21 research outputs found
Hadron cancer therapy complex using nonscaling fixed field alternating gradient accelerator and gantry design
Nonscaling fixed field alternating gradient (FFAG) rings for cancer hadron therapy offer reduced physical aperture and large dynamic aperture as compared to scaling FFAGs. The variation of tune with energy implies the crossing of resonances during acceleration. Our design avoids intrinsic resonances, although imperfection resonances must be crossed. We consider a system of three nonscaling FFAG rings for cancer therapy with 250 MeV protons and 400 MeV/u carbon ions. Hadrons are accelerated in a common radio frequency quadrupole and linear accelerator, and injected into the FFAG rings at v/c=0.1294. H^{+}/C^{6+} ions are accelerated in the two smaller/larger rings to 31 and 250 MeV/68.8 and 400 MeV/u kinetic energy, respectively. The lattices consist of doublet cells with a straight section for rf cavities. The gantry with triplet cells accepts the whole required momentum range at fixed field. This unique design uses either high-temperature superconductors or superconducting magnets reducing gantry magnet size and weight. Elements with a variable field at the beginning and at the end set the extracted beam at the correct position for a range of energies
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
Proof-of-Principle Experiment for FEL-Based Coherent Electron Cooling,”
Abstract Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, highintensity 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 paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC
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Muon Acceleration with RLA and Non-scaling FFAG Arcs
Recirculating Linear Accelerators (RLA) are the most likely means to achieve the rapid acceleration of shortlived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper, we present a novel return-arc optics design based on a Non Scaling Fixed Field Alternating Gradient (NS-FFAG) lattice that allows 5 and 9 GeV/c muons of both charges to be transported in the same string of magnets. The return arcs are made up of super cells with each super cell consisting of three triplets. By employing combined function magnets with dipole, quadrupole, sextupole and octupole magnetic field components, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both 5 and 9 GeV/c muon momenta. This solution would reduce the number of arcs by a factor of 2, simplifying the overall design
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A Non-Scaling Radial-Sector Fixed Field Alternating Gradient (FFAG) Ring for Carbon Cancer Therapy
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A Non-Scaling Radial-Sector Fixed Field Alternating Gradient (FFAG) Ring for Carbon Cancer Therapy
A non-scaling radial-sector FFAG is investigated as a machine to produce 2 x 10{sup 9} particles of C{sup 6+} per pulse, at an energy of 400 MeV. This is accomplished by having an ECR ion source (producing C{sup 4+} at 40 keV per nucleon), followed by an RFQ (that accelerates to a few MeV/u) and then a rapidly cycling synchrotron or linac that takes the carbon ions from 1 MeV/u to 31 MeV/u. The carbon is then fully stripped and accelerated in one FFAG to 119 MeV/u and then in a second FFAG to 414 MeV/u. The top FFAG has a radius of only 8.1 m and an aperture of 20 cm. The magnets are superconducting and have a maximum pole tip field of 5.3 T. The fields are linear, so the dynamic aperture is large. On the other hand, because the FFAG is non-scaling the tunes vary during acceleration and the rate of acceleration must be rapid enough to pass through resonances without unacceptable degradation of the beam
Beta-2 microglobulin removal with postdilution online hemodiafiltration – comparison of three different dialysis membranes
Introduction Accumulation of middle molecular weight uremic toxins causes various complications in chronic hemodialysis (HD) patients. Postdilution online hemodiafiltration (OL-HDF) efficiently removes these molecules. This study aimed to assess the effectiveness of three different dialysis membranes in removing β2-microglobulin (β2 m) within a single session of postdilution OL-HDF. Method A prospective single-center study was carried out in 30 patients (23 males and seven females, average age 54.87 ± 11.66 years, time on dialysis 4.95 ± 5.4 years) on maintenance HD. Each patient was followed for three consecutive weeks on OL-HDF with three different dialyzers: DiacapPro 19H, FX CorDiax 800, and Elisio 21H, randomly switched weekly. The reduction ratios (RR) of β2 m and albumin were compared individually. The results were analyzed with the Kolmogorov–Smirnov test, ANOVA, and the Kruskal–Wallis test. Results The average convective volume for all patients was 21.38 ± 2.97 L/session. β2-m RR was 70.86 ± 6.87%, 74.69 ± 6.51%, and 70.04 ± 9.37% with Diacap Pro 19H, FX CorDiax 800 and Elisio 21H membrane, respectively (p = 0.054). Albumin RR was 6.20 ± 2.12% with Diacap Pro 19H membrane, 6.01 ± 2.97% with FX CorDiax 800 membrane, and 6.46 ± 2.91% with Elisio 21H membrane (p = 0.812). Albumin loss was < 4 g/dialysis treatment for all membranes. Conclusion All investigated membranes effectively remove β2-m in postdilution OL-HDF with a tolerable albumin loss. The highest β2-m RR was determined for FX CorDiax 800 membrane, but with no statistically significant difference
Fixed Field Alternating Gradient Accelerators (FFAG) for Fast Hadron Cancer Therapy
Cancer accelerator therapy continues to be ever more prevalent with new facilities being constructed at a rapid rate. Some of these facilities are synchrotrons, but many are cyclotrons and, of these, a number are FFAG cyclotrons. The therapy method of "spot scanning” requires many pulses per second (typically 200 Hz), which can be accomplished with a cyclotron (in contrast with a synchrotron). We briefly review commercial scaling FFAG machines and then discuss recent work on non-scaling FFAGs, which may offer the possibility of reduced physical aperture and a large dynamic aperture. However, a variation of tune with energy implies the crossing of resonances during the acceleration process. A design can be developed such as to avoid intrinsic resonances, although imperfection resonances must still be crossed. Parameters of two machines are presented; a 250 MeV proton therapy accelerator and a 400 MeV carbon therapy machine