Stray radiation measurements made at 23 particle accelerator sites are summarized and discussed. Conclusions with regard to safe accelerator operation are drawn, as well as general conclusions regarding radiation dosimetry, maximum permissible levels, and instrumentation. (auth)
DOE Information Bridge
Radiation survey work at the Berkeley Bevatron has been a continuous project of the Health Physics Group since start-up of the accelerator in November 1954. A substantial body of survey data has accummulated, from which a general pattern for the stray radiation field can be constructed. This report includes ...
Energy Citations Database
This book is covered under the following topics: stray light concepts and theory; stray radiation in optical system; BRDF instrumentation; and BSDF data and tests.
Samples of soil, water, aluminum, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper-dump in the Beam Dump East facility at SLAC. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the ...
The dosimetry of stray radiation fields around pulsed accelerators is complicated by the fact that the radiation comes in pulses and by the mixed nature of the radiation usually produced by these accelerators. Suitable instrumentation for pulsed ...
Sources of stray XUV-visible radiation. The plots show the spectral flux for direct illumination by the following sources: ...
NASA Website
The restricted dose mean linear energy transfer (LET) (L500,D) of the stray radiation field a few centimeters outside the treatment volume has been measured for 12 and 18 MV photons produced by a clinical Therac-20 (AECL) accelerator. The measurements were performed as a function of field size and distance from the edge of the ...
PubMed
The stray radiation rejection requirements for the Synchronous Earth Observation Satellite telescope
NASA Technical Reports Server (NTRS)
... a typical conventional cylindrical chemical laser supporting ... an already existing laser damage to the ... additional stray beams of radiation that would ...
DTIC Science & Technology
The production of aluminum can produce large dynamic stray currents in the earth surrounding the production plant. When coated pipelines that are not grounded pass through the dynamic stray current area, they can realize failures at accelerated rates, even with traditional cathodic protection systems in operation. This article tracks a ...
For absorbed- dose computation or optimum- shielding determination, it is necessary to know the energy spectrum of stray x radiation. Stray radiation includes scattered, secondary, and leakage radiation. The objective of this investigation is to provide the spectral data on ...
STRAY-ELECTRON ACCUMULATION AND EFFECTS IN HIF ACCELERATORS R.H. Cohen1,2,* , A. Friedman1,2 , M National Laboratory, Berkeley, CA 94720 4 TechX Corp., Boulder, CO Abstract Stray electrons can- electron emission. Electron accumulation is impacted by the ion beam potential, accelerating fields
E-print Network
With recent developments, X-ray beam position monitors (BPMs) are capable of making accurate photon position measurements down to the sub-micron level. The true performance of X-ray beam position monitors when installed on insertion device beamlines is, however, severely limited due to the stray radiation traveling along the beamline that contaminates the ...
The Advanced Solar Coronal Explorer (ASCE) is a mid-explorer (MidEx) mission selected, together with other five, for the a Phase A Concept Study in the 1999 round of MidEX proposal. ASCE's spacecraft bus is a SPARTAN 400 reusable carrier deployed in low Earth orbit by the Space Shuttle. ASCE's payload comprises two instrument modules, the Spectroscopic and Polarimetric Coronagraph (SPC) and the ...
NASA Astrophysics Data System (ADS)
The aim of this study was to quantify stray radiation dose from neutrons emanating from a proton treatment unit and to evaluate methods of reducing this dose for a pediatric patient undergoing craniospinal irradiation. The organ equivalent doses and effective dose from stray radiation were estimated for a 30.6-Gy ...
PubMed Central
fiber face. glass window. Primary mirror. Secondary mirror. Stray light baffles. NEW! National Aeronautics and Space Administration Radiation Science Program.
Classical radiation from an accelerated charge is reviewed along with the reciprocal topic of accelerated observers detecting radiation from a static charge.
A radiation detection device is designed for detecting overheated bearings of railway carriages by means of their infrared emission. The device uses optical modulators and filters for deriving two separated beams from a radiation superimposed on an undesired or stray radiation and for alternately ...
The proposed superconducting linear accelerator that accelerates muons from 190 MeV to 2.45 GeV will use superconducting solenoids for focusing the muon beam. The accelerator will use superconducting RF cavities. These cavities are very sensitive to stay magnetic field from the focusing magnets. Superconducting solenoids can have large ...
The Argonne Zero Gradient Synchrotron capable of accelerating some 5 x 10/sup 13/ protons per pulse to an energy of 12.5 Bev is due to initiate operation in early 1963. During the planning stages of this facility, Radiation Safety cooperated with the various design groups incorporating control, warning, and monitoring features. Every access to ...
The Langley method has been applied to the measurements of direct solar radiation made by Brewer spectrophotometers to obtain the aerosol optical thickness (AOT) of the atmosphere in the ultraviolet-B range. In several cases the AOT increased with wavelength, which raises suspicion about the stray-light effect. To investigate the quality of the AOT ...
Effects of stray electrons are a main factor limiting performance of many accelerators. Because heavy-ion fusion (HIF) accelerators will operate in regimes of higher current and with walls much closer to the beam than accelerators operating today, stray electrons might have a large, detrimental ...
... RADIATION, SOURCES, SYMPOSIA, SYNCHROTRONS, ELECTRON ACCELERATORS, LINEAR ACCELERATORS, ELECTRON OPTICS ...
The interference of stray electrons (also called �electron clouds�) with accelerator beams is important in modern intense-beam accelerators, especially those with beams of positive charge. In magnetic wigglers, used, for instance, for transverse emittance damping, the intense synchrotron radiation produced by ...
Everyday features of the accelerator environment include long cable runs, high power and low level equipment sharing building space, stray electromagnetic fields and ground voltage differences between the sending and receiving ends of an installation. Thi...
National Technical Information Service (NTIS)
Superconducting accelerator magnets usually have magnetic iron yokes to obtain maximum magnetic field and to limit stray field. However, the iron is expensive and heavy. The smaller size and weight of an iron-free magnet can result in lower magnet and ref...
A paint for protection against stray radiation was tested. The paint in question consists of three coatings, namely, lead suboxide as a basic coating, iron oxide as an intermediate layer, and titan white as the top coating. It was found that, when the base board was merely plywood, the amount of stray ...
We review the current and future accelerator technologies for generation of high brightness radiation beam.
... with respect to nuclear radiation event rate, adequate off-axis distance from strong potential sources of stray light, and satellite scanning rate. ...
... was conducted by using survey data that spanned an 8-y period (1978-1985) in conjunction with operator dose equivalent and exposure estimates ...
ghosts (false spectral lines), stray or scattered radiation, ... false spectral lines (ghosts). 3. Gratings can be fabricated free of optical aberrations, ...
... on the telescope primary mirror is the principal source of stray radiation and the bidirectional reflectance distribution function (BRDF) of the primary ...
The dosimetry of small fields as used in stereotactic radiotherapy, radiosurgery and intensity-modulated radiation therapy can be challenging and inaccurate due to partial volume averaging effects and possible disruption of charged particle equilibrium. Consequently, there exists a need for an integrating, tissue equivalent dosimeter with high spatial resolution to avoid ...
Stray electrons can be introduced in positive-charge accelerators for heavy ion fusion (or other applications) as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. Electron accumulation is impacted by the ion beam potential, accelerating fields, ...
Quantitative data are presented on the effectiveness of interference filters for reduction or elimination of stray light effects in optical spectrometers employed for trace atomic emission analyses. Specific attention is focused on those analyte species that contribute significant stray light at wavelengths far removed from the offending ...
Charge coupled devices (CCDs) are being increasingly used in radiation therapy for dosimetric purposes. However, CCDs are sensitive to stray radiation. This effect induces transient noise. Radiation-induced noise strongly alters the image and therefore limits its quantitative analysis. The purpose of this work is ...
Cryogenic space remote sensor(CSRS), working on the Sun-synchronous orbit, is used to make observation of deep space and implement scientific research tasks. To observe small targets in deep space, CSRS should have quite low noise. Stray light is a major part of noise that affects the imaging quality, therefore, stray light control is a critical part of ...
A test procedure is described that has been used to determine if casing (tubulars) from various mills will corrode in a general or pitting-type pattern. The equipment required to run the test is relatively inexpensive and gives meaningful results in one to two weeks. The Stray Current Accelerated Test (SCAT) accelerates the corrosion ...
This report discusses the following topics: Composition of Accelerator Radiation Fields; Shielding of Electrons and Photons at Accelerators; Shielding of Hadrons at Accelerators; Low Energy Prompt Radiation Phenomena; Induced Radioactivity at Accelerators...
We find that quasiparticle generation from stray infrared light creates a significant loss mechanism in superconducting resonators and qubits. We show that resonator quality factors and qubit energy relaxation times are limited by a quasiparticle density of approximately 200 ?m-3, induced by 4 K blackbody radiation from the environment. We demonstrate how ...
frequencies by the stray acceleration noise in the orbits of the nominally free-falling test masses that serve#12;guration and is not present in LISA. Limiting this noise source requires both high actuation voltage stray force sources with LTP Several key random force noise sources are plotted in Fig. 2 for LTP
... SHIELDING), (*NUCLEAR RADIATION, SHIELDING), LINEAR ... HAZARDS, MATERIALS, SAFETY ... NUCLEAR RADIATION SHIELD, PROTECTION & ...
This report discusses the following topics: Composition of Accelerator Radiation Fields; Shielding of Electrons and Photons at Accelerators; Shielding of Hadrons at Accelerators; Low Energy Prompt Radiation Phenomena; Induced Radioactivity at Accelerators; Topics in ...
A time-of-flight mass spectrometer is designed with means for eliminating stray ions. In the mass spectrometer, ionized particles are accelerated at right angles to their initial velocity and collected at a point in the path of the resultant velocity. (D.L.C.)
The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of ad...
Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the e...
As the Stanford Synchrotron Radiation Lightsource (SSRL) of the SLAC National Accelerator Laboratory (SLAC) is moving toward Top-Off injection mode, SLAC's Radiation Protection Department is working with SSRL on minimizing the radiological hazards of this mode. One such hazard is radiation that is created ...
In the first chapter, terminology, physical and radiological quantities, and units of measurement used to describe the properties of accelerator radiation fields are reviewed. The general considerations of primary radiation fields pertinent to accelerators are discussed. The primary radiation ...
... joint planning, national and international ... ETA (Experimental Test Accelerator) Beam Channel. ... BEAMS, *PARTICLE ACCELERATORS, RADIATION ...
Critical UV applications such as disinfections and dermatological treatments call for accurate UV spectral irradiation measurements. Single monochromators and spectrographs are not able to provide satisfying accuracy due to poor stray light rejection. The main drawbacks of a double monochromator scanning system are the need for motion synchronization, the inconvenience in ...
... Development of a linear accelerator for production of a bunched ... This accelerator was ... Calibration of an analyzing magnet intended to produce, by ...
An environmental test chamber providing acceleration of UV radiation and precise temperature control
Because of its advantageous depth-dose relationship, proton radiotherapy is an emerging treatment modality for patients with liver cancer. Although the proton dose distribution conforms to the target, healthy tissues throughout the body receive low doses of stray radiation, particularly neutrons that originate in the treatment unit or in the patient. The ...
... IRRADIATION, LOW PASS FILTERS, RADIATION DOSAGE, CAPACITANCE, ELECTRON ACCELERATORS, LINEAR ACCELERATORS. ...
Spurious response in a scanning optical system was traced to various pathways for stray radiation. The term 'spurious response' refers to any false pulses appearing in the signal-train of an electrooptical system. Such responses can result from a variety of stray light paths. A description is given of a particular scanning optical ...
This report discusses: accelerators; radiation; radiation from accelerator operations; calculation and control of radiation from accelerator operations; radiation considerations in the design of the SSC; and reporting requirements and historical ...
Superconducting accelerator magnets usually have magnetic iron yokes to obtain maximum magnetic field and to limit stray field. However, the iron is expensive and heavy. The smaller size and weight of an iron-free magnet can result in lower magnet and refrigeration costs. However in a colliding beam accelerator the ...
INO has extensive experience in the design and fabrication of focal plane arrays (FPAs) of uncooled microbolometers. In particular, the FPA of 512�3 microbolometers, developed in collaboration with the Canadian Space Agency (CSA), has been selected for use in the NIRST (New Infrared Sensor Technology) radiometer of the SAC-D Aquarius mission. The FPA has been designed for pushbroom scanning of ...
... radiation facilities, (3) free electron lasers, (4) accelerator applications, (5) radiation monitoring and safety, (6) high energy hadron accelerators and ...
Tests SLAC National Accelerator Laboratory About FACET Home What Is FACET? Research Plasma Wakefield Acceleration THz Radiation Plasma Focusing Dielectric Wakefield Acceleration...
Science.gov Websites
... neutrons. A linear accelerator provided the radiation for both tests (10-Mev electrons and uranium photoneutrons respectively). ...
... Descriptors : *NUCLEAR RADIATION, *ELECTRON BEAMS, *LINEAR ACCELERATORS, TRANSISTORS, DAMAGE, SOLID STATE PHYSICS ...
... Descriptors : *SYNCHROTRON RADIATION, *BETATRONS, *EMISSION, POLARIZATION, ACCELERATION, ENERGY, INTENSITY, TIME ...
... with microscopic particles; 2 ... COHERENT RADIATION, INTERACTIONS), (*ELECTROMAGNETIC RADIATION, *PARTICLE ACCELERATORS), GAS ...
Measurements of outgassing have been made from Martin black and a variety of diffuse absorptive baffle materials under development for radiation resistant stray light management. Outgassing measurements were made during pumpdown from atmosphere at room te...
Tables worked out in accordance to the dimensioning method following DIN 54113 are given for the determination protective barriers thicknesses against effective and stray radiation in practical operation conditions. The tables comprise irradiation operati...
An improved sample holder is designed for a nuclear magnetic resonance apparatus. The sample holder permits the manipulation of both the coil and sample relative to the magnet pole faces and has electrostatic and magnetic flux shielding to prevent pickup of stray radiation. (D.J.C.)
The Spatial Infrared Imaging Telescope III (SPIRIT III) sensor on the Midcourse Space Experiment (MSX) satellite observed stray radiation from the lower atmosphere and terrestrial surface, nonrejected Earth radiance, at angles of approximately 2 to 14 deg...
The most common sources of error in optical pyrometry are examined. They can be classified as either noise and uncertainty errors, stray radiation errors, or speed-of-response errors. Through judicious choice of detectors and optical wavelengths the effec...
Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in th...
Proton beam radiotherapy unavoidably exposes healthy tissue to stray radiation emanating from the treatment unit and secondary radiation produced within the patient. These exposures provide no known benefit and may increase a patient's risk of developing a radiogenic cancer. The aims of this study were to calculate doses to major ...
A method is developed for calculating the quantum radiation from accelerated bodies with a mirror boundary. Expressions are derived for G and Gren for a scalar field in the radiation zone.
... the beam covering about four TLD's fairly evenly ... RADIATION HARDENING, LINEAR ACCELERATORS, DOSIMETRY, RADIATION RESISTANCE ...
... iiances These are discussed in the next section. B. Radiation Belt Dynamics ... getic protons in the earth's radiation belts. ...
Stray electrons can arise in positive-ion accelerators for heavy ion fusion or other applications as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary- electron emission. We summarize resu...
Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power ...
Everyday features of the accelerator environment include long cable runs, high power and low level equipment sharing building space, stray electromagnetic fields and ground voltage differences between the sending and receiving ends of an installation. This paper pictures some Fermilab installations chosen to highlight significant features and presents ...
Fiber-coupled organic plastic scintillators enable on-line dose rate monitoring in conjunction with pulsed radiation sources like linear medical accelerators (linacs). The accelerator, however, generates a significant amount of stray ionizing radiation. This radiation ...
The movement of electrons or positrons in an accelerator along a curved trajectory is accompanied by continuous radiation of electromagnetic energy. The movement of electrons in a central force field of the atomic nuclei is not accompanied by continuous radiation. In atomic systems only quantum radiation, ...
Stray light is one of the major limitations in fiber-optic probes toward achieving better accuracy and higher sensitivity. Natural reflection off surfaces of the optical components can be reduced by using an index-matching fluid. The residual stray light can be further suppressed by high-frequency modulation and phase discrimination, since light returning ...
Topics by chapter title include: fundamental particles and their interactions with matter; radiation fields: their specification and measurement; particle accelerators and their radiation environments; human response to ionizing radiation; the measurement of radiation fields- ...
