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Inclusive neutral particle production

Description: Results of recent inclusive neutral particle production experiments are compared to existing experimental results. These experiments range from 15 to 2000 GeV/c in laboratory beam momentum and use $pi$$sup -$, $pi$$sup +$, p and anti p beams. (auth)
Date: January 1, 1975
Creator: Kahn, S.
Partner: UNT Libraries Government Documents Department

Reflection grating spectrometer for the x-ray multi-mirror (XMM) space observatory: design and calculated performance

Description: A spectrometer design candidate is presented for the X-ray Multi-Mirror (XMM) observatory, being planned by the European Space Agency (ESA) as a long-lived large-area of telescopes. The science requirement of moderate resolution (E/..delta..E approx.100) spectroscopy in a two octave region (0.5 to 2 keV) with extremely high throughput (effective area > 500 cm/sup 2/) results in the use of grazing incidence reflection gratings. Due to the low image quality of the telescopes (approx. 1 minute of arc), the grating dispersion must be maximized by use of the classical grating mount in which the spectrum is dispersed within the plane of incident radiation. Due to the small field of view by the x-ray telescopes, the gratings must be situated in the converging beam at the exit of the telescope. A spectrometer module consists of a thin-foil conical mirror telescope, a stack of plane varied-space reflection gratings and an imaging proportional counter. This system is analyzed on the basis of dispersion, geometric aberrations and efficiency. At a spectral resolution of 0.15 A, a twenty module XMM would attain an average effective area of approx.900 cm/sup 2/, reaching twice this value at the peak wavelength (15 A). Similar throughput is obtained in second order centered at 7.5 A, the two spectral orders separated by the non-dispersive energy resolution of the proportional counter. Continuous spectra are obtained in the 6-25 A band (0.5 to 2 keV), and can be extended to 45 A if desired by tuning of the grating. The instrument sensitivity is sufficient to allow the first spectral detection of soft x-ray features in external galaxies, with access to an estimated population of several hundred active galactic nuclei. Such observations will expand vastly the roles feasible for spectroscopy in x-ray astrophysics, marking the beginning of a new era in space astronomy.
Date: October 1, 1985
Creator: Hettrick, M.C. & Kahn, S.M.
Partner: UNT Libraries Government Documents Department

Experimental limits on neutrino oscillators

Description: Neutrino oscillations were sought in a wideband neutrino beam at Fermilab using the 15-foot bubble chamber. No evidence was found for neutrino oscillations and set upper limits on the mixing angles and neutrino mass differences in the transitions: ..nu../sub ..mu../ ..-->.. ..nu../sub e/, ..nu../sub tau/, and ..nu../sub e/ ..-->.. ..nu../sub e/.
Date: January 1, 1981
Creator: Baker, N.J.; Connolly, P.L. & Kahn, S.A.
Partner: UNT Libraries Government Documents Department

Field quality control through the production phase of RHIC arc dipoles

Description: The field quality in the arc dipoles built thus far for the Relativistic Heavy Ion Collider (RHIC) not only meets machine requirements but is significantly better than that expected from scaling laws based on previous large scale superconducting magnet production for particle accelerators. In this paper the authors describe the evolution of the present cross section and the design philosophy that has led to these improvements. The techniques described here have been found quite efficient to adopt in the production environment, where schedule and cost considerations become important. Moreover, the techniques developed during the R&D program have resulted in making the saturation induced harmonics negligible, despite the fact that the iron is very close to the coil.
Date: May 1, 1995
Creator: Gupta, R.; Jain, A. & Kahn, S.
Partner: UNT Libraries Government Documents Department

NEUTRINO SUPER BEAM FACILITY FOR A LONG BASELINE EXPERIMENT FROM BNL TO HOMESTAKE.

Description: An upgrade to the BNL Alternate Gradient Synchrotron (AGS) could produce a very intense proton source at a relatively low cost. Such a proton beam could be used to generate a conventional neutrino beam with a significant flux at large distances from the laboratory. This provides the possibility of a very long baseline neutrino experiment at the Homestake mine. The construction of this facility would allow a program of experiments to study many of the aspects of neutrino oscillations including CP violations. This study examines a 1 MW proton source at BNL and a large 1 megaton detector positioned at the Homestake Mine as the ultimate goal of a staged program to study neutrino oscillations.
Date: October 21, 2002
Creator: KAHN,S.
Partner: UNT Libraries Government Documents Department

Preliminary results on nu/sub. mu. / + e/sup -/. -->. nu/sub. mu. / + e/sup -/

Description: We present here preliminary results on a recent experiment on nu/sub ..mu../ - e/sup -/ elastic scattering. A brief review of the Glashow-Salam-Weinberg theory is given, indicating how the measurement of the total cross section gives rise to an ambiguous solution for sin/sup 2/ THETA/sub w/, and showing how the differential cross section can be used to resolve the ambiguity. The experimental configuration and the extraction of the signal are described. The data are compared with those from our previous experiment, and relevant distributions from the combined data sample are presented. The differential cross section is examined in an attempt to resolve the ambiguity in sin/sup 2/ THETA/sub w/, the lower value of sin/sup 2/ THETA/sub w/ = 0.20 being favored.
Date: June 1, 1982
Creator: Baker, N.J.; Connolly, P.L. & Kahn, S.A.
Partner: UNT Libraries Government Documents Department

Recent results from neutrino interactions in heavy neon

Description: Recent results presented from a study of muon neutrinos interacting in heavy neon include dilepton production, strange particle rates, the D/sup 0/..-->..K/sup 0/..pi../sup +/..pi../sup -/ decay, the lack of observation of new particles, and the cross section for nu/sub e/ + e elastic scattering. 8 references (JFP)
Date: January 1, 1978
Creator: Cnops, A.M.; Connolly, P.L. & Kahn, S.A.
Partner: UNT Libraries Government Documents Department

Magnetic properties of iron yoke laminations for SSC dipole magnets

Description: We examine the magnetic properties for the iron used in the SSC yoke laminations so that the accelerator tolerances can be met. The accelerator requirements for field quality specify a tolerance on the variation in the central field. At machine injection the variation in field is attributed to coercivity, H{sub c}. Requirements on the magnitude and the variation of H{sub c} are presented. At the 6.65 tesla operating field the variation in the saturation magnetization dominates the magnetic tolerance for the iron. 4 refs., 3 figs., 2 tabs.
Date: January 1, 1991
Creator: Kahn, S.A. & Morgan, G.H.
Partner: UNT Libraries Government Documents Department

Comparison of magnetic field calculations to measurements on a CBA 2-in-1 magnet system

Description: The CBA 2-in-1 dipole magnet provides a complex system to test field calculation techniques. In particular the quadrupole term in one half of the magnet induced by the operation of the other half of the magnet is studied. A comparison with field measurement data is made for calculated magnetic field harmonics as a function of current for symmetric and asymmetric operations of the two sides of the magnets. The calculations are made using both differential equation solving programs (PE2D, POISSON) and integration based programs (GFUN). These programs are compared to each other and to the measured data. 5 refs., 5 figs., 1 tab.
Date: January 1, 1985
Creator: Kahn, S.; Gupta, R.; Morgan, G. & Thompson, P.
Partner: UNT Libraries Government Documents Department

Observation of a visible charmed particle decay in neutrino interactions

Description: In a sample of 250 semileptonic charmed particle decays (..nu../sub ..mu../ + Neon ..-->.. ..mu../sup -/ + e/sup +/ + ... events), one clear event is found where the e/sup +/ does not come directly from the ..nu.. interaction vertex but from a decay point 1.1 cm downstream of the vertex. This event is interpreted as a visible charmed particle decay: into an e/sup +/ and a positive and a negative charged track. The observation of a visible charm decay in the sample is consistent with what is expected if the charm lifetime were of the order 5 x 10/sup -13/ sec. 5 references.
Date: January 1, 1979
Creator: Cnops, A.M.; Connolly, P.L. & Kahn, S.A.
Partner: UNT Libraries Government Documents Department

Measurement of the nu/sub. mu. / charged-current cross section

Description: The Fermilab 15-ft bubble chamber, filled with a heavy neon-hydrogen mix, was exposed to a narrow band nu/sub ..mu../ beam. Based on the observation of 830 charged current nu/sub ..mu../ interactions, the cross section was found to rise linearly with the neutrino energy in the interval, 10 GeV less than or equal to E/sub nu/ less than or equal to 240 GeV, with a constant slope of: sigma/sub nu/E/sub nu/ = (0.64 +- 0.05) 10/sup -38/ cm/sup 2/ GeV/sup -1/. This result is discussed in relation to other experiments.
Date: January 1, 1982
Creator: Baker, N.J.; Connolly, P.L & Kahn, S.A.
Partner: UNT Libraries Government Documents Department

Laboratory x-ray spectroscopy experiments in support of NASA`s x-ray satellite missions

Description: With support from NASA, we are performing a series of laboratory astrophysics investigations designed to address fundamental uncertainties in basic atomic physics processes relevant to the interpretation of discrete X-ray spectra of cosmic plasmas. Moderate resolution spectra acquired by the ASCA Observatory already demonstrate the inadequacy of currently available spectral modelling codes for this wavelength band. With the upcoming launches of AXAF, XMM, ASTRO E, and Spektrum Roentgen-Gamma, the demand for significant advances in this field will increase dramatically. Our program is based on the exploitation of the Electron Beam Ion Trap facility at the Lawrence Livermore National Laboratory, and a unique set of spectrometers and experimental techiques specifically developed for this purpose. Recent experiments have been devoted to definitive measurements of line emissivities for iron L-shell ions in optically thin, collisional plasmas.
Date: May 22, 1998
Creator: Kahn, S. M., Columbia University
Partner: UNT Libraries Government Documents Department

FIELD QUALITY CONTROL THROUGH THE PRODUCTION PHASE OF RHIC ARC DIPOLES.

Description: The field quality in the arc dipoles built thus far for the Relativistic Heavy Ion Collider (RHIC) not only meets machine requirements, but is significantly better than that expected from scaling laws based on previous large scale superconducting magnet production for particle accelerators. In this paper we describe the evolution of the present cross section and the design philosophy that has led to these improvements. The techniques described here have been found quite efficient to adopt in the production environment, where schedule and cost considerations become important. Moreover, the techniques developed during the R and D program have resulted in making the saturation induced harmonics negligible, despite the fact that the iron is very close to the coil.
Date: May 1, 1995
Creator: GUPTA,R.; JAIN,A. & KAHN,S.
Partner: UNT Libraries Government Documents Department

A general purpose calibration facility for use in x-ray astronomy

Description: An x-ray calibration facility for use in the 0.2--25 keV region is described. The facility employs several types of specially modified sources and detectors to produce and detect both line and continuum radiation in this energy range. We describe an inexpensive commercial x-ray source which has been modified for efficient high intensity operation as well as production of x-rays up to 25 keV. We also describe a system that utilizes multilayer mirrors alone or in a double Bragg geometry to select an energy bandpass. This system is controlled by a microcomputer which translates and rotates the multilayers to provide an easily selectable monochromatic beam with good resolution over a broad energy range. A long focal length Kirkpatrick--Baez mirror pair has been coupled to a pivoting beam line in order to accurately characterize gratings for use in soft x-ray astronomy. The beam line is scanned through the various grating orders. All aspects of the facility incorporate high degree of flexibility so that a wide variety of calibrations can be easily performed. 12 refs., 5 figs.
Date: August 11, 1988
Creator: Craig, W.W.; Hailey, C.J.; Morales, R.I.; Kahn, S.M. & Wargelin, B.J.
Partner: UNT Libraries Government Documents Department

Coil and iron design for SSC 50 mm magnet

Description: In this paper we present the design of the two dimensional coil and iron cross section, referred to as DSX201/W6733, for the 50 mm aperture dipole magnet being built at the Brookhaven National Laboratory for the Superconducting Super Collider (SSC). The computed values of the allowed field harmonics as a function of current, the quench performance predictions, the stored energy calculations, the effect of random errors on the coil placement and the Lorentz forces on the coil will be presented. The yoke has been optimized to reduce iron saturation effects on the field harmonics. We shall present the summary of this design which will include the expected overall performance of this cross section. 4 refs., 8 figs., 12 tabs.
Date: January 1, 1990
Creator: Gupta, R.C.; Kahn, S.A. & Morgan, G.H.
Partner: UNT Libraries Government Documents Department

SSC 50 mm dipole cross section

Description: In this paper we present the magnetic design of the two dimensional coil and iron cross section, referred to as DSX201/W6733, for the 50 mm aperture main ring dipole magnet for the Superconducting Super Collider (SSC). The computed values of the allowed field harmonics as a function of current, the quench performance predictions, the stored energy calculations, the effect of random errors on the coil placement and the Lorentz forces on the coil will be presented. The yoke has been optimized to reduce iron saturation effects on the field harmonics. We shall present the summary of this design which will include the expected overall performance of this cross section. Prototypes of these dipoles are being built at the Brookhaven National Laboratory (BNL) and at the Fermi National Accelerator Laboratory (FNAL). There are slight differences between the cross sections at the two laboratories. 7 refs., 6 figs., 11 tabs.
Date: January 1, 1991
Creator: Gupta, R.C.; Kahn, S.A. & Morgan, G.H.
Partner: UNT Libraries Government Documents Department

Warm measurements of CBA superconducting magnets

Description: We present results on magnetic field measurements of CBA dipole magnets in the warm (normal conductor) and cryogenic (superconducting) states. We apply two methods for the warm measurements, a dc and ac method. We find a good correlation between warm and cryogenic measurements which lends itself to a reliable diagnosis of magnet field errors using warm measurements early in the magnet assembly process. We further find good agreement between the two warm measurement methods, both done at low currents.
Date: January 1, 1983
Creator: Engelmann, R.; Herrera, J.; Kahn, S.; Kirk, H.; Willen, E. & Yamin, P.
Partner: UNT Libraries Government Documents Department

Monte Carlo study of inclusive W/sup +/ production at CBA

Description: The UA1 and UA2 experiments at the CERN SPS anti pp collider observed several events which they have interpreted to be the leptonic decay of the charged intermediate vector boson, W/sup +-/ + e/sup +-/nu. All of these events have an electron with large transverse momentum and large mission transverse energy. The experiments had remarkably little background in the region of large transverse momentum of the electron (P/sub Te/). In this report we examine the possibility of doing a high statistics experiment producing several million W's per year. Large statistics are necessary to obtain a precise measurement of the W/sup +/ mass and of the Z/sup 0/-W mass difference. We use the Jacobian peak in the electron P/sub T/ distribution to obtain the W/sup +/mass. We examine in detail the P/sub T/ distribution of the electron produced by the leptonic decay of the W/sup +/ ..-->.. e/sup +/nu. We investigate backgrounds to this reaction from the pileup of minimum bias events, from leading ..pi../sup 0/s in light quark jets simulating electrons and from the decay of heavy quark jets producing electrons.
Date: July 8, 1983
Creator: Kahn, S.A.; Killian, T.J.; Murtagh, M.J. & Grannis, P.
Partner: UNT Libraries Government Documents Department

DESIGN OF A MAGNET SYSTEM FOR A MUON COOLING RING EXPERIMENT.

Description: A muon cooling ring is currently being investigated as a possible muon cooling experiment that can demonstrate 6D cooling. The cooling ring.consists of long solenoid channels with liquid H{sub 2} absorbers and RF cavities, shorter field flipped solenoids with LiH wedge absorbers and wedge shaped 45{sup o} bending dipole magnets. The ring is designed to cool muons with E{sub kin}=250 MeV. This study examines the magnetic system of the muon ring cooler. The purpose at this point is to establish physical fields for the magnetic system that can be used in tracking studies.
Date: June 18, 2001
Creator: KAHN, S.; HANSON, G.; SCHWANDT, P.; BALBEKOV, V.; RAJA, R. & USUBOV, Z.
Partner: UNT Libraries Government Documents Department

Performance of three 4. 5 m dipoles for SSC reference design D

Description: Three 4.5 m long dipoles for Reference Design D of the proposed Superconducting Super Collider have been successfully tested. The magnets are cold-iron (and cold bore) 1-in-1 dipoles, wound with current density-graded high homogeneity NbTi cable in a two-layer cos theta coil of 40 mm inner diameter. The coil is prestressed by 15 mm wide stainless steel collars, and mounted in a circular, split iron yoke of 267 mm outer diameter, supported in a cylindrical yoke containment vessel. At 4.5 K the magnets reached a field of about 6.6T with little training, or the short sample limit of the conductor, and in subcooled (2.6 to 2.4 K) liquid, 8T was achieved. The allowed harmonics were close to the predicted values, and the unallowed harmonics small. The sextupole trim coil operated at eight times the required current without training.
Date: January 1, 1985
Creator: Dahl, P.; Cottingham, J.; Fernow, R.; Garber, M.; Ghosh, A.; Goodzeit, C. et al.
Partner: UNT Libraries Government Documents Department

Field quality aspects of CBA superconducting magnets

Description: A series of superconducting dipole magnets for the BNL Colliding Beam Accelerator which were manufactured to have the proper field quality characteristics has been tested. This report presents the analysis of the field harmonics of these magnets.
Date: January 1, 1983
Creator: Kahn, S.; Engelmann, R.; Fernow, R.; Greene, A.F.; Herrera, J.; Kirk, H. et al.
Partner: UNT Libraries Government Documents Department

A hard x-ray spectrometer for high angular resolution observations of cosmic sources

Description: LAXRIS (large area x-ray imaging spectrometer) is an experimental, balloon-borne, hard x-ray telescope that consists of a coaligned array of x-ray imaging spectrometer modules capable of obtaining high angular resolution (1--3 arcminutes) with moderate energy resolution in the 20- to 300-keV region. Each spectrometer module consists of a CsI(Na) crystal coupled to a position-sensitive phototube with a crossed-wire, resistive readout. Imaging is provided by a coded aperture mask with a 4-m focal length. The high angular resolution is coupled with rather large area (/approximately/800 cm/sup 2/) to provide good sensitivity. Results are presented on performance and overall design. Sensitivity estimates are derived from a Monte-Carlo code developed to model the LAXRIS response to background encountered at balloon altitudes. We discuss a variety of observations made feasible by high angular resolution. For instance, spatially resolving the nonthermal x-ray emission from clusters of galaxies is suggested as an ideal program for LAXRIS. 15 refs., 5 figs.
Date: August 12, 1988
Creator: Hailey, C.J.; Ziock, K.P.; Harrison, F.; Kahn, S.M.; Liedahl, D.; Lubin, P.M. et al.
Partner: UNT Libraries Government Documents Department

Performance of four 4. 5 m two-in-one superconducting R and D dipoles for the SSC

Description: Four 4.5 m long superconducting dipoles built to specifications similar to those for SSC Reference Design A have been successfully tested. They were wound with NbTi cable in two-layer costheta coils of 3.2 cm inner diameter. The coil ends were flared to increase the minimum bending radius, anticipating coils wound from prereacted Nb/sub 3/Sn. The coils were mounted in a reusable ''two-in-one'' iron yoke prestressed by means of a bolted stainless steel shell. The first two magnets as well as the fourth one, a special magnet designed to study cross-talk between the bores, used CBA/Tevatron cable. The third utilized cable with improved (''high homogeneity'') NbTi conductor. All four reached central fields corresponding to their short sample limits at 4.5K without training, nearly 6.0T for the first two magnets, 6.5T for the third, and 5.4T for the fourth. At 2.5K modest training was required to reach short sample limits of 7.2T, 7.1T, 7.8T, and 6.6T respectively. The measured values of the allowed harmonics were within several x 10/sup -4/ of the calculated ones.
Date: January 1, 1985
Creator: Dahl, P.; Cottingham, J.; Fernow, R.; Garber, M.; Ghosh, A.; Goodzeit, C. et al.
Partner: UNT Libraries Government Documents Department