The Rapid Cycling Medical Synchrotron RCMS. (open access)

The Rapid Cycling Medical Synchrotron RCMS.

Thirteen hadron beam therapy facilities began operation between 1990 and 2001 - 5 in Europe, 4 in North America, 3 in Japan, and 1 in South Africa [l]. Ten of them irradiate tumors with protons, 2 with Carbon- 12 ions, and 1 with both protons and Carbon-12. The facility with the highest patient throughput - a total of 6 174 patients in 11 years and as many as 150 patient treatments per day -is the Loma Linda University Medical Center, which uses a weak focusing slow cycling synchrotron to accelerate beam for delivery to passive scattering nozzles at the end of rotatable gantries [2, 3,4]. The Rapid Cycling Medical Synchrotron (RCMS) is a second generation synchrotron that, by contrast with the Loma Linda synchrotron, is strong focusing and rapid cycling, with a repetition rate of 30 Hz. Primary parameters for the RCMS are listed in Table 1.
Date: June 2, 2002
Creator: Peggs, S.; Barton, D.; Beebe-Wang, J.; Cardona, J.; Brennan, M.; Fischer, W. et al.
Object Type: Article
System: The UNT Digital Library
Design of the RCMS Lattice Optics (open access)

Design of the RCMS Lattice Optics

THE RAPID CYCLING MEDICAL SYNCHROTRON (RCMS) IS DESIGNED TO BE A VERY LIGHT AND INEXPENSIVE ACCELERATOR. THIS IS POSSIBLE DUE TO THE SMALL BEAM SIZE THAT HAS BEEN CHOSEN EARLY DURING THE DESIGN STAGE. THIS CHOICE HAS IMPLICATIONS IN THE DESIGN OF THE LATTICE OPTICS. IN THIS PAPER, WE PRESENT AN OVERVIEW OF THE RCMS OPTICS LATTICE, THE KIND OF MAGNETS TO BE USED AND ALSO A DESCRIPTION OF A SPECIAL OPTIC MODULE THAT MATCHES THE ROTATING GANTRY WITH THE REST OF THE FIXED ACCELERATOR. TECHNIQUESDEVELOPED TO WIN ADDITIONAL SPACE BETWEEN QUADRUPOLES WITHOUT DISTRUBING BETA FUNCTIONS ARE ALSO PRESENTED.
Date: June 2, 2002
Creator: Cardona, J.; Kewisch, J. & Peggs, S.
Object Type: Article
System: The UNT Digital Library
Agent-Based Mediation and Cooperative Information Systems (open access)

Agent-Based Mediation and Cooperative Information Systems

This report describes the results of research and development in the area of communication among disparate species of software agents. The two primary elements of the work are the formation of ontologies for use by software agents and the means by which software agents are instructed to carry out complex tasks that require interaction with other agents. This work was grounded in the areas of commercial transport and cybersecurity.
Date: June 2, 2002
Creator: PHILLIPS, LAURENCE R.; LINK, HAMILTON E. & GOLDSMITH, STEVEN Y.
Object Type: Report
System: The UNT Digital Library
LINEAR OPTICS DURING THE RHIC 2001 - 2 RUN. (open access)

LINEAR OPTICS DURING THE RHIC 2001 - 2 RUN.

The RHIC 2001-2 Au and polarized proton runs used several different low-beta optics configurations. Low-beta squeezes were routinely performed through the Au acceleration ramp to optimize injection and transition optics; the polarized proton run injected and accelerated with constant low-beta optics to optimize polarization preservation. This paper summarizes tools, methods and results for linear optics measurement and correction during these runs as well as future plans.
Date: June 2, 2002
Creator: Satogata, T.; Cardona, J.; Ptitsyn, V.; Tepikian, S. & Van Zeijts, J.
Object Type: Article
System: The UNT Digital Library
A P + Deuteron Proton Polarimeter at 200 MEV (open access)

A P + Deuteron Proton Polarimeter at 200 MEV

There has been concern about the analyzing power of the p-Carbon polarimeter at the end of 200 MeV LINAC of BNL. A new polarimeter based on proton-deuteron scattering was installed and we have repeated the calibration of proton-Carbon scattering at 12 degrees and 200 MeV against proton-deuteron scattering. The result is consistent with the value of A=0.62 now used to measure the beam polarization at the end of the LINAC.
Date: June 2, 2002
Creator: Huang, H.; Roser, T.; Zelenski, A.; Kurita, K.; Stephenson, E. & Toole, R.
Object Type: Article
System: The UNT Digital Library
Transient Electric Birefringence Studies of CdSe Nanorods (open access)

Transient Electric Birefringence Studies of CdSe Nanorods

None
Date: June 2, 2002
Creator: Li, Liang-Shi & Alivisatos, A. Paul
Object Type: Article
System: The UNT Digital Library
Rhic Bpm System Performance, Upgrades, and Tools. (open access)

Rhic Bpm System Performance, Upgrades, and Tools.

During the RHIC 2001-2 run, the beam position monitor (BPM) system provided independent average orbit and turn-by-turn (TBT) position measurements at 162 locations in each measurement plane and RHIC ring. TBT acquisition was successfully upgraded from 128 turns to 1024 turns per trigger, including injection. Closed orbits were acquired and automatically archived every two seconds through each acceleration ramp for orbit analysis and feed-forward orbit correction. This paper presents the overall system performance during this run, including precision, reproducibility, radiation damage, and analysis tools. We also summarize future plans, including million-turn TBT acquisition for nonlinear dynamics studies.
Date: June 2, 2002
Creator: Satogata, T.; Cameron, P.; Cerniglia, P.; Cupolo, J.; Dawson, C.; Degen, C. et al.
Object Type: Article
System: The UNT Digital Library
LINEAR AND NONLINEAR CORRECTIONS IN THE RHIC INTERACTION REGIONS. (open access)

LINEAR AND NONLINEAR CORRECTIONS IN THE RHIC INTERACTION REGIONS.

A method has been developed to measure operationally the linear and non-linear effects of the interaction region triplets, that gives access to the multipole content through the action kick, by applying closed orbit bumps and analysing tune and orbit shifts. This technique has been extensively tested and used during the RHIC operations in 2001. Measurements were taken at 3 different interaction regions and for different focusing at the interaction point. Non-linear effects up to the dodecapole have been measured as well as the effects of linear, sextupolar and octupolar corrections. An analysis package for the data processing has been developed that through a precise fit of the experimental tune shift data (measured by a phase lock loop technique to better than 10{sup -5} resolution) determines the multipole content of an IR triplet.
Date: June 2, 2002
Creator: Pilat, F.; Cameron, P.; Ptitsyn, V. & Koutchouk, J. P.
Object Type: Article
System: The UNT Digital Library
Improvements of the RHIC Ramp Efficiency (open access)

Improvements of the RHIC Ramp Efficiency

The last nms in both gold-gold and polarized proton-proton required necessary corrections in the ramp as the intensities in the two rings were rising towards design values. Corrections were made with respect to the beam-beam effects, transverse and longitudinal instabilities, transition crossing (for the gold-gold ramps), transverse tune resonances, local and global coupliug problems, aperture restrictions, chromatic effects. Along the ramps we had to use the beam separation, ''Landau'' cavities, chromatic and tune control, orbit correction, special gamma-t quadrupole system for the transition crossing in the gold run, correction octupole circuits, beam position monitor system decoupling etc.
Date: June 2, 2002
Creator: Trbojevic, D.; Ptitsyn, V.; Fischer, W.; Ahrens, L.; Blaskiewicz, M.; Hayes, T. et al.
Object Type: Article
System: The UNT Digital Library
TRANSVERSE IMPEDANCE MEASUREMENT AT THE RHIC. (open access)

TRANSVERSE IMPEDANCE MEASUREMENT AT THE RHIC.

The RHIC transverse impedance was measured during the last operation run. Measurement of the imaginary part of the broadband impedance was the main goal. No large difference between the two rings was found nor in either plane. The measured tune shift is larger than the expected by a factor of 2.5 to 3. Several other issues such as the real part impedance measurement are also presented.
Date: June 2, 2002
Creator: Zhang, S. Y.; Huang, H.; Cameron, P.; Drees, A.; Fliller, R. & Satogata, T.
Object Type: Article
System: The UNT Digital Library
Commissioning Cni Proton Polarimeters in Rhic. (open access)

Commissioning Cni Proton Polarimeters in Rhic.

Two polarimeters based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region have been installed and commissioned in the Blue and Yellow rings of RHIC during the first RHIC polarized proton collider run. Each polarimeter consists of ultra-thin carbon targets and six silicon detectors. With newly developed wave form digitizers, they provide fast and reliable polarization information for both rings.
Date: June 2, 2002
Creator: Huang, H.; Bravar, A.; Li, Z.; MacKay, W. W.; Makdisi, Y.; Rescia, S. et al.
Object Type: Article
System: The UNT Digital Library
Coupling Measurement and Correction at Rhic. (open access)

Coupling Measurement and Correction at Rhic.

Coupling correction at RHIC has been operationally achieved through a two-step process: using local triplet skew quadrupoles to compensate coupling corn rolled low-beta triplet quadrupoles, and minimizing the tune separation and residual coupling with orthogonal global skew quadrupole families. An application has been developed for global correction that allows skew quadrupole tuning and tune display with a choice of different tune measurement techniques, including tune-meter, Schottky and phase lock loop (PLL). Coupling effects have been analysed by using 1024-turn (TBT) information from the beam position monitor (BPM) system. These data allow the reconstruction of the off-diagonal terms of the transfer matrix, a measure of global coupling. At both injection and storage energies, coordination of tune meter kicks with TBT acquisition at 322 BPM's in each ring allows the measurement of local coupling at all BPM locations.
Date: June 2, 2002
Creator: Pilat, F.; Beebe-Wang, J.; Fischer, W.; Ptitsyn, V. & Satogata, T.
Object Type: Article
System: The UNT Digital Library
Space Charge Dynamics Simulated in 3-D in the Code Orbit. (open access)

Space Charge Dynamics Simulated in 3-D in the Code Orbit.

Several improvements have been done on space charge calculations in the PIC code ORBIT, specialized for high intensity circular hadron accelerators. We present results of different Poisson solvers in the presence of conductive walls.
Date: June 2, 2002
Creator: Luccio, A. U.; Dimperio, N. L. & Beebe-Wang, J.
Object Type: Article
System: The UNT Digital Library
Intra - Beam Scattering Measurements in Rhic. (open access)

Intra - Beam Scattering Measurements in Rhic.

RHIC in gold operation shows significant intra-beam scattering due to the high charge state of the stored ions. Intra-beam scattering leads to longitudinal and transverse emittance growth. The longitudinal emittance growth causes debunching in operation; the transverse emittance growth contributes to the reduction of the beam and luminosity lifetimes. The longitudinal and transverse beam growth was measured. Beam growth measurement are compared with computations.
Date: June 2, 2002
Creator: Fischer, W.; Connolly, R.; Tepikian, S.; Van Zeijts, J. & Zeno, K.
Object Type: Article
System: The UNT Digital Library
RHIC Spin Flipper Commissioning. (open access)

RHIC Spin Flipper Commissioning.

An ac dipole with horizontally oriented oscillating magnetic field (spin flipper) was installed in FU-IIC to reverse the spin direction in the presence of two full Siberian snakes, thereby reducing the systematic errors for the spin physics experiments in RHIC. With two full snakes, the spin vector completes one full precession around the vertical direction in two revolutions, and the spin depolarization resonances due to the machine imperfections and betatron oscillations are eliminated. Since the spin flipper provides an oscillating horizontal dipole field, a ''spin resonance'' can occur if the spin flipper frequency is placed in the neighborhood of the spin precession frequency [ 1,2,3]. By slowly sweeping the spin flipper frequency across the spin precession frequency, a full spin flip can be achieved. This paper reports the results of the FZUC spin flipper commissioned during the RHIC 2002 polarized proton run. By running the spin flipper at a slightly different configuration, one can also measure the spin precession tune.
Date: June 2, 2002
Creator: Bai, M.; MacKay, W. W.; Ranjbar, V. & Roser, T.
Object Type: Article
System: The UNT Digital Library
Commissioning of RHIC at 100 GEV / Nucleon (open access)

Commissioning of RHIC at 100 GEV / Nucleon

This report describes commissioning of the Relativistic Heavy Ion Collider (RHIC) for 100 GeV/nucleon collisions at designed luminosity. To achieve these goals new systems had to be commissioned: Gamma-t transition crossing jump quadrupoles, rebucketing with the new RF storage cavities, phase lock loop feedback, betatron and crystal collimation, beta squeeze along the ramp, Siberian snake magnets for the proton polarization run, AC dipole system chromaticity measurements along the acceleration ramp, orbit correction, new ramp management system, upgraded sequencer, new data instrumentation and logger acquisition system etc.
Date: June 2, 2002
Creator: Trbojevic, D.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Bai, M.; Cameron, P. et al.
Object Type: Article
System: The UNT Digital Library
A Heavy Ion Microbeam Facility Using Micron Resolution Detectors for 3 GEV/Nucleon Beams (open access)

A Heavy Ion Microbeam Facility Using Micron Resolution Detectors for 3 GEV/Nucleon Beams

None
Date: June 2, 2002
Creator: Brown, K. A.; Fliller, R.; Zheng, L.; Peggs, S.; Prigl, R.; Radeka, V. et al.
Object Type: Article
System: The UNT Digital Library
Measurements of Mechanical Triplet Vibrations in Rhic. (open access)

Measurements of Mechanical Triplet Vibrations in Rhic.

Mechanical vibrations of the RHIC interaction region triplets has been identified as the dominant source of orbit jitter for frequencies up to 20 Hz. We report the results of detailed measurements that were performed to characterize these effects. We discuss the impact on beam dynamics and possible cures.
Date: June 2, 2002
Creator: Montag, C.; Brennan, M.; Butler, J.; Bonati, R. & Koello, P.
Object Type: Article
System: The UNT Digital Library
RHIC Abort Kicker With Reduced Coupling Impedance (open access)

RHIC Abort Kicker With Reduced Coupling Impedance

Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.
Date: June 2, 2002
Creator: Hahn, H. & Davino, D.
Object Type: Article
System: The UNT Digital Library
Accelerating and Colliding Polarized Protons in RHIC With Siberian Snakes (open access)

Accelerating and Colliding Polarized Protons in RHIC With Siberian Snakes

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV. We report on our experiences during commissioning and operation of collider with polarized protons.
Date: June 2, 2002
Creator: Roser, T.; Ahrens, L.; Alessi, J.; Bai, M.; Beebe-Wang, J.; Brennan, J. M. et al.
Object Type: Article
System: The UNT Digital Library
THE RHIC BEAM ABORT SYSTEM - OPERATION DURING THE RHIC 2001 GOLD RUN. (open access)

THE RHIC BEAM ABORT SYSTEM - OPERATION DURING THE RHIC 2001 GOLD RUN.

None
Date: June 2, 2002
Creator: Ahrens, L.; Mi, J. L. & Zhang, W.
Object Type: Article
System: The UNT Digital Library
Determination of Linear and Non Linear Components in Rhic Interaction Regions From Difference Orbit Measurements. (open access)

Determination of Linear and Non Linear Components in Rhic Interaction Regions From Difference Orbit Measurements.

None
Date: June 2, 2002
Creator: Cardona, J.; Peggs, S.; Pilat, F.; Ptitsyn, V. & Satogata, T.
Object Type: Article
System: The UNT Digital Library
Analysis of Beam Induced Pressure Increases in Rhic Warm Vacuum Sections. (open access)

Analysis of Beam Induced Pressure Increases in Rhic Warm Vacuum Sections.

With increasing intensity of gold and proton beams during recent RHIC operations, pressure rises of several decades were observed at a few RHIC warm vacuum sections. The pressure increases were analyzed and compared with the beam parameters such as ion species, bunch intensity, total intensity, number ofbunches, bunch spacing and beam loss. Most of these pressure increases were found to be consistent with those induced by either beam loss and/or electron multipacting.
Date: June 2, 2002
Creator: Hseuh, H. C.; Smart, L. A. & Zhang, S. Y.
Object Type: Article
System: The UNT Digital Library
Observations of Schottky Signals in Rhic and Their Potential for Stochastic Cooling. (open access)

Observations of Schottky Signals in Rhic and Their Potential for Stochastic Cooling.

None
Date: June 2, 2002
Creator: Brennan, J. M.; Blaskiewicz, M.; Cameron, P. & Wei, J.
Object Type: Article
System: The UNT Digital Library