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Results from heater-induced quenches of a 4. 5 m two-in-one superconducting R and D dipole for the SSC

Description: Quench studies were performed using a 4.5 m long SSC R and D dipole to determine the temperature rise during a quench by measuring the resistance of the conductor cable in the immediate vicinity of the quench. The 2-in-1 magnet was wound with improved ''high homogeneity'' NbTi conductor in a 2-layer cosine theta coil configuration of 3.2 cm inner diameter with each layer powered separately to simulate graded conductor. Twelve pairs of voltage taps were installed at various locations in the coils around one bore of the magnet. ''Spot'' heaters were placed between the voltage taps of 8 of these pairs to initiate magnet quenches. The resistance of the conductor was obtained from observations of the current and voltage during a magnet quench. The temperature of the conductor was then determined by comparing its resistance to an R vs T curve measured independently for the conductor. The quantity ..integral..I/sup 2/dt is presented as a function of current and location, and the maximum conductor temperature is shown as a function of ..integral..I/sup 2/dt and location. Measured longitudinal and azimuthal quench propagation velocities are also presented.
Date: January 1, 1985
Creator: Ganetis, G. & Prodell, A.
Partner: UNT Libraries Government Documents Department

Results from heater-induced quenches of A 4. 5 m Reference Design D dipole for the SSC

Description: Quench studies were performed using a 4.5 m long Reference Design D, SSC dipole to determine the temperature rise of the magnet conductor during a quench by measuring the resistance of the conductor cable in the immediate vicinity of the quench. The single bore magnet was wound with improved NbTi conductor in a 2-layer cosine theta coil configuration of 4.0 cm inner diameter. Eight pairs of voltage taps were installed at various locations on the right side of the inner coil of the magnet. ''Spot'' heaters were centrally located between the voltage taps of 4 of these pairs on the midplane turn of the inner coil to initiate magnet quenches. A redundant array of voltage taps and heaters was also installed on the left side of the inner coil. The resistance of the conductor was obtained from observations of the current and voltage during a magnet quench. The temperature of the conductor was then determined by comparing its resistance to an R vs T curve appropriate for the conductor. The quantity ..integral.. I/sup 2/dt and the temperature, T, are presented as a function of current, and the maximum conductor temperature is shown as a function of ..integral.. I/sup 2/dt. Measured longitudinal and azimuthal quench propagation velocities are also presented as a function of magnet current, and the temperatures at several locations on the inner magnet coil are plotted as a function of the time after a quench was initiated.
Date: January 1, 1986
Creator: Ganetis, G. & Prodell, A.
Partner: UNT Libraries Government Documents Department

Electrical measurements during magnet construction

Description: Throughout the construction phase of the cold mass for SSC magnets, electrical tests are made to determine that no faults in the coil structure have developed. These tests include ones designed to measure turn-to-turn voltage hold-off, hypot tests to ground, coil resistance, and instrumentation checks. These various tests will be described and the test parameters that are used will be covered. 4 figs.
Date: January 1, 1989
Creator: Sintchak, G.; Ganetis, G. & Cottingham, G.
Partner: UNT Libraries Government Documents Department

Superconducting sextupoles and trim quadrupoles for RHIC

Description: RHIC requires 288 sextupole and 72 trim quadrupole magnets. These iron poletip superconducting magnets have been constructed by Everson Electric Co. Room temperature field measurements have been completed for 75% of these magnets with acceptable results. Approximately 15% of them have been tested at 4.6 K for maximum (quench) current. The quench performance for the early magnets was good and improved to excellent during the production run. These magnets have more than 100% margin at quench.
Date: May 1, 1995
Creator: Thompson, P.; Anerella, M. & Ganetis, G.
Partner: UNT Libraries Government Documents Department

Combined element magnet production for the relativistic heavy ion collider (RHIC) at BNL

Description: The production of 432 combined element magnets for RHIC is well underway. These magnets consist of a superconducting corrector, a quadrupole, and a sextupole combined into an integrated cold mass which is inserted into a cryostat. Production experiences as well as test results are reported.
Date: May 1, 1995
Creator: Mulhall, S.; Foelsche, H. & Ganetis, G.
Partner: UNT Libraries Government Documents Department

Superconducting 8 CM Corrector magnets for the relativistic heavy ion collider (RHIC)

Description: RHIC will require 420 80 mm Corrector magnets. The magnets are made up of coils wound on a computer controlled wiring machine using ultrasonic power to bond the wire into an epoxy coated flat substrate. The coils are wrapped onto support tubes and concentrically assembled inside an iron yoke. These magnets are being built at Brookhaven National Laboratory (BNL) with more than 280 constructed by May 1, 1995. Design, construction and test results are presented.
Date: May 1, 1995
Creator: Morgillo, A.; Escallier, J. & Ganetis, G.
Partner: UNT Libraries Government Documents Department

Measurement of internal forces in superconducting accelerator magnets with strain gauge transducers

Description: An improved method has been developed for the measurement of internal forces in superconducting accelerator magnets, in particular the compressive stresses in coils and the end restraint forces on the coils. The transducers have been designed to provide improved sensitivity to purely mechanical strain by using bending mode deflections for sensing the applied loads. Strain gauge resistance measurements are made with a new system that eliminates sources of errors due to spurious resistance changes in interconnecting wiring and solder joints. The design of the transducers and their measurement system is presented along with a discussion of the method of compensation for thermal and magnetic effects, methods of calibration with typical calibration data, and measured effect in actual magnets of the thermal stress changes from cooldown and the Lorentz forces during magnet excitation. 13 figs., 1 tab.
Date: January 1, 1988
Creator: Goodzeit, C.L.; Anerella, M.D. & Ganetis, G.L.
Partner: UNT Libraries Government Documents Department

OVERVIEW OF THE AGS COLD SNAKE POWER SUPPLIES AND THE NEW RHIC SEXTUPOLE POWER SUPPLIES

Description: The two rings in the Relativistic Heavy Ion Collider (RHIC) were originally constructed with 24 sextupole power supplies, 12 for each ring. Before the start of Run 7, 24 new sextupole power supplies were installed, 12 for each ring. Individual sextupole power supplies are now each connected to six sextupole magnets. A superconducting snake magnet and power supplies were installed in the Alternating Gradient Synchrotron (AGS) and commissioned during RHIC Run 5, and used operationally in RHIC Run 6. The power supply technology, connections, control systems and interfacing with the Quench Protection system for both these systems will be presented.
Date: June 25, 2007
Creator: BRUNO,D.; GANETIS, G.; SANDBERG, J. & LOUIE, W.
Partner: UNT Libraries Government Documents Department

RHIC INSERTION REGION, SHUNT POWER SUPPLY CURRENT ERRORS.

Description: The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region contain's many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. Power Supply current error measurements were performed during the commissioning of RHIC. Models of these power supply systems were produced to predict and improve these power supply current errors using the circuit analysis program MicroCap V by Spectrum Software (TM). Results of the power supply current errors are presented from the models and from the measurements performed during the commissioning of RHIC.
Date: June 18, 2001
Creator: BRUNO,D.; GANETIS,G.; LAMBIASE,R.F. & SANDBERG,J.
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

Alignment and survey of the elements in RHIC

Description: The Relativistic Heavy Ion Collider (RHIC) consists of two rings with cryogenic magnets at a 4.5K operating temperature. Control of positions of the dipole and quadrupole cold masses (iron laminations) and the beam position monitors (BPM`s) during production and installation is presented. The roll of the dipoles is controlled by a combination of rotating coil measurements with the surveying measurements. The center of the quadrupole magnetic field is obtained by direct measurement of the field shape within a colloidal cell placed inside the quadrupoles. Special attention is given to the triplet quadrupole alignment and determination of the field center position.
Date: May 1, 1995
Creator: Trbojevic, D.; Cameron, P. & Ganetis, G.L.
Partner: UNT Libraries Government Documents Department

Electrical insulation requirements and test procedures for SSC dipole magnets

Description: The development of the basic requirements for the turn-to-turn, coil-to-coil, and coil-to-ground insulation for SSC dipoles is discussed. The insulation method is also described along with test procedures for verification of insulation integrity. Electrical tests are performed throughout the magnet assembly and fabrication process to verify that coil integrity and insulation quality of the various components and sub-assemblies are within nominal limits. These tests are also required to certify each dipole for SSC acceptance before it is installed in the cryostat and leaves the factory for final installation. The following series of tests, which are conducted at room temperature, are: resistance; inductance and Q''; hypot; impulse; and ratiometer.
Date: January 1, 1990
Creator: Sintchak, G.F.; Cottingham, J.G. & Ganetis, G.L.
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

Optimizing the design of very high power, high performance converters

Description: This paper describes how various technologies are used to achieve the desired performance in a high current magnet power converter system. It is hoped that the discussions of the design approaches taken will be applicable to other power supply systems where stringent requirements in stability, accuracy and reliability must be met.
Date: January 1, 1980
Creator: Edwards, R J; Tiagha, E A; Ganetis, G & Nawrocky, R J
Partner: UNT Libraries Government Documents Department

Field measuring probe for SSC (Superconducting Super Collider) magnets

Description: The field probe developed for measuring the field in SSC dipole magnets is an adaptation of the rotating tangential coil system in use at Brookhaven for several years. Also known as the MOLE, it is a self-contained room-temperature mechanism that is pulled through the aperture of the magnet with regular stops to measure the local field. Several minutes are required to measure the field at each point. The probe measures the multipole components of the field as well as the field angle relative to gravity. The sensitivity of the coil and electronics is such that the field up to the full 6.6 T excitation of the magnet as well as the field when warm with only 0.01 T excitation can be measured. Tethers are attached to both ends of the probe to carry electrical connections and to supply dry nitrogen to the air motors that rotate the tangential windings as well as the gravity sensor. A small computer is attached to the probe for control and for data collection, analysis and storage. Digital voltmeters are used to digitize the voltages from the rotating coil and several custom circuits control motor speeds in the probe. The overall diameter of the probe is approximately 2 cm and its length is 2.4 m; the field sensitive windings are 0.6 m in length.
Date: March 1, 1987
Creator: Ganetis, G.; Herrera, J.; Hogue, R.; Skaritka, J.; Wanderer, P. & Willen, E.
Partner: UNT Libraries Government Documents Department

RHIC POWER SUPPLIES-FAILURE STATISTICS FOR RUNS 4, 5, AND 6

Description: The two rings in the Relativistic Heavy Ion Collider (RFIIC) require a total of 933 power supplies to supply current to highly inductive superconducting magnets. Failure statistics for the RHIC power supplies will be failure associated with the CEPS group's responsibilities. presented for the last three RHIC runs. The failures of the power supplies will be analyzed. The statistics associated with the power supply failures will be presented. Comparisons of the failure statistics for the last three RHIC runs will be shown. Improvements that have increased power supply availability will be discussed.
Date: June 25, 2007
Creator: BRUNO,D.; GANETIS, G.; SANDBERG, J.; LOUIE, W.; HEPPNER, G. & SCHULTHEISS, C.
Partner: UNT Libraries Government Documents Department

Vibration Measurements to Study the Effect of Cryogen Flow in Superconducting Quadrupole.

Description: The conceptual design of compact superconducting magnets for the International Linear Collider final focus is presently under development. A primary concern in using superconducting quadrupoles is the potential for inducing additional vibrations from cryogenic operation. We have employed a Laser Doppler Vibrometer system to measure the vibrations in a spare RHIC quadrupole magnet under cryogenic conditions. Some preliminary results of these studies were limited in resolution due to a rather large motion of the laser head as well as the magnet. As a first step towards improving the measurement quality, a new set up was used that reduces the motion of the laser holder. The improved setup is described, and vibration spectra measured at cryogenic temperatures, both with and without helium flow, are presented.
Date: June 25, 2007
Creator: He,P.; Anerella, M.; aydin, S.; Ganetis, G. Harrison, M.; Jain, A. & Parker, B.
Partner: UNT Libraries Government Documents Department

OVERVIEW OF THE RHIC INSERTION REGION, SEXTUPOLE, AND SNAKE POWER SUPPLY SYSTEMS.

Description: The Relativistic Heavy Ion Collider (RHIC) was commissioned in 1999 and 2000. RHIC requires power supplies to supply currents to highly inductive superconducting magnets. The RHIC Insertion Region (IR) contains many shunt power supplies to trim the current of different magnet elements in a large superconducting magnet circuit. There are a total of 237 Insertion Region power supplies in both RHIC rings. RHIC also requires sextupole power supplies. One sextupole power supply is connected across 12 sextupole magnets. There are a total of 24 sextupole power supplies in both rings. Snake magnets are also a part of the RHIC ring, and these snake magnets also require power supplies. There shall be a total of 24 snake power supplies in both rings. Power supply technology, connections, control systems and interfacing with the Quench Protection System will be presented.
Date: June 18, 2001
Creator: BRUNO,D.; ENG,W.; GANETIS,G.; LAMBIASE,R.F. & SANDBERG,J.
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

UNIQUE FEATURES IN MAGNET DESIGNS FOR R AND D ENERGY RECOVERY LINAC AT BNL.

Description: In this paper we describe the unique features and analysis techniques used on the magnets for a R&D Energy Recovery Linac (ERL) [1] under construction at the Collider Accelerator Department at BNL. The R&D ERL serves as a test-bed for future BNL ERLs, such as an electron-cooler-ERL at RHIC [2] and a future 20 GeV ERL electron-hadron at eRHIC [3]. Here we present select designs of various dipole and quadruple magnets which are used in Z-bend merging systems [4] and the returning loop, 3-D simulations of the fields in aforementioned magnets, particle tracking analysis, and the magnet's influence on beam parameters. We discuss an unconventional method of setting requirements on the quality of magnetic field and transferring them into measurable parameters as well as into manufacturing tolerances. We compare selected simulation with results of magnetic measurements. A 20 MeV R&D ERL (Fig. 1) is in an advanced phase of construction at the Collider-Accelerator Department at BNL, with commissioning planned for early 2009. In the R&D ERL, an electron beam is generated in a 2 MeV superconducting RF photo-gun, next is accelerated to 20 MeV in a 5 cell SRF linac, subsequently passed through a return loop, then decelerated to 2 MeV in the SRF linac, and finally is sent to a beam dump. The lattice of the R&D ERL is designed with a large degree of flexibility to enable the covering of a vast operational parameter space: from non-achromatic lattices to achromatic with positive, zero and negative R56 parameter. It also allows for large range tunability of Rlz and lattice RS4 parameters (which are important for transverse beam-break-up instability). Further details of the R&D ERL can be found elsewhere in these proceedings [5]. The return loop magnets are of traditional design with the following exceptions: (a) The bending radius of ...
Date: June 25, 2007
Creator: MENG,W.; JAIN, A.; GANETIS, G.; KAYRAN, D.; LITVINENKO, V.N.; LONGO, C. et al.
Partner: UNT Libraries Government Documents Department