17 Matching Results

Search Results

Advanced search parameters have been applied.

BNL kaon beams, present and planned

Description: At the present time, there are three electrostatically purified (separated) kaon beams in operation at the Brookhaven AGS. They are optimized for .8 GeV/c, 1.1 GeV/c and 6 GeV/c. A fourth beam has been designed for a maximum momentum of 2.0 GeV/c. It features two-stage purification and higher order optical corrections. Anticipated performance figures for the beam, which is capable of delivering more than 10/sup 6/ kaons per spill, are given, as well as measured performance figures for the existing beams. Possible purification schemes for momenta above 6 GeV/c are discussed. Performance data from neutral and unpurified beams are presented.
Date: January 1, 1986
Creator: Lazarus, D.M.
Partner: UNT Libraries Government Documents Department

Diffusion in Metals. Progress Report and Publication List

Description: Information concerning diffusion is presented, including a study of the relative rates of diffusion of Fe/sup 55/ and Fe/sup 59/ in Ag, diffusion of Ru in Ag, self-diffusion in AgCd and AgIn. chemical and tracer diffusion in Ag-alpha AgCd diffusion couples, the influence of pressure on diffusion in AgZn alloys, the energy of motion of vacancies in Au at high pressure, and ionic conductivity of alkali halides as a function of pressure and temperature. A list of publications containing diffusion information is also included. (J.R.D.)
Date: May 15, 1958
Creator: Seitz, F. & Lazarus, D.
Partner: UNT Libraries Government Documents Department

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

Description: 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 conditions. A high resolution purified source of antiprotons in the 2-10 GeV/c range at BNL would cost $3.0M - $4.1M including an experimental hall. There are contributed papers in the appendices.
Date: May 7, 1987
Creator: Lazarus, D. (ed.)
Partner: UNT Libraries Government Documents Department

Particle production and targeting experience at the Brookhaven AGS

Description: Experience in production of secondary pions (neutrinos), kaons and antiprotons by 28.5 GeV/c protons incident on various target materials is given. The problems associated with various target materials with respect to target heating, physical degradation and in some cases, disintegration, are discussed. The effect of target length and production angle on secondary beam flux and optical quality will be illustrated by some incomplete but nonetheless informative data.
Date: January 1, 1986
Creator: Lazarus, D.M.
Partner: UNT Libraries Government Documents Department

Potential kaon and antiproton beams at BNL

Description: The AGS at Brookhaven is the worlds most prolific producer of kaons and low energy antiprotons during operations. With the imminent operation of the AGS Booster which will increase intensities by an anticipated factor of six in the next few years, it will become possible to have purified beams of particles containing strange quarks and anti-quarks with intensities comparable to the pion beams which have so successfully dominated precision hadron spectroscopy in the past. 10 refs., 3 figs.
Date: January 1, 1991
Creator: Lazarus, D.M.
Partner: UNT Libraries Government Documents Department

BACKWARD K~;;p ELASTIC SCATTERING AND 0 PRODUCTION

Description: A high precision measurement of the momentum dependence of backward {sup -}p elastic scattering from 476 to 1077 MeV/c incident momentum has been performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron. With the same apparatus they have also measured the 0{sup o} production of pions in the reaction K{sup -}p {yields} {Sigma}{sup -}{pi}{sup +}. The forward and backward angular distributions decomposed into partial waves are particularly simple since the Legendre polynomials are either {+-}1, and the spin-flip amplitude is absent. The forward elastic cross section is well determined through the total cross section using the optical theorem and dispersion relations. The backward elastic cross section has been found by bubble chamber experiments to quite small, generally an order of magnitude smaller than the forward cross section. This is easily understood; the many absorption channels present make the amplitudes largely imaginary so that even and odd parity states cancel in their contributions to backward scattering. For this reason a small resonant amplitude will be expected to reveal itself most prominently in the backward direction. If a resonance has too small an elasticity to be seen in the elastic channel, but has a large branching fraction into {Sigma}{pi} then it should be observed at 0{sup o} in this reaction.
Date: August 1, 1978
Creator: Alston-Garnjost, M.; Hamilton, R.; Kenny, R.; Nicholson, H.; Lazarus, D.; Pollard, D. et al.
Partner: UNT Libraries Government Documents Department

MICRO-BUNCHING OF THE AGS SLOW EXTRACTED BEAM FOR A RARE KAON DECAY SEARCH.

Description: The AGS Slow Extracted Beam (SEB) must be chopped with 250 ps bursts every 40 ns to permit time-of-flight (ToF) measurement of the secondary K{sup 0} beam. Standard techniques to produce this level of bunching would require excessive rf voltage, thus we have developed a ''Micro-Bunching'' technique of extracting the beam as it is forced between empty rf buckets. A specification of the required rf system will be given. Four-dimensional model simulations of particle dynamics for the planned rf and extraction systems will be shown. Simulations of previous tests along with the test measurements are also presented. Measurement of tight bunching requires dedicated instrumentation. The design of a detector system to measure bunch widths and the extinction factor between bunches will be given; considerations include the various particles produced and transported, timing precision and background.
Date: June 18, 2001
Creator: GLENN,J.; SIVERTZ,M.; CHIANG,I.; LAZARUS,D. & KOSCIELNIAK,S.
Partner: UNT Libraries Government Documents Department

Status and first results of BNL experiment 777: A search for K/sup +/. -->. pi. /sup +/. mu. /sup +/e/sup -/ and a study of K/sup +/. -->. mu. /sup +/e/sup +/e/sup -/

Description: Results of our search for short lived neutral particles emitted in K/sup +/ decay are given. We also seek to make an accurate measurement of the branching ratio for ..pi../sup 0/ ..-->.. e/sup +/e/sup -/ by looking for the decay chain K/sup +/ ..-->.. ..pi../sup +/..pi../sup 0/, ..pi../sup 0/ ..-->.. e/sup +/e/sup -/. The world average branching ratio for this decay is (1.8 +- 0.7) x 10/sup -7/ based on about 30 events from two experiments. Theory predicts that this branching ratio should be of order 6 x 10/sup -8/. If the branching ratio remains at the 2 x 10/sup -7/ level when measured with smaller errors, this could be an indication of new physics. 24 refs., 7 figs.
Date: October 1, 1987
Creator: Baker, N.J.; Gordon, H.A.; Lazarus, D.M.; Polychronakos, V.A.; Rehak, P.; Tannenbaum, M.J. et al.
Partner: UNT Libraries Government Documents Department

Commissioning the polarized beam in the AGS

Description: After the successful operation of a high energy polarized proton beam at the Argonne Laboratory Zero Gradient Synchrotron (ZGS) was terminated, plans were made to commission such a beam at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). On February 23, 1984, 2 ..mu..A of polarized H/sup -/ was accelerated through the Linac to 200 MeV with a polarization of about 65%. 1 ..mu..A was injected into the AGS and acceleration attempts began. Several relatively short runs were then made during the next three months. Dedicated commissioning began in early June, and on June 26 the AGS polarized beam reached 13.8 GeV/c to exceed the previous ZGS peak momentum of 12.75 GeV/c. Commissioning continued to the point where 10/sup 10/ polarized protons were accelerated to 16.5 GeV/c with 40% polarization. Then, two experiments had a short polarized proton run. We plan to continue commissioning efforts in the fall of this year to reach higher energy, higher intensity, and higher polarization levels. We present a brief description of the facility and of the methods used for preserving the polarization of the accelerating beam.
Date: January 1, 1985
Creator: Ratner, L.G.; Brown, H.; Chiang, I.H.; Courant, E.; Gardner, C.; Lazarus, D. et al.
Partner: UNT Libraries Government Documents Department

ELECTRON BUNCH CHARACTERIZATION WITH SUBPICOSECOND RESOLUTION USING ELECTRO-OPTIC TECHNIQUE.

Description: In the past decade, the bunch lengths of electrons in accelerators have decreased dramatically and are in the range off a few millimeters. Measurement of the length as well as the longitudinal profile of these short bunches have been a topic of research in a number of institutions. One of the techniques uses the electric field induced by the passage of electrons in the vicinity of a birefringent crystal to change its optical characteristics. Well-established electro-optic techniques can then be used to measure the temporal characteristics of the electron bunch. The inherent fast response of the crystal facilitates the measurement to femtosecond time resolution. However, the resolution in experiments so far has been limited to 70 ps, by the bandwidth of the detection equipment. Use of a streak camera can improve this resolution to a few picoseconds. In this paper we present a novel, non-invasive, single-shot approach to improve the resolution to tens of femtoseconds so that sub mm bunch length can be measured.
Date: June 11, 2001
Creator: SEMERTZIDIS, Y.K.; CASTILLO, V.; LARSEN, R.; LAZARUS, D.M.; NIKAS, D.; OZBEN, C. et al.
Partner: UNT Libraries Government Documents Department

Report of the AGS Experimental Area Shielding Upgrade Committee

Description: The proton intensity delivered to the AGS experimental areas is expected to increase fourfold when the full potential of the Booster is realized. It is therefore necessary to anticipate the modifications to the shielding and radiation monitoring that will be required in order to insure safe operation within the appropriate guidelines for radiation exposure. This report examines the consequences of site boundary requirements and soil and air activation as well as the protection of radiation workers, i.e., AGS personnel and experimenters, from unnecessary radiation exposure in the experimental areas. Where possible, Health Physics surveys and fault studies carried out in the Spring of 1990 have been used to estimate levels in and around the experimental areas with 5 {times} 10{sup 13} protons per pulse or 75% of the total anticipated intensity delivered to each of the target stations under normal'' as well as fault conditions. Where fault studies were not possible due to construction, the new beams and facilities were designed for the higher intensities that will be available and radiation patterns were calculated. Weak spots were identified and improvements recommended. Capital and manpower estimates were developed for the upgrades. 7 refs.
Date: August 1, 1990
Creator: Beavis, D.; Brown, H.N.; Bunce, G.; Carroll, A.S.; Chiang, I.H.; Glenn, J.W. et al.
Partner: UNT Libraries Government Documents Department

Rare K sup + decays in flight: Latest results and future plans

Description: E777 at the Brookhaven AGS has published a final branching ratio limit for the lepton family violating decay K{sup +} {yields} {pi}{sup +}{mu}{sup +}e{sup {minus}} of 2.1 {times} 10{sup {minus}10} (90% C.L.). New results based on approximately 500 events of the G.I. M. suppressed decay K{sup +} {yields} {pi}{sup +}e{sup +}e{sup {minus}} have yielded a branching ratio of (2.75 {plus minus} 0.23 {plus minus} 0.13) {times} 10{sup {minus}7} assuming a vector interaction with, a form factor = 0.105 {plus minus} 0.035 {plus minus} 0.015. The branching ratio times decay probability for K{sup 0} {yields} {pi}{sup +} X{sup 0}, ,{sup 0} {yields} e{sup +}e{sup {minus}} was found to less than 1.5 {times} 10{sup {minus}8} (99% C.L.) in the e{sup +}e{sup {minus}} invariant mass range of 150 to 340 MeV/c. An approved second generation experiment sensitive to K{sup +} {yields} {mu}{sup +}e{sup {minus}} at the 10{sup {minus}12} level is discussed. 5 refs., 3 figs.
Date: January 1, 1991
Creator: Alliegro, C.; Zeller, M.E. (Yale Univ., New Haven, CT (United States)); Campagnari, C. (Chicago Univ., IL (United States)); Chaloupka, V.; Lubatti, H.J.; Zhao, T. (Washington Univ., Seattle, WA (United States)) et al.
Partner: UNT Libraries Government Documents Department

A search for the coherent production of axions in the milli eV range

Description: Axions provide a natural explanation for the absence of CP violation in the strong interaction. As weakly interacting light particles they are also candidates for the much sought after dark matter allegedly responsible for our lack of understanding of galactic dynamics. Beam dump, particle decay and astrophysical measurements carried out over the past decade have failed to provide positive evidence for their existence over a wide range of masses and coupling strengths. This experiment attempts to produce and detect scalar and pseudoscalar particles coherently produced through the interaction of laser photons with the virtual photons of the magnetic fields of superconducting dipole magnets as manifested by small changes in the polarization state of the laser light. A limit on the coupling of the axion to 2 photons of g{sub a{gamma}{gamma}} < 6.67 {times} 10{sup {minus}7} GeV{sup {minus} 1} was achieved. 8 refs., 3 figs.
Date: January 1, 1991
Creator: Cameron, R.; Melissinos, A.C.; Semertzidis, Y. (Rochester Univ., NY (United States)); Cantatore, G.; Rizzo, C.; Ruoso, P. et al.
Partner: UNT Libraries Government Documents Department