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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 small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. Additional strong focusing magnets following the gantry have also to be adjustable to provide required spot size and radial scanning above the patients. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.
Date: June 23, 2006
Creator: TRBOJEVIC, D.; GUPTA, R.; PARKER, B.; KEIL, E. & SESSLER, A.M.
Partner: UNT Libraries Government Documents Department

The Transverse Linac Optics Design in Multi-pass ERL

Description: In this paper, we analyzed the linac optics design requirement for a multi-pass energy recovery linac (ERL) for arbitrary number of linacs. A set of general formula of constrains for the 2-D transverse matrix is derived to ensure design optics acceptance matching throughout the entire accelerating and decelerating process. Meanwhile, the rest free parameters can be adjusted for fulfilling other requirements or optimization purpose. As an example, we design the linac optics for the future MeRHIC (Medium Energy eRHIC) project and show the optimization for small {beta} function.
Date: May 23, 2010
Creator: Hao, Y.; Kewisch, J.; Litvinenko,V.; Pozdeyev, E.; Ptitsyn, V.; Trbojevic, D. et al.
Partner: UNT Libraries Government Documents Department

COMPARISON BETWEEN THE PREDICTIONS AND MEASUREMENTS FOR THE BEAM GAS INTERACTIONS DURING THE LAST GOLD AND PROTON RUNS IN RHIC.

Description: The last gold-gold and polarized proton-proton collision runs were performed at energies of 100 GeV/nucleon. The beam gas interactions in RHIC are very important for the beam lifetime in RHIC. In this report the lifetime predicted by pressure data differences between the beams ON and beams OFF, at the energies of 100 GeV/nucleon. are compared to the predictions for the beam gas interaction and beam lifetimes.
Date: June 2, 2002
Creator: TRBOJEVIC,D.; HSEUH,H.C.; FISCHER,W.; ZHANG,S.Y. & MACKAY,W.W.
Partner: UNT Libraries Government Documents Department

A study of betatron and momentum collimators in RHIC

Description: The Relativistic Heavy Ion Collider (RHIC) has two interaction regions where {beta}* = 1--2m, with large detectors PHENIX and STAR. The transverse and longitudinal emittances are expected to double in size between one to two hours due to intra-beam scattering which may lead to transverse beam loss. Primary betatron collimators are positioned in the ring to allow efficient removal of particles with large betatron amplitudes. The authors have investigated distributions and losses coming from the out-scattered particles from the primary collimators, as well as the best positions for the secondary momentum and betatron collimators.
Date: July 1, 1997
Creator: Trbojevic, D.; Stevens, A.J.; Harrison, M.A.; Dell, F. & Peggs, S.
Partner: UNT Libraries Government Documents Department

Measurements of the betatron functions and phases in RHIC

Description: The Relativistic Heavy Ion Collider (RHIC) consists of two rings with six fold symmetry. The six interaction regions (IR)s are connected with twelve FODO cells. RHIC quadrupoles in the interaction regions have independent tuning capability. The betatron functions will be measured by a three methods. First, tunable IR quadrupoles will be adjusted to measure betatron functions at those locations through the change in tune. Second, sinusoidal coherent dipole oscillations will be used to measure the betatron phases and functions (as performed in LEP). Third, a correction dipole kick technique will be used (as at Fermilab). special attention will be given to the betatron squeeze procedure by which the two large experiments PHENIX and STAR will achieve minimum betatron functions between 1 and 2 m.
Date: August 1, 1998
Creator: Trbojevic, D.; Kewisch, J.; Peggs, S.; Satogata, T.; Tepikian, S. & Goddere, G.
Partner: UNT Libraries Government Documents Department

MEASUREMENTS OF THE BETATRON FUNCTIONS IN RHIC.

Description: The Relativistic Heavy Ion Collider (RHIC) provides collisions of the fully stripped gold ions for four experiments. This report shows results from measurements of the betatron functions within the Interaction Regions (IR) as well as in the arcs in both ''blue'' and ''yellow'' rings. A single quadrupole excitation or the beam position monitors' RMS. values at injection are used to obtain the betatron amplitude function.
Date: June 18, 2001
Creator: TRBOJEVIC,D.; AHRENS,L.; BAI,M.; PTITSYN,V.; SATOGATA,T. & VAN ZEIJTS,J.
Partner: UNT Libraries Government Documents Department

BEAM LIFETIME DEPENDENCE ON THE BEAM-GAS INTERACTIONS IN RHIC.

Description: In the Relativistic Heavy ion Collider (RHIC) much larger background signals were occurring at BRAMS, one of the four experiments. This was especially pronounced at the time when vacuum conditions deteriorated due to the beam ionization profile monitor replacements. Recording the beam intensities during the store provided the beam lifetime. Predictions from the beam gas interactions to the above measured values are compared The ionization gauges simultaneously recorded the vacuum pressure data.
Date: June 18, 2001
Creator: TRBOJEVIC,D.; HSUEH,H.C.; MACKAY,W.; DREES,A. & FLILLER,R.
Partner: UNT Libraries Government Documents Department

MEASUREMENTS OF THE BETATRON FUNCTIONS IN RHIC.

Description: The Relativistic Heavy Ion Collider (RI-UC) provides collisions of the fully stripped gold ions for four experiments. This report shows results from measurements of the betatron functions within the Interaction Regions (IR) as well as in the arcs in both ''blue'' and ''yellow'' rings. A single quadrupole excitation or the beam position monitors' RMS. values at injection are used to obtain the betatron amplitude function.
Date: June 18, 2001
Creator: TRBOJEVIC,D.; AHRENS,L.; BAI,M.; PTITSYN,V.; SATOGATA,T. & VAN ZEIJTS,J.
Partner: UNT Libraries Government Documents Department

BEAM LIFETIME DEPENDENCE ON THE BEAM-GAS INTERACTIONS IN RHIC.

Description: In the Relativistic Heavy ion Collider (RHIC) much larger background signals were occurring at BRAMS, one of the four experiments. This was especially pronounced at the time when vacuum conditions deteriorated due to the beam ionization profile monitor replacements. Recording the beam intensities during the store provided the beam lifetime. Predictions from the beam gas interactions to the above measured values are compared The ionization gauges simultaneously recorded the vacuum pressure data.
Date: June 18, 2001
Creator: TRBOJEVIC,D.; HSUEH,H.C.; MACKAY,W.; DREES,A. & FLILLER,R.
Partner: UNT Libraries Government Documents Department

OPTIMIZATION OF THE PARAMETERS IN THE RHIC SINGLE CRYSTAL HEAVY ION COLLIMATION.

Description: In the framework of the project to design and test a collimation system prototype using bent channeling crystal for cleaning of the RHIC heavy ion beam halo, we have studied the optimal length and bending angle of a silicon (110) single crystal proposed to be a primary element situated upstream of the traditional heavy amorphous collimator. Besides the matters of the channeling and collimation efficiency, we also looked into the impact the crystal may have on the non-channeled particles that go on circulating in the ring, so as to reduce the momentum offset of the particles scattered of the crystal.
Date: March 29, 1999
Creator: BIRYUKOV,V. M.; CHESNOKOV,Y. A.; KOTOV,V. I.; TRBOJEVIC,D. & STEVENS,A.
Partner: UNT Libraries Government Documents Department

1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS.

Description: A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) proton Accelerator is being studied as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The major benefit is that it would considerably shorten the overall AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power at the top energy of 28 GeV. This paper describes the FFAG design for acceleration of protons from 400 MeV to 1.5 GeV, with the same circumference of the AGS, and entirely housed in the AGS tunnel.
Date: July 5, 2004
Creator: Ruggiero, A. G.; Blaskiewicz, M.; Trbojevic, D.; Tsoupas, N. & Zhang, W.
Partner: UNT Libraries Government Documents Department

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 machine has been surveyed and the resulting as-built measured position of the fiducials have been stored and structured in the survey database. We describe how the alignment errors, inferred by comparison of ideal and as-built data, have been processed and analyzed by including them in the RHIC modeling software. The RHIC model, which also includes individual measured errors for all magnets in the machine and is automatically generated from databases, allows the study of the impact of the measured alignment errors on the machine.
Date: March 29, 1999
Creator: PILAT,F.; HEMMER,M.; PTITSIN,V.; TEPIKIAN,S. & TRBOJEVIC,D.
Partner: UNT Libraries Government Documents Department

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

BEAM DIFFUSION MEASUREMENTS AT RHIC.

Description: During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold ions, deuterons, and protons. We compare these results with measurements from previous years, and simulations, and discuss any factors that relate to beam growth in RHIC.
Date: May 12, 2003
Creator: FLILLER,R. P.,IIIDREES,A. GASSNER,D. MCINTYRE,G. PEGGS,S. TRBOJEVIC,D.
Partner: UNT Libraries Government Documents Department

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

FEL potential of eRHIC

Description: Brookhaven National Laboratory plans to build a 5-to-30 GeV energy-recovery linac (ERL) for its future electron-ion collider, eRHIC. In past few months, the Laboratory turned its attention to the potential of this unique machine for free electron lasers (FELS), which we initially assessed earlier. In this paper, we present our current vision of a possible FEL farm, and of narrow-band FEL-oscillators driven by this accelerator. eRHIC, the proposed electron-ion collider at BNL, takes advantage of the existing Relativistic Heavy Ion Collider (RHIC) complex. Plans call for adding a six-pass super-conducting (SRF) ERL to this complex to collide polarized- and unpolarized- electron beams with heavy ions (with energies up to 130 GeV per nucleon) and with polarized protons (with energies up to 325 GeV). RHIC, with a circumference of 3.834 km, has three-fold symmetry and six straight sections each {approx} 250 m long. Two of these straight sections will accommodate 703-MHz SRF linacs. The maximum energy of the electron beam in eRHIC will be reached in stages, from 5 GeV to 30 GeV, by increasing the lengths of its SRF linacs. We plan to install at the start the six-pass magnetic system with small gap magnets. The structure of the eRHIC's electron beam will be identical with that of its hadron beam, viz., 166 bunches will be filled, reserving about a one-microsecond gap for the abort kicker. With modest modifications, we can assure that eRHIC's ERL will become an excellent driver for continuous wave (CW) FELs (see Fig.1). The eRHIC's beam structure will support the operation of several such FELs in parasitic mode.
Date: August 23, 2010
Creator: Litvinenko, V.N.; Ben-Zvi, I.; Hao, Y.; Kao, C-C.; Kayran, D.; Murphy, J.B. et al.
Partner: UNT Libraries Government Documents Department

Comparison of accelerator technologies for use in ADSS

Description: Accelerator Driven Subcritical (ADS) fission is an interesting candidate basis for nuclear waste transmutation and for nuclear power generation. ADS can use either thorium or depleted uranium as fuel, operate below criticality, and consume rather than produce long-lived actinides. A case study with a hypothetical, but realistic nuclear core configuration is used to evaluate the performance requirements of the driver proton accelerator in terms of beam energy, beam current, duty factor, beam distribution delivered to the fission core, reliability, and capital and operating cost. Comparison between a CW IC and that of a SRF proton linac is evaluated. Future accelerator R&D required to improve each candidate accelerator design is discussed. ADS fission has interesting potential for electric power generation and also for destruction of long-lived actinide waste produced by conventional critical reactors. ADS systems offer several interesting advantages in comparison to critical reactors: (1) ADS provides greater flexibility for the composition and placement of fissile, fertile, or fission product waste within the core, and require less enrichment of fissile content; (2) The core can be operated with a reactivity k{sub eff} that cannot reach criticality by any failure mode; (3) When the beam is shut off fission ceases in the core; (4) Coupling the fast neutron spectrum of the spallation drive to fast core neutronics offers a basis for more complete burning of long-lived actinides; and (5) ADS designs can provide sufficient thermal mass that meltdown cannot occur from radioactive heat after fission is stopped. In order to drive a {approx}GW{sub e} fission core a CW proton beam of >700 MeV and {approx}15 MW beam power is required. A previous study of the accelerator performance required for ADS systems concluded that present accelerator performance is approaching those requirements, but accelerator system cost and reliability remain particular concerns. The obvious candidates ...
Date: March 28, 2011
Creator: Weng, W.T.; Ludewig, H.; Raparia, D.; Trbojevic, D.; Todosow, M.; McIntyre, P. et al.
Partner: UNT Libraries Government Documents Department

Re-visit local coupling correction in the interaction regions of RHIC

Description: In this article we will re-visit the local coupling correction in the interaction regions (IRs) of the Relativistic Heavy Ion Collider (RHIC). We will review the measurement data of triplet quadrupole rolls, the local coupling correction strengths in the RHIC control system, and the methods for the local coupling correction with local skew quadrupole correctors. Based on the in-turnnel measurement data of triplet roll errors in 2011, we will analytically calculate and simulate IR-bump method to find out the local skew correction strengths and compare them at store and at injection with the Blue and Yellow ring lattices in the 2011 polarized proton (p-p) and Au-Au runs. The vertical dispersion from the triplet roll errors, local and global coupling correction skew quadrupoles, and the vertical dipole correctors are calculated and discussed.
Date: November 1, 2011
Creator: Luo, Y.; Fischer, W.; Liu, C.; Marusic, A.; Minty, M.; Ptitsyn, V. et al.
Partner: UNT Libraries Government Documents Department

Lattice design for the future ERL-based electron hadron colliders eRHIC and LHeC

Description: We present a lattice design of a CW Electron Recovery Linacs (ERL) for future electron hadron colliders eRHIC and LHeC. In eRHIC, an six-pass ERL installed in the existing Relativistic Heavy Ion Collider (RHIC) tunnel will collide 5-30 GeV polarized electrons with RHIC's 50-250 (325) GeV polarized protons or 20-100 (130) GeV/u heavy ions. In LHeC a stand-along, 3-pass 60 GeV CW ERL will collide polarized electrons with 7 TeV protons. After collision, electron beam energy is recovered and electrons are dumped at low energy. Two superconducting linacs are located in the two straight sections in both ERLs. The multiple arcs are made of Flexible Momentum Compaction lattice (FMC) allowing adjustable momentum compaction for electrons with different energies. The multiple arcs, placed above each other, are matched to the two linac's straight sections with splitters and combiners.
Date: March 28, 2011
Creator: Trbojevic, D.; Beebe-Wang, J.; Hao, Y.; Litvinenko, V.N.; Ptitsyn, V.; Kayran, D. et al.
Partner: UNT Libraries Government Documents Department

A new luminescence beam profile monitor for intense proton and heavy ion beams

Description: A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.
Date: October 1, 2008
Creator: Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T. et al.
Partner: UNT Libraries Government Documents Department

Dynamic aperture evaluation of the proposed lattices for the RHIC 2009 polarized proton run

Description: In the article we evaluate the dynamic apertures of the proposed lattices for the coming Relativistic Heavy Ion Collider (RHIC) 2009 polarized proton (pp) 100 GeV and 250 GeV runs. One goal of this study is to find out the appropriate {beta}* for the coming 2009 pp runs. Another goal is to study the effect of second order chromaticity correction in the RHIC pp runs.
Date: January 2, 2009
Creator: Luo,Y.; Bai, M.; Beebe-Wang, J.; Fischer, W.; Montag, C.; Robert-Demolaize, G. et al.
Partner: UNT Libraries Government Documents Department