92 Matching Results

Search Results

Advanced search parameters have been applied.

EXOTIC MAGNETS FOR ACCELERATORS.

Description: Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.
Date: September 18, 2005
Creator: WANDERER, P.
Partner: UNT Libraries Government Documents Department

Solenoid spectrometer magnets

Description: Three solenoid detectors are considered for Isabelle. They are characterized by their diameters of 3, 5, and 8 meters. The size of an experimental hall is then considered, taking into account the likely physics goals, detector and return yoke geometries, thickness of superconducting coils, necessary space for detector repair, etc. Comments and major conclusions are presented. (GHT)
Date: unknown
Creator: Baltay, C.; Danby, G.; Mishina, M.; Wanderer, P. & Willis, W.
Partner: UNT Libraries Government Documents Department

Construction and testing of arc dipoles and quadrupoles for the relativistic heavy ion collider (RHIC) at BNL

Description: The production run of superconducting magnets for the Relativistic Heavy Ion Collider (RHIC) project at Brookhaven National Laboratory (BNL) is well underway. Of the 288 arc dipoles needed for the collider, more than 120 have been delivered. More than 150 arc quadrupoles have been delivered. All of these magnets have been accepted for RHIC. This paper reports the construction and performance of these magnets. Novel features of design and test, introduced to enhance technical performance and control costs, are also discussed. Other papers submitted to this Conference summarize work on the sextupoles and tuning quads, arc correctors, and combined corrector-quadrupole-sextupole assemblies (CQS).
Date: May 1, 1995
Creator: Wanderer, P.; Muratore, J. & Anerella, M.
Partner: UNT Libraries Government Documents Department

Magnetization, critical current, and injection field harmonics in superconducting accelerator magnets

Description: The very large energy ratio of machines such as the SSC dictates rather low injection field (for 6T, 20 TeV it is approximately 0.3T). Since the harmonic content at such low fields is largely determined by magnetization currents in the superconductor, the random errors depend on the uniformity of the superconducting wire. In principle the magnitude of the residual fields can be reduced indefinitely by using finer filaments, but in practice there is a lower limit of a few microns. We have compared the injection field harmonics for a number of accelerator dipoles with magnetization measurements made on samples of the conductor used to wind the coils. In addition both the magnetization and harmonics have been compared with short sample critical current measurements made at 5T. The results indicated that an accurate estimate of the variation in injection field harmonics can only be obtained from direct measurements of the magnetization of the cable. It appears feasible to use such measurements to ''shuffle'' magnets for a large accelerator by predicting the low field properties of a magnet before actually winding the coils. 10 refs., 4 figs., 2 tabs.
Date: January 1, 1985
Creator: Ghosh, A.K.; Sampson, W.B. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Detecting heavy flavors at CBA

Description: In the CBA luminosity range (L approx. = 10/sup 32/-10/sup 33/cm/sup -2/sec/sup -1/) the expected rate of bare heavy flavor production is high enough to allow for detection schemes which rely on relatively small leptonic branching ratios. These provide a clean separation of the signal from the gluon plus light quark background, while retaining sufficient statistics for further study. The current status of the investigation of lepton-related triggers and cuts is presented, and the jet topologies of events (both signal and background) with high-P/sub T/ leptons are discussed. While these studies have been carried out with samples of high-P/sub T/ q anti q and gluon jets generated with ISAJET, other sources of heavy flavor production at CBA are surveyed.
Date: March 1, 1983
Creator: Aronson, S.; Ogilvie, M.; Stumer, I.; Tanaka, M. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Random errors in the magnetic field coefficients of superconducting magnets

Description: Random errors in the multipole magnetic coefficients of superconducting magnet have been of continuing interest in accelerator research. The Superconducting Super Collider (SSC) with its small magnetic aperture only emphasizes this aspect of magnet design, construction, and measurement. With this in mind, we present a magnet model which mirrors the structure of a typical superconducting magnet. By taking advantage of the basic symmetries of a dipole magnet, we use this model to fit the measured multipole rms widths. The fit parameters allow us then to predict the values of the rms multipole errors expected for the SSC dipole reference design D, SSC-C5. With the aid of first-order perturbation theory, we then give an estimate of the effect of these random errors on the emittance growth of a proton beam stored in an SSC. 10 refs., 6 figs., 2 tabs.
Date: January 1, 1985
Creator: Herrera, J.; Hogue, R.; Prodell, A.; Wanderer, P. & Willen, E.
Partner: UNT Libraries Government Documents Department

Workshop on the AGS fixed-target research program

Description: The summarized results of a two day workshop to determine experiment programs for the Brookhaven AGS during the construction period of the ISABELLE storage rings and after are presented. Topics covered include: experiments with low-energy beams; experiments with higher energy beams; neutrino physics; and polarized protons. (GHT)
Date: January 1, 1978
Creator: Ahrens, L.; Schewe, P.; Wanderer, P. & Weisberg, H.
Partner: UNT Libraries Government Documents Department

Design and B-field measurements of a Lambertson injection magnet for the RHIC machine

Description: Two Lambertson-type injection magnets have been designed, constructed and tested magnetically. One magnet is the mirror image of the other and each will serve as an injector in the rings of die Relativistic Heavy Ion Collider (RHIC) accelerators under construction at Brookhaven National Laboratory (BNL). To obtain the required field quality in the injected beam region and low stray fields in the circulating beam region of the magnet, an optimization study was performed using computer codes to provide solutions for a two and three dimensional model of the magnet. The calculations are compared to the magnetic field measurements taken in the injected and circulating beam regions mentioned above. Field inhomogeneities in the injected beam region were less than 6 {times} 10{sup {minus}4}, for either measured or calculated B-fields. The magnetic-field strength in the circulating beam region was less than 0.1 Gauss (measured or calculated). A description of the mechanical design of the magnet as well as a detailed comparison of the measured magnetic fields to those calculated using the two and three dimensional computer codes is presented here.
Date: May 1, 1995
Creator: Tsoupas, N.; Rodger, E.; Claus, J.; Foelsche, H.W. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.

Description: In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RDIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.
Date: June 11, 1995
Creator: JAIN, A.; GUPTA, P.; THOMPSON, P. & WANDERER, P.
Partner: UNT Libraries Government Documents Department

Quench observation using quench antennas on RHIC IR quadrupole magnets

Description: Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals.
Date: July 1995
Creator: Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Quench antennas for RHIC quadrupole magnets

Description: Quench antennas for RHIC quadrupole magnets are being developed jointly by KEK and BNL. A quench antenna is a device to localize a quench origin using arrays of pick-up coils lined up along the magnet bore. Each array contains four pick-up coils: sensitive to normal sextupole, skew sextupole, normal octupole, and skew octupole field. This array configuration allows an azimuthal localization of a quench front while a series of arrays gives an axial localization and a quench propagation velocity. Several antennas have been developed for RHIC magnets and they are now routinely used for quench tests of production magnets. The paper discusses the description of the method and introduces a measured example using an antenna designed for quadrupole magnets.
Date: May 1, 1995
Creator: Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Skew quadrupole in RHIC dipole magnets at high fields

Description: In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RHIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.
Date: July 1, 1995
Creator: Jain, A.; Gupta, P.; Thompson, P. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Measurement of the magnetic field coefficients of particle accelerator magnets

Description: An important aspect in the development of magnets to be used in particle accelerators is the measurement of the magnetic field in the beam aperture. In general it is necessary to measure the harmonic multipoles in the dipole, quadrupole, and sextupole magnets for a series of stationary currents (plateaus). This is the case for the Superconducting Super Collider (SSC) which will be ramped to high field over a long period (/approximately/1000 sec.) and then remain on the flat top for the duration of the particle collision phase. In contrast to this mode of operation, the Booster ring being constructed for the Brookhaven AGS, will have a fast ramp rate of approximately 10 Hz. The multipole fields for these Booster magnets must therefore be determined ''on the ramp.'' In this way the effect of eddy currents will be taken into account. The measurement system which we will describe in this paper is an outgrowth of that used for the SSC dipoles. It has the capability of measuring the field multipoles on both a plateau or during a fast ramp. In addition, the same basic coil assembly is used to obtain the magnetic multipoles in dipole, quadrupole, and sextupole magnets. 2 refs., 3 figs., 1 tab.
Date: January 1, 1989
Creator: Herrera, J.; Ganetis, G.; Hogue, R.; Rogers, E.; Wanderer, P. & Willen, E.
Partner: UNT Libraries Government Documents Department

SSC 17-meter dipole magnet DD000Z test results and investigation of coil failure: The report of the {open_quotes}Z{close_quotes} Committee

Description: Following the failure of the lower inner coil of magnet DD000Z on November 3, 1987, a committee was formed on November 11 and given the following charges: `To review the events leading up to and including the failure of the coils of magnet DD000Z. The intent of the review will be to determine the cause of the failure and to make recommendations to reduce the likelihood of such failures in the future. Given the fact that this is the first long magnet to be disassembled, the committee may uncover leads which point to other opportunities for improvement. The committee should follow up on these leads. The committee should prepare a plan to serve as an initial guide for the disassembly and provide guidance as the disassembly progresses.` The committee held its first meeting at FNAL on 17 and 18 Nov to review the record of events leading up to the failure and to establish an initial disassembly procedure. This was followed by further meetings at FNAL, BNL, and CDG, leading to this final report. Committee activities included interviewing personnel who had been involved in the design, assembly and testing of DD000Z, reviewing all documents relating to the magnet and its failure, and participating in and providing guidance during the disassembly. The intention of the committee was to report factual findings, to consider well founded hypotheses, not to consider conjecture and to avoid speculation.
Date: March 1988
Creator: Coombes, R.; Mirk, K.; Tompkins, J.; Zbasnik, J.; Lundy, R.; Schneider, W. et al.
Partner: UNT Libraries Government Documents Department

CHANGE IN FIELD HARMONICS AFTER QUENCH AND THERMAL CYCLES IN SUPERCONDUCTING MAGNETS.

Description: A change in field harmonics after quench and thermal cycles has been observed in superconducting magnets for the Relativistic Heavy Ion Collider (RHIC). This paper presents the results of a systematic investigation of this effect in a number of RHIC dipole and quadrupole magnets. These changes in field harmonics may limit the ultimate field quality and its reproducibility in superconducting magnets. A change in pre-stress has also been observed after quench and thermal cycles. A possible link between these two changes is explored.
Date: May 12, 1997
Creator: GUPTA,R.; JAIN,A.; MURATORE,J.; WANDERER,P.; WILLEN,E. & WYSS,C.
Partner: UNT Libraries Government Documents Department

A comparison of calculations and measurements of the field harmonics as a function of current in the SSC dipole magnets

Description: A large number of short and long superconducting dipole magnets for the Superconducting Super Collider (SSC) have been constructed and measured for their magnetic field properties at Brookhaven National Laboratory (BNL). In this paper we compare the calculations and measurements for the variation of field harmonics as a function of current in 40 mm aperture and 50 mm aperture dipole magnets. The primary purpose of this paper is to examine the iron saturation effects on the field harmonics. The field harmonics also change due to the persistent current in the superconducting wires and due to the deformation of the coil shape because of Lorentz forces. We discuss the variation in the sextupole harmonics (b{sub 2}) with current and explain the differences between the calculations and measurements. We also discuss the skew quadrupole harmonic at high field in the long dipole magnets. 3 refs., 3 figs., 1 tab.
Date: January 1, 1991
Creator: Gupta, R.C.; Cottingham, J.G.; Kahn, S.A.; Morgan, G.H. & Wanderer, P.
Partner: UNT Libraries Government Documents Department

Magnetic Field Mapping and Integral Transfer Function Matching of the Prototype Dipoles for the NSLS-II at BNL

Description: The National Synchrotron Light Source-II (NSLS-II) storage ring at Brookhaven National Laboratory (BNL) will be equipped with 54 dipole magnets having a gap of 35 mm, and 6 dipoles having a gap of 90 mm. Each dipole has a field of 0.4 T and provides 6 degrees of bending for a 3 GeV electron beam. The large aperture magnets are necessary to allow the extraction of long-wavelength light from the dipole magnet to serve a growing number of users of low energy radiation. The dipoles must not only have good field homogeneity (0.015% over a 40 mm x 20 mm region), but the integral transfer functions and integral end harmonics of the two types of magnets must also be matched. The 35 mm aperture dipole has a novel design where the yoke ends are extended up to the outside dimension of the coil using magnetic steel nose pieces. This design increases the effective length of the dipole without increasing the physical length. These nose pieces can be tailored to adjust the integral transfer function as well as the homogeneity of the integrated field. One prototype of each dipole type has been fabricated to validate the designs and to study matching of the two dipoles. A Hall probe mapping system has been built with three Group 3 Hall probes mounted on a 2-D translation stage. The probes are arranged with one probe in the midplane of the magnet and the others vertically offset by {+-}10 mm. The field is mapped around a nominal 25 m radius beam trajectory. The results of measurements in the as-received magnets, and with modifications made to the nose pieces are presented.
Date: March 28, 2011
Creator: He, P. & Jain, A., Gupta, R., Skaritka, J., Spataro, C., Joshi, P., Ganetis, G., Anerella, M., Wanderer, P.
Partner: UNT Libraries Government Documents Department

Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade

Description: After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.
Date: June 23, 2008
Creator: Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R. et al.
Partner: UNT Libraries Government Documents Department

Coldmass for LHC Dipole Insertion Magnets

Description: Brookhaven National Laboratory (BNL) is building a number of magnets for the insertion regions of the Large Hadron Collider (LHC). This paper presents the magnetic design and the expected field quality in 2-in-1 dipole magnets. A unique feature of this cold mass design is the use of an oblate-shaped yoke. This concept permits a variety of BNL-built magnets to have a similar overall design and allows the LHC main dipole cryostat, post, etc., to be used in these magnets. The proposed oblate-shaped yoke also offers a way to reduce the overall cryostat size in future magnets. The dipoles will use the same 80 mm aperture coils as used in the Relativistic Heavy Ion Collider (RHIC) dipole magnets, but will use stainless steel collars. The design presented here is still evolving and the magnets may be built differently than described here.
Date: October 18, 1997
Creator: Gupta, R.; Alforque, R.; Anerella, M.; Kelly, E.; Plate, S.; Rufer, C. et al.
Partner: UNT Libraries Government Documents Department

Alternative Mechanical Structure for LARP Nb3Sn Quadrupoles

Description: An alternative structure for the 120 mm Nb{sub 3}Sn quadrupole magnet presently under development for use in the upgrade for LHC at CERN is presented. The goals of this structure are to build on the existing technology developed in LARP with the LQ and HQ series magnets and to further optimize the features required for operation in the accelerator. These features include mechanical alignment needed for field quality and provisions for cold mass cooling with 1.9 K helium in a helium pressure vessel. The structure will also optimize coil azimuthal and axial pre-load for high gradient operation, and will incorporate features intended to improve manufacturability, thereby improving reliability and reducing cost.
Date: August 1, 2010
Creator: Anerella, M.; Cozzolino, J.; Ambrosio, G.; Caspi, S.; Felice, H.; Kovach, P. et al.
Partner: UNT Libraries Government Documents Department