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Improvement of the high voltage properties of the Fermilab electrostatic septa

Description: In the Fermilab Tevatron Switchyard proton beam splits ae initiated by a wire array electrostatic septum. At 1 TeV energy, and with fields limited to 50 kV/cm, an electrostatic septum more than 20 meters in length is required to produce the required angular separation between the beams for the Proton and Neutrino/Meson lines. New techniques have been investigated that will allow reliable operation at fields above 75 kV/cm with resultant beam line economy. Changes in construction and conditionin… more
Date: June 1, 1985
Creator: Trbojevic, D.; Crawford, C.; Childress, S. & Tinsley, D.
Partner: UNT Libraries Government Documents Department
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Magnetic measurements of the correction and adjustment magnets of the main ring

Description: Correction magnets correct the field imperfections and alignment errors of the main quadrupole and bend magnets. For reducing and controlling chromaticity there are 186 sextupoles and 78 octupoles, while for suppressing various resonances there are 12 normal and 18 skew sextupoles and 24 normal and 19 skew quadrupoles. Beam positions are individually controlled by 108 horizontal and 108 skew dipoles. This report includes results of the all Main Ring correction and adjustment magnet harmonic mea… more
Date: July 1, 1986
Creator: Trbojevic, D.
Partner: UNT Libraries Government Documents Department
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Examination of the stability of the advanced imaginary. gamma. sub t lattice

Description: An advanced imaginary -{gamma}{sub t} lattice for the Fermilab Main Injector is examined for its response to quadrupole field errors, quadrupole misalignment errors, as well as its dynamical aperture. We find that the lattice is tunable except near an integer tune. The misalignment sensitivity factors are acceptable and can be lowered if the low-beta triplet quadrupoles are specially aligned. The dynamical aperture is very large provided that a family of harmonic sextupoles is installed. 6 refs… more
Date: May 1, 1991
Creator: Ng, K. Y.; Trbojevic, D. & Lee, S. Y.
Partner: UNT Libraries Government Documents Department
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Experience with IBS-suppression lattice in RHIC

Description: An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-… more
Date: June 23, 2008
Creator: Litvinenko,V. N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M. et al.
Partner: UNT Libraries Government Documents Department
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A Dramatically Reduced Size in the Gantry Design for the Proton-Carbon Therapy.

Description: Gantries in the proton/carbon cancer therapy machines represent the major cost and are of the largest size. This report explains a new way to the gantry design. The size and cost of the gantries are reduced and their use is simplified by using the fixed magnetic field. The ''new'' gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and s… more
Date: June 23, 2006
Creator: Trbojevic, D.; Gupta, R.; Parker, B.; Keil, E. & Sessler, A. M.
Partner: UNT Libraries Government Documents Department
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IBS suppression lattice in RHIC: theory and experimental verification

Description: Intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for Relativistic Heavy Ion Collider (RHIC) operation with heavy ions. Over the last few years the process of IBS was carefully studied in RHIC with dedicated IBS measurements and their comparison with the theoretical models. A new lattice was recently designed and implemented in RHIC to suppress transverse IBS growth, which lowered the average arc dispersion by about 20% [1]. This lattice became operational during RHI… more
Date: August 25, 2008
Creator: Fedotov, A. V.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Cupolo, J. et al.
Partner: UNT Libraries Government Documents Department
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Design and multiparticle simulation of the half integer slow extraction system for the Main Injector

Description: One of the roles of the new Main Injector ring, in the second phase of the Fermilab upgrade, is to deliver all year around the slow extracted 120 GeV test beams. The half-integer slow extraction system design and results from a Monte-Carlo simulation of fast spill are presented. The simulation was performed with a computer tracking program based on the TEVLAT program with a large number of particles (up to 1000). Particle tracking included the systematic errors produced by the magnetic multipol… more
Date: May 1, 1991
Creator: Trbojevic, D. & Harrison, M.
Partner: UNT Libraries Government Documents Department
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Modification of the horizontal dispersion in the Fermilab Main Ring with additional quadrupoles

Description: In the normal Main Ring lattice, the horizontal dispersion includes a dispersion wave'' which peaks at 6.2 meters because the horizontal dispersion of the arcs is not matched into the straight sections. Six additional small quadrupoles have been installed, one in each sector, and powered at low energies (up to 30 GeV) in order to reduce the amplitude of the dispersion wave. The maxima of the dispersion function were thereby reduced to less than 4.7 meters, thus improving the momentum acceptance… more
Date: May 1, 1991
Creator: Trbojevic, D.; Kourbanis, I. & Ankenbrandt, C.
Partner: UNT Libraries Government Documents Department
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A transitionless lattice for the Fermilab Main Injector

Description: Medium energy (1 to 30 GeV) accelerators are often confronted with transition crossing during acceleration. A lattice without transition is presented, which is a design for the Fermilab Main Injector. The main properties of this lattice are that the {gamma}{sub t} is an imaginary number, the maxima of the dispersion function are small, and two long-straight section with zero dispersion. 7 refs., 5 figs.
Date: May 1, 1991
Creator: Ng, K. Y.; Trbojevic, D. & Lee, S. Y.
Partner: UNT Libraries Government Documents Department
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Decoupling correction system in RHIC

Description: A global linear decoupling in the Relativistic Heavy Ion Collider (RHIC) is going to be performed with the three families of skew quadrupoles. The operating horizontal and vertical betatron tunes in the RHIC will be separated by one unit v{sub x}=28.19 and v{sub y}=29.18. The linear coupling is corrected by minimizing the tune splitting Dn-the off diagonal matrix m. The skew quadrupole correction system is located close to the each of the six interaction regions. A detail study of the system is… more
Date: December 31, 1993
Creator: Trbojevic, D.; Tepikian, S. & Peggs, S.
Partner: UNT Libraries Government Documents Department
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An improved imaginary transition {gamma}{sub t} lattice for the Main Injector

Description: An improved imaginary-{gamma}{sub t} lattice for the 150 GeV Fermilab Main Injector is presented. It has the properties of small dispersion function, good tunability, small tune dependences on momentum with the presence of chromaticity sextupoles, and a large dynamical aperture. In addition, many of the quadrupoles can be recycled from the present Main Ring.
Date: August 1, 1992
Creator: Ng, K. Y. & Trbojevic, D.
Partner: UNT Libraries Government Documents Department
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A first order matched transition jump at RHIC

Description: RHIC, the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, will be the first superconducting accelerator to cross transition, when ramping begins in 1998. All ion species except for protons will cross transition. Simulations show gold ion losses of 70%, and longitudinal emittance growth of 60%, if nothing is done to ameliorate the crossing. RHIC will also be the first accelerator to use a matched first order transition jump to modify {gamma}T for a short time, by pulsing a set… more
Date: June 1, 1993
Creator: Peggs, S.; Tepikian, S. & Trbojevic, D.
Partner: UNT Libraries Government Documents Department
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RHIC susceptibility to variations in systematic magnetic harmonic errors

Description: Results of a study to determine the sensitivity of tune to uncertainties of the systematic magnetic harmonic errors in the 8 cm dipoles of RHIC are reported. Tolerances specified to the manufacturer for tooling and fabrication can result in systematic harmonics different from the expected values. Limits on the range of systematic harmonics have been established from magnet calculations, and the impact on tune from such harmonics has been established.
Date: August 1, 1994
Creator: Dell, G. F.; Peggs, S.; Pilat, F.; Satogata, T.; Tepikian, S.; Trbojevic, D. et al.
Partner: UNT Libraries Government Documents Department
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ELECTRON CLOUD AND PRESSURE RISE SIMULATIONS FOR RHIC.

Description: Beam induced electron multipacting may be among the main reasons for the vacuum pressure rise when circulating high intensity ion and proton beams in RHIC. Latest simulation results are benchmarked with recent experimental observations for RHIC, and compared to other general computer codes. The influence of the electron multipacting to the vacuum properties is also discussed.
Date: May 12, 2003
Creator: IRISO-ARIZ,U. BLASKIEWICZ,M. DREES,A. FISCHER,W. PEGGS,S. TRBOJEVIC,D.
Partner: UNT Libraries Government Documents Department
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FFAG LATTICE FOR MUON ACCELERATION WITH DISTRIBUTED RF.

Description: A future muon collider or neutrino factory requires fast acceleration to minimize muon decay. We have previously described an FFAG ring that accelerated muons from 10 to 20 GeV in energy. The ring achieved its large momentum acceptance using a low-emittance lattice with a small dispersion. In this paper, we present an update on that ring. We have used design tools that more accurately represent the ring's behavior at large momentum offsets. We have also improved the dynamic aperture from the ea… more
Date: May 12, 2003
Creator: COURANT,E. D..TRBOJEVIC,D. BERG,S. J. BLASKIEWICZ,M. COURANT,E. D..TRBOJEVIC,D. BERG,S. J. BLASKIEWICZ,M. M. PALMER,R. GARREN,A.
Partner: UNT Libraries Government Documents Department
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Commissioning Spin Rotators in RHIC.

Description: During the summer of 2002, eight superconducting helical spin rotators were installed into RHIC in order to control the polarization directions independently at the STAR and PHENIX experiments. Without the rotators, the orientation of polarization at the interaction points would only be vertical. With four rotators around each of the two experiments, we can rotate either or both beams from vertical into the horizontal plane through the interaction region and then back to vertical on the other s… more
Date: May 12, 2003
Creator: MacKay, W. W.; Bai, M.; Courant, E. D.; Fischer, W.; Huang, H.; Luccio, A. et al.
Partner: UNT Libraries Government Documents Department
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Luminescence Beam Profile Monitor for the RHIC Polarized Hydrogen Jet Polarimeter.

Description: A new polarized hydrogen jet target was used to provide improved beam polarization measurements during the second polarized proton m in the Relativistic Heavy Ion Collider (RHIC). The luminescence produced by beam-hydrogen excitations was also used to test the feasibility of a new beam profile monitor for RFPIC based on the detection of the emitted light. Lenses, a view-port and a sensitive CCD camera were added to the system to record the optical signals from the interaction chamber. The first… more
Date: May 16, 2005
Creator: Luciano, N.; Nass, A.; Makdisi, Y.; Thieberger, P.; Trbojevic, D. & Zelenski, A.
Partner: UNT Libraries Government Documents Department
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NON-SCALING FIXED FIELD GRADIENT ACCELERATOR (FFAG) DESIGN FOR THE PROTON AND CARBON THERAPY.

Description: The non-scaling Fixed Field Alternating Gradient (FFAG-from now on) accelerator provides few advantages with respect to the other fixed field accelerators like CYCLOTRONS or scaling-FFAG's. One of the advantages is smaller required aperture due to small orbit offsets during acceleration. The large and heavy magnets are avoided. The beam is very well controlled in a strong focusing regime. This concept has been extensively investigated during the last eight FFAG workshops in Japan, USA, Canada, … more
Date: June 5, 2005
Creator: Trbojevic, D.; Keil, E. & Sessler, A.
Partner: UNT Libraries Government Documents Department
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COMPARISON OF OFF-LINE IR BUMP AND ACTION-ANGLE KICK MINIMIZATION.

Description: The interaction region bump (IR bump) nonlinear correction method has been used for the sextupole and octupole field error on-line corrections in the Relativistic Heavy Ion Collider (RHIC) . Some differences were found for the sextupole and octupole corrector strengths between the on-line IR bump correction and the predictions from the action-angle kick minimization. In this article, we compare the corrector strengths from these two methods based on the RHIC Blue ring lattice with the IR nonlin… more
Date: May 16, 2005
Creator: Luo, Y.; Pilat, F.; Ptitsyn, V.; Trbojevic, D. & Wei, J.
Partner: UNT Libraries Government Documents Department
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Processing and Analysis of the Measured Alignment Errors for Rhic.

Description: All elements of the Relativistic Heavy Ion Collider (RHIC) have been installed in ideal survey locations, which are defined as the optimum locations of the fiducials with respect to the positions generated by the design. The alignment process included the presurvey of all elements which could affect the beams. During this procedure a special attention was paid to the precise determination of the quadrupole centers as well as the roll angles of the quadrupoles and dipoles. After installation the… more
Date: March 29, 1999
Creator: Pilat, F.; Hemmer, M.; Ptitsin, V.; Tepikian, S. & Trbojevic, D.
Partner: UNT Libraries Government Documents Department
open access

Non-Scaling Fixed Field Gradient Optimization.

Description: Optimization of the non-scaling FFAG lattice for the specific application of the muon acceleration with respect to the minimum orbit offsets, minimum path length and smallest circumference is described. The short muon lifetime requires fast acceleration. The acceleration is in this work assumed to be with super-conducting cavities. This sets up a condition of acceleration at the top of the sinusoidal RF wave.
Date: October 13, 2004
Creator: Trbojevic, D.
Partner: UNT Libraries Government Documents Department
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Coherent electron cooling demonstration experiment

Description: Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, high-intensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this p… more
Date: September 4, 2011
Creator: Litvinenko, V. N.; Belomestnykh, S.; Ben-Zvi, Ilan; Brutus, J. C.; Fedotov, A.; Hao, Y. et al.
Partner: UNT Libraries Government Documents Department
open access

The effects of betatron phase advances on beam-beam and its compensation in RHIC

Description: In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and t… more
Date: March 28, 2011
Creator: Luo, Y.; Fischer, W.; Gu, X.; Tepikian, S. & Trbojevic, D.
Partner: UNT Libraries Government Documents Department
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