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HESQ (Helical Electrostatic Quadrupole), a low energy beam transport for the SSC linac

Description: A Helical Electrostatic Quadrupole (HESQ) is an option for the low energy beam transport (LEBT) of the SSC linac to transport and match a 35 keV H{sup {minus}} beam from a circular symmetric Magnetron ion source to a 428 MHz RFQ. Being an electrostatic focusing lens, the HESQ avoids neutralization of the H{sup {minus}} beam due to the background gas. The HESQ lenses provide stronger first-order focusing in contrast to weak second-order focusing of einzel lenses and is also stronger than alternating gradient focusing. In this paper, we will present a design and results of a PIC code simulation with space charge.
Date: September 1, 1990
Creator: Raparia, D.
Partner: UNT Libraries Government Documents Department

Design study of a medical proton linac for neutron therapy

Description: This paper describes a design study which establishes the physical parameters of the low energy beam transport, radiofrequency quadrupole, and linac, using computer programs available at Fermilab. Beam dynamics studies verify that the desired beam parameters can be achieved. The machine described here meets the aforementioned requirements and can be built using existing technology. Also discussed are other technically feasible options which could be attractive to clinicians, though they would complicate the design of the machine and increase construction costs. One of these options would allow the machine to deliver 2.3 MeV protons to produce epithermal neutrons for treating brain tumors. A second option would provide 15 MeV protons for isotope production. 21 refs., 33 figs.
Date: August 26, 1988
Creator: Machida, S. & Raparia, D.
Partner: UNT Libraries Government Documents Department

LOW LOSS DESIGN OF THE LINAC AND ACCUMULATOR RING FOR THE SPALLATION NEUTRON SOURCE.

Description: The Spallation Neutron Source (SNS) is a second generation pulsed neutron source and is presently in the fourth year of a seven-year construction cycle at Oak Ridge National Laboratory. A collaboration of six national laboratories (ANL, BNL, LANL, LBNL, ORNL, TJNAF) is responsible for the design and construction of the various subsystems. The operation of the facility will begin in 2006 and deliver a 1.0 GeV, 1.4 MW proton beam with pulse length of 650 nanosecond at a repetition rate of 60 Hz, on a liquid mercury target. It consists of an RF volume H{sup -} source of 50 mA peak current at 6% duty; an all electrostatic Low-Energy Beam Transport (LEBT) which also serves as a first stage beam chopper with {+-} 25 ns rise/fall time; a 402.5 MHz, 4-vane Radio-Frequency Quadrupole (RFQ) for acceleration up to 2.5 MeV; a Medium Energy Beam Transport (MEBT) housing a second stage chopper (<{+-} 10ns rise/fall), an adjustable beam halo scraper, and diagnostics devices; a 6-tank Drift Tube Linac (DTL) with permanent magnet quadrupoles up to 87 MeV; an 805 MHz, 4-module, Side Coupled Cavity Linac (CCL) up to 186 MeV; an 805 MHz, superconducting RF (SRF) linac with eleven medium beta ({beta} = 0.61) cryo-modules and twelve high beta ({beta} = 0.81) cryo-modules accelerating the beam to the full energy; a High Energy Beam transport (HEBT) for diagnostics, transverse and longitudinal collimation, energy correction, painting and matching; an accumulator ring compressing the 1 GeV, 1 ms pulse to 650 ns for delivery onto the target through a Ring to Target Beam Transport (RTBT) with transverse collimators.
Date: February 3, 2003
Creator: RAPARIA,D.
Partner: UNT Libraries Government Documents Department

Dipole magnet for use of RHIC EBIS HEBT line.

Description: Construction and magnetic field measurement of dipole magnets for RHIC-EBIS HEBT line have completed. These magnets will be used to guide highly charged ion beams ranging from proton to Uranium provided by a new injector toward the Booster ring in BNL. In this paper, overview of the magnetic design of the dipoles and results of magnetic field measurement are summarized.
Date: June 23, 2008
Creator: Kanesue,T.; Okamura, M.; Ritter, J. & Raparia, D.
Partner: UNT Libraries Government Documents Department

Design study of a DPIS injector for a heavy ion FFAG

Description: A new heavy ion injector linac is proposed for providing heavy ion beams to a fixed field alternating gradient (FFAG) accelerator in Kyushu University. A combination of the new intense laser source based injector and the FFAG will be able to accelerate high current ion beams with 100 Hz of a repetition rate. The planned average current reaches 7 {micro}A with carbon 6+ beam.
Date: September 29, 2008
Creator: Okamura,M.; Raparia, D.; Ishibashi, K.; Yonemura, Y. & Kanesue, T.
Partner: UNT Libraries Government Documents Department

Steering magnet design for a limited space

Description: We compare two extreme designs of steering magnets. The first one is a very thin steering magnet design which occupies only 6 mm in length and can be additionally installed as needed. The other is realized by applying extra coil windings to a quadrupole magnet and does not consume any length. The properties and the features of these steering magnets are discussed.
Date: May 4, 2009
Creator: Okamura,M.; Fite, J.; Lodestro, V.; Raparia, D. & Ritter, J.
Partner: UNT Libraries Government Documents Department

The Algebraic Reconstruction Technique (ART)

Description: Projections of charged particle beam current density (profiles) are frequently used as a measure of beam position and size. In conventional practice only two projections, usually horizontal and vertical, are measured. This puts a severe limit on the detail of information that can be achieved. A third projection provides a significant improvement. The Algebraic Reconstruction Technique (ART) uses three or more projections to reconstruct 3-dimensional density profiles. At the 200 MeV H-linac, we have used this technique to measure beam density, and it has proved very helpful, especially in helping determine if there is any coupling present in x-y phase space. We will present examples of measurements of current densities using this technique.
Date: July 1, 1997
Creator: Raparia, D.; Alessi, J. & Kponou, A.
Partner: UNT Libraries Government Documents Department

A new optical design for the BNL isotope production transport line

Description: The 200 MeV linac at BNL has recently been upgraded. As a result, 2.5 times more average beam current can be delivered to the Brookhaven Isotope Resource Center (BIRC), formerly called BLIP, a facility which produces radionuclides and radiopharmaceutical for the medical community, and also supports a research program seeking more effective diagnostic and therapeutic agents. The optics of the beam transport line to BIRC was redesigned to (a) reduce transverse fluctuations of the beam at the target due to any linac energy fluctuations, (b) produce a flat beam distribution at the target, in order to avoid melting certain target materials, and (c) handle the higher beam intensity while keeping radiation levels low. A profile monitor was also modified to monitor the flatness of the beam using the algebraic reconstruction technique (ART). The above improvements will be described, and results of the commissioning of the line during the 1996 running period will be discussed.
Date: October 1, 1996
Creator: Kponou, A.; Alessi, J.G.; Raparia, D.; Mapes, M. & Tsoupas, N.
Partner: UNT Libraries Government Documents Department

Comparisons between modeling and measured performance of the BNL Linac

Description: Quite good agreement has been achieved between computer modeling and actual performance of the Brookhaven 200 MeV Linac. We will present comparisons between calculated and measured performance for beam transport through the RFQ, the 6 m transport from RFQ to the linac, and matching and transport through the linac.
Date: October 1, 1996
Creator: Raparia, D.; Alessi, J.G. & Kponou, A.
Partner: UNT Libraries Government Documents Department

A SUPER-CONDUCTING LINAC INJECTOR FOR THE BNL-AGS.

Description: This paper reports on the feasibility study of a proton Super-Conducting Linac (SCL) as a new injector to the Alternating Gradient Synchrotron (AGS) of the Brookhaven National Laboratory (BNL). The Linac beam energy is in the range of 1.5 to 2.4 GeV. The beam intensity is adjusted to provide an average beam power of 4 MW at the top energy of 24 GeV. The repetition rate of the SCL-AGS facility is 5 beam pulses per second.
Date: August 21, 2000
Creator: Raparia, D. & Ruggiero, A.G.
Partner: UNT Libraries Government Documents Department

A SUPER-CONDUCTING LINAC DRIVER FOR THE HFBR.

Description: This paper reports on the feasibility study of a proton Super-Conducting Linac (SCL) as a driver for the High-Flux Breeder Reactor (HFBR) at Brookhaven National Laboratory (BNL). The Linac operates in Continuous Wave (CW) mode to produce an average 10 MW of beam power. The Linac beam energy is 1.0 GeV. The average proton beam intensity in exit is 10 mA.
Date: August 21, 2000
Creator: Alessi, J.; Raparia, D. & Ruggiero, A.G.
Partner: UNT Libraries Government Documents Department

THE COLLIMATION SYSTEM OF THE SNS TRANSFER LINES.

Description: The High Energy Beam Transport (HEBT) and Ring to Target Beam Transport (RTBT) lines of the Spallation Neutron Source (SNS) include collimation systems that protect the line itself, as well as the systems downstream. Due to the one-pass mechanism in a transfer line, collimation can only provide protection against accidental losses while shaping the beam is reserved for multi-pass systems as rings. Efficiency has to be improved by increasing the impact parameter in the collimator in the first passage. In the HEBT line the use of stripers for collimation of the H-beam enhances the final capture efficiency but introduces some limitations in the layout geometry. In the RTBT, protection is provided by the optics of the line and collimator optimization is reduced to considerations of length and the amount of free space available. We revisited the design of the collimation systems for both transfer lines attending to various criteria including loss scenarios and flexibility. With the revised design, we estimated the final performance and cleaning efficiency under nominal conditions for both systems.
Date: June 18, 2001
Creator: CATALAN-LASHERAS,N. & RAPARIA,D.
Partner: UNT Libraries Government Documents Department

BEAM TRANSFER LINES FOR THE SPALLATION NEUTRON SOURCE.

Description: Beam transfer lines for the Spallation Neutron Source (SNS) are designed to have low beam losses for hand on maintenance while satisfying the facility footprint requirements. There are two main beam transfer lines, High Energy Beam Transport (HEBT) line which connect super conducting linac to the accumulator ring and Ring to Target Beam transport (RTBT) which transfers beam from accumulator ring to the target. HEBT line not only transfer the beam from linac to ring but also prepare beam for ring injection, correct the energy jitter from the linac, provide required energy spread for the ring injection, clean the transverse and longitudinal halo particles from the beam, determine the linac beam quality, and provide the protection to the accumulator ring. RTBT line transport the beam from ring to target while fulfilling the target requirements of beam size, maximum current density, beam moment on the target in case of ring extraction kicker failure. and protect the target from the ring fault conditions.
Date: April 8, 2002
Creator: RAPARIA,D.; LEE,Y.Y.; WENG,W.T. & WEI,J.
Partner: UNT Libraries Government Documents Department

AGS SUPER NEUTRINO BEAM FACILITY ACCELERATOR AND TARGET SYSTEM DESIGN (NEUTRINO WORKING GROUP REPORT-II).

Description: This document describes the design of the accelerator and target systems for the AGS Super Neutrino Beam Facility. Under the direction of the Associate Laboratory Director Tom Kirk, BNL has established a Neutrino Working Group to explore the scientific case and facility requirements for a very long baseline neutrino experiment. Results of a study of the physics merit and detector performance was published in BNL-69395 in October 2002, where it was shown that a wide-band neutrino beam generated by a 1 MW proton beam from the AGS, coupled with a half megaton water Cerenkov detector located deep underground in the former Homestake mine in South Dakota would be able to measure the complete set of neutrino oscillation parameters: (1) precise determination of the oscillation parameters {Delta}m{sub 32}{sup 2} and sin{sup 2} 2{theta}{sub 32}; (2) detection of the oscillation of {nu}{sub {mu}}-{nu}{sub e} and measurement of sin{sup 2} 2{theta}{sub 13}; (3) measurement of {Delta}m{sub 21}{sup 2} sin 2{theta}{sub 12} in a {nu}{sub {mu}} {yields} {nu}{sub e} appearance mode, independent of the value of {theta}{sub 13}; (4) verification of matter enhancement and the sign of {Delta}m{sub 32}{sup 2}; and (5) determination of the CP-violation parameter {delta}{sub CP} in the neutrino sector. This report details the performance requirements and conceptual design of the accelerator and the target systems for the production of a neutrino beam by a 1.0 MW proton beam from the AGS. The major components of this facility include a new 1.2 GeV superconducting linac, ramping the AGS at 2.5 Hz, and the new target station for 1.0 MW beam. It also calls for moderate increase, about 30%, of the AGS intensity per pulse. Special care is taken to account for all sources of proton beam loss plus shielding and collimation of stray beam halo particles to ensure equipment reliability and ...
Date: April 21, 2003
Creator: DIWAN,M.; MARCIANO,W.; WENG,W. & RAPARIA,D.
Partner: UNT Libraries Government Documents Department

Ionization of polarized 3He+ ions in EBIS trap with slanted electrostatic mirror.

Description: Methods of producing the nuclear polarized {sup 3}He{sup +} ions and their ionization to {sup 3}H{sup ++} in ion trap of the electron Beam Ion Source (EBIS) are discussed. Computer simulations show that injection and accumulation of {sup 3}He{sup +} ions in the EBIS trap with slanted electrostatic mirror can be very effective for injection times longer than the ion traversal time through the trap.
Date: September 10, 2007
Creator: Pikin, A.; Zelenski, A.; Kponou, A.; Alessi, J.; Beebe, E.; Prelee, K. et al.
Partner: UNT Libraries Government Documents Department

Matching the BtA line to the bare-AGS (Part 1)

Description: The Booster to AGS (BtA) transfer line [Ref for BtA line] transports the beam bunches from the AGS-Booster to the AGS synchrotron, and also matches the beam parameters ({beta}{sub x,y}, {alpha}{sub x,y}) and dispersion functions ({eta}{sub x,y}, {eta}{prime}{sub x,y}) of the transported beam to the corresponding quantities of the circulating beam in AGS, at the AGS injection point. In this technical note we describe in details, the calculations of the matching procedure of the BtA line to the bare-AGS, and provide magnet settings for the MAD-model of the BtA transfer line which is 'matched' to the bare-AGS. In a separate but more concise technical note (Part II) we will present results on the beam optics of the BtA beam line which is 'matched' to the AGS with two helical snakes.
Date: November 1, 2008
Creator: Tsoupas,N.; Glenn, J. W.; Huan, H.; MacKay, W. W.; Raparia, D. & Zeno, K.
Partner: UNT Libraries Government Documents Department

MODEL SIMULATIONS OF CONTINUOUS ION INTERJECTION INTO EBIS TRAP WITH SLANTED ELECTROSTATIC MIRROR.

Description: The efficiency of trapping ions in an EBIS is of primary importance for many applications requiring operations with externally produced ions: RIA breeders, ion sources, traps. At the present time, the most popular method of ion injection is pulsed injection, when short bunches of ions get trapped in a longitudinal trap while traversing the trap region. Continuous trapping is a challenge for EBIS devices because mechanisms which reduce the longitudinal ion energy per charge in a trap (cooling with residual gas, energy exchange with other ions, ionization) are not very effective, and accumulation of ions is slow. A possible approach to increase trapping efficiency is to slant the mirror at the end of the trap which is opposite to the injection end. A slanted mirror will convert longitudinal motion of ions into transverse motion, and, by reducing their longitudinal velocity, prevent these ions from escaping the trap on their way out. The trade off for the increased trapping efficiency this way is an increase in the initial transverse energy of the accumulated ions. The slanted mirror can be realized if the ends of two adjacent electrodes- drift tubes - which act as an electrostatic mirror, are machined to produce a slanted gap, rather than an upright one. Applying different voltages to these electrodes will produce a slanted mirror. The results are presented of 2D and 3D computer simulations of ion injection into a simplified model of EBIS with slanted mirror.
Date: August 26, 2007
Creator: PIKIN,A.; KPONOU, A.; ALESSI, J.G.; BEEBE, E.N.; PRELEC, K. & RAPARIA, D.
Partner: UNT Libraries Government Documents Department

An 8 GeV H- multi-turn injection system for the Fermilab Main Injector

Description: An 8 GeV superconducting linear accelerator (SCL) has been proposed [1] as a single stage H{sup -} injector into the Main Injector (MI) synchrotron . This would be the highest energy H{sup -} multi-turn injection system in the world. The conceptual design of an injection system has been further refined by addressing transverse phase space painting issues, chicane dipole fields and foil location, foil temperature issues, and initial longitudinal phase space painting simulations. We present the current state of design.
Date: June 1, 2007
Creator: Johnson, D.E.; Yoon, P.; /Fermilab; Liaw, C-J.; Raparia, D.; Bebee-Wang, J. et al.
Partner: UNT Libraries Government Documents Department

A new medium energy beam transport line for the proton injector of AGS-RHIC

Description: In Brookhaven National Laboratory (BNL), a 750 keV medium energy beam transport line between the 201 MHz 750 keV proton RFQ and the 200 MeV Alvarez DTL is being modified to get a better transmission of the beam. Within a tight space, high field gradient quadrupoles (65 Tm) and newly designed steering magnets (6.5 mm in length) will be installed considering the cross-talk effects. Also a new half wave length 200 MHz buncher is being prepared. The beam commissioning will be done in this year. To enhance the performance of the proton linacs, the MEBT is being modified. New quadrupole magnets, steering magnets and a half wave length buncher as shown in Figure 7 will be installed and be commissioned soon.
Date: September 12, 2010
Creator: Okamura, M.; Briscoe, B.; Fite, J.; LoDestro, V.; Raparia, D.; Ritter, J. et al.
Partner: UNT Libraries Government Documents Department

The NSNS high energy beam transport line

Description: In the National Spallation Neutron Source (NSNS) design, a 180 meter long transport line connects the 1 GeV linac to an accumulator ring. The linac beam has a current of 28 mA, pulse length of 1 ms, and 60 hz rep rate. The high energy transport line consists of sixteen 60{degree} FODO cells, and accommodates a 90{degree} achromatic bend, an energy compressor, collimators, part of the injection system, and enough diagnostic devices to measure the beam quality before injection. To reduce the uncontrolled beam losses, this line has nine beam halo scrapers and very tight tolerances on both transverse and longitudinal beam dynamics under space charge conditions. The design of this line is presented.
Date: July 1, 1997
Creator: Raparia, D.; Alessi, J.; Lee, Y.Y. & Weng, W.T.
Partner: UNT Libraries Government Documents Department