtain eigenvalues and eigenfunctions for the 1s22p2Po, 1s2p22P, and 1s2p22D states of the lithium sequence. Expansions in inverse powers of the nuclear charge Z are obtained also for the dipole-matrix elements and oscillator strengths of the 1s22p2Po-1s2p22P and 1s22p2Po-1s2p22D transitions, valid for Z > 3. …

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The Haupt Effect: Coupled Rotational And Dipolar Relaxation Of Methyl Groups, Peter A. Beckmann, S. Clough, J. W. Hennel, J. R. Hill Jan 1977

The Haupt Effect: Coupled Rotational And Dipolar Relaxation Of Methyl Groups, Peter A. Beckmann, S. Clough, J. W. Hennel, J. R. Hill

Physics Faculty Research and Scholarship

A theory is described for the dynamic proton dipolar polarization observed by Haupt (1972) in 4-methylpyridine following a sudden temperature change. The theory differs from that of Haupt in assuming that transitions which change the rotational quantum number of the 4-methyl group by +or-3 occur very rapidly, maintaining thermal equilibrium within each of the three subsets of rotational levels corresponding to the three methyl group proton spin symmetry species A, Ea and Eb. The difference of A and E species populations approaches the new equilibrium value slowly and exponentially, following the temperature jump, and generates dipolar polarization in the process. …

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Final-State Effects In Carbon Auger Spectra Of Transition-Metal Carbides, M. A. Smith, L. L. Levenson Jan 1977

Final-State Effects In Carbon Auger Spectra Of Transition-Metal Carbides, M. A. Smith, L. L. Levenson

Physics Faculty Research & Creative Works

The carbon Auger spectra of TiC, VC, and Cr3C2 are measured with a resolution of 1.2 eV. Background subtraction is performed, and a deconvolution technique is used to remove energy-dependent broadening from the spectra. An analysis of the data in terms of density-of-states calculations, x-ray emission work, and x-ray photoelectron data shows that final-state effects dominate the Auger spectra. For all of the carbides three peaks are identified as spectral terms resulting directly from final-state hole interactions. Other peaks appearing in the Auger spectra can be identified without final-state considerations. © 1977 The American Physical Society.

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Λ And K⁰ Production In P↑P Interactions At 6 Gev/C, R. L. Eisner, William J. Fickinger, S. L. Glickman, J. A. Malko, J. F. Owens, D. K. Robinson Jan 1977

Λ And K⁰ Production In P↑P Interactions At 6 Gev/C, R. L. Eisner, William J. Fickinger, S. L. Glickman, J. A. Malko, J. F. Owens, D. K. Robinson

Faculty Scholarship

Results on K0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K0 inclusive production, and on the reactions p↑p → pΛK+(pΣ0K+). The beam asymmetry parameter for Image is determined to be (−0.52 ± 0.12).

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Absolute Doubly Differential Cross Sections For Ejection Of Secondary Electrons From Gases By Electron Impact. I. 100- And 200-Ev Electrons On Helium, M. Eugene Rudd, R. D. Dubois Jan 1977

Absolute Doubly Differential Cross Sections For Ejection Of Secondary Electrons From Gases By Electron Impact. I. 100- And 200-Ev Electrons On Helium, M. Eugene Rudd, R. D. Dubois

M. Eugene Rudd Publications

We have measured absolute values of the cross sections for ejection of electrons from helium gas by 100- and 200-eV electrons. These cross sections were measured for emission angles from 10° to 150° and for electron energies from 3 eV to a value equal to the primary energy minus the ionization potential. The measurements were made using a static-gas target and an electrostatic analyzer. The resulting cross sections agree reasonably well with those of Opal, Peterson, and Beaty near 90°, but show the need for an adjustment of their angular distributions. Comparison with Born-approximation calculations of Manson et al. at …

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