Showing papers on "Linear particle accelerator published in 1973"
46 citations
TL;DR: The LBL SuperHilac as discussed by the authors was used as an injector for the LBL Bevatron to produce high energy, high intensity beams of a variety of heavy-ions.
Abstract: An economical means for the production of high energy, high intensity beams of a variety of heavy-ions is to utilize the existing LBL SuperHilac as an injector for the existing LBL Bevatron. Particle energies from 0.25 to 2.6 GeV/nucleon will be realized. The description of this facility, which will be in operation in late 1973, includes the general arrangements, the modest changes to each accelerator, beam transport line design, and a new bio-medical experimental area.
29 citations
TL;DR: A hospital-based negative pi-meson radiotherapy facility is now being designed for Stanford University Medical Center, providing maximal flexibility in shaping the “star region” of the beam to the continuously changing X-Y contours of the tumor while the patient is moved in the Z axis.
Abstract: A hospital-based negative pi-meson radiotherapy facility is now being designed for Stanford University Medical Center A 500-MeV electron beam from a superconducting linear electron accelerator will generate negative pions, which will then be directed by superconducting magnets through a novel 60-sectored pion channel, making possible simultaneous multiport irradiation The pion channel design permits the magnetic field to be varied in time, and the number of sectors transmitting pions can be preselected and adjusted during treatment, thus providing maximal flexibility in shaping the “star region” of the beam to the continuously changing X-Y contours of the tumor while the patient, on a specially designed support assembly, is moved in the Z axis
26 citations
Patent•
26 Feb 1973
TL;DR: In this article, a linear particle accelerator with detection apparatus for detecting the presence of and correcting for beam misalignment is described, where a target is disposed in the particle beam path for emitting X-rays upon being struck by the charged particles.
Abstract: A linear particle accelerator having detection apparatus for detecting the presence of and correcting for beam misalignment. The linear accelerator includes a charged particle accelerator system and deflection coils for changing both the positional and angular displacement of a charged particle beam. A target is disposed in the particle beam path for emitting X-rays upon being struck by the charged particles. The photon field developed by the target takes the form of a forward-peaked lobe configuration extending from the target. An ionization chamber is disposed in the radiation field for developing electrical signals responsive to changes in the lobe field. The ionization chamber includes a housing member, and insulative sheet, such as a sheet of thin glass or mica, is supported within the housing member. A pattern of detection electrodes is formed on the insulative sheet by vacuum deposition or other similar process. A high voltage electrode comprising a sheet of conductive material is supported within the housing member in spaced parallel relationship with the detection electrodes.
25 citations
Patent•
05 Jul 1973
TL;DR: In this paper, a linear accelerator structure comprising a succession of cylindrical resonant cavities which are accelerating cavities, and coupling annular cavities located at the periphery thereof, is described.
Abstract: High efficiency linear accelerator structures comprising a succession of cylindrical resonant cavities which are accelerating cavities, and coupling annular cavities which are located at the periphery thereof, each of these annular cavities being coupled to two adjacent cylindrical cavities.
22 citations
TL;DR: The fast neutron contamination associated with the 25 MV X-ray beam of a clinical linear accelerator and with the 19 MVX-raybeam of a betatron has been measured at the patient treatment location, using both fission fragment track detectors and silicon diode dosemeters.
Abstract: The fast neutron contamination associated with the 25 MV X-ray beam of a clinical linear accelerator and with the 19 MV X-ray beam of a betatron has been measured at the patient treatment location, using both fission fragment track detectors and silicon diode dosemeters. Measurements are made of the neutron fluence and dose, both in and out of the primary photon beam, at distances up to 60 cm from the central axis. Neutron distributions are similar for the linac and the betatron, with approximately ten times greater neutron dose in the X-ray field than at 20 cm outside it.
20 citations
Patent•
09 Nov 1973
TL;DR: An x-ray beam flattening filter is used in radiation therapy for providing uniform radiation intensity distribution across large linear accelerator produced xray fields, at any depth of treatment within a patient as discussed by the authors.
Abstract: An x-ray beam flattening filter used in radiation therapy for providing uniform radiation intensity distribution across large linear accelerator produced x-ray fields, at any depth of treatment within a patient. The filter includes a solid generally planar filter member, of material semi-permeable to x-rays, and having an accurately defined surface configuration symmetrically oriented about a central axis. The filter member is affixed to a base which is designed for mounting external of the x-ray beam emergence outlet of a linear accelerator for completely intercepting the x-ray beam produced thereby, to accurately and selectively filter x-rays of the beam for producing uniform radiation intensity across the x-ray therapy fields of the accelerator apparatus.
20 citations
TL;DR: In this paper, the high-order polynomial, triangular, finite element method is applied to field calculation in linac cavities of arbitrary longitud - inal cross section. But this method is not suitable for linear accelerators.
Abstract: The design of linear accelerator (linac) cavities necessitates the field solution of axisymmetric electromagnetic resonators. Mathematically this involves the solution of the one-component vector Helmholtz equation in cylindrical coordinates subject to boundary conditions which are dictated by the physics of the electromagnetic field problem. In this paper it is shown how the high-order polynomial, triangular, finite element method can be applied to field calculation in linac cavities of arbitrary longitud - inal cross section.
19 citations
TL;DR: The Argonne electron linear accelerator as discussed by the authors produces a pulse as short as 40 ps in duration with a charge of at least 7 nC (180A in amplitude) for use with experiments in the very "short" time reaction region.
Abstract: We have completed the design and installation of a new bunching system for the Argonne electron linear accelerator originally placed into operation in 1969. It now routinely produces a pulse as short as 40 ps in duration with a charge of at least 7 nC (180A in amplitude) for use with experiments in the very "short" time reaction region. Such a pulse is produced over an energy range of 4 to 20 MeV with an accompanying total energy spread of 300 keV. Frequency of production is variable from one single pulse up to a PRR of 800 P/s. Efficiency of acceleration from the gun to the output of the accelerator is 50 percent. Details of the bunching system, including the method of calculation with space charge inclusion, geometrical factors and hardware, and operational results are given.
16 citations
TL;DR: In this paper, the authors presented a linac which accelerates charged microparticles in the 1-10 μ diam range to meteoric velocities using the Sloan-Lawrence (low-frequency, ac driven) type and contains 92 accelerating gaps with 100 kV accelerating potential applied at each gap.
Abstract: Theory, design parameters, and construction details are presented for a linac which accelerates charged microparticles in the 1–10 μ diam range to meteoric velocities. The linac is of the Sloan‐Lawrence (low‐frequency, ac driven) type and contains 92 accelerating gaps with 100 kV accelerating potential applied at each gap. Particles are injected into the linac after preacceleration by a 1.6 MV modified Van de Graaff, giving a total accelerating potential of 10.8 MV for the system. In a significant departure from conventional accelerator practice, the linac is adapted to single particle operation by employing a square wave driving voltage with the frequency automatically adjusted from 12.5 to 125 kHz according to the variable velocity of each injected particle. Radial focusing is entirely second‐order and is adequate to contain the particle ``beam'' within 1.8 cm diam. Compared to the Van de Graaff alone, the linac provides a particle mass increase of about 300 times for a given velocity, or a velocity increase of about 2.5 times for a given mass.
13 citations
TL;DR: A balloon-borne measurement of the cosmic ray electron spectrum from 10 to 200 GeV is reported in this article, in which two new techniques have been used to remove proton background contamination.
Abstract: A balloon-borne measurement of the cosmic ray electron spectrum from 10 to 200 GeV is reported in which two new techniques have been used to remove proton background contamination. First, the depth of the spectrometer was more than 40 radiation lengths, the equivalent of more than 3 mean free paths of material, enabling hadronically and electromagnetically induced cascades to be differentiated for a subset of the data. Second, electromagnetic cascade starting points were determined to within plus or minus 0.1 radiation lengths on the basis of a calibration with electrons from 5.4 to 18 GeV at the Stanford Linear Accelerator, greatly reducing the chances for a proton to simulate an electron. The resulting spectrum, when fitted with a power law, is quite steep, -3.2 plus or minus 0.1, but the fit to a power law is marginal.
TL;DR: In this article, the computer control system of the National Accelerator Laboratory at the University of California, Los Angeles is described, which utilizes fifteen interconnected computers to control and monitor this equipment.
Abstract: Equipment associated with the accelerator and experimental areas at the National Accelerator Laboratory is distributed throughout some ten miles of beam paths. The computer control system, which utilizes fifteen interconnected computers to control and monitor this equipment, is described. The clock, closed-circuit television, beam abort, and fire and utility monitoring systems are also reviewed.
TL;DR: In this article, the design of a flexible arrangement with good resolution is discussed, and examples are given to illustrate the quality of the experimental results of the experiments with neutrons as primary or secondary particles.
TL;DR: A racetrack microtron whose energy can be varied continuously from 45 to 18 MeV has been built at the University of Western Ontario, and has been operated to full energy.
Abstract: A racetrack microtron whose energy may be varied continuously from 45 to 18 MeV has been built at the University of Western Ontario, and has been operated to full energy Electrons from an external electron gun are injected with an electrostatic inflector, and accelerated in a short sidecoupled linac section The RF power delivered to the linac section can be varied by means of a power splitter, thus allowing the energy gain in the section to be adjusted continuously from 15 to 3 MeV The accelerator can be operated in three different modes: single traversal of the linac section with a final beam energy of 15 to 3 MeV, n = 2 with three traversals of the linac covering the final energy range from 45 to 9 MeV and n = 1 with six traversals of the linac and a corresponding energy range of 9 to 18 MeV The magnetic guide field consists of two 180° magnets with alternating high and low field regions To satisfy the resonance conditions the average induction can be varied up to 06 T and the lengths of the drift space between the magnets can be adjusted by moving the pole pieces of the magnets
TL;DR: In this paper, a superconducting-helix accelerator is described and design considerations are discussed, and the results obtained during 120 hours of beam acceleration are given, including a wealth of practical engineering experience, the demonstration of stable operation with external phase control, and measurements of various kinds of acceleratorphysics data.
Abstract: A prototype superconducting-helix accelerator is described and design considerations are discussed. The results obtained during 120 hours of beam acceleration are given. These include a wealth of practical engineering experience, the demonstration of stable operation with external phase control, and measurements of various kinds of accelerator-physics data.
TL;DR: Initial operating experience with the various high power sub-systems is discussed, and the results of electron beam tests at progressive stages of completion of the linac are presented, including the achievement of an extremely low emittance.
Abstract: Initial operating experience with the various high power sub-systems is discussed, and the results of electron beam tests at progressive stages of completion of the linac are presented. A highly stable analyzed beam containing greater than 85% of the accelerated current has been demonstrated routinely using ±0.11% analyzing slits at both the 20 MeV and 120 MeV stations. Of particular importance, especially for beam transportation and future considerations of beam recirculation, has been the achievement of an extremely low emittance. Beam measurements at the 20 MeV station have confirmed that essentially all of the accelerated current is contained within an emittance of 7±2×10-4 ?moc-cm; i.e., ~0.2 mm mrad at 20 MeV. System checkout is currently in progress to bring the linac up to its maximum operating condition of 430 MeV at a duty factor of 1.8 per cent.
TL;DR: In this article, the difference signals from radial pi induction electrodes located in the eight straight section boxes of the ZGS were used to determine equilibrium orbit warps, and a debunched linac beam was injected in the ring and the eight coasting beam signals were analyzed.
Abstract: The difference signals from radial pi induction electrodes located in the eight straight section boxes of the ZGS are used to determine equilibrium orbit warps. A 1 ?s, debunched linac beam is injected in the ZGS ring and the eight coasting beam signals are analyzed. Since the effective electrode centers and inflector magnet positions are known, one can obtain orbit positions around the ZGS ring. The zero crossing times of all eight coasting beam bow-tie patterns are entered into our CDC-924A computer. The computer graphically displays orbit warps via CRT terminal. An additional feature to be described is that betatron tunes at injection can be very easily obtained from the coasting beam patterns.
TL;DR: The power-current microtron as discussed by the authors, a cyclic electron accelerator up to energies of 30-35 MeV has been developed at the Institute on Physical Problems of the Academy of Sciences of the USSR.
Abstract: Based on studies of variable multiplicity electron acceleration, the power-current microtron, a cyclic electron accelerator up to energies of 30–35 MeV has been developed at the Institute on Physical Problems of the Academy of Sciences of the USSR. The 1–1.5 kW electron beam of the microtron is comparable to the power output of modern linear accelerators operating at similar energies. At the same time, the microtron has a number of significant advantages, due to the simplicity of design of both accelerator and ultrahigh-frequency tract, the high efficiency of ultrahigh-frequency power utilization, good operating characteristics, strictly monochromatic electron beams (variations not exceeding ±50 keV at 30 MeV) and the possibility of continuously changing particle energy as required by the given experimental task.
TL;DR: In this paper, the energy available from a superconducting linear electron accelerator (SCA) may be increased many times by means of an economical multi-orbit recirculation system, which preserves the most desirable characteristics of the SCA: good energy resolution (~10-4), high current and unity duty cycle.
Abstract: The energy available from a superconducting linear electron accelerator (SCA) may be increased many times by means of an economical multi-orbit recirculation system, which preserves the most desirable characteristics of the SCA: good energy resolution (~10-4), high current and unity duty cycle. Furthermore, these properties of the SCA and its excellent emittance considerably simplify the design of the transport system and minimize aperture requirements. In order to maintain energy resolution each orbit of the recirculation system must be isochronous with respect to all phase space variables and beams must be reinjected into the linac precisely at the correct phase. These conditions have been achieved in a compact separated orbit design which uses multi-channel uniform field bending magnets. It is suggested that such a device be called a recyclotron. At HEPL a prototype 4 orbit recirculation system is being planned as part of the SCA program. Cost estimates for machines of this type have been made and show considerable advantage over other types of accelerator, especially at very high energies. The configuration also shows promise as an intermediate energy, high current accelerator, which could provide a source for a medical pion therapy facility.
TL;DR: In this article, the design of a flexible linear accelerator for heavy ions is described, where an array of short, independently phased helix resonators are used with a 4 MV injector having a positive ion source.
Abstract: The design of a flexible linear accelerator for heavy ions is described. An array of short, independently phased helix resonators is used with a 4 MV injector having a positive ion source.
TL;DR: The NAL accelerator achieved design energy of 200 GeV on March 1, 1972 and has operated as high as 400 GeV and regularly operates at 300 GeV as discussed by the authors, achieving the highest intensity to date has been 1.8 × 1012 protons per pulse at 300 GV.
Abstract: The NAL accelerator achieved design energy of 200 GeV on March 1, 1972. Since that time, the main accelerator has operated as high as 400 GeV and regularly operates at 300 GeV. The highest intensity to date has been 1.8 × 1012 protons per pulse at 300 GeV. This beam has been extracted from the accelerator using a half-integral resonance system to give a slow spill over approximately 250 ms. The extracted beam is presently being split and sent into three different experimental areas. In addition, a target area in the main accelerator enclosure allows experiments to be done on the internal, circulating beam.
01 Oct 1973
TL;DR: In this paper, the microwave properties of beams from electron linear accelerators or from possible remodulated external proton beams at proton synchrotrons are used for time measurement.
Abstract: A picosencond time measurement method is described based on the microwave properties of beams from electron linear accelerators or from possible remodulated external proton beams at proton synchrotrons. A conventional RF separator (RFS) is used operating at the same frequency as the microwave structure of beams and driven by the same master oscillator which modulates the beam. For example, the 2856 MHz microwave at SLAC corresponds to 350 psec between beam RF buckets; accelerated electrons with an RF phase bite of about 5 degrees are time structured and correspondingly have about 5 psec time spread in every 350 psec interval. Charged particles produced in interactions or decays originate with this time structure. An RFS is placed at the last stage of a double focussing spectrometer, providing a lever arm between it and the final (few mm) small spot size focus. Reference calibration charged particles are timed by setting the RFS relative phase to null deflections. Other observed particles arriving at different times than this standardare deflected a few tenths ofa anm per psec of delay. A multi-wire proportional chamber (IMPC) having a 0.05 mm space resolution can provide time measurements with sub-picosecond resolution. The technique is used in an experiment to search for changes in the velocity of light with high energy photons at SLAC. The devised timing method is presented and the properties of a new, fine space resolution MWPC is demonstrated.
TL;DR: A prototype linear accelerator treatment unit capable of providing two different electron treatment modalities in addition to 6 MV megavoltage x-ray treatments is described.
Abstract: A prototype linear accelerator treatment unit capable of providing two different electron treatment modalities in addition to 6 MV megavoltage x-ray treatments is described. This unit offers 5 MeV large-field superficial total-body treatment at a SSD of 3.5 m as well as electron treatment at 10 MeV or lower energies for small fields at a SSD of 100 cm.
TL;DR: In this article, the transverse and longitudinal effect in short high current RF buckets of cylindrical geometry and uniform charge distribution are considered in free space, where the beam is radially constructed and free both radially and longitudinally.
Abstract: The transverse and longitudinal effect in short high current RF buckets of cylindrical geometry and uniform charge distribution are considered in free space. Two cases are examined (a) The beam is radially constructed (magnetically) and (b) The beam is free both radially and longitudinally. Transverse expansion of a beam in space with a non-symmetrical conducting boundary is presented.