Three different intensity monitors were tested in the external proton beam at LAMPF, and together cover the entire range of beam currents available. A 800 kg Faraday cup was installed and used to measure the absolute intensity to better than 1 percent for...
National Technical Information Service (NTIS)
The CEBAF accelerator delivers a CW electron beam at fundamental 1497 MHz, with average beam current up to 200 {mu}A. Accurate, stable nonintercepting beam current monitors are required for: setup/control, monitoring of beam current and ...
DOE Information Bridge
time and the movement of the beam at a rate of 3.5per minute. ..... temperatures , voltages, and currents); and to determine the spacecraft attitude solution ...
NASA Website
This paper describes the design, construction, and testing of a probe for the measurement of electric current in a circuit. This measurement is performed by using Faraday rotation produced in a beam of polarized light that encircles the current-carrying c...
Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe ({Delta}x {approximately} 10{mu}m), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will ...
The future experimental program at Jefferson Lab requires an absolute current calibration of a 1{mu}A CW electron beam to better than 1% accuracy. This paper presents the mechanical and electrical design of a Tungsten calorimeter that is being constructed to provide an accurate measurement of the deposited energy. The energy is ...
The future experimental program at Jefferson Lab requires an absolute current calibration of a 1 {mu}A CW electron beam to better than 1% accuracy. This paper presents the mechanical and electrical design of a Tungsten calorimeter that is being constructed to provide an accurate measurement of the deposited energy. The energy is ...
AURORA is an electron storage ring of the weak focusing type composed of a single body superconducting magnet and does not allow the use of a conventional method for the measurement of stored beam current. A new method has been developed, in which the power conservation in the RF accelerating system and the normalized load impedance are taken into account ...
NASA Astrophysics Data System (ADS)
We report on the implementation of a beam charge, transverse beam position and bunch length measurement system for low energy electrons in the CESR injector. The core of the instrument is a piece of scintillating ceramic made from chromium doped alumina with a 200� gold layer. Charge and current is measured when the ...
Clouds of stray electrons are ubiquitous in particle accelerators and frequently limit the performance of storage rings. Earlier measurements of electron energy distribution and flux to the walls provided only a relative electron-cloud density. We have measured electron accumulation using ions expelled by the beam. The ion energy distribution maps the depressed ...
PubMed
Clouds of stray electrons are ubiquitous in particle accelerators and frequently limit the performance of storage rings. Earlier measurements of electron energy distribution and flux to the walls provided only a relative electron cloud density. We have measured electron accumulation using ions expelled by the beam. The ion energy distribution maps the depressed ...
The absolute cross sections for the double, triple, and quadruple ionization of Rb/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 3000 eV. This determination has been accomplished using a crossed-beam facility in which monoenergetic beams of ions and electrons are caused to ...
Energy Citations Database
... on GaAs(1-x)P(x) LEDs (Light Emitting Diodes). ... wavelength, absolute and relative light output intensities ... A simple model of LED current controlling ...
DTIC Science & Technology
For the past year or so we have been examining the properties and limitations of the beam bugs in use in the ETA program at LLNL with a view toward improving the accuracy of beam position and current measurements. When considering measurements of beam position, it is very important to distinguish between relative ...
A beam current monitor system was developed to measure the CW electron beam current delivered to the CEBAF Hall A. The experiments require non-invasive measurements during beam delivery, with an absolute accuracy better than 0.2% in the current range ...
A mobile self-contained Faraday cup system for beam current measurments of nominal 600 MeV protons was designed, constructed, and used at the NASA Space Radiation Effects Laboratory. The cup is of reentrant design with a length of 106.7 cm and an outside ...
A technique to determine the number and current density of MeV protons in an intense beam was tested on the GAMBEL II generator. Diode current and voltage and an absolute measurement of K-line radiation emitted from a 6 ..mu..m thick aluminum target were used to determine the number and current ...
A technique to determine the number and current density of MeV protons in an intense beam was tested on the GAMBLE 2 generator. Diode current and voltage and an absolute measurement of K-line radiation emitted from a 6 micrometer thick aluminum target were used to determine the number and ...
A technique to determine the number and current density of MeV protons in an intense beam was tested on the GAMBLE II generator. Diode current and voltage and an absolute measurement of K-line radiation emitted from a 6-micron-thick aluminum target were used to determine the number and current ...
A technique to determine the number and current density of MeV protons in an intense beam was tested on the GAMBLE II generator. Diode current and voltage and an absolute measurement of K-line radiation emitted from a 6 micrometer thick aluminum target were used to determine the number and ...
Over the last few years, electron beam ionization has been shown to be a viable generator of high density plasmas with numerous applications in materials modification. To better understand these plasmas, we have fielded electron beam diagnostics to more clearly understand the propagation of the beam as it travels through the background ...
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 expelled ions that are originated from the beam-background gas interaction, rather than by measuring ...
Electron beam temperature, {beta}{perpendicular} (= v{perpendicular}/v), is important to control for the development of high dose flash radiographic bremsstrahlung sources. At high voltage (> 5 MV) increasing electron beam temperature has a serious deleterious effect on dose production. The average and time resolved behavior of ...
The performance of Free-Electron Lasers depends critically on the quality of the alignment of the electron beam to the wiggler's magnetic axis and the deviation of this axis from a straight fine. The measurement of the electron beam position requires numerous beam position monitors in the wiggler, where space is at premium. ...
This article gives a detailed description of a single shot electron spectrometer which was used to characterize electron beams produced by laser-plasma interaction. Contrary to conventional electron sources, electron beams from laser-plasma accelerators can produce a broad range of energies. Therefore, diagnosing these electron spectra requires specific ...
... CURRENT UNDERSTANDING OF THE ABSOLUTE MEASUREMENTS OF THE AMOUNT, FREQUENCY SPECTRA, AND WAVE FORMS OF THE ...
In this work, an absolute distance measurement method based on the self-mixing interference is presented. The principles of the method used three-mirror cavity equivalent model are studied in this paper, and the mathematical model is given. Wavelength modulation of the laser beam is obtained by saw-tooth modulating the infection ...
... The beam current monitoring system at the ... No dependence on beam current was ... DOSIMETERS), ELECTRON BEAMS, NUCLEAR SCATTERING ...
A pulse generator comprises a toroid of a superconducting material such as niobium on a glass or ceramic substrate. A cryogenic source such as liquid helium cools the toroid to within a few degrees of absolute zero and a perpetually circulatory current is set up in the toroid. A laser beam is fired at the toroid to cause localized ...
A technique to determine the number and current density of MeV protons in an intense beam was tested on the GAMBLE II generator. Diode current and voltage and an absolute measurement of K-line radiation emitted from a 6 micrometer thick aluminum target we...
A method for absolute dose rate determinations in the range of 10/sup 7/ rad (Si) s/sup -/1 to greater than 10/sup 1/0 rad (Si) s/sup -/1 is reported here. The method is useful in determining the simultaneous dose rate delivered to a device under test which is small enough that it does not significantly affect the beam current. The ...
LEDs of the ternary alloy GaAs(.7)P(.3), were irradiated with a 30 MeV electron beam. The effects this exposure had on peak wavelength, absolute and relative light output intensities, and current-forward bias characteristics were studied. A simple model o...
Relative and absolute populations of 19 levels in beam-foil-excited neutral helium at 0.275 MeV have
NASA Technical Reports Server (NTRS)
In this paper we have demonstrated absolute wavelength tuning in an optical fiber multiwavelength filter based on a polarization-diversity loop structure by controlling electrical currents injected into enameled wires wound on polarization-maintaining fibers (PMFs), that is, adjusting Joule heat generated from current-flowing enameled ...
The potential for understanding spectacular stellar explosions such as novae, supernovae, and X-ray bursts will be greatly enhanced by the availability of the low-energy, high-intensity, accelerated beams of proton-rich radioactive nuclei currently being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge ...
Electron accelerator sources of radiation for industrial processes must maintain constant and reproducible irradiation parameters in order to provide satisfactory dose quality assurance. The advanced control system used in AECL's IMPELATM series of accelerators ensures this by making it possible to decouple the primary accelerator variables, beam energy and ...
A new type of beam transformer, based on the principle of a Cryogenic Current Comparator (CCC), was built to measure extracted ion beams from the SIS, the heavy ion synchroton at GSI. A current resolution of 0.006-0.065 nA/{radical}(Hz), depending on the frequency range, could be achieved allowing us to measure ion ...
A new 14.0 GHz electron-cyclotron resonance ion source, the so-called Caprice source, has been in operation at JPL/Caltech for over a year. The source produces ample currents of multiply-charged ions (MCIs) for atomic-physics measurements, in particular of MCIs that are of astrophysical interest. Studies at JPL are carried out using Caprice and a three-way ...
The absolute cross sections for the single, double, triple and quadruple ionization of Cs/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 5000 eV. This determination has been accomplshed using a crossed beam facility in which monoenergetic beams of ions and electrons are caused ...
The absolute instability is a subject of considerable physics interest as well as a major source of self-oscillations in the gyrotron traveling-wave amplifier (gyro-TWT). We present a theoretical study of the absolute instabilities in a TE01 mode, fundamental cyclotron harmonic gyro-TWT with distributed wall losses. In this high-order-mode circuit, ...
We have developed a Mott electron polarimeter for the Mainzer microtron (MAMI) accelerator in Mainz, Germany. At beam energies ranging between 1.0 and 3.5 MeV two double focusing magnet spectrometers collect elastically backscattered electrons from gold targets. In spite of the small spectrometer acceptance, a sufficient statistical efficiency is achieved to provide very fast ...
The absolute differential cross section for the {sup 2}H({gamma},{ital p}){ital n} reaction has been measured using a large solid angle detector, with a tagged photon beam of mean energy 67 MeV. The data have been compared with nine different theoretical calculations of the cross section, which account for the data to varying degrees. Best agreement is ...
We present an analysis of a free-electron laser within a three-dimensional model, in which the finite transverse dimensions of the electron beam are taken into account together with the confinement of the electromagnetic modes by a guiding structure. The analysis is based on the expansion of the beam's self-potential into an infinite set of modes ...
The Muon Ionization Cooling Experiment (MICE) is an experiment currently under construction at the Rutherford Appleton Laboratory (RAL) in the UK. The aim of the experiment is to demonstrate the concept of ionization cooling for a beam of muons, crucial for the requirements of a Neutrino Factory and a Muon Collider. Muon cooling is achieved by measuring ...
Very high dose per pulse (3-13 cGy/pulse) high energy electron beams are currently produced by special linear accelerators (linac) dedicated to Intra Operative Radiation Therapy (IORT). The electron beams produced by such linacs are collimated by special Perspex applicators of various size and cylindrically shaped. The biggest problems ...
An integrated dosimetry and cell irradiation system (IDOCIS) with laser-accelerated proton beams was developed, characterized, calibrated and successfully used for systematic in vitro experiments. Due to the broad exponentially shaped energy spectrum, the low-energy range of the protons (<20 MeV) and the high pulse dose, the absolute dosimetry for this ...
The average power in the LAMPF primary beam is now approximately 450 kW. At these power levels errant beams can quickly destroy accelerator or experimental area beam line components, while the long-term deposition of even a small fraction (<<1%) of the beam energy in unintended locations can result in ...
Modern diagnostic techniques provide detailed information on beam conditions in injector, transport, and final focus experiments in the HIF-VNL. Parameters of interest include beam current, beam energy, transverse and longitudinal distributions, emittance, and space charge neutralization. Imaging techniques, based ...
... Accession Number : ADD316386. Title : FINITE ELEMENT MODELING OF ABSOLUTE EDDY CURRENT PROBE SIGNALS. Corporate Author : ...
Laboratory high energy density experiments using ion beam drivers rely upon the delivery of high-current, high-brightness ion beams with high peak intensity onto targets. Solid-state scintillators are typically used to measure the ion beam spatial profile but they display dose-dependent degradation and aging ...
Nuclear design studies have been performed for two reactor-based epithermal neutron beams for cancer treatment by neutron capture therapy (NCT). An intermediate-intensity epithermal beam has been designed and implemented at the Brookhaven Medical Research Reactor (BMRR). Measurements show that the BMRR design predictions for the principal characteristics ...
The 3 GeV rapid cycling synchrotron (RCS) at Japan Proton Accelerator Research Complex is already in user operation stage, delivering a stable and relatively high power beam to the Material and Life Science Experimental Facility as well as to the main ring. RCS utilizes multiturn H- charge-exchange injection for which a hybrid-type boron doped carbon stripper foil known as HBC ...
CEBAF accelerator delivers continuous wave (CW) electron beams to three experimental Halls. In Hall A, all experiments require continuous, non-invasive current measurements and a few experiments require an absolute accuracy of 0.2 % in the current range from 1 to 180 {micro}A. A Parametric ...
The pulse spreading of the forward propagating absolute instability in gyro-peniotron interaction can be utilized to provide the feedback mechanism for establishing forward wave oscillators. By properly choosing the interaction length and beam current, high efficiency stable output at high harmonic operation can be attained. This is ...
... Abstract : Absolutely uniform illumination of spherical laser fusion pellets is possible when the energy deposition from a single laser beam is given ...
... to applications requiris.(g electron beams that are ... represented the beam currents that each apparatus received. In addition, the beam current was ...
The CEBAF accelerator delivers a CW electron beam at fundamental 1497 MHz, with average beam current up to 200 (mu)A. Accurate, stable nonintercepting beam current monitors are required for: setup/control, monitoring of beam current and ...
Multichannel crossed-beam photothermal refraction experiments have been performed. Iron(II)-phenanthroline in methanol was the test solute. The response as a function of concentration exhibited a nonlinear relationship, which does not agree with the current theoretical description of the phenomena. Although photophysical and photochemical processes were ...
The optimization of radiotherapy for the treatment of malignant mesothelioma highlights many of the currently outstanding problems in clinical radiation physics. The experimental investigation of an intuitively attractive irradiation technique with combined photon and electron beams using a specially constructed phantom has established that, due to the ...
A theoretical analysis of the scaling law and the value of the threshold current for beam plasma discharge is presented, based on the requirement for an absolute instability near the plasma frequency. It is shown that both the scaling law as well as the numerical values of I sub C are consistent with the experimental data, both in the ...
In the most accurate cold neutron beam determination of the neutron lifetime based on the absolute counting of decay protons, the largest uncertainty was attributed to the absolute determination of the capture flux of the cold neutron beam. Currently an experimental effort is underway at the ...
We have developed an optical diagnostic system suitable for characterizing the performance of energetic neutral beams. An absolutely calibrated CCD video camera is used to view the neutral beam as it passes through a relatively high pressure (10/sup -5/ Torr) region outside the neutralizer: collisional excitation of the fast deuterium ...
For quality assurance measurements in radiotherapy with scanned ion beams, such as beam profile measurements and dosimetrical verification of patient plans, high spatial accuracy is required. We investigated the Gafchromic EBT film, which is the ancestor of the currently available EBT2 film, for this purpose. The excellent spatial ...
... Title : A BIBLIOGRAPHY ELECTRON BEAM INDUCED CURRENT ANALYSIS OF SEMICONDUCTOR DEVICES. Corporate Author : ...
... pertibation of the beam potential. ... corroborated with ion current density measurements ... Descriptors : *PROTON BEAMS, *ION BEAMS, *VOLTAGE ...
... Descriptors : *ELECTRON BEAMS, *BEAM FORMING, *PARTICLE BEAM WEAPONS, CURRENT DENSITY, ENERGY TRANSFER, EROSION ...
... High current electron beam transport in ... Descriptors : *BEAM FORMING, *ELECTRON ACCELERATORS, *ELECTRON BEAMS, HIGH ENERGY ...
The absolute cross sections for the double, triple, and quadruple ionization of Rb/sup +/ ions by electron impact have been measured from below their respective thresholds to approximately 3000 eV. This determination has been accomplished using a crossed beam facility in which monoenergetic beams of ions and electrons are caused to ...
In this study, higher order beam elements are developed based on the absolute nodal coordinate formulation. The absolute nodal coordinate formulation is a finite element procedure that was recently proposed for flexible multibody applications. Many different elements based on the absolute nodal coordinate ...
The present paper reports on experimental observations of saturation of absolute beam-plasma instability that can be shown to result from beam trapping. The details of the trapping differ from the convectively unstable case in that the wave is large near the electron gun, and the beam is suddenly trapped in this ...
Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization ...
X-ray fluorescence from thin foils inserted into the NPS linac has been used to measure the integrated electron beam intensity when the accelerator is operating with dark current. The measured x-ray flux, the known inner shell ionization cross sections and radiative transition probabilities are used to obtain measurements of dark ...
... current limitation can occur in beams emitted into ... a wide range of beam currents and energies ... To follow the development of current saturation and ...
The low beta of proton or ion beams favors an electrostatic pickup to measure the transverse beam centroid position. Often papers on beam position monitors (BPM) are focused on a particular aspect of the problem; however, it is important to consider all various issues of a position measurement system. Based on our experience at the ...
The intensity of the high-energy heavy ion beam, extracted from the heavy ion synchrotron (SIS) at the GSI, Darmstadt, is determined with three types of detectors: scintillator counters, ionisation chambers (ICs), and secondary electron monitors (SEMs). The accuracy of the ICs, compared to a general formula, is about 25{percent}; for the SEMs it is within a factor of two. ...
Significantly improved measurements of the A and B coefficients in neutron beta decay can be used to test the charged current sector of the electroweak theory. Absolute neutron polarization measurements with at least 0.1% accuracy are now required. The uncertainties in neutron beam polarization measurements conducted with supermirror ...
... a balance between inward and outward currents. ... and interactions between the beam and local ... These current limiting mechanisms have been ...
... the return current must equal the beam current. ... to measure the current at the ... Descriptors : *ELECTRON BEAMS, *ELECTROSTATIC ANALYZERS ...
We examine the interaction of an electron beam penetrating a strongly correlated plasma. Conditions are established for this unstable interaction to lead to an absolute instability. We propose the absolute instability as a means for probing the strongly correlated plasmas.
Absolutely uniform illumination of spherical laser fusion pellets is possible when the energy deposition from a single laser beam is given by a simple cos exp 2 theta distribution. Conditions can be derived for which the laser beam targeting angles allow ...
Absolutely uniform illumination of spherical laser fusion pellets is possible when the energy deposition from a single laser beam is given by a simple cos 3 theta distribution. Conditions can be derived for which the laser beam targeting angles allow this...
Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics un...
Intense 1 MeV proton beams, produced with the GAMBLE 2 generator were transported efficiently over a distance of one meter in a wall stabilized current carrying plasma channel. Ion beams from a pinch reflex diode were ballistically focused in a neutral gas background so that a current neutralized ...
the verification of the antenna beam alignment of all frequencies and polarizations,. the determination of the absolute calibration factor from the image ...
... of the absolute total cross-sections for the ... studies, and a new crossed ion-supersonic ... molecule beams apparatus, designed to remove the thermal ...
While a torsion balance in vacuum can easily measure the momentum transfer from a gas beam impinging
... of a Prompt Gamma Ray Detector for Intense Bursts of Protons. ... for determining the intensity and duration of kiloampere pulsed proton beams is ...
... have devised for measuring the absolute H density involves absorption spectroscopy on the Lyman-alpha transition of ...
The problem of convective and absolute instability in the interactions of charged particle beams with plasma and with each other was analyzed. (R.V.J.)
The measurements of the neutron lifetime using ``bottled'' ultra- cold neutrons that claim the smallest experimental uncertainties are seriously discrepant with respect to each other. Given that the statistical contribution to their uncertainty is much smaller than the discrepancy, it is likely that one or more of these measurements suffers from an unidentified systematic effect. In the most ...
A collinear fast ion beam laser apparatus was constructed and tested. It will be used on-line to the SLOW RI radioactive beam facility in RIKEN (Japan) and as in the present experiment for precision absolute frequency measurements of astrophysically important reference lines. In the current work we conducted ...
A practical method has been developed to determine the absolute contents of elements in materials by charged-particle activation and gamma-ray spectroscopy. The n unknown weight fractions (fi) of the n elements in a sample are determined from the mathematical solution of a system of n equations obtained from their sum and from their ratios (ri): ri = fi/fj [i =1/(n-1); j = ...
... overlimiting beam currents has solutions for growth ... beams the respective growth rates have another ... increasing of the beam current its proper ...
... Accession Number : ADA137146. Title : A Beam Current Density Monitor for Intense Electron Beams. Descriptive Note : Memorandum rept.,. ...
A calorimeter is being fabricated to provide 0.5% - 1.0% absolute measurement of the beam current in the Hall A end station of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB). Modern powder metallurgy processes have produced high density, high thermal conductivity tungsten-copper ...
Secondary and back-scattered electron yields can be measured with a variety of electron detectors. However, measurements of absolute yields are difficult with most collection schemes and normalization against a known standard is required. The design, construction and calibration of a custom two grid retarding field analyzer--similar to a standard LEED detector--is described in ...
The problem of beam background in Squid Polarimetry is not without residual benefits. The authors may deliberately generate beam background by gently kicking the beam at the spin tune frequency. This signal may be used to accomplish a simple and accurate absolute calibration of the polarimeter. The authors present ...
beam short circuits by monitoring beam voltage on a strip-chart recorder; a low beam voltage indicated over current and therefore a beam short circuit. ...
Suitable shaping (in particular, flattening and broadening) of the laser beam has recently been proposed as an effective device to reduce internal (mirror) thermal noise in advanced gravitational-wave interferometric detectors. Based on some recently published analytic approximations (valid in the infinite-test-mass limit) for the Brownian and thermoelastic mirror noises in ...
Reactions involving radioactive nuclei play an important role in explosive stellar events such as novae, supernovae, and X-ray bursts. The development of accelerated, proton-rich radioactive ion beams provides a tool for directly studying many of the reactions that fuel explosive hydrogen burning. The experimental nuclear astrophysics program at the Holifield Radioactive Ion ...
We have developed a version of the Frankfurt Penning ion source that produces ion beams with very low energy spreads of �3 eV, while operating in a new discharge mode characterized by very high pressure, low voltage, and high current. The extracted ions also comprise substantial metastable and doubly charged species. Detailed studies of the operating ...
... Title : DESIGN AND SPECIFICATIONS OF A HIGH SATURATION ABSOLUTE EDDY CURRENT PROBE WITH INTERNAL REFERENCE. ...
... CAN BE MADE OF ELECTRICAL CONDUCTIVITY. ... BY VARIATIONS IN THE COIL AND SAMPLE ... AND MISALIGNMENT OF THE COILS HAS BEEN ...
... With an anode foil in place, extracted currents ... Self Force, External B , Initial Beam Quality and ... Techniques for Pulsed High Current Electron Beams ...
... Unfortunately, these charged particle beams have only been ... of a low emitted current and a ... ionic systems can produce high beam currents at high ...
Two identical CsI-coated, low noise microchannel plate (MCP) detectors were taken to the Daresbury Synchrotron Radiation Source (SRS) to measure their quantum efficiencies over two different energy ranges - 450 eV to 1200 eV and 4.5 eV to 9.5 eV. The SRS was run in low ring current with the beam flux monitored using single wire gas proportional counters. ...
A survey of our present understanding of absolute spectroscopic factors near stable closed-shell nuclei is given based on our current interpretation of the (e, e'p) reaction. Uncertainties associated with the imprecise knowledge of the degree of nonlocality of the optical potential of the knocked out proton are identified. Theoretical expectations for the ...
Absolute cross sections were determined for several (d, alpha ) reactions. Thin targets were bombarded by a beam of 7.8-Mev deuterons which were collected iii a Faraday cup and measured by a current integrator. Product nuclei were separated chemically from extrancous activities. Absolute disintegration ...
... Abstract : IN-PLANT EXPERIENCE WITH IGA SUGGESTS AN ABSOLUTE EDDY CURRENT COIL MODE IS THE KEY IN ACHIEVING RELIABLE ...
The paper describes the experimental technique and procedure for studying the electronic excitation of atoms of alkaline earth elements. Data are given on the absolute effective excitation cross sections of singlet and triplet transitions of the magnesium atom as well as ionic transitions. Most of the results were obtained by the method of intersecting atomic and ...
Several collisional-radiative (CR) models (Anderson et al 2000 Plasma Phys. Control. Fusion 42 781-806, Hutchinson 2002 Plasma Phys. Control. Fusion 44 71-82, Marchuk et al 2008 Rev. Sci. Instrum. 79 10F532) have been developed to calculate the attenuation and the population of excited states of hydrogen or deuterium beams injected into tokamak plasmas. The datasets generated ...
... generated by the TRITON electron beam generator ... rather than the beam electrons themselves ... current persisted which precluded axial containment. ...
The effect of the beam current on the spectrum of a beam plasma discharge (BPD) in N2 at 50, 100, or
... Relativistic electron beam; Return current; Resistive instability; Hollowing; Hose instability. Descriptors : *ELECTRON BEAMS, *RELATIVITY ...
... point, and a net current monitor at the ... hose motion and enhance beam transport. Keywords: Relativistic electron beams; Electron beam propagation ...
... report reviews the results of calculations which concern techniques of beam handling and emittance control for high current beams in advanced ...
... harmonics of the beam current as ... parameters of the buncher gap and ... Descriptors : *ELECTRON BEAMS, *MODULATION, VELOCITY, COMPUTER ...
... metal-oxide-semiconductor transistors (MOST's). ... and the electron beam current was ... Descriptors : *ELECTRON BEAMS, DAMAGE, TRANSISTORS ...
... Sea, using climatological and historical data from the ... DC Keywords: Absolute velocity; Bathymetry; Ocean current velocities; Ocean models ...
As part of the Strategic Defense Initiative (SDI) Brookhaven National Laboratory (BNL) has constructed a Neutral Beam Test Facility (NBTF) and a Radiation Effects Facility (REF). These two facilities use the surplus capacity of the 200-MeV Linac injector for the Alternating Gradient Synchrotron (AGS). The REF can be used to simulate radiation damage effects in space from both ...
The absolute cross section for the reaction U+O2-->UO2++e has been remeasured in an experiment where a beam of U atoms from a tungsten oven passes through O2 gas at low pressure, and ions formed by the reaction are collected at one of two condenser plates on either side of the beam. Uranium atom density was determined from the ...
The appearance of large amplitude oscillations and attenuation of beam current have been observed in
We review the current and future accelerator technologies for generation of high brightness radiation beam.
An inexpensive beam current integration system is described which measures the total integrated charge in a direct current accelerator beam during electron damage or ion implantation experiments over a wide range of positive or negative beam currents used...
A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal ...
A noninterceptive measurement system has been built to measure the energy and synchronous phase of a 6.7-MeV proton beam drifting from the ramped-gradient, drift-tube linac (RGDTL) in the accelerator test stand (ATS) facility. Axially-symmetric, capacitive probes used in these measurements produce signals that are proportional to the beam image ...
A review of recent developments in intense ion beam diagnostics used in the light ion inertial confinement fusion (ICF) program on the PBFA-2 accelerator at Sandia National Laboratories will be presented. These developments have occurred in each of several generic classes of diagnostics, namely, imaging diagnostics, particle spectrograph diagnostics, nuclear activation, and ...
Thermal intensity sensors based on the transformation of the incident ultrasonic energy into heat inside a small cylindrical absorber have been developed at PTB in the past, in particular to determine the acoustic output of medical diagnostic ultrasound equipment. Currently, this sensor technique is being expanded to match the measurement challenges of high intensity ...
We report a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are ...
From 12 000 charged-current ..nu../sub ..mu../D events obtained in an exposure of the Fermilab 15-ft bubble chamber to a high-energy wide-band neutrino beam, the absolute neutrino flux is determined using the reaction ..nu../sub ..mu../n..--> mu../sup -/p. For the total charged-current cross section, sigma/sub ...
... the current treatment options for localized prostate cancer are: � Radical prostatectomy (RP) (open, laparoscopic, robot-assisted) � External beam ...
Center for Biologics Evaluation and Research (CBER)
... conventional and e-beam lithography techniques. ... current at high current density and ... LITHOGRAPHY, ELECTRON BEAMS, CYLINDRICAL BODIES ...
... Accession Number : ADA133337. Title : Beam Current Limitations Due to Instabilities in Modified and Conventional Betatrons. ...
... Descriptors : *ELECTRON BEAMS, *COBALT, *IONIC CURRENT, ION BEAMS, ELECTRON TRANSITIONS, ELECTRON FLUX, ION DENSITY ...
The authors have used the beam-beam simulation code CBI to study the beam-beam interaction for the LHC. We find that for nominal LHC parameters, and assuming only one bunch per beam, there are no collective (coherent) beam-beam instabilities. We have investigated the effect of sweeping one of the ...
An inclined electron beam - ion beam experiment to study electron impact excitation of positives ions is described. Electron impact excitation cross sections for C/sup 3 +/ (2s ..-->.. 2p) and C/sup +/ (2s/sup 2/2p/sup 2/P/sup 0/ ..-->.. 2s2p/sup 22/D) were determined by detecting a known fraction of the photons produced by the radiative decay of the ...
High-power stabilized pinches are subject to magnetic disturbances and leakage of energetic particles. A diffusion theory describing the leakage in terms of interconnection of flux surfaces is consistent with the experimental data. Direct observation of the leakage phenomenon was realized in a 4-in., 100- kamp linear pinch tube, along which is passed a 200-kv, 10-mamp electron ...
Ionization at near-threshold collision energies has recently received much attention. The first measurements to compare with theory at a few keV/u are not of sufficient accuracy to test the theory, (M. Pieksma et al.), Phys. Rev. A. 73, 46 (1994). but suggest that the cross section may have contributions from other mechanisms. Currently, the (ORNL) ion-atom ...
A precision detector to measure synchrotron radiation beam positions has been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolute...
Determination of the offset of the electrical center of the beam position monitor (BPM) relative to the mechanical center is required for the absolute beam position measurement in the injector synchrotron and the storage ring of the APS. Conventionally, R...
An experimental study of the injection of an intense relativistic electron beam into a plasma confined in a toroidal magnetic field is described. An increase in toroidal current after beam injection was observed and argued to be the result of both beam-induced and additional OH-driven plasma ...
PROOF COPY [AP7157]019010PRA Absolute measurement of the resonance lines in heliumlike vanadium measurements of the energies of resonance lines in heliumlike vanadium on an electron-beam ion trap at an absolute precision measurement of heliumlike resonance lines in vanadium (Z 23) to investi- gate
E-print Network
Absolutely uniform illumination of spherical laser fusion pellets is possible when the energy deposition from a single laser beam is given by a simple cos 3 theta distribution. Conditions can be derived for which the laser beam targeting angles allow this absolute illumination uniformity. Configurations based upon ...
The physics reach of the SSC can eventually be extended considerably by an increase in luminosity. New heavy particles and other phenomena with robust signatures would be readily identified even in the presence of large numbers of simultaneous background interactions. As an example, this note examines the case in which the number of protons per SSC bunch is increased by a factor of ..sqrt..10, ...
The radiation from the 5 cm period undulator at the Advanced Light Source (ALS) has been characterized using a transmission grating spectrometer. Spectral and angular distributions of radiation were measured for deflection parameter [ital K] values between 0.45 and 2.12 at low storage ring current (0.1--0.5 mA). From the calibration of the spectrometer, the ...
The radiation from the 5 cm period undulator at the Advanced Light Source (ALS) has been characterized using a transmission grating spectrometer. Spectral and angular distributions of radiation were measured for deflection parameter K values between 0.45 and 2.12 at low storage ring current (0.1--0.5 mA). From the calibration of the spectrometer, the ...
The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average ...
... diodes (LED's) are characterized by optical beam induced current (OBIC ... INDIUM, *LIGHT EMITTING DIODES, *PHOTON BEAMS, *DIODE LASERS ...
... energy electrons with a beam current which was ... During the highest beam currents the accelerator payload ... percent greater than the beam energy. ...
... beam current, more beam power, and less stringent requirements on cathode current density and ... Amplifier, Electron beam, Klystron, Electron tube. ...
... encircling beam and (b) an axis-encircling beam. frequencies ... The current weight ... given currents [1]. Surrounding the interaction circuit is a lossy ...
The experiments at the GSI for the injection of high current beams into heavy ion accelerators are described. The ion source, the beam extraction, and the beam transport are considered. (ERA citation 10:003140)
... During 50 eV beam operations, current levels ... Current levels of 1 microAmps and 100 ... WAVES, ELECTRONS, ELECTRON BEAMS, HEATING, HEAT ...
... 48 CHAPTER 3 CURRENT TECHNOLOGY 3.0 INTOUCTION ... The ADC operates at a 2MHZ rate. Three fixed beams (one sum beam and two ...
Some of the problems associated with the monitoring of accelerator beams, particularly storage rings' beams, are reviewed along with their most common solutions. The various electrode structures used for the measurement of beam current, beam position, and...
