Workshop on radiological aspects of SSC operations (open access)

Workshop on radiological aspects of SSC operations

Integral to the design of an accelerator facility is the provision of adequate shielding to contain any radiation arising from operation of the facility. Complementary to the questions of environmental shielding are a number of radiation questions related to operation of the completed facility. One obvious need is the specification of systems for monitoring environmental emissions to ensure consistency between the design criteria and the actual levels during operation. Another question is the effect on the components of the machine of the radiation within the environmental shield. These questions were examined at the workshop. This report is a summary of the materials presented at the workshop.
Date: May 1, 1987
Creator: Toohig, T. E.
System: The UNT Digital Library
The Imaging Technology Used for Angiography at the Stanford Synchrotron Laboratory (open access)

The Imaging Technology Used for Angiography at the Stanford Synchrotron Laboratory

None
Date: May 6, 1987
Creator: Zeman, H. D.; Otis, J. N.; Hofstadter, R.; Thompson, A. C.; Brown, G. S.; Thomlinson, W. et al.
System: The UNT Digital Library
High Energy Polarized Electron Beams (open access)

High Energy Polarized Electron Beams

In nearly all high energy electron storage rings the effect of beam polarization by synchrotron radiation has been measured. The buildup time for polarization in storage rings is of the order of 10{sup 6} to 10{sup 7} revolutions; the spins must remain aligned over this time in order to avoid depolarization. Even extremely small spin deviations per revolution can add up and cause depolarization. The injection and acceleration of polarized electrons in linacs is much easier. Although some improvements are still necessary, reliable polarized electron sources with sufficiently high intensity and polarization are available. With the linac-type machines SLC at Stanford and CEBAF in Virginia, experiments with polarized electrons will be possible.
Date: May 1, 1987
Creator: Rossmanith, Robert
System: The UNT Digital Library
Human somatic, germinal and heritable mutagenicity (open access)

Human somatic, germinal and heritable mutagenicity

This report deals with the general process of variant formation rather than with the consequences of a specific variant being present. It focusses on mutational mechanisms, mutagens, and the method for detecting de novo mutants and estimating mutation rate. It is to human genetics much like disease causation and prevention medicine are to medicine as a whole. The word ''mutagenicity'' is used in the title and throughout the text to connote the causation of all classes of genetic damage. Mutagenicity and the corresponding words mutation, mutagen and mutagenesis can have multiple meaning, sometimes relating to gene mutation, sometimes to heritable mutation, and somtimes to all types of genetic damage. 38 refs., 1 tab.
Date: May 1, 1987
Creator: Mendelsohn, M.L.
System: The UNT Digital Library
The numerical simulation of accelerator components (open access)

The numerical simulation of accelerator components

The techniques of the numerical simulation of plasmas can be readily applied to problems in accelerator physics. Because the problems usually involve a single component ''plasma,'' and times that are at most, a few plasma oscillation periods, it is frequently possible to make very good simulations with relatively modest computation resources. We will discuss the methods and illustrate them with several examples. One of the more powerful techniques of understanding the motion of charged particles is to view computer-generated motion pictures. We will show several little movie strips to illustrate the discussions. The examples will be drawn from the application areas of Heavy Ion Fusion, electron-positron linear colliders and injectors for free-electron lasers. 13 refs., 10 figs., 2 tabs.
Date: May 1, 1987
Creator: Herrmannsfeldt, W.B. & Hanerfeld, H.
System: The UNT Digital Library
Progress toward identification of gluonic states (open access)

Progress toward identification of gluonic states

Progress in the last two years toward identification of gluonic states is reviewed. Discovery of additional pseudoscalars tends to confirm the glueball interpretation of iota(1460). A variety of evidence indicates new physics in the J = 1 channel in the E mass region. 65 refs., 1 tab.
Date: May 29, 1987
Creator: Chanowitz, Michael S.
System: The UNT Digital Library
Improving Hatchery Effectiveness as Related to Smoltification: Proceedings of a Workshop held at Kah-Nee-Tah Lodge, Warm Springs, Oregon, May 20-23, 1985. (open access)

Improving Hatchery Effectiveness as Related to Smoltification: Proceedings of a Workshop held at Kah-Nee-Tah Lodge, Warm Springs, Oregon, May 20-23, 1985.

The Bonneville Power Administration (BPA) intends to develop a smoltification research effort that would have broad support among the interested parties. BPA sponsored this workshop on smoltification and related research to gather leading technical experts in the field in smoltification, permit them to exchange information about the state of the art of smoltification research, and allow them to identify and rank high-priority projects. This document includes keynote speeches, technical papers, and other sessions that summarize both what is known and what information is needed.
Date: May 1, 1987
Creator: Bouck, Gerald R.
System: The UNT Digital Library
Probability of causation: Implications for radiological protection and dose limitation (open access)

Probability of causation: Implications for radiological protection and dose limitation

This report on the probability of causation of radiation-induced cancer is an attempt to bring together biology, chemistry, physics and statistics to calculate a value in the form of a ratio expressed as a percentage. In involves the interactions of numerous cancer risk factors, and all are fraught with technical difficulties and uncertainties. It is a computational approach to a societal problem that should be resolved in the political arena by men and women of government and law. But, it must be examined, because at the present, we have no reasonable method to explain the complexity of the mechanism of radiation-induced cancer and the probability of injury to an individual exposed in the past to ionizing radiation, and because society does not know how to compensate such a person who may have been injured by radiation, and particularly low-level radiation. Five questions are discussed that concern probability of causation of radiation-induced cancer. First, what is it and how can we best define the concept Second, what are the methods of estimation and cancer causation Third, what are the uncertainties involved Fourth, what are the strengths and limitation of the computational approach And fifth, what are the implications for radiological protection …
Date: May 1, 1987
Creator: Fabrikant, Jacob I.
System: The UNT Digital Library
Challenges of nuclear fusion (open access)

Challenges of nuclear fusion

After 30 years of research and development in many countries, the magnetic confinement fusion experiments finally seem to be getting close to the original first goal: the point of ''scientific break-even.'' Plans are being made for a generation of experiments and tests with actual controlled thermonuclear fusion conditions. Therefore, engineers and material scientists are hard at work to develop the required technology. In this paper the principal elements of a generic fusion reactor are described briefly to introduce the reader to the nature of the problems at hand. The main portion of the presentation summarizes the recent advances made in this field and discusses the major issues that still need to be addressed in regard to materials and technology for fusion power. Specific examples are the problems of the first wall and other components that come into direct contact with the plasma, where both lifetime and plasma contamination are matters of concern. Equally challenging are the demands on structural materials and on the magnetic-field coils, particularly in connection with the neutron-radiation environment of fusion reactors. Finally, the role of ceramics must be considered, both for insulators and for fuel breeding purposes. It is evident that we still have a formidable …
Date: May 1, 1987
Creator: Kunkel, W.B.
System: The UNT Digital Library
Searching for 4th generation fermions at high-energy e/sup +/e/sup -/ machines (open access)

Searching for 4th generation fermions at high-energy e/sup +/e/sup -/ machines

This writeup summarizes Monte Carlo studies on the feasibility of searching for 4th family fermions at high energy e/sup +/e/sup -/ machines. By high energy it is meant at energies beyond the Z/sup 0/; the Z/sup 0/ searches having been studied extensively by the SLC and LEP collaborations. The specific examples of ..sqrt..s = 200 GeV (namely LEP200) and ..sqrt..s = 600 GeV (in line with work being done at SLAC to investigate the potential of a future linear collider) were chosen. The studies have been performed with the four vectors produced by the models and no attempt has been made to account for the effects of finite resolution and inefficiencies due to a real detector environment.
Date: May 1, 1987
Creator: Dorfan, J. & Van Kooten, R.J.
System: The UNT Digital Library
The maximum likelihood estimator method of image reconstruction: Its fundamental characteristics and their origin (open access)

The maximum likelihood estimator method of image reconstruction: Its fundamental characteristics and their origin

We review our recent work characterizing the image reconstruction properties of the MLE algorithm. We studied its convergence properties and confirmed the onset of image deterioration, which is a function of the number of counts in the source. By modulating the weight given to projection tubes with high numbers of counts with respect to those with low numbers of counts in the reconstruction process, we have confirmed that image deterioration is due to an attempt by the algorithm to match projection data tubes with high numbers of counts too closely to the iterative image projections. We developed a stopping rule for the algorithm that tests the hypothesis that a reconstructed image could have given the initial projection data in a manner consistent with the underlying assumption of Poisson distributed variables. The rule was applied to two mathematically generated phantoms with success and to a third phantom with exact (no statistical fluctuations) projection data. We conclude that the behavior of the target functions whose extrema are sought in iterative schemes is more important in the early stages of the reconstruction than in the later stages, when the extrema are being approached but with the Poisson nature of the measurement. 11 refs., …
Date: May 1, 1987
Creator: Llacer, J. & Veklerov, E.
System: The UNT Digital Library
Steady-state deformation of some lithium ceramics (open access)

Steady-state deformation of some lithium ceramics

The stress-strain behavior of Li/sub 2/O, LiAlO/sub 2/ and Li/sub 2/ZrO/sub 3/ polycrystals, with densities varying from 0.70 to 0.95 of the theoretical, has been measured in constant-crosshead-speed compression tests at temperatures of 700 to 1000/sup 0/C with strain rates ranging from about 10/sup -6/ to 10/sup -4/ s/sup -1/. A steady-state stress, sigma/sub s/, for which the work-hardening rate becomes zero, was achieved. These results, therefore, yield information equivalent to that obtained from creep experiments. Limited data on LiAlO/sub 2/ and Li/sub 2/ZrO/sub 3/ were obtained. Nevertheless, under comparable conditions the lithium aluminate and zirconate were considerably stronger than the Li/sub 2/O. This finding may be related to differences in crystal structure. It is, however, likely that in operation as a function breeder blanket material, the oxide will swell whereas the aluminate and the zirconate will crack. 5 refs., 6 figs., 1 tab.
Date: May 1, 1987
Creator: Poeppel, R.B.; Routbort, J.L.; Billone, M.C.; Applegate, D.S.; Buchmann, E. & Londschien, B.
System: The UNT Digital Library
Effects of Impurities on Domain Growth (open access)

Effects of Impurities on Domain Growth

In the present report, the effects of both static and diffusing impurities on domain growth kinetics are considered. In particular, the Monte Carlo simulations for nonconservative (Glauber) dynamics are employed to examine the effects of quenched impurities on domain growth in the Potts model with varying degeneracy Q (2 less than or equal to Q less than or equal to 48). The effects of diffusing impurities are examined within the framework of the Ising model (i.e., Potts model with Q = 2) as a function of impurity diffusivity. Finally, a theoretical analysis of the diffusing-impurity results is presented.
Date: May 1, 1987
Creator: Srolovitz, D. J.; Grest, G. S.; Hassold, G. N. & Eykholt, R.
System: The UNT Digital Library
Blown-up orbifolds (open access)

Blown-up orbifolds

A method to repair - ''blow-up'' - the singularities of the Abelian (2,2) orbifolds to obtain the corresponding (2,2) Calabi-Yau manifolds is presented. This approach makes use of the fact that with each orbifold singularity there are associated massless scalar fields - blowing-up modes - whose potential is flat to all orders in the string perturbation theory. The zero vacuum expectation values (VEV's) of the blowing-up modes correspond to the orbifold limit, while nonzero VEV's yield the corresponding Calabi-Yau manifold. One can then calculate explicitly, for such Calabi-Yau manifolds, the mass spectrum, Yukawa couplings, and all the other parameters of the effective Lagrangian by inserting successively all the background blowing-up modes with nonzero vacuum expectation value into the corresponding orbifold amplitudes. The results are exact at the string tree-level; however, they are perturbative in the blowing-up procedure. Mass spectra and Yukawa couplings for the blown-up Z/sub 3/ and Z/sub 4/ orbifolds are explicitly calculated. In particular all the E/sub 6/ singlets except the ones associated with the moduli-space of the blown-up orbifolds receive the mass; while the 27's and anti 27's do not pair up.
Date: May 1, 1987
Creator: Cvetic, M.
System: The UNT Digital Library
Relativistic 3-D nuclear hydrodynamics with Monte Carlo pions (open access)

Relativistic 3-D nuclear hydrodynamics with Monte Carlo pions

A model for relativistic three-dimensional hydrodynamical nuclear fluids has been coupled to a Monte Carlo pion model which treats the production, scattering, and absorption of pions in relativistic nuclear fluids. The model is dynamic and allows us to explicitly follow the temporal and spatial development of pion components through an entire collision process and into the final state. Such calculations will be necessary to extract meaningful information from measured RHIC pion distributions. We present preliminary results and discussion for /sup 139/La + /sup 139/La collisions at 1350 MeV/nuc (lab) and at various impact parameters. 13 refs., 2 figs.
Date: May 1, 1987
Creator: Zingman, J. A.; McAbee, T. L.; Wilson, J. R. & Alonso, C. T.
System: The UNT Digital Library
Effect of Dy additions on microstructure and magnetic properties of Fe-Nd-B magnets (open access)

Effect of Dy additions on microstructure and magnetic properties of Fe-Nd-B magnets

It is shown that increasing additions of Dy causes the remanence B/sub r/ to decrease linearly. The intrinsic coercivity, iHc, increases sharply for small additions of Dy, but the increase is not proportional for higher Dy contents. The iHc increases almost linearly with the effective anisotropy field of the RE/sub 2/Fe/sub 14/B phase until the Dy content is about 10% of the total rare earth content. Above this concentration, there is strong deviation from linearity. Various types of possible concentration profiles of the substituted rare earth are suggested. It is also argued that preferential segregation of Dy to the interfaces could be beneficial in increasing the nucleation field. Morphologically there is no apparent effect of Dy on the microstructure. However, in the 5 atomic % Dy sample, Dy rich oxides were observed. It is shown through Energy Dispersive Xray Spectroscopy (EDXS) line profiling that Dy partitions preferentially into the RE/sub 2/Fe/sub 14/B phase in all the cases. No segregation of Dy to the interphase interfaces has been detected.
Date: May 1, 1987
Creator: Ramesh, R.; Thomas, G. & Ma, B.M.
System: The UNT Digital Library
Exotic damping ring lattices (open access)

Exotic damping ring lattices

This paper looks at, and compares three types of damping ring lattices: conventional, wiggler lattice with finite ..cap alpha.., wiggler lattice with ..cap alpha.. = 0, and observes the attainable equilibrium emittances for the three cases assuming a constraint on the attainable longitudinal impedance of 0.2 ohms. The emittance obtained are roughly in the ratio 4:2:1 for these cases.
Date: May 1, 1987
Creator: Palmer, Robert B.
System: The UNT Digital Library
Cryogenic detection of particles: Development effort in the United States (open access)

Cryogenic detection of particles: Development effort in the United States

The development of cryogenic detectors of particles, with emphasis on large mass devices, has been reviewed. Most groups are still tooling up and exploring basic properties of sensors. The main discussion themes are summarized and some of the early experimental results are described.
Date: May 1, 1987
Creator: Sadoulet, B.
System: The UNT Digital Library
Is Dark Matter made out of particles. Current searches and detector developments (open access)

Is Dark Matter made out of particles. Current searches and detector developments

The hypothesis that Dark Matter is made out of exotic particles is definite enough to be testable in a variety of ways. We review the first generation experiments looking for dark matter particles, using conventional techniques. They may find those particles and in any case will provide powerful constraints. We argue that in the long run, cryogenic detectors will have to be used for that type of physics, and since the European effort is covered by other speakers, we review the present developments in this area in the USA. 18 refs., 1 fig.
Date: May 1, 1987
Creator: Sadoulet, B.
System: The UNT Digital Library
Use of permanent magnets in accelerator technology: Present and future (open access)

Use of permanent magnets in accelerator technology: Present and future

This report is a collection of viewgraphs discussing accelerator magnets. Permanent magnet systems have some generic properties that, under some circumstances, make them not only mildly preferable over electromagnets, but make it possible to do things that can not be done with any other technology. After a general discussion of these generic advantages, some specific permanent magnet systems will be described. Special emphasis will be placed on systems that have now, or are likely to have in the future, a significant impact on how some materials research is conducted. 4 refs., 33 figs.
Date: May 1, 1987
Creator: Halbach, K.
System: The UNT Digital Library
Proceedings of the 1986 summer workshop on antiproton beams in the 2-10 GeV/c range (open access)

Proceedings of the 1986 summer workshop on antiproton beams in the 2-10 GeV/c range

The possibilities for building a facility for the formation spectroscopy of ''charmonium'' and the study of ''exotics'' at the AGS with high intensity antiproton beams of good resolution and enhanced purity are explored. The performance potential of a number of long beams and the AGS booster are evaluated and costs are estimated. Fluxes of several 10/sup 7/ antiprotons per pulse with purities of 5% to 99% are possible with conventional long beams. A similar total antiproton flux would be available with the Booster with no beam contamination. This could effectively be enhanced by two orders of magnitude by reducing the momentum spread in order to scan very narrow (less than 1 MeV) resonances. The maximum momentum attainable with the present Booster magnet design is 5.6 GeV/c which only reaches the Chi/sub 0/ (3415) charmonium state. Modifications are possible which would raise the maximum momentum to 6.3 GeV/c to include all states up to and including eta'/sub c/ (3590) in its range. The performance potential for this physics at the AGS is found to compare favorably with that at other laboratories with more antiprotons delivered annually, running in the post-Booster era, than at FNAL or Super-Lear with ACOL under typical scheduling …
Date: May 7, 1987
Creator: Lazarus, D. (ed.)
System: The UNT Digital Library
Geology of Platanares geothermal area, Copan, Honduras (open access)

Geology of Platanares geothermal area, Copan, Honduras

The Platanares, Copan (Honduras) geothermal area is located in a highly faulted terrain of Paleozoic(.) metamorphic rocks, Cretaceous clastic sedimentary rocks, and Tertiary volcanic rocks. All thermal manifestations are located along faults. The volcanic rocks are probably too old to represent the surface expression of an active crustal magma body. Thus, the thermal water is interpreted to be heated during deep circulation in a regime of elevated heat flow. The water chemistry suggests that the geothermal reservoir originates within the Cretaceous sedimentary sequence and that the reservoir temperature may be as high as 240/sup 0/ C. Two exploration coreholes penetrated the volcanic sequence and bottomed within Cretaceous redbeds. Well PLTG-1 is 650 m deep and flows at 3 Mw thermal from a 160/sup 0/ C permeable zone. Well PLTG-2 is 401 m deep and has a thermal gradient of 139/sup 0/ C/km. Exploration drilling is continuing, with a third corehole to be drilled in May, 1987.
Date: May 1, 1987
Creator: Heiken, G.; Duffield, W.; Wohletz, K.; Priest, S.; Ramos, N.; Flores, W. et al.
System: The UNT Digital Library
Search for close-mass lepton pairs (L/sup -/,L/sup 0/) (open access)

Search for close-mass lepton pairs (L/sup -/,L/sup 0/)

Preliminary results are reported of a search in 207 pb/sup -1/ of MARK II PEP data at ..sqrt..s = 29 GeV for lepton pairs (L/sup -/,L/sup 0/) where the L/sup 0/ mass can be close to, but not exceed, the L/sup -/ mass. The numbers of e - ..mu.., and 3 or more charged hadrons versus isolated e or ..mu.., events are compared to Monte Carlo predictions for e/sup +/e/sup -/ ..-->.. tau/sup +/tau/sup -/, e/sup +/e/sup -/ ..-->.. q anti q, and two-virtual-photon processes. Possible residual signals for (L/sup -/,L/sup 0/) pairs are compared to Monte Carlo simulations and 2sigma confidence level limits on the L/sup -/ and L/sup 0/ masses are presented.
Date: May 1, 1987
Creator: Stoker, D. P. & Perl, M. L.
System: The UNT Digital Library
The influence of N-ion irradiation on superconducting TiN (open access)

The influence of N-ion irradiation on superconducting TiN

The influence of disorder on the properties of the B1 phase superconductive compound titanium nitride has been investigated. Following synthesis and characterization of thin films of TiN, the materials were disordered progressively and uniformly by irradiation with nitrogen ions. The superconducting transition temperature T/sub c/ decreased and the low temperature electrical resistivity rho increased as lattice damage was introduced. The dependence of both T/sub c/ and rho on N-ion fluence phi could be described by exponentially saturating functions of phi with similar rate constants. These constants correspond to characteristic damage energy densities of 14 and 12 eV/atom, respectively.
Date: May 1, 1987
Creator: Thompson, J. R.; Ellis, J. T.; Christen, D. K.; Sekula, S. T.; Lewis, J. D. & Williams, J. M.
System: The UNT Digital Library