Linac Research Papers - Academia.edu (original) (raw)

The low phase-noise master oscillator (MO) generates and distributes the various frequencies required for the LLRF system controlling ILC Test Accelerator (ILCTA) cavities. Two chassis have been developed for this design, generating the programmable frequencies and performing the distribution and amplification, respectively. It has been successfully used with the SNS and the DESY-SIMCON LLRF systems, driving two different superconducting cavities. The design approach and characterization of the master oscillator are presented in this paper. The measurement results include the phase and amplitude noise spectrums of the multiple frequency outputs.

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- Linac

- by Julien Branlard
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- Linac
- by Daniel Roos
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- Radiosurgery, Survival Analysis, Adolescent, Hospitals
- by Muhammad Irfan
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- Linac, Cobalt, K3, Kesehatan Dan Keselamatan Kerja
- by Fernando Mirapeix
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- Linac, Power Couplers, IFMIF, Fernando Mirapeix

Magnets to be used for the internal quadrupoles of an interdigital H-mode drift tube linear accelerator (IH-DTL) using KONUS beam dynamics should be both compact in size and high in focusing field gradient. Permanent magnets are an attractive solution, but then the ability to adjust the field strength is lost. We investigated two different solutions to this problem: the first using external adjustable electromagnets; the second using internal adjustable permanent magnets. The first method moves the variability out of the resonant cavity, using adjustable electromagnet quadrupole doublets before entry into the IH-DTL to compensate for the lack of internal variability. We carried out optimization simulations with custom code that ran many instances of the LORASR beam dynamics simulation software, using different values of field strength for the external doublets. By optimizing the magnet settings for different values of input current, we were able to compensate for the space-charge forces involved in accelerating a high-intensity continuous-wave (CW) deuteron beam. Second, we designed some novel adjustable permanent-magnet quadrupoles to be used inside the cavity, which combine the advantages of small cross-section and variable field gradient. This allows much more control over the beam, and even other ion species with differing charge-to-mass ratios can be accommodated within the same accelerator design. We developed two adjustable permanent-magnet designs: one with an electromagnetic component, and the other with two concentric moving rings of Halbach-array quadrupoles.

- by Matt Easton and +2
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- Linac, Permanent Magnets, Magnets, Particle Accelerator
- by Hector Rene Vega-Carrillo
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- Monte Carlo, Linac, Clinical Sciences
- by Paolo Puggioni
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- Linac
- by Hector Rene Vega-Carrillo
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- Analytical Chemistry, Inorganic Chemistry, Monte Carlo, Linac
- by Graeme Melville
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- Cancer treatment, Linac, Cancer Therapy, Scaling up
- by R. Block
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- Geochemistry, Imaging, Linac, Medical Linear Accelerator
- by Barry Allen
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- Cancer treatment, Linac, Cancer Therapy, Scaling up
- by man Li
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- Magnetic Resonance Imaging, Colorectal cancer, Humans, Linac
- by Gary Luxton
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- Physics, Radiosurgery, Comparative Study, Humans

Future ion accelerators for fundamental and for applied research will need a significant improvement in injector capabilities. While the pulsed acceleration of intense proton beams has a long tradition, a reduction of linac faults as well as an increase in beam transmission, stability and brilliance is needed for new facilities. The international FAIR facility at GSI Darmstadt will include a antiproton research program. The needed intensities can be provided only by adding a high current proton injector to the existing synchrotron SIS 18. This injector is designed for 70 MeV end energy at a current limit of 70 mA. A 350 MHz, 3 MeV RFQ will inject into the 350 MHz CH - DTL, which will accelerate the protons to 70 MeV within about 22 m. 6 commercial 3 MW klystrons will feed the CH-DTL. Each RF amplifier drives one resonator consisting of two CH-modules coupled by a short central coupling module. This concept led to a significant cost reduction for RF equipment and accelerator fabricat...

- by Ulrich Ratzinger
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- Linac
- by Alex Blas
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- Linac, Vacuum, Ion, Injection
- by R. Block
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- Imaging, X-ray imaging, Linac, CCD camera

We consider possible configurations for injection of photocathode-produced electron beams straight into linear accelerating sections. A slightly convergent beam into the linac is required for maximum transmission through the linac sections and therefore a solenoid pair is considered. We describe strategies for placing the rf gun injector and the strength of the solenoids so as to minimize the emittance growth

- by Harold Kirk
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- Physics, Linac, Acceleration, Medical Linear Accelerator
- by S. Zavgorodni and +1
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- Radiosurgery, Adolescent, Humans, Child
- by Derick Aranda and +1
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- Clinical Neuroscience, Radiosurgery, Head and Neck, Humans
- by John Buatti
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- Algorithms, Radiosurgery, Optimization, Humans
- by Daniel Roos
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- Radiosurgery, Adolescent, Humans, Child

The Linear particle accelerator (LINAC) is a tool for radiation therapy that can emit photons and electrons. Radiation of X-ray photons and LINAC electrons is obtained from the interaction of electrons fired into the target plate (tungsten). This radiation can not only affect the target organ but can also affect unwanted organs around the exposure area. Radiation irradiation effects on the organs in the exposure area can be known through simulation of LINAC and phantom radiation processes. Simulation and calculation using Monte Carlo method. This program is operated by MCNPX software. Phantom geometry uses the phantom ORNL MIRD, whereas linac geometry consists of linac blankets, tungsten plates and collimators. Radiation from linac is directed to the left lung as a target and from the simulation results of traces of radical particles shows that radiation emission from linac there are some scattering, but scattering this does not have a significant impact because the amount is not too large. Radiation effect on the organs is indicated by the effective dose quantities in which the left lung has a greater effective dose than the surrounding organs. While the right lung gets a large enough effect from other organs around the target organ. This is because the organ is located close to the target organ and has a smaller type of meeting of the other organs. Not so with the ribs, although it is the first organ exposed to radiation. Radiation that concerns the ribs has no significant effect. This is because of the enormous type of meeting. The effects of radiation on organs are not only influenced by the size of the meeting of organ types but also influenced by the weight factor.

- by David Grote
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- Transport, Linac, Acceleration, Lattices
- by Roland Garoby
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- Linac, Synchrotron, Prospective Study
- by MALA DAS
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- Linac, Metastability, Spectrum, Ambient Temperature
- by Mariana Hernandez Hernandez
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- Surgery, Magnetic Resonance Imaging, Radiosurgery, MRI

The Spallation Neutron Source (SNS) is being designed for operation in 2004. The SNS is a 1 GeV machine consisting of a combination normal-conducting and super-conducting linac as well as a ring and target area. The linac front end is a... more

- by Amy Regan
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- Control system, Linac
- by Simone Maria Liuzzo
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- Accelerator Physics, Monte Carlo Simulation, Matlab, IORT
- by Richard York
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- Materials Engineering, Environmental Science, Condensed Matter Physics, Design
- by jesus velazquez
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- Monte Carlo, Linac, Clinical Sciences
- by Waclaw Gudowski
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- Linac, Spectrum, Reaction Rate, Particle Acceleration
- by Peter Lindvall
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- Neurosurgery, Adolescent, Humans, Linac
- by Peter Lindvall
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- Neurosurgery, Adolescent, Humans, Linac

RF CONTROL REQUIREMENTS FOR THE CEBAF ENERGY UPGRADE CAVITIES* C. Hovater, J. Delayen, L. Merminga, T. Powers, C. Reece, Jefferson Lab, Newport News, VA Abstract ... In addition we would like to thank Sherry Thomas with the poster design.... more

- by JEAN DELAYEN
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- Control system, Linac, Medical Linear Accelerator, Lorentz Force

ÖZ Soda-lime cam örneklerin optik geçirgenlik ve soğurma spektrumları 8 MeV elektron ve γ-ışını demetlerine maruz bırakılması sonrasında çalışıldı. Elektron demeti üretimi için modifiye klinik LINAC kullanılırken buna karşılık γ-ışını kaynağı olarak 60 Co kullanıldı. Cam numunelerin optik özellikleri, farklı dozlar ve radyasyon türleri için analiz edildi. Her iki durumda da cam örneklerinde radyasyonun sebep olduğu renk merkezleri gözlendi. Dahası da, ışınlama kaynağı kapatıldıktan sonra zamana bağlı optik özellikler de elde edilerek bu renk merkezlerinin oda sıcaklığında bile yavaşça kaybolduğu gözlendi. 8 MeV elektron ve γ-ışını demetlerine maruz bırakılan örneklerin optik geçirgenlik spektrumu, görünür bölgede sıradışı soğurma bandı göstermektedir. Öte yandan, ışınlanmış numuneler 100 °C' nin üzerinde kısa bir süre fırınlanınca bu soğurma bantları neredeyse kaybolmaktadır. Anahtar Kelimeler: ışınlama, soda-lime cam, gama, elektron demeti, LINAC ve 60 Co Optical properties of the electron and gamma-ray irradiated soda-lime glass samples ABSTRACT Optical transmission and absorption spectra of Soda-lime glass samples were studied after irradiation by 8 MeV electron and γ-ray beams. We used modified clinical LINAC for production of electron beam whereas 60 Co was used as a γ-ray source. Optical properties of glass samples were analyzed for different doses and radiation types. Irradiation induced color centers in the glass samples were observed in both cases. Moreover, time-dependent optical properties were also acquired after irradiation source was turned off and we observed that these colour centers disappear slowly even at room temperature. Optical transmission spectra of 8 MeV electron and γ-ray beam irradiated samples show spectacular absorption band in the visible region. On the other hand, these absorption bands nearly recover themselves when the irradiated samples are baked for a short time above 100 • C.

- by Gülten Onay
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- Optics, Linac, Cobalt- 60
- by An-cheng Shiau
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- Chemical Engineering, Monte Carlo Simulation, Linac
- by Eric Norum
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- Biomedical Engineering, Linac, Acceleration, Medical Linear Accelerator
- by MALA DAS
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- Linac, Metastability, Clinical Sciences, Spectrum

A big effort in R&D focused to the LINAC devices
together with the know-how already deployed through
emblematic projects, places DMP in the state of the art of
the extreme precision mechanics. This mechanic culture
makes DMP a natural partner in early stages of design or
driver of a comprehensive solution, optimizing industrial
risks, quality and due date. Surface roughness below
1 nanometer, figure errors better than 50 nanometers in
OFE copper enhances lifetime and performance of many
devices for LINACs. Research in joining techniques and
combining several alternative technologies to traditional
machining, improves figure stability and makes complex
cooling systems possible.

- by Fernando Mirapeix
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- Precision manufacturing, Ultra High Vacuum Systems, Linac, Particle Accelerator
- by lingga putra
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- Computer Science, Physics, Finite element method, Finite Element
- by Larry Rybarcyk
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- Painting, Linac, Dynamic Simulation, Ring
- by deepak raparia
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- Design, Proceedings, Linac, Arm
- by T. Raubenheimer
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- Linac, Medical Linear Accelerator, Center of Mass, Linear collider

EPID images acquired in cine mode during arc therapy have inaccurate gantry angles recorded in their image headers. In this work, methods were developed to assess the accuracy of the gantry potentiometer for linear accelerators. As well, assessments of the accuracy of other, more accessible, sources of gantry angle information (i.e., treatment log files, analysis of EPID image headers) were investigated. The methods used in this study are generally applicable to any linear accelerator unit, and have been demonstrated here with Clinac/Trilogy systems. Gantry angle data were simultaneously acquired using three methods: i) a direct gantry potentiometer measurement, ii) an incremental rotary encoder, and iii) a custom-made radiographic gantry-angle phantom which produced unique wire intersections as a function of gantry angle. All methods were compared to gantry angle data from the EPID image header and the linac MLC DynaLog file. The encoder and gantry-angle phantom were used to valida...

- by Peter McCowan
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- Algorithms, Humans, Computer Simulation, Linac
- by Johannes Kuchta
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- Computed Tomography, Adolescent, Parameter estimation, Brain
- by Johannes Kuchta
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- Computed Tomography, Adolescent, Parameter estimation, Brain
- by kiyoshi yoda
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- Biomedical Engineering, Construction Materials, Biomedical, X Rays
- by R. Block
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- Geochemistry, Imaging, Linac, Medical Linear Accelerator