Foil changing apparatus

International Nuclear Information System (INIS)

Crist, C.E.; Ives, H.C.; Leifeste, G.T.; Miller, R.B.

1988-01-01

A self-contained foil changer apparatus for replenishing foil material across the path of a high energy particle beam is described comprising: a cylindrical hermetically sealed housing comprising an end plate having an aperture defining a beam passageway therethrough; foil supply means disposed inside the housing for storing a foil web and supporting a portion of the web across the beam passageway to form a plane perpendicular to the beam path; a barrel assembly disposed inside the housing; web control means extending through the housing and operably connected to the foil supply means for selectively advancing the foil web to replenish a portion across the beam passageway; and barrel control means extending through the housing and operably connected to the barrel assembly for selectively moving the barrel to and from the advanced and retracted positions

Effect of thickness of foil strippers in transmission of beams through 15 UD pelletron accelerator at IUAC

International Nuclear Information System (INIS)

Ojha, S.; Pankaj Kumar; Gargari, S.; Joshi, R.; Abhilash; Kabiraj, D.; Chopra, S.

2009-01-01

15 UD Pelletron accelerator at IUAC, New Delhi is equipped with a foil stripper and a gas stripper at high voltage terminal. Besides these, we have foil stripper assemblies at High Energy Dead Section (HEDS) of Pelletron and after analyser magnet. Incoming negative ion looses electrons when they pass through the strippers at terminal and becomes positively charged. The next foil stripper at HEDS increases the positive charge state of ion by removing more electrons which helps in delivering beams at higher energy. Typical thickness of carbon foils loaded in the foil stripper assembly in the terminal is around 4 microgram per square centimetre (4 μg/cm 2 ). Thicker foils were installed in the terminal assembly to study the effect of thickness of foil on charge state distribution and transmission of ion beams. Charge state distribution of ions produced out of molecular beam was also studied. In this paper we present and discuss the results and observations with thicker foils on ion as well as molecular beams. (author)

Comparison of carbon stripper foils produced by ARC discharge and laser ablation

Energy Technology Data Exchange (ETDEWEB)

Ophel, T.R.; Rhode, A.; Lobanov, N.; Weisser, D.C.; Turkentine, R.; Wolf, B.; Wlliman, R.G. [Australian National Univ. Canberra, ACT (Australia). Research School of Physical Sciences and Engineering

1998-06-01

The present work describes a series of investigations which compared the arc-deposited foils, prepared at ANU with a batch of foils from Munich, prepared by laser-ablation. The two foil types were bombarded with a beam of 6.8 MeV of {sup 197}Au recording their behaviour and monitoring the total stripped current. Optical and electron spectroscopy was carried out and indicate that the arc-deposited foils were relatively amorphous and smooth, while the laser-ablated foils appears to be much more crystalline. It was found that the average useful lifetimes of the Munich foils were at least ten times longer than arc-deposited foils. Furthermore, they maintained a constant beam output during the time in marked contrast to the arc-deposited foils, for which the output decreased quite rapidly. The longevity, and no less importantly, the constant beam output of the laser-ablated foils have emerged as critical to the continuance of the ERDA program. More significantly though, such qualities have provoked re-examination of likely energies for heavy beams that could be obtained with the Linac booster if foil stripping were used in the 14UD terminal, rather than gas that had previously been considered the only viable option. A program is in progress to explore the means to produce laser-ablated foils, or their equivalent, locally. Extended abstract. 1 ref., 2 figs.

Comparison of carbon stripper foils produced by ARC discharge and laser ablation

International Nuclear Information System (INIS)

Ophel, T.R.; Rhode, A.; Lobanov, N.; Weisser, D.C.; Turkentine, R.; Wolf, B.; Wlliman, R.G.

1998-01-01

The present work describes a series of investigations which compared the arc-deposited foils, prepared at ANU with a batch of foils from Munich, prepared by laser-ablation. The two foil types were bombarded with a beam of 6.8 MeV of 197 Au recording their behaviour and monitoring the total stripped current. Optical and electron spectroscopy was carried out and indicate that the arc-deposited foils were relatively amorphous and smooth, while the laser-ablated foils appears to be much more crystalline. It was found that the average useful lifetimes of the Munich foils were at least ten times longer than arc-deposited foils. Furthermore, they maintained a constant beam output during the time in marked contrast to the arc-deposited foils, for which the output decreased quite rapidly. The longevity, and no less importantly, the constant beam output of the laser-ablated foils have emerged as critical to the continuance of the ERDA program. More significantly though, such qualities have provoked re-examination of likely energies for heavy beams that could be obtained with the Linac booster if foil stripping were used in the 14UD terminal, rather than gas that had previously been considered the only viable option. A program is in progress to explore the means to produce laser-ablated foils, or their equivalent, locally

Envelope model for passive magnetic focusing of an intense proton or ion beam propagating through thin foils

Directory of Open Access Journals (Sweden)

Steven M. Lund

2013-04-01

Full Text Available Ion beams (including protons with low emittance and high space-charge intensity can be propagated with normal incidence through a sequence of thin metallic foils separated by vacuum gaps of order the characteristic transverse beam extent to transport/collimate the beam or to focus it to a small transverse spot. Energetic ions have sufficient range to pass through a significant number of thin foils with little energy loss or scattering. The foils reduce the (defocusing radial electric self-field of the beam while not altering the (focusing azimuthal magnetic self-field of the beam, thereby allowing passive self-beam focusing if the magnetic field is sufficiently strong relative to the residual electric field. Here we present an envelope model developed to predict the strength of this passive (beam generated focusing effect under a number of simplifying assumptions including relatively long pulse duration. The envelope model provides a simple criterion for the necessary foil spacing for net focusing and clearly illustrates system focusing properties for either beam collimation (such as injecting a laser-produced proton beam into an accelerator or for magnetic pinch focusing to a small transverse spot (for beam driven heating of materials. An illustrative example is worked for an idealization of a recently performed laser-produced proton-beam experiment to provide guidance on possible beam focusing and collimation systems. It is found that foils spaced on the order of the characteristic transverse beam size desired can be employed and that envelope divergence of the initial beam entering the foil lens must be suppressed to limit the total number of foils required to practical values for pinch focusing. Relatively modest proton-beam current at 10 MeV kinetic energy can clearly demonstrate strong magnetic pinch focusing achieving a transverse rms extent similar to the foil spacing (20–50  μm gaps in beam propagation distances of tens of mm

Control of proton beam divergence in intense-laser foil-plasma interaction

International Nuclear Information System (INIS)

Kawata, S.; Sonobe, R.; Miyazaki, S.; Sakai, K.; Kikuchi, T.

2006-01-01

Quality of an ion beam is one of the critical factors in intense-laser ion beam generation. A purpose of this study is the suppression of transverse proton divergence by a controlled electron cloud in laser-foil interactions. In this study, the foil target has a hole at the opposite side of the laser illumination. The electrons accelerated by an intense laser are limited in transverse by a neutral plasma at a protuberant part. Therefore the protons are accelerated and also controlled transversely by the electron cloud structure. In our 2.5-dimensional Particle-in-Cell simulations we demonstrate that the transverse shape of the electron cloud is well controlled and the collimated proton beam is generated successfully in the target with the hole. (authors)

Beam-foil level lifetimes in krypton III

International Nuclear Information System (INIS)

Coetzer, F.J.; Kotze, P.B.; Westhuizen, P. van der

1982-01-01

The radiative lifetimes of levels in doubly-ionized Krypton have been measured after foil excitation of a beam of Krypton particles in the wavelength range 120-500 nm. The results are compared with the experimental values obtained by Fink et al., as well as theoretical values resulting from Coulomb (C.A.) and single configuration Hartree-Fock (H.F.) calculations. (orig.)

Hydrodynamic simulations of light ion beam-matter interactions: ablative acceleration of thin foils

International Nuclear Information System (INIS)

Devore, C.R.; Gardner, J.H.; Boris, J.P.; Mosher, D.

1984-01-01

A one-dimensional model is used to study the hydrodynamic response of thin foils to bombardment by an intense proton beam. The beam targets are single- and multilayer planar foils of gold and polystyrene. The main conclusion is that the efficiency of conversion of incident beam energy to directed kinetic energy of the target is maximized by using a multilayer design. For beam parameters associated with the Gamble II device at the Naval Research Laboratory, the simulations yield payload velocities of over 5 cm/μs and energy conversion efficiencies of over 30%. The implications of these results for inertial confinement fusion research are discussed. (author)

Ablative acceleration of thin foil targets by intense proton beams

International Nuclear Information System (INIS)

Miyamoto, S.; Ozaki, T.; Imasaki, K.; Higaki, S.; Nakai, S.

1981-01-01

A focused proton beam of up to 2 x 10 10 w/cm 2 was obtained using pinch-reflex ion diode connected to Reiden IV generator. Experiments of beam target interaction have been done using thin foil targets. In this power range the interaction was explained classically. The experimental dependence of ablation pressure on proton beam intensity was obtained as P sub(a) = 3 x 10 -3 I sup(0.7) bar (I in w/cm 2 ). (author)

Corrections in the gold foil activation method for determination of neutron beam density

DEFF Research Database (Denmark)

Als-Nielsen, Jens Aage

1967-01-01

A finite foil thickness and deviation in the cross section from the 1ν law imply corrections in the determination of neutron beam densities by means of foil activation. These corrections, which depend on the neutron velocity distribution, have been examined in general and are given in a specific...

Thrombogenicity tests on ar-irradiated polycarbonate foils

Energy Technology Data Exchange (ETDEWEB)

Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H., E-mail: g.ferraz@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Fisica; Delgado, Adriana O. [Universidade Federal de Sao Carlos (UFSCAR), Sorocaba, SP (Brazil); Cunha, Tatiana F. [Biosintesis P and D do Brasil, Sao Paulo, SP (Brazil); Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

2013-07-01

Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

Thrombogenicity tests on ar-irradiated polycarbonate foils

International Nuclear Information System (INIS)

Trindade, Gustavo F.; Rizzutto, Marcia A.; Silva, Tiago F.; Moro, Marcos V.; Added, Nemitala; Tabacniks, Manfredo H.; Cunha, Tatiana F.; Higa, Olga Z.

2013-01-01

Understanding polymer surface properties is extremely important for the most wide range of their applications, from basic coating to the most complex composites and biomaterials. Low energy ion beam irradiation of polymer can improve such surface properties. By modifying its surface biocompatibility, polymers are excellent candidates for biomaterials, due to its malleability and low weight, when compared to metals. In this work, we irradiated 30-μm Bisphenol-A Polycarbonate foils with 23-keV Argon ion beam at six different doses. Aluminium foils were simultaneously irradiated in order to measure the doses by Rutherford Backscattering Spectroscopy. The surface modifications after the argon ion beam irradiation were analyzed by water contact angle measurements and atomic force microscopy. Platelet adhesion tests were used in order to investigate thrombogenicity, showing a growing tendency with the irradiated Argon dose. (author)

Use of spectra from foil-excited heavy-ion beams to interpret radiation from plasmas

International Nuclear Information System (INIS)

Johnson, B.M.

1978-01-01

Spectra from foil-excited heavy ion beams can be used to investigate the relative abundance and charge state composition of heavy metal contaminants which cause severe radiative energy losses in tokamak-produced plasmas. The degree of ionization of these metals in the tokamak plasma is not well known because of uncertainties in ionization and recombination rates and particle confinement times. Only a few stages of ionization are typically prominent in foil-excited spectra, however, and both the most probable charge state and distribution width are well known. Highly ionized heavy ions (e.g., Ti, Mo, W and Au) which span the range of charge states found in present tokamaks were produced by passing beams from the Brookhaven MP tandem Van de Graaff accelerator facility through 20 μg/cm 2 carbon stripping foils. EUV radiation was recorded with a grazing incidence spectrometer. Comparisons of the beam-foil spectra with radiation from plasmas, and recent direct determinations of atomic oscillator strengths for principal resonance lines of such highly ionized species as Li-like iron (Fe 23+ ), Na-like bromine (Br 24+ ), and Cu-like iodine (I 24+ ) are discussed

Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

International Nuclear Information System (INIS)

Fan, Qiwen; Du, Yinghui; Zhang, Rong; Xu, Guoji

2013-01-01

Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm 2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm 2 in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine–saccharose as releasing agent, which were previously covered with evaporated carbon layers ∼1μg/cm 2 in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4 for the 197 Au − (∼9MeV, ∼1μA) and 63 Cu − (∼9MeV, ∼1μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp 3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (I D /I G ) measured by the Raman spectroscopy is 0.78

Angularly resolved characterization of ion beams from laser-ultrathin foil interactions

Science.gov (United States)

Scullion, C.; Doria, D.; Romagnani, L.; Ahmed, H.; Alejo, A.; Ettlinger, O. C.; Gray, R. J.; Green, J.; Hicks, G. S.; Jung, D.; Naughton, K.; Padda, H.; Poder, K.; Scott, G. G.; Symes, D. R.; Kar, S.; McKenna, P.; Najmudin, Z.; Neely, D.; Zepf, M.; Borghesi, M.

2016-09-01

Methods and techniques used to capture and analyze beam profiles produced from the interaction of intense, ultrashort laser pulses and ultrathin foil targets using stacks of Radiochromic Film (RCF) and Columbia Resin #39 (CR-39) are presented. The identification of structure in the beam is particularly important in this regime, as it may be indicative of the dominance of specific acceleration mechanisms. Additionally, RCF can be used to deconvolve proton spectra with coarse energy resolution while mantaining angular information across the whole beam.

Angularly resolved characterization of ion beams from laser-ultrathin foil interactions

International Nuclear Information System (INIS)

Scullion, C.; Doria, D.; Ahmed, H.; Alejo, A.; Jung, D.; Naughton, K.; Kar, S.; Zepf, M.; Romagnani, L.; Ettlinger, O.C.; Hicks, G.S.; Poder, K.; Najmudin, Z.; Gray, R.J.; Padda, H.; McKenna, P.; Green, J.; Scott, G.G.; Symes, D.R.; Neely, D.

2016-01-01

Methods and techniques used to capture and analyze beam profiles produced from the interaction of intense, ultrashort laser pulses and ultrathin foil targets using stacks of Radiochromic Film (RCF) and Columbia Resin #39 (CR-39) are presented. The identification of structure in the beam is particularly important in this regime, as it may be indicative of the dominance of specific acceleration mechanisms. Additionally, RCF can be used to deconvolve proton spectra with coarse energy resolution while mantaining angular information across the whole beam.

Investigating the foil-generated deuteron beam interaction with a DT target in degenerate and classical plasma

Science.gov (United States)

Mehrangiz, M.; Ghasemizad, A.

2017-06-01

Deuteron fast ignition of a conically guided pre-compressed DT fuel is investigated. For this purpose, the acceleration of the deuterated thin foil by the intense laser beam is evaluated. The acceleration values and the number of foil-generated deuterons are calculated in terms of the laser pulse duration. Using the created deuterons as the fast ignitors, we investigate the fast ignition scheme by comparing fully degenerate, partial degenerate and classical types of DT plasma. The total energy gain of deuterons "beam fusion" is calculated to show the efficiency of beam reactions in increasing fusion rate. Besides, the stopping time and stopping range of incident deuterons are evaluated. Our numerical results indicate that degeneracy increases the beam-target collisions. Thus, it prepares the ignition situation sooner than the classical plasma. Moreover, the number of generated deuterons and their acceleration depend on the foil thickness and laser parameters. We show that when a 4ps laser with intensity of 10^{19} W/cm^2 focused onto a 20μm foil, 35× 10^{15} deuterons are generated. Moreover, under our analysis, in order to have a practicable fast ignition, 18% of the laser energy is necessary to convert into a deuteron driver.

Study of the light emission from hydrogen atoms excited by the beam-foil technique

International Nuclear Information System (INIS)

Broll, Norbert.

1976-01-01

Zero-field and Stark-induced quantum beat measurements have been performed for beam foil excited hydrogen (H + and H 2 + beam). Experimental evidence of coherent excitation of S and P states of Lyman α line has been demonstrated [fr

Development of a multipurpose beam foil spectroscopy set-up for the low cross-section measurements

Energy Technology Data Exchange (ETDEWEB)

Sharma, Gaurav [Department of Applied Physics, Delhi Technological University, New Delhi, Delhi 110042 (India); Nandi, T. [Inter University Accelerator Centre, New Delhi 110067 (India); Berry, H.G. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Puri, Nitin K., E-mail: nitin.phy@dce.edu [Department of Applied Physics, Delhi Technological University, New Delhi, Delhi 110042 (India)

2016-08-01

A multipurpose facility for low cross section measurements has been developed at Inter University Accelerator Centre, New Delhi, India. The facility consists of a multipurpose miniature chamber equipped with 1 m focal length normal incidence Monochromator and charge coupled device based detection system which has been aligned to realize the best resolution of the spectrometer. The chamber in this facility collects radiation 100 times more efficiently from the older system, without using any extra focusing mirror assembly. It is ensured to have the provision of mounting an X-ray detector and the spectrometer transverse to the beam direction simultaneously in the same chamber. The atomic spectroscopic studies can be performed by interaction of ions beams with both thin foil and gas targets. Provision for using photomultiplier tube instead of charge coupled device, is employed in the system depending on the condition of the source strength or other detection issues. We observed the essence of a very weak atomic phenomenon, a triply excited autoionizing forbidden transition, using the above facility to demonstrate its capability for measuring such low cross section phenomena. The present developed facility covers a large spectroscopic region from X-rays to the near infrared (0.1–10,000 Å).

Acceleration region influence on beam parameters on stripping foil

International Nuclear Information System (INIS)

Samsonov, E.V.; Tomic, S.

1999-01-01

Some formulas describing the beam parameters on the stripping foil (SF) as a function of the radial amplitude of betatron oscillations and energy gain are derived. The results computed by these formulas are in good agreement with the results of the numerical calculations. Obtained results show that between the radial emittance and the energy spread exists parametric dependence via amplitude of radial betatron oscillations. This conclusion allows one to create a working diagram of expected beam parameters on SF. This diagram may be particularly useful for the extraction system designers since it gives relationship between parameters considered as the extraction system input parameters. (author)

The Stark effect of 1H and 4He+ in the beam foil source

International Nuclear Information System (INIS)

Doobov, M.H.; Hay, H.J.; Sofield, C.J.; Newton, C.S.

1974-01-01

The appearance of Stark patterns obtained with a beam-foil source differed from those characteristically obtained from gas discharge sources. In the former source excitation of the hydrogenic ions occurred in a brief time interval ( 14 s) during the passage of a high velocity unidirectional beam of ions which produces non-statistical population distributions for the Stark perturbed states. The relative intensities of Stark perturbed components of the Hsub(β) hydrogen line and the Fsub(α) ionized helium line have been measured in a beam-foil source. In each case an initial population of states of principal quantum number n = 4 due to radiative decay and Stark mixing, and comparing the resultant patterns with the observed patterns. The inferred population distributions indicate that the states of low orbital angular momentum (L) are preferentially populated, and alignment referred to the beam axis is produced such that states with lower z component of L are preferentially populated. (author)

Improving beam spectral and spatial quality by double-foil target in laser ion acceleration for ion-driven fast ignition

International Nuclear Information System (INIS)

Huang, Chenkun; Albright, Brian J.

2010-01-01

Mid-Z ion driven fast ignition inertial fusion requires ion beams of 100s of MeV energy and < 10% energy spread. An overdense run-scale foil target driven by a high intensity laser pulse can produce an ion beam that has attractive properties for this application. The Break Out Afterburner (BOA) is one laser-ion acceleration mechanism proposed to generate such beams, however the late stages of the BOA tend to produce too large of an energy spread. The spectral and spatial qualities of the beam quickly evolve as the ion beam and co-moving electrons continue to interact with the laser. Here we show how use of a second target foil placed behind a nm-scale foil can substantially reduce the temperature of the co-moving electrons and improve the ion beam energy spread. Particle-In-Cell simulations reveal the dynamics of the ion beam under control. Optimal conditions for improving the spectral and spatial spread of the ion beam is explored for current laser and target parameters, leading to generation of ion beams of energy 100s of MeV and 6% energy spread, a vital step for realizing ion-driven fast ignition.

The use of the foil technique for the elimination of charging, and for beam monitoring in microbeam analysis of thick insulating samples

International Nuclear Information System (INIS)

Chaudhri, M.A.; Melbourne Univ., Austin

1982-01-01

It has been demonstrated that the 'thin-foil-technique' for the elimination of charging and accurate beam current/charge measurement, first developed by us, can also be conveniently applied to microbeam analysis of thick insulating samples. We have calculated the spatial broadening of proton microbeams of 1-20 MeV energies at the target, due to thin carbon foils of different thicknesses ranging from 10-40 μg/cm 2 placed either 2 or 5 mm in front of the target by using Moliere's theory of multiple scattering. The results show that at higher proton energies there is very little broadening of the incident beam even from thicker foils. But for lower energy protons (1 and 2 MeV) this broadening or worsening of the spatial resolution is relatively larger, especially from thicker foils. However, we have further shown that, even at these energies, the beam broadening can be minimized to acceptable limits by selecting a suitable thickness of carbon foil and placing it as close to the insulating target as possible. A comprehensive table is provided, which would help in selecting the most suitable carbon-foil thickness and the distance in front of the target where this foil should be placed, for microprobe application requiring different beam spots and proton energies. The advantages of this foil technique are described. (orig.)

Beam-foil lifetimes of highly ionized silicon

International Nuclear Information System (INIS)

Traebert, E.; Heckmann, P.H.; Buttlar, H. v.

1977-01-01

Electronically excited states of Si ions are created by passing a 20 MeV Si 5+ beam through a thin carbon foil. The EUV-radiation (lambda = 13-61 nm) emitted by the beam is analyzed using a grazing-incidence spectrometer. From the decay curves, lifetimes of 24 low lying levels in Si VIII to Si XII and of the 4f and 5g levels of Si XI and Si XII are derived. Cascades from doubly excited states turn out to be an important contribution to the radiation observed. The lifetime values of this work are compared to theoretical data mainly of Wiese, Sinanoglu and Dankwort/Trefftz. Most experimental values agree with at least one of the theoretical values. The decay time 560 ps of the 2s2p 3 3 D 0 3 state of Si IX is clearly longer than the theoretical prediction (highest value 455 ps by Sinanoglu). (orig.) [de

Moving foil stripper for a particle accelerator

International Nuclear Information System (INIS)

Gorka, A.J. Jr.

1975-01-01

Thin foils for stripping a particle beam are stored on the edge of a disk spinning in the accelerator vacuum. Cutting a foil at one edge releases the foil to project beyond the disk for insertion into the beam at a time determined by controlling the phase of the disk. A wiper removes a spent foil from the disk. The foil release and wiper are operable from a remote location. (U.S.)

A new, simple and precise method for measuring cyclotron proton beam energies using the activity vs. depth profile of zinc-65 in a thick target of stacked copper foils

International Nuclear Information System (INIS)

Asad, A.H.; Chan, S.; Cryer, D.; Burrage, J.W.; Siddiqui, S.A.; Price, R.I.

2015-01-01

The proton beam energy of an isochronous 18 MeV cyclotron was determined using a novel version of the stacked copper-foils technique. This simple method used stacked foils of natural copper forming ‘thick’ targets to produce Zn radioisotopes by the well-documented (p,x) monitor-reactions. Primary beam energy was calculated using the "6"5Zn activity vs. depth profile in the target, with the results obtained using "6"2Zn and "6"3Zn (as comparators) in close agreement. Results from separate measurements using foil thicknesses of 100, 75, 50 or 25 µm to form the stacks also concurred closely. Energy was determined by iterative least-squares comparison of the normalized measured activity profile in a target-stack with the equivalent calculated normalized profile, using ‘energy’ as the regression variable. The technique exploits the uniqueness of the shape of the activity vs. depth profile of the monitor isotope in the target stack for a specified incident energy. The energy using "6"5Zn activity profiles and 50-μm foils alone was 18.03±0.02 [SD] MeV (95%CI=17.98–18.08), and 18.06±0.12 MeV (95%CI=18.02–18.10; NS) when combining results from all isotopes and foil thicknesses. When the beam energy was re-measured using "6"5Zn and 50-μm foils only, following a major upgrade of the ion sources and nonmagnetic beam controls the results were 18.11±0.05 MeV (95%CI=18.00–18.23; NS compared with ‘before’). Since measurement of only one Zn monitor isotope is required to determine the normalized activity profile this indirect yet precise technique does not require a direct beam-current measurement or a gamma-spectroscopy efficiency calibrated with standard sources, though a characteristic photopeak must be identified. It has some advantages over published methods using the ratio of cross sections of monitor reactions, including the ability to determine energies across a broader range and without need for customized beam degraders. - Highlights: • Simple

Treatment of H0 and H- beams spilled at the stripper foil at full energy charge-exchange injection scheme

International Nuclear Information System (INIS)

Yamane, Isao

1991-01-01

The charge-exchange injection into a synchrotron to generate high-intensity pulsed proton beams for a spallation neutron source is reviewed while focusing on the treatment of H 0 and H - beams spilled at the stripper foil. After charge-exchange injection is briefly outlined, scattering by foil atoms and causes to spill H 0 and H - beams are described. These spilled beams can amount to several μA and should be carefully treated. It is then shown that a direct H - injection system needs to be considerably long and requires a very long straight section. Because of its simplicity, two-step H 0 injection has very wide applicability to various types of rings. However, it has a problem of emittance growth due to angular divergence in the stripper magnet and an ionoptical mismatch at the stripper foil. These problems are discussed, including a new proposal for a measure to remedy this problem. The laser photoionization injection is also briefly mentioned. (author)

Single-jet gas cooling of in-beam foils or specimens: Prediction of the convective heat-transfer coefficient

Science.gov (United States)

Steyn, Gideon; Vermeulen, Christiaan

2018-05-01

An experiment was designed to study the effect of the jet direction on convective heat-transfer coefficients in single-jet gas cooling of a small heated surface, such as typically induced by an accelerated ion beam on a thin foil or specimen. The hot spot was provided using a small electrically heated plate. Heat-transfer calculations were performed using simple empirical methods based on dimensional analysis as well as by means of an advanced computational fluid dynamics (CFD) code. The results provide an explanation for the observed turbulent cooling of a double-foil, Havar beam window with fast-flowing helium, located on a target station for radionuclide production with a 66 MeV proton beam at a cyclotron facility.

Experimental and simulated beam-foil decay curves for some transitions in Zn II

International Nuclear Information System (INIS)

Hultberg, S.; Liljeby, L.; Mannervik, S.; Veje, E.; Lindgaard, A.

1980-01-01

Experimental beam-foil decay curves for the 4s-4p, 4p-4d, 4d-4f, and the 4p-5s transitions in Zn II are compared to decay curves synthesized from transition probabilities calculated in the numerical Coulomb approximation and either measured initial level populations or population models. Good agreement exists between experimental curves and those based on the measured initial level populations for the 5s, 4d, and 4f levels while certain deviations are noted for the 4p term. None of the applied population models reproduce all experimental curves satisfyingly well. In addition, lifetimes are determined experimentally for 7 terms in Zn II, and good agreement with the numerical Coulomb approximation lifetimes is generally found except for some p terms. Beam-foil excitation-mechanism results for zinc are presented and compared to previous results from light projectiles. (Auth.)

Hertzian spectroscopy application to excited states in accelerated ion beams

Energy Technology Data Exchange (ETDEWEB)

Gaillard, M L

1974-01-01

Accelerated ion beams enables the application of optical hertzian spectrometry methods to be extended to research on the excited states of free ionic systems. The photon beat method has proved especially simple to apply in beam foil geometry because of the unidirectional beam velocity while the beam gas device is suitable for experiments of the energy level crossing type. Only the resonance technique involving direct application of high-frequency magnetic fields poses serious problems because of the high HF powers necessary. So far structure intervals have been measured in ions carrying up to three charges (seven in the special case of Lamb shift measurements) with a precision of a few percent. Study of hydrogen-like or helium-like ions of high Z allows the fundamental calculations of quantum electrodynamics to be checked with regard to the Lamb shift or the spontaneous emission theory. In more complex electronic systems, optical spectroscopy of accelerated ion beams gives wavelengths with a resolution reaching 10/sup -5/, lifetimes with an accuracy better than 10% when the cascade effects are properly studied, and Lande factors with a precision of several % under present technical conditions. The photon beat method concerns hyperfine nuclear effects in light atoms of Z < = 20. (FR)

INJECTION CARBON STRIPPING FOIL ISSUES IN THE SNS ACCUMULATOR RING

International Nuclear Information System (INIS)

BEEBE-WANG, J.; LEE, Y.Y.; RAPARIA, D.; WEI, J.

2001-01-01

We are reporting the results of studies on issues related to the injection stripping foil in the Spallation Neutron Source (SNS) accumulator ring. The problems related to foil heating and foil lifetime, such as current density distribution and temperature distribution in the foil, are investigated. The impact of injection errors on the beam losses at the foil is studied. The particle traversal rate and the beam losses due to scattering in the foil are summarized. Finally, SNS end-to-end simulation results of the foil-missing rate, the foil-hitting rate and the maximum foil temperature are presented

Synthesization of the Ar VIII 3s-3p beam-foil decay curve

International Nuclear Information System (INIS)

Lindgaard, A.; Veje, E.

1981-01-01

The beam-foil decay curve for the 3s-3p transition in Ar VIII has been simulated from experimentally determined relative initial level populations and transition probabilities calculated in the numerical Coulomb approximation. Good agreement is observed between simulated and measured decay curves. A discussion of the simulation is given. (Auth.)

Evidence of circular Rydberg states in beam-foil experiments: Role of the surface wake field

Science.gov (United States)

Sharma, Gaurav; Puri, Nitin K.; Kumar, Pravin; Nandi, T.

2017-12-01

We have employed the concept of the surface wake field to model the formation of the circular Rydberg states in the beam-foil experiments. The experimental studies of atomic excitation processes show the formation of circular Rydberg states either in the bulk of the foil or at the exit surface, and the mechanism is explained by several controversial theories. The present model is based on the interesting fact that the charge state fraction as well as the surface wake field depend on the foil thickness and it resolves a long-standing discrepancy on the mechanism of the formation of circular Rydberg states. The influence of exit layers is twofold. Initially, the high angular momentum Rydberg states are produced in the last layers of the foil by the Stark switching due to the bulk wake field and finally, they are transferred to the circular Rydberg states as a single multiphoton process due to the influence of the surface wake field.

Design considerations for foil windows for PET radioisotope targets

International Nuclear Information System (INIS)

Hughey, B.J.; Shefer, R.E.; Klinkowstein, R.E.; Welch, M.J.

1992-01-01

This paper describes the results of a study performed at SRL to develop analytical and computational techniques for optimizing the design of conduction-cooled foil windows for PET targets. Single foil conduction cooled windows have been found to be good target entrance windows for both low energy accelerators and medium energy cyclotrons. Detailed thermal analysis has given an approximate analytical expression for the maximum temperature reached in a foil window under conditions of realistic ion beam bombardment. The effects of 'hot spots' in the beam density profile were investigated. It was shown that a factor of two safety margin in window design should be adequate to compensate for any possible beam hot spots. In addition, the reduction of foil stress by slack mounting was verified by experiments. The properties of conventional and novel foil materials were investigated for use in conduction cooled windows. Novel foil materials include two-component Al/Ti and Al/Havar foil. Results on the testing of candidate foil materials for thermal conductivity and mechanical strength at elevated temperature were presented. Two optimum foil window geometries were analyzed: a high aspect ratio window and a multiply slotted window. The multiply slotted window combines the advantages of a high aspect ratio foil window with a circular beam strike and is a promising window design for both TCA and cyclotron targets. A multiply slotted window for a N 2 gas target for 15 O production was designed using the methodologies discussed above. This prototype target was successfully tested using the TCA beam at SRL. (author) 6 figs., 3 tabs., 10 refs

Part 1, Angular distribution measurement of beam-foil muonium, Part 2, Muon injection simulation for a new muon g-2 experiment

International Nuclear Information System (INIS)

Ahn, H.E.

1992-10-01

The angular and energy distributions of positive muons μ + and muonium M produced by the beam-foil method have been measured for the first time. A 7 MeV/c subsurface μ + beam was delivered to our apparatus from the Stopped Muon Channel at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF). The μ + formed M by electron capture in a thin Al target foil. A low pressure multi-wire proportional chamber upstream of the target foil was used both as a moderator and as a muon counter. To observe muonium, muons sere swept away by a bending magnet which was placed downstream of the target foil. This magnet was turned off while measuring the μ + distribution. Beyond the magnetic field, particles were collimated and then stopped by a microchannel plate detector located at various angles to the incident muon beam axis. Two pairs of scintillators mounted above (St) and below (Sb) the MC-P were used to detect the decay positrons to verify from the lifetime spectrum that the particles detected by the MCP are muons. The intensities of μ + and M emerging from the Al foil at different angles were obtained from both a time-of-flight spectrum and a lifetime spectrum

Relative and absolute level populations in beam-foil--excited neutral helium

International Nuclear Information System (INIS)

Davidson, J.

1975-01-01

Relative and absolute populations of 19 levels in beam-foil--excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n -3 , but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. The overpopulation decreases with increasing principal quantum number

Photoelectron photoion molecular beam spectroscopy

International Nuclear Information System (INIS)

Trevor, D.J.

1980-12-01

The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed

Relative and absolute level populations in beam-foil-excited neutral helium

Science.gov (United States)

Davidson, J.

1975-01-01

Relative and absolute populations of 19 levels in beam-foil-excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n to the -3rd power, but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range from 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. The overpopulation decreases with increasing principal quantum number.

Neutron Spectroscopy for pulsed beams with frame overlap using a double time-of-flight technique

Science.gov (United States)

Harrig, K. P.; Goldblum, B. L.; Brown, J. A.; Bleuel, D. L.; Bernstein, L. A.; Bevins, J.; Harasty, M.; Laplace, T. A.; Matthews, E. F.

2018-01-01

A new double time-of-flight (dTOF) neutron spectroscopy technique has been developed for pulsed broad spectrum sources with a duty cycle that results in frame overlap, where fast neutrons from a given pulse overtake slower neutrons from previous pulses. Using a tunable beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory, neutrons were produced via thick-target breakup of 16 MeV deuterons on a beryllium target in the cyclotron vault. The breakup spectral shape was deduced from a dTOF measurement using an array of EJ-309 organic liquid scintillators. Simulation of the neutron detection efficiency of the scintillator array was performed using both GEANT4 and MCNP6. The efficiency-corrected spectral shape was normalized using a foil activation technique to obtain the energy-dependent flux of the neutron beam at zero degrees with respect to the incoming deuteron beam. The dTOF neutron spectrum was compared to spectra obtained using HEPROW and GRAVEL pulse height spectrum unfolding techniques. While the unfolding and dTOF results exhibit some discrepancies in shape, the integrated flux values agree within two standard deviations. This method obviates neutron time-of-flight spectroscopy challenges posed by pulsed beams with frame overlap and opens new opportunities for pulsed white neutron source facilities.

Foil changer for the Chalk River superconducting cyclotron

International Nuclear Information System (INIS)

Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.E.; Proulx, D.R.; Weaver, J.F.

1985-01-01

Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

Fast antihydrogen beam spectroscopy

International Nuclear Information System (INIS)

Neumann, R.

1989-01-01

The motivation for production and precision spectroscopy of antihydrogen atoms is outlined. An experimental configuration is considered, concerning laser-microwave spectroscopy of a fast hydrogen beam with characteristics similar to those of an antihydrogen beam emanating from an antiproton-positron overlap region in an antiproton storage ring. In particular, a possible experiment for the measurement of the ground state hyperfine structure splitting is described. (orig.)

Development of a new foil compounded from carbon nanotubes and sputter-deposition carbon

International Nuclear Information System (INIS)

Hiroo Hasebe; Hironori Kuboki; Hiroki Okuno; Isao Yamane; Hiroshi Imao; Nobuhisa Fukunishi; Masayuki Kase; Osamu Kamigaito

2014-01-01

New carbon-nanotube-sputter-deposition-carbon (CNT-SDC) foils were developed and used in the U beam time at the RIKEN RI Beam Factory (RIBF) from October to December 2011. The lifetimes of these new foils were drastically extended, and stable, high-intensity U beams were successfully provided to users. The lifetime of the CNT-SDC foils was 2-5 C, which was 100 times longer than those of static C-foils previously used. The qualitative analysis of the CNT-SDC foils clearly showed that the CNT structure and bundles were broken by beam irradiation. In addition, it was found that CNT bundles in the CNT-SDC foil were grown after the carbon deposition procedure. This structure was considered to be the reason that the CNT-SDC foils maintain advantages of both CNT and SDC foils. (author)

Fine Structure in Helium-like Fluorine by Fast-Beam Laser Spectroscopy

Science.gov (United States)

Myers, E. G.; Thompson, J. K.; Silver, J. D.

1998-05-01

With the aim of providing an additional precise test of higher-order corrections to high precision calculations of fine structure in helium and helium-like ions(T. Zhang, Z.-C. Yan and G.W.F. Drake, Phys. Rev. Lett. 77), 1715 (1996)., a measurement of the 2^3P_2,F - 2^3P_1,F' fine structure in ^19F^7+ is in progress. The method involves doppler-tuned laser spectroscopy using a CO2 laser on a foil-stripped fluorine ion beam. We aim to achieve a higher precision, compared to an earlier measurement(E.G. Myers, P. Kuske, H.J. Andrae, I.A. Armour, H.A. Klein, J.D. Silver, and E. Traebert, Phys. Rev. Lett. 47), 87 (1981)., by using laser beams parallel and anti-parallel to the ion beam, to obtain partial cancellation of the doppler shift(J.K. Thompson, D.J.H. Howie and E.G. Myers, Phys. Rev. A 57), 180 (1998).. A calculation of the hyperfine structure, allowing for relativistic, QED and nuclear size effects, will be required to obtain the ``hyperfine-free'' fine structure interval from the measurements.

Foil changer for the Chalk River superconducting cyclotron

International Nuclear Information System (INIS)

Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.F.; Proulx, D.R.; Weaver, J.F.

1985-01-01

Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

Quantum beats study of the 4He+ beam-carbon foil interaction

International Nuclear Information System (INIS)

Denis, A.; Desesquelles, J.

1979-01-01

Excitation cross-sections are deduced from the analysis of quantum beats in an electric field for an 4 He + (n=4) ion beam scattering through a thin carbon foil. The population distribution obtained at 1 MeV for 4S, 4P, 4D and 4F levels is in good agreement with a second-order Born approximation calculation of the electronic capture He ++ +C→He + (n=4) + C + . The alignment is found to be negative for P, D and F levels. The coherences Δl=+-1 have been measured, for amplitudes and phases [fr

Allotropic effects on the energy loss of swift H+ and He+ ion beams through thin foils

International Nuclear Information System (INIS)

Garcia-Molina, Rafael; Abril, Isabel; Denton, Cristian D.; Heredia-Avalos, Santiago

2006-01-01

We have developed a theoretical treatment and a simulation code to study the energy loss of swift H + and He + ion beams interacting with thin foils of different carbon allotropes. The former is based on the dielectric formalism, and the latter combines Monte Carlo with the numerical solution of the motion equation for each projectile to describe its trajectory and interactions through the target. The capabilities of both methods are assessed by the reasonably good agreement between their predictions and the experimental results, for a wide range of projectile energies and target characteristics. Firstly, we apply the theoretical procedure to calculate the stopping cross sections for H + and He + beams in foils of different allotropic forms of carbon (such as diamond, graphite, amorphous carbon, glassy carbon and C 60 -fullerite), as a function of the projectile energy. We take into account the electronic structure of the projectile, as well as the different charge states it can acquire, the energy loss associated to the electronic capture and loss processes, the polarization of the projectile, and a realistic description of the target. On the other hand, the simulation code is used to evaluate the energy distributions of swift H + and He + ion beams when traversing several foils of the above mentioned allotropic forms of carbon, in order to analyze the influence of the chemical and physical state of the target in the projectile energy loss. These allotropic effects are found to become more important around the maximum of the stopping cross-section

Experimental study of relative level populations in beam-foil excited Ar+7 and Kr+7

International Nuclear Information System (INIS)

Bashkin, S.; Oona, H.; Veje, E.

1981-01-01

The relative level populations in beam-foil excited sodium-like argon (Ar VIII) and copper-like krypton (Kr VIII) have been studied at 2 MeV projectile energy. In Ar VIII, the 3p and the 3d terms are strongly excited. The level population decreases rapidly with increasing value of the principal quantum number n, reaches a minimum for levels with n = 5 or 6, but increases then and reaches a strong maximum for levels with n approximately 11. Also the Kr VIII data show a population maximum for levels with n = 11. The strong 3p and 3d level excitations in Ar VIII are explained as selective inner-shell processes which can be understood in the molecular-orbital electron-promotion picture. The preferential population of high-flying Rydberg states is explained as resulting from a near-resonance electron transfer from the valence band of the carbon foil to the projectile. This process takes place when the projectile leaves the back of the foil. (Auth.)

Atomic spectroscopy sympsoium, Gaithersburg, Maryland, September 23--26, 1975

International Nuclear Information System (INIS)

1975-01-01

Abstracts of one hundred papers given at the conference are presented along with the conference program and an author index. Session topics include: highly ionized atoms; laser spectroscopy and hyperfine structure; complex spectra; laser spectroscopy, radiation theory; theory of highly ionized atoms and analysis of plasmas; plasma spectroscopy, line strengths; spectral analysis, instrumentation, reference wavelengths; beam foil spectroscopy, line strengths, energy levels; absorption spectroscopy, autoionization, and related theory; and spectral analysis, instrumentation, and VUV physics

Monte Carlo simulation for scanning technique with scattering foil free electron beam: A proof of concept study.

Directory of Open Access Journals (Sweden)

Wonmo Sung

Full Text Available This study investigated the potential of a newly proposed scattering foil free (SFF electron beam scanning technique for the treatment of skin cancer on the irregular patient surfaces using Monte Carlo (MC simulation. After benchmarking of the MC simulations, we removed the scattering foil to generate SFF electron beams. Cylindrical and spherical phantoms with 1 cm boluses were generated and the target volume was defined from the surface to 5 mm depth. The SFF scanning technique with 6 MeV electrons was simulated using those phantoms. For comparison, volumetric modulated arc therapy (VMAT plans were also generated with two full arcs and 6 MV photon beams. When the scanning resolution resulted in a larger separation between beams than the field size, the plan qualities were worsened. In the cylindrical phantom with a radius of 10 cm, the conformity indices, homogeneity indices and body mean doses of the SFF plans (scanning resolution = 1° vs. VMAT plans were 1.04 vs. 1.54, 1.10 vs. 1.12 and 5 Gy vs. 14 Gy, respectively. Those of the spherical phantom were 1.04 vs. 1.83, 1.08 vs. 1.09 and 7 Gy vs. 26 Gy, respectively. The proposed SFF plans showed superior dose distributions compared to the VMAT plans.

Monte Carlo simulation for scanning technique with scattering foil free electron beam: A proof of concept study.

Science.gov (United States)

Sung, Wonmo; Park, Jong In; Kim, Jung-In; Carlson, Joel; Ye, Sung-Joon; Park, Jong Min

2017-01-01

This study investigated the potential of a newly proposed scattering foil free (SFF) electron beam scanning technique for the treatment of skin cancer on the irregular patient surfaces using Monte Carlo (MC) simulation. After benchmarking of the MC simulations, we removed the scattering foil to generate SFF electron beams. Cylindrical and spherical phantoms with 1 cm boluses were generated and the target volume was defined from the surface to 5 mm depth. The SFF scanning technique with 6 MeV electrons was simulated using those phantoms. For comparison, volumetric modulated arc therapy (VMAT) plans were also generated with two full arcs and 6 MV photon beams. When the scanning resolution resulted in a larger separation between beams than the field size, the plan qualities were worsened. In the cylindrical phantom with a radius of 10 cm, the conformity indices, homogeneity indices and body mean doses of the SFF plans (scanning resolution = 1°) vs. VMAT plans were 1.04 vs. 1.54, 1.10 vs. 1.12 and 5 Gy vs. 14 Gy, respectively. Those of the spherical phantom were 1.04 vs. 1.83, 1.08 vs. 1.09 and 7 Gy vs. 26 Gy, respectively. The proposed SFF plans showed superior dose distributions compared to the VMAT plans.

Fusion welding of thin metal foils

International Nuclear Information System (INIS)

Casey, H.

1975-01-01

Aspects of fusion welding of thin metal foils are reviewed and the current techniques employed at LASL to join foils are described. Techniques for fusion welding approximately 0.025-mm-thick foils of copper, aluminum, and stainless steels have been developed using both electron beam and laser welding equipment. These techniques, together with the related aspects of joint design, tooling and fixturing, joint preparation, and modifications to the commercially available welding equipment, are included in the review. (auth)

Stripping foils for the PSB H- injection system

CERN Document Server

Aiba, M; Goddard, B; Weterings, W

2009-01-01

Beam physics considerations for the stripping foil of the PSB H- injection system are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The required movement ranges and tolerances are detailed, together with the assumptions used.

Alignment and orientation effects in beam-foil experiments

International Nuclear Information System (INIS)

Band, Y.B.

1975-01-01

A theory of the orientation and alignment of atoms observed upon emergence from tilted foils is presented. The interaction with the foil surface is taken into account in the production process of particular states. Once they are produced, the evolution of these states, under the influence of the residual field near the surface, is calculated in the fashion introduced by Eck. The most general effect of this evolution is presented

Gas Gain Measurement Of GEM-Foil In Argon-Carbon Dioxide Mixture

International Nuclear Information System (INIS)

Nguyen Ngoc Duy; Vuong Huu Tan; Le Hong Khiem

2011-01-01

Nuclear reaction measurement with radioactive beam at low energy plays an important role in nuclear astrophysics and nuclear structure. The trajectory of particle beams can be obtained by using an active gas target, multiple-sampling and tracking proportional chamber (MSTPC), as a proportional counter. Because of intensity of low energy radioactive beam, in the stellar reaction such as (α, p), (p, α), it is necessary to increase the gain for the counter. In this case, a gas electrons multiplier (GEM) foil will be used, so the proportional counter is called GEM-MSTPC. The efficient gas gain of GEM foils which relates to foil thickness and operating pressure was investigated with two type of the foils, 400 μm and 200 μm, in Argon (70%) + Carbon dioxide (30%) mixture. (author)

Micro-strip Metal Foil Detectors for the Beam Profile Monitoring

CERN Document Server

Pugatch, V M; Fedorovitch, O A; Mikhailenko, A V; Prystupa, S V; Pylypchenko, Y

2005-01-01

The Micro-strip Metal Foil Detectors (MMFD) designed and used for the Beam Profile Monitoring (BPM) are discussed. Fast particles hitting a metal strip initiate Secondary Electron Emission (SEE) which occurs at 10 - 50 nm surface layers of a strip. The SEE yield is measured by a sensitive Charge Integrator with built-in current-to-frequency converter (1 Hz per 1 fA). The MMFD (deposited onto the 20 μm thick Si-wafer) with 32 Al strips (10 μm wide, 32 μm pitch) has been used for the BPM of the 32 MeV alpha-particle beam at the MPIfK (Heidelberg) Tandem generator for Single-Event-Upset studies of the BEETLE micro-chip. Similar MMFD (0.5 μm thick Ni-strips) with totally removed Si-wafer (by plasma-chemistry, at the working area of 8 x 10 mm2) has been applied for the on-line X-ray BPM at the HASYLAB (DESY). The number of photons (11.3 GeV, mean X-ray energy 18 keV) producing out of a strip a single SEE was evaluated as (1.5 ±0.5)* 104. MMFD has demonstrated stable...

The influence of target properties on nuclear spectroscopy measurements

International Nuclear Information System (INIS)

Dionisio, J.S.; Vieu, C.; Lagrange, J.M.; Pautrat, M.; Vanhorenbeeck, J.; Passoja, A.

1988-01-01

A broad review of different kinds of in-beam nuclear spectroscopy measurements particularly influenced by the target properties is outlined. To illustrate such an influence a few typical examples of in-beam electron and gamma-ray spectroscopy measurements, performed at the Orsay MP Tandem accelerator, are reported. In particular several applications of the recoil ion catcher method in the study of short-lived nuclear isomers (with half-lives between ten and few hundred nanoseconds) are briefly described. This method is operated mostly with a pulsed heavy ion beam, bombarding a thin self-supported target but avoiding hitting the catcher foil. Moreover, the time of flight filtering properties of this experimental device is improved by a fast detection of compound nucleus deexcitation (performed with an array of several BaF 2 crystals). This kind of measurement shows clearly the importance of the target qualities as well as the need of good focusing properties and time structure for the accelerated particle beam. Finally, the required characteristics of the targets and recoil stopper foils needed for these measurements (and similar ones performed with the recoil ion shadow method) are analyzed in detail for a few typical experimental arrangements. (author). Abstract only

A new method for designing dual foil electron beam forming systems. I. Introduction, concept of the method

Energy Technology Data Exchange (ETDEWEB)

Adrich, Przemysław, E-mail: Przemyslaw.Adrich@ncbj.gov.pl

2016-05-01

In Part I of this work existing methods and problems in dual foil electron beam forming system design are presented. On this basis, a new method of designing these systems is introduced. The motivation behind this work is to eliminate the shortcomings of the existing design methods and improve overall efficiency of the dual foil design process. The existing methods are based on approximate analytical models applied in an unrealistically simplified geometry. Designing a dual foil system with these methods is a rather labor intensive task as corrections to account for the effects not included in the analytical models have to be calculated separately and accounted for in an iterative procedure. To eliminate these drawbacks, the new design method is based entirely on Monte Carlo modeling in a realistic geometry and using physics models that include all relevant processes. In our approach, an optimal configuration of the dual foil system is found by means of a systematic, automatized scan of the system performance in function of parameters of the foils. The new method, while being computationally intensive, minimizes the involvement of the designer and considerably shortens the overall design time. The results are of high quality as all the relevant physics and geometry details are naturally accounted for. To demonstrate the feasibility of practical implementation of the new method, specialized software tools were developed and applied to solve a real life design problem, as described in Part II of this work.

A new method for designing dual foil electron beam forming systems. I. Introduction, concept of the method

International Nuclear Information System (INIS)

Adrich, Przemysław

2016-01-01

In Part I of this work existing methods and problems in dual foil electron beam forming system design are presented. On this basis, a new method of designing these systems is introduced. The motivation behind this work is to eliminate the shortcomings of the existing design methods and improve overall efficiency of the dual foil design process. The existing methods are based on approximate analytical models applied in an unrealistically simplified geometry. Designing a dual foil system with these methods is a rather labor intensive task as corrections to account for the effects not included in the analytical models have to be calculated separately and accounted for in an iterative procedure. To eliminate these drawbacks, the new design method is based entirely on Monte Carlo modeling in a realistic geometry and using physics models that include all relevant processes. In our approach, an optimal configuration of the dual foil system is found by means of a systematic, automatized scan of the system performance in function of parameters of the foils. The new method, while being computationally intensive, minimizes the involvement of the designer and considerably shortens the overall design time. The results are of high quality as all the relevant physics and geometry details are naturally accounted for. To demonstrate the feasibility of practical implementation of the new method, specialized software tools were developed and applied to solve a real life design problem, as described in Part II of this work.

Interaction of relativistic H- ions with thin foils

International Nuclear Information System (INIS)

Mohagheghi, A.H.

1990-09-01

The response of relativistic H - ions to thin carbon foils was investigated for beam energies ranging from 226 MeV to 800 MeV. For the foil thicknesses we have studied, ranging from 15 to 300 μg/cm 2 , an appreciable fraction of the H - beam survives intact, some H - ions are stripped down to protons, and the remainder is distributed over the states of H 0 . This experiment is different from the low energy studies in that the projectile velocity is comparable to the speed of light, leading to an interaction time of typically less than a femtosecond. The present results challenge the theoretical understanding of the interaction mechanisms. An electron spectrometer was used to selectively field-ionize the Rydberg states, 9 < n < 17, at beam energies of 581 MeV and 800 MeV. The yield of low-lying states were measured by Doppler tuning a Nd:YAG laser to excite transitions to a Rydberg state which was then field-ionized and detected. A simple model is developed to fit the yield of each state as a function of foil thickness. The simple model is successful in predicting the general features of the yield data. However, the data are suggestive of a more complex structure in the yield curves. The yield of a given state depends strongly on the foil thickness, demonstrating that the excited states are formed during the passage of the ions through a foil. The optimum thickness to produce a given state increases with the principal quantum number of the state suggesting an excitation process which is at least pratially stepwise. The results of a Monte Carlo simulation are compared with the experimental data to estimate the distribution of the excited states coming out of a foil. The distributions of the excited states and their dependence on foil thickness are discussed

Spectroscopy Division progress report (January 1991 to June 1992)

International Nuclear Information System (INIS)

Ahmad, S.A.; Kartha, V.B.

1993-01-01

The research and development activities of the Spectroscopy Division during the calendar year 1990-1992 are reported in the form of individual summaries. These are arranged under the headings: (1) analytical spectroscopy, (2) infrared and Raman spectroscopy, (3) atomic spectra, (4) molecular and electronic spectra, (5) laser spectroscopy (6) synchrotron, beam foil and plasma spectroscopy, (7) optics, (8) design, fabrication and workshop etc. The list of publications and papers presented at the various conferences, symposia etc. by the staff members of the Division during the report period is given at the end. (author). figs

Improving depth resolutions in positron beam spectroscopy by concurrent ion-beam sputtering

Science.gov (United States)

John, Marco; Dalla, Ayham; Ibrahim, Alaa M.; Anwand, Wolfgang; Wagner, Andreas; Böttger, Roman; Krause-Rehberg, Reinhard

2018-05-01

The depth resolution of mono-energetic positron annihilation spectroscopy using a positron beam is shown to improve by concurrently removing the sample surface layer during positron beam spectroscopy. During ion-beam sputtering with argon ions, Doppler-broadening spectroscopy is performed with energies ranging from 3 keV to 5 keV allowing for high-resolution defect studies just below the sputtered surface. With this technique, significantly improved depth resolutions could be obtained even at larger depths when compared to standard positron beam experiments which suffer from extended positron implantation profiles at higher positron energies. Our results show that it is possible to investigate layered structures with a thickness of about 4 microns with significantly improved depth resolution. We demonstrated that a purposely generated ion-beam induced defect profile in a silicon sample could be resolved employing the new technique. A depth resolution of less than 100 nm could be reached.

Production and thickness determination of thin plastic scintillator foils

International Nuclear Information System (INIS)

Xiao, B.; Lee, S.; Hagel, K.; Haddad, F.; Li, J.; Lou, Y.; Mdeiwayeh, N.; Tezkratt, R.; Wada, R.; Utley, D.; Natowitz, J.B.

1995-01-01

A method of making large thin plastic scintillator foils with good uniformity is presented. The use of Fourier Transform Infrared Spectroscopy (FTIR) to test the foil uniformity and to establish an empirical thickness calibration curve is described. ((orig.))

X-ray spectroscopy of a thin foil plasma produced by a short-pulse high-intensity laser

International Nuclear Information System (INIS)

Audebert, P.; Nagels, V.; Geindre, J.P.; Dorchies, F.; Peyrusse, O.; Gary, S.; Girard, F.; Shepherd, R.; Gauthier, J.C.; Chenais-Popovics, C.

2003-01-01

High density and temperature plasmas have been generated by irradiating thin foils of various elements with a high-energy subpicosecond laser pulse. The X-ray emission duration was studied by time-resolved X-ray spectroscopy. Frequency domain interferometry provided a measurement of the hydrodynamic expansion of the back of the foil as a function of time. The effect of longitudinal temperature gradients, i.e., gradients perpendicular to the surface, were decreased using very thin foil targets. Additionally, radial gradients effects, i.e., gradients parallel to the surface, were limited by using a 50 μm pinhole on target. The Al, Se and Sm spectra, recorded in the range 7.7-8 Angst. using a conical crystal spectrometer coupled to an 800 fs resolution streak camera, lasted a few picoseconds. Sm spectra showed no spectral features in this wavelength range, providing a spectrally homogeneous backlighter for future experiments. The main features of the experimental time-resolved spectra have been well reproduced with one-dimensional hydrodynamic simulations of the free expansion of a plasma heated at a given initial temperature obtained from the expansion velocity of the rear critical surface of the plasma

Spectroscopy Division progress report (July 1992-June 1993)

International Nuclear Information System (INIS)

Singh, Mahavir

1994-01-01

The research and development activities of the Spectroscopy Division during the year July 1992-June 1993 are reported in the form of individual summaries. These are arranged under the headings: (1) analytical spectroscopy, (2) infrared and Raman spectroscopy, (3) atomic spectra, (4) electronic spectra, (5) laser spectroscopy, (6) synchrotron beam foil and plasma spectroscopy, (7) optics, (8) electronics and instrumentation, and (9) design, fabrication and workshop etc. The list of publications and papers presented at the various conferences, symposia, workshops etc. by the staff members of the Division during the report period is also given. (author)

Stripper foil failure modes and cures at the Oak Ridge Spallation Neutron Source

Directory of Open Access Journals (Sweden)

M. A. Plum

2011-03-01

Full Text Available The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and a liquid mercury target. To manage the beam loss caused by the H^{0} excited states created during the H^{-} charge-exchange injection into the accumulator ring, the stripper foil is located inside one of the chicane dipoles. This has some interesting consequences that were not fully appreciated until the beam power reached about 840 kW. One consequence was sudden failure of the stripper foil system due to convoy electrons stripped from the incoming H^{-} beam, which circled around to strike the foil bracket and cause bracket failure. Another consequence is that convoy electrons can reflect back up from the electron catcher and strike the foil and bracket. An additional contributor to foil system failure is vacuum breakdown due to the charge developed on the foil by secondary electron emission. In this paper we detail these and other interesting failure mechanisms and describe the improvements we have made to mitigate them.

Stripping Foil Issues for H- Injection into the CERN PSB at 160 MeV

CERN Document Server

Goddard, B; Bracco, C; Carli, C; Meddahi, M; Weterings, W J M

2010-01-01

Beam physics considerations for the stripping foil of the 160 MeV PSB H- injection systems are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The different beam loss mechanisms are quantified in the context of the aperture limits, operational considerations and collimation requirements.

Atomic spectroscopy sympsoium, Gaithersburg, Maryland, September 23--26, 1975. [Program, abstracts, and author index

Energy Technology Data Exchange (ETDEWEB)

1975-01-01

Abstracts of one hundred papers given at the conference are presented along with the conference program and an author index. Session topics include: highly ionized atoms; laser spectroscopy and hyperfine structure; complex spectra; laser spectroscopy, radiation theory; theory of highly ionized atoms and analysis of plasmas; plasma spectroscopy, line strengths; spectral analysis, instrumentation, reference wavelengths; beam foil spectroscopy, line strengths, energy levels; absorption spectroscopy, autoionization, and related theory; and spectral analysis, instrumentation, and VUV physics. (GHT)

Observation of transient lattice vacancies produced during high-energy ion irradiation of Ni foils

International Nuclear Information System (INIS)

Tsuchida, Hidetsugu; Iwai, Takeo; Awano, Misa; Kishida, Mutsumi; Katayama, Ichiro; Jeong, Sun-Chang; Ogawa, Hidemi; Sakamoto, Naoki; Komatsu, Masao; Itoh, Akio

2007-01-01

Real-time positron annihilation spectroscopy has been applied for the first time for the investigation of lattice vacancies produced during ion irradiation. Measurements were performed for thin nickel foils irradiated with 2.5 MeV C ions. Doppler broadenings of positron annihilation γ-rays were measured alternately during beam-on and beam-off conditions. It was found that the Doppler broadening line-shape parameter measured during irradiation is larger than those obtained before and after irradiation. This evidently implies that transient or non-survivable vacancy defects are produced during ion irradiation. On the other hand, no such significant change in the line-shape parameter was observed for other face-centred-cubic metal forms of aluminium

Dissociation of fast HeH+ ions in foils and gases

International Nuclear Information System (INIS)

Gemmell, D.S.; Cooney, P.J.; Pietsch, W.J.; Ratkowski, A.J.; Vager, Z.

1978-01-01

To gain understanding of phenomena observed when very simple light diatomic ions are incident at high velocities upon thin foils and gaseous targets, an extensive set of measurements on the dissociation products arising from beams of HeH + was made. Experimental and calculated joint distributions in energy and angle for protons emerging (near the beam direction) from an 85-A carbon foil bombarded by 2.0-MeV HeH + ions are presented

Micron-scale resolution radiography of laser-accelerated and laser-exploded foils using an yttrium x-ray laser

International Nuclear Information System (INIS)

Cauble, R.; Da Silva, L.B.; Barbee, T.W. Jr.; Celliers, P.; Moreno, J.C.; Mrowka, S.; Perry, T.S.; Wan, A.S.

1994-09-01

The authors have imaged laser-accelerated foils and exploding foils on the few-micron scale using an yttrium x-ray laser (155 angstrom, 80 eV, ∼200 ps duration) and a multilayer mirror imaging system. At the maximum magnification of 30, resolution was of order one micron. The images were side-on radiographs of the foils. Accelerated foils showed significant filamentation on the rear-side (away from the driving laser) of the foil, although the laser beam was smoothed. In addition to the narrow rear-side filamentation, some shots revealed larger-scale plume-like structures on the front (driven) side of the Al foil. These plumes seem to be little-affected by beam smoothing and are likely a consequence of Rayleigh-Taylor instability. The experiments were carried out at the Nova two-beam facility

Carbon stripper foils held in place with carbon fibers

International Nuclear Information System (INIS)

Jolivet, Connie S.; Miller, Shawn A.; Stoner, John O.; Ladd, Peter

2008-01-01

The Spallation Neutron Source (SNS) currently under construction at Oak Ridge National Laboratory, Oak Ridge, Tennessee, is planned to initially utilize carbon stripper foils having areal densities approximately 260 μg/cm 2 . The projected design requires that each foil be supported by only one fixed edge. For stability of the foil, additional support is to be provided by carbon fibers. The feasibility of manufacturing and shipping such mounted carbon foils produced by arc evaporation was studied using two prototypes. Production of the foils is described. Fibers were chosen for satisfactory mechanical strength consistent with minimal interference with the SNS beam. Mounting of the fibers, and packaging of the assemblies for shipping are described. Ten completed assemblies were shipped to SNS for further testing. Preliminary evaluation of the survivability of the foils in the SNS foil changer is described

Peculiar time dependence of unexpected lines in delayed beam-foil X-ray spectra of V, Fe and Ni

International Nuclear Information System (INIS)

Ahmad, Nissar; Karn, Ranjeet K.; Marketos, Pan; Nandi, T.

2005-01-01

Delayed beam-foil X-ray spectra of highly charged ions of V, Fe and Ni show a few lines at energies higher than the H-like Lyman α-line of the respective projectile ions. These can only be attributed to heavier ions. Further the time dependence of such unexpected lines display a peculiar behavior. This work presents the experimental observations systematically

Magnetic collimation and metal foil filtering for electron range and fluence modulation

International Nuclear Information System (INIS)

Phaisangittisakul, N.; D'Souza, W.D.; Ma Lijun

2004-01-01

We investigated the use of magnetically collimated electron beams together with metal filters for electron fluence and range modulation. A longitudinal magnetic field collimation method was developed to reduce skin dose and to improve the electron beam penumbra. Thin metal foils were used to adjust the energies of magnetically collimated electrons. The effects for different types of foils such as Al, Be, Cu, Pb, and Ti were studied using Monte Carlo calculations. An empirical pencil beam dose calculation model was developed to calculate electron dose distributions under magnetic collimation and foil modulation. An optimization method was developed to produce conformal dose distributions for simulated targets such as a horseshoe-shaped target. Our results show that it is possible to produce an electron depth dose enhancement peak using similar techniques of producing a spread-out Bragg peak. In conclusion, our study demonstrates new aspects of using magnetic collimation and foil filtration for producing fluence and range modulated electron dose distributions

Fabrication of a micro-hole array on metal foil by nanosecond pulsed laser beam machining using a cover plate

International Nuclear Information System (INIS)

Ha, Kyoung Ho; Lee, Se Won; Jee, Won Young; Chu, Chong Nam; Kim, Janggil

2015-01-01

A novel laser beam machining (LBM) method is proposed to achieve higher precision and better quality beyond the limits of a commercialized nanosecond pulsed laser system. The use of a cover plate is found to be effective for the precision machining of a thin metal foil at micro scale. For verifying the capability of cover plate laser beam machining (c-LBM) technology, a 30 by 30 array of micro-holes was fabricated on 8 µm-thick stainless steel 304 (STS) foil. As a result, thermal deformation and cracks were significantly reduced in comparison with the results using LBM without a cover plate. The standard deviation of the inscribed and circumscribed circle of the holes with a diameter of 12 µm was reduced to 33% and 81%, respectively and the average roundness improved by 77%. Moreover, the smallest diameter obtainable by c-LBM in the given equipment was found to be 6.9 µm, which was 60% less than the minimum size hole by LBM without a cover plate. (technical note)

EXAFS-spectroscopy on synchrotron radiation beam

CERN Document Server

Aksenov, V L; Kuzmin, A Y; Purans, Y

2001-01-01

In the review the basis theoretical principles of EXAFS spectroscopy are given, as one of principal directions of an absorption spectroscopy permitting with a high accuracy to gain parameters of the short-range order in multicomponent amorphous and quasi-crystal mediums. The methods of the analysis of EXAFS spectra with allowance of effects of multiply scattering are featured. The exposition of the experimental set-ups, which realize the method of EXAFS spectroscopy on beams of SR, requirement of the monochromatization of radiation beams are given. For investigation of phase transition and external effects the energy-dispersive EXAFS spectrometer is creating at the National center of SR Kurchatov Institute which can measure the EXAFS spectrum with a time resolution 3-5 ms. The experimental results on investigation (by the EXAFS spectroscopy method) of oxides of tungsten and molybdenum are given, which have unique property: the variable valence of an ion of metal is depending on external action. The most inter...

Three-dimensional thermal simulations of thin solid carbon foils for charge stripping of high current uranium ion beams at a proposed new heavy-ion linac at GSI

Directory of Open Access Journals (Sweden)

N. A. Tahir

2014-04-01

Full Text Available This paper presents an extensive numerical study of heating of thin solid carbon foils by 1.4  MeV/u uranium ion beams to explore the possibility of using such a target as a charge stripper at the proposed new Gesellschaft für Schwerionenforschung high energy heavy–ion linac. These simulations have been carried out using a sophisticated 3D computer code that accounts for physical phenomena that are important in this problem. A variety of beam and target parameters have been considered. The results suggest that within the considered parameter range, the target will be severely damaged by the beam. Thus, a carbon foil stripper does not seem to be a reliable option for the future Gesellschaft für Schwerionenforschung high energy heavy–ion linac, in particular, at FAIR design beam intensities.

Spectra from foil-excited molybdenum ions

International Nuclear Information System (INIS)

Johnson, B.M.; Jones, K.W.; Cecchi, J.L.; Kruse, T.H.

1978-01-01

The extreme-ultraviolet spectra (5 to 55 nm) for foil-excited molybdenum ions have been measured using 22 to 200 MeV beams from the Brookhaven National Laboratory MP tandem Van de Graaff accelerator facility, 20 μg/cm 2 C stripping foils, and a grazing incidence spectrometer. The mean ion charge states (13 to 28) and the narrow distribution widths (about 2 charge states) were accurately predictable from experimental parameters. Where possible, comparisons are given with Mo radiation from tokamaks, vacuum sparks, and laser-excited plasmas

Spectroscopy of multi-charged ions: a short review

International Nuclear Information System (INIS)

Berry, H.G.

1983-01-01

Recent and future applications of multiply charged ions to spectroscopy and atomic structure are discussed. The experimental techniques use either very fast ions produced in heavy ion accelerators, or slow ions produced directly both in electron beam ion sources and from collisions of fast accelerated ions. For the accelerated fast ions, spectroscopic measurements on using gas target excitation, solid foil excitation and laser excitation. In gas target excitation, both X-ray and electron spectroscopy have been applied to analyse atomic structures and secondary collision effects. Highlycharged secondary ions have also been trapped electro-magnetically for further similar studies in controlled conditions. Spectroscopic detection following solid foil interaction has led to atomic lifetime measurements, principally of metastable level, analysis of complex highly-ionized heavy ion spectra, and investigations of relativistic and QED effects in few electron ions

The stripping foil test stand in the Linac4 transfer line

CERN Document Server

Weterings, W; Noulibos, R; Sillanoli, Y; van Trappen, P

2015-01-01

The 160 MeV H− beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H− charge-exchange injection system. It will include a stripping foil, to convert H− into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters.

The stripping foil test stand in the Linac4 transfer line

International Nuclear Information System (INIS)

Weterings, W.; Bracco, C.; Noulibos, R.; Sillanoli, Y.; Trappen van, P.

2015-01-01

The 160 MeV H - beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H - charge-exchange injection system. It will include a stripping foil, to convert H - into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters. (author)

First experience with carbon stripping foils for the 160 MeV H- injection into the CERN PSB

Science.gov (United States)

Weterings, Wim; Bracco, Chiara; Jorat, Louise; Noulibos, Remy; van Trappen, Pieter

2018-05-01

160 MeV H- beam will be delivered from the new CERN linear accelerator (Linac4) to the Proton Synchrotron Booster (PSB), using a H- charge-exchange injection system. A 200 µg/cm2 carbon stripping foil will convert H- into protons by stripping off the electrons. The H- charge-exchange injection principle will be used for the first time in the CERN accelerator complex and involves many challenges. In order to gain experience with the foil changing mechanism and the very fragile foils, in 2016, prior to the installation in the PSB, a stripping foil test stand has been installed in the Linac4 transfer line. In addition, parts of the future PSB injection equipment are also temporarily installed in the Linac4 transfer line for tests with a 160 MeV H- commissioning proton beam. This paper describes the foil changing mechanism and control system, summarizes the practical experience of gluing and handling these foils and reports on the first results with beam.

Spectroscopy Division: progress report for 1990

International Nuclear Information System (INIS)

Sharma, A.; Marathe, S.M.

1991-01-01

This report summarises the work done by members of the Spectroscopy Division both within BARC as well as in scientific institutions elsewhere during the calendar year 1990. Main areas of research activity include atomic spectroscopy for hyperfine structure and isotope shift determination, theoretical and experimental studies of diatomic molecules, infrared and Raman spectroscopy of polyatomic molecules, design and fabrication of beam line optics for INDUS-I synchrotron radiation source, beam foil spectroscopy and laser spectroscopy of various atomic and molecular systems. Major experimental facilities that have been utilised include a fourier transform spectrometer, an excimer laser pumped dye-laser and a continous wave argon-ion laser. The report also includes the spectroscopic analytical service rendered for various DAE units and describes briefly some new analytical facilities like laser enhanced ionization in flames and resonance ionization mass spectroscopy using pulsed lasers which are being set up. The above activites were reported by members of the Spectroscopy Division via invited lectures, papers presented in various national and international conferences and publication in scientific journals. Details of these are given at the end of the report. (author). figs., tabs

A code to determine the energy distribution, the incident energy and the flux of a beam of light ions into a stack of foils

International Nuclear Information System (INIS)

Sonzogni, A.A.; Romo, A.S.M.A.; Frosch, W.R.; Nassiff, S.J.

1992-01-01

The stacked-foil technique is one of the most used methods to obtain excitation functions of nuclear reactions using light ions as projectiles. The purpose of this program is the calculation of the energy of the beam in the stack, as well as to obtain the incident energy and the flux of the beam by using monitor excitation functions. (orig.)

Simulation of turn-by-turn passage of protons through the H-minus stripping foil in booster

Energy Technology Data Exchange (ETDEWEB)

Gardner, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-07-06

Equations for transverse emittance growth due to multiple passes of circulating proton beam through the H-minus stripping foil in Booster were developed in [1]. These were based on simple principles of statistics and simple assumptions about the initial distribution of particles incident on the foil. It was assumed there that the foil dimensions and position of the incoming beam are such that all particles hit the foil on every turn around the machine. In the present note we assume only that all incoming H-minus ions from Linac hit the foil and are stripped of their electrons. The resulting protons circulate indefinitely around the machine. Setups in which the foil width is reduced so that not all protons hit the foil on every turn are studied here by simulation. The aim is to determine the effectiveness of such setups in reducing the emittance growth of circulating proton beam during the injection of H-minus beam. The simulations also serve as a check of the equations developed in [1], and vice versa. The particulars of the simulation setup are given in Sections 1 through 11. Figures 1 through 12 show simulation results for the case in which all particles hit the foil on every turn. The results are in good agreement with those obtained from the equations of reference [1]. Figures 13 through 19 show simulation results for various setups in which the foil width is reduced. These results are summarized in Section 12. In all gures the horizontal axis gives the turn number. The unit of the vertical axis is micrometers ( m) in all plots of emittance.

Characterization of laser-cut copper foil X-pinches

Science.gov (United States)

Collins, G. W.; Valenzuela, J. C.; Hansen, S. B.; Wei, M. S.; Reed, C. T.; Forsman, A. C.; Beg, F. N.

2016-10-01

Quantitative data analyses of laser-cut Cu foil X-pinch experiments on the 150 ns quarter-period, ˜250 kA GenASIS driver are presented. Three different foil designs are tested to determine the effects of initial structure on pinch outcome. Foil X-pinch data are also presented alongside the results from wire X-pinches with comparable mass. The X-ray flux and temporal profile of the emission from foil X-pinches differed significantly from that of wire X-pinches, with all emission from the foil X-pinches confined to a ˜3 ns period as opposed to the delayed, long-lasting electron beam emission common in wire X-pinches. Spectroscopic data show K-shell as well as significant L-shell emission from both foil and wire X-pinches. Fits to synthetic spectra using the SCRAM code suggest that pinching foil X's produced a ˜1 keV, ne ≥ 1023 cm-3 plasma. The spectral data combined with the improved reliability of the source timing, flux, and location indicate that foil X-pinches generate a reproducible, K-shell point-projection radiography source that can be easily modified and tailored to suit backlighting needs across a variety of applications.

Stresses in the foil of an electron accelerator extraction channel

International Nuclear Information System (INIS)

Abroyan, M.A.; Makarenko, T.I.; Tokmakov, I.L.

1983-01-01

Stresses in the foil of an electron accelerator extraction channel are assessed with account of contributions of thermal expansion and stress concentrations during switchings. Optimization of extraction grid parameters of the electron accelerator extraction channel and choice of foil material for high current electron beam is conducted. It is suggested that an extraction grid with circular cells and Al-Mg foil should be used. A simple formula applicable for design calculations is proposed for evaluation of stress concentration coefficient during phase switchings

Integral window/photon beam position monitor and beam flux detectors for x-ray beams

Science.gov (United States)

Shu, Deming; Kuzay, Tuncer M.

1995-01-01

A monitor/detector assembly in a synchrotron for either monitoring the position of a photon beam or detecting beam flux may additionally function as a vacuum barrier between the front end and downstream segment of the beamline in the synchrotron. A base flange of the monitor/detector assembly is formed of oxygen free copper with a central opening covered by a window foil that is fused thereon. The window foil is made of man-made materials, such as chemical vapor deposition diamond or cubic boron nitrate and in certain configurations includes a central opening through which the beams are transmitted. Sensors of low atomic number materials, such as aluminum or beryllium, are laid on the window foil. The configuration of the sensors on the window foil may be varied depending on the function to be performed. A contact plate of insulating material, such as aluminum oxide, is secured to the base flange and is thereby clamped against the sensor on the window foil. The sensor is coupled to external electronic signal processing devices via a gold or silver lead printed onto the contact plate and a copper post screw or alternatively via a copper screw and a copper spring that can be inserted through the contact plate and coupled to the sensors. In an alternate embodiment of the monitor/detector assembly, the sensors are sandwiched between the window foil of chemical vapor deposition diamond or cubic boron nitrate and a front foil made of similar material.

Reliable measurement of the Li-like 2248Ti 1s2s2p 4P5/2o level lifetime by beam-foil and beam-two-foil experiments

International Nuclear Information System (INIS)

Nandi, T.; Ahmad, Nissar; Wani, A. A.; Marketos, P.

2006-01-01

We have determined the lifetime of the Li-like 22 48 Ti 1s2s2p 4 P 5/2 o level (210.5±13.5 ps) using data from its x-ray decay channel through beam single- and two-foil experiments, coupled to a multicomponent iterative growth and decay analysis. Theoretical lifetime estimates for this zero-nuclear-spin ion lies within the uncertainty range of our experimental results, indicating that blending contributions to this level from the He-like 1s2p 3 P 2 o and 1s2s 3 S 1 levels are eliminated within the current approach. A previously reported discrepancy between experimental and theoretical 1s2s2p 4 P 5/2 o level lifetimes in 23 51 V may, as a result, be attributed to hyperfine quenching

Magazine for handling stripping foils in a particle accelerator

International Nuclear Information System (INIS)

Gorka, A.J. Jr.

1975-01-01

Thin foils for stripping a particle beam are stored in a magazine that is operable remotely to display an individual foil, release it when it is spent, and repeat this process. The magazine is operable in the high-vacuum, high-radiation environment in the interior of a particle accelerator, and it uses the magnetic field of the accelerator to operate the display and dropping mechanism. (U.S.)

Calculation of electron transmission through aluminium foil

International Nuclear Information System (INIS)

Abroyan, M.A.; Mel'ker, A.I.; Mikhajlin, A.I.; Sirotinkin, V.V.; Tokmakov, I.L.

1987-01-01

Calculated by Monte Carlo method energy and angular distributions of electrons transmitted through aluminium foil with 50 μm thickness are presented. 200-500 electron energy ranges and angles of electron incidence on foil from 0 to 40 deg C are considered. That allows to use results for more universal accelerator group, for example, for accelerators with scanning beam used in industry. The received values of angular and energy characteristics allow to increase essentially estimation accuracy of accelerator extraction devices and dose distribution on irradiating item

Fast beam radiofrequency spectroscopy

International Nuclear Information System (INIS)

Pipkin, F.M.

1983-01-01

The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

Characteristics of a plasma flow field produced by a metal array bridge foil explosion

Science.gov (United States)

Junying, WU; Long, WANG; Yase, LI; Lijun, YANG; Manzoor, SULTAN; Lang, CHEN

2018-07-01

To improve the energy utilization efficiency of metal bridge foil explosion, and increase the function range of plasmas, array bridge foil explosion experiments with different structures were performed. A Schlieren photographic measurement system with a double-pulse laser source was used to observe the flow field of a bridge foil explosion. The evolution laws of plasmas and shock waves generated by array bridge foil explosions of different structures were analyzed and compared. A multi-phase flow calculation model was established to simulate the electrical exploding process of a metal bridge foil. The plasma equation of state was determined by considering the effect of the changing number of particles and Coulomb interaction on the pressure and internal energy. The ionization degree of the plasma was calculated via the Saha–Eggert equation assuming conditions of local thermal equilibrium. The exploding process of array bridge foils was simulated, and the superposition processes of plasma beams were analyzed. The variation and distribution laws of the density, temperature, pressure, and other important parameters were obtained. The results show that the array bridge foil has a larger plasma jet diameter than the single bridge foil for an equal total area of the bridge foil. We also found that the temperature, pressure, and density of the plasma jet’s center region sharply increase because of the superposition of plasma beams.

Design and Analysis Methodologies for Inflated Beams

NARCIS (Netherlands)

Veldman, S.L.

2005-01-01

The central theme of the thesis is bending behaviour of inflated beams. Three different types of beams have been analysed for the bending load case: a straight cylindrical beam made of anisotropic foil material, a conical beam made of an isotropic foil material, and a carbon fibre braided beam. The

BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

Science.gov (United States)

Bonomo, F.; Ruf, B.; Barbisan, M.; Cristofaro, S.; Schiesko, L.; Fantz, U.; Franzen, P.; Pasqualotto, R.; Riedl, R.; Serianni, G.; Wünderlich, D.

2015-04-01

The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

The development of fast tantalum foil targets for short-lived isotopes

CERN Document Server

Bennett, J R J; Drumm, P V; Ravn, H L

2003-01-01

The development of fast tantalum foil targets for short-lived isotopes was discussed. It was found that the effusion was faster but the diffusion out of the foils was a limiting factor. The performance of the targets at ISOLDE with beams of **1**1Li, **1**2Be and **1**4Be was also analyzed. (Edited abstract) 13 Refs.

Real-time simulator for designing electron dual scattering foil systems.

Science.gov (United States)

Carver, Robert L; Hogstrom, Kenneth R; Price, Michael J; LeBlanc, Justin D; Pitcher, Garrett M

2014-11-08

The purpose of this work was to develop a user friendly, accurate, real-time com- puter simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator allows for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator also is a powerful educational tool. The simulator consists of an analytical algorithm for calculating electron fluence and X-ray dose and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with the reduced Gaussian formalism for scattering powers. The simulator also estimates central-axis and off-axis X-ray dose arising from the dual foil system. Once the geometry of the accelerator is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scat- tering foil material and Gaussian shape (thickness and sigma), and beam energy. The off-axis electron relative fluence or total dose profile and central-axis X-ray dose contamination are computed and displayed in real time. The simulator was validated by comparison of off-axis electron relative fluence and X-ray percent dose profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV, using present foils on an Elekta radiotherapy accelerator, the simulator was able to reproduce MC profiles to within 2% out to 20 cm from the central axis. The central-axis X-ray percent dose predictions matched measured data to within 0.5%. The calculation time was approximately 100 ms using a single Intel 2.93 GHz processor, which allows for real-time variation of foil geometrical parameters using slider bars. This work demonstrates how the user-friendly GUI and real-time nature of the simulator make it an effective educational tool for gaining a better understanding of the effects that various system

A convenient way to double the capacity of a NEC type foil stripper

International Nuclear Information System (INIS)

Chapman, K.R.

1988-01-01

A convenient method is described to increase the capacity of a NEC type terminal stripper. This renders the necessity for tank entry to renew foils less frequent. This is especially useful when the use of heavy ion beams renders foil lifetimes very short. (orig.)

Transmission of fast molecular ions through thin foils

International Nuclear Information System (INIS)

Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

1979-01-01

New results on the transmission of fast molecular ions through thin foils are presented and a mechanism for the transmission process is proposed. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target

Interaction of positron beams with thin silver foils and surfaces

International Nuclear Information System (INIS)

Rysholt Poulsen, M.

1994-01-01

Experimental investigations of positron interactions with solid silver and the necessary platform to analyse the data have been presented. The main objective was to study Ps formation at a Ag(100) surface. The different ingredients of the scenario, including thermalization and diffusion of positrons and emission of Ps, were analysed and quantified in whatever way appropriate. The scattering and possible thermalization were described. The parametrization of Monte-Carlo simulated implantation profiles for semi-infinite materials were presented and the applicability of such profiles to thin foils assessed. The latter was done in conjunction with an analysis of experimental data on thermalization and diffusion in 1900 Aa Ag(100) foils. The necessity for MC simulated rather than parametrized implantation profiles was argued. The velocity of thermally desorbed Ps from a Ag(100) surface at ∼800 K appeared to obey and one-dimensional Maxwell Boltzmann distribution multiplied by a velocity dependent factor. More experimental investigations are needed before firm conclusions can be made on the nature of the emission process. The velocity distribution, though, was found to be near-thermal and indicative of the sample temperature. It has been shown that positrons can be converted into Ps atoms in the transmission geometry of a thin 1900 Aa Ag(100) foil with a high efficiency. Furthermore, 61% of the emitted Ps will have a mean velocity of v z =1.2x10 5 m/sec and 39% will have a maximum kinetic energy of 1.5 eV (v z =5.1x10 5 m/sec) at a foil temperature of 800 K, all velocities that are suitable for producing a 'dense' Ps gas target. (EG) 12 refs

Uniformity of the soft-x-ray emissions from gold foils irradiated by OMEGA laser beams determined by a two-mirror normal-incidence microscope with multilayer coatings

International Nuclear Information System (INIS)

Seely, John F.; Boehly, Thomas; Pien, Gregory; Bradley, David

1998-01-01

A two-mirror normal-incidence microscope with multilayer coatings was used to image the soft-x-ray emissions from planar foils irradiated by OMEGA laser beams. The bandpass of the multilayer coatings was centered at a wavelength of 48.3 Angstrom (257-eV energy) and was 0.5 Angstrom wide. Five overlapping OMEGA beams, without beam smoothing, were typically incident on the gold foils. The total energy was 1500 J, and the focused intensity was 6x10 13 Wcm -2 . The 5.8x magnified images were recorded by a gated framing camera at various times during the 3-ns laser pulse. A pinhole camera imaged the x-ray emission in the energy range of >2 keV. On a spatial scale of 10 μm, it was found that the soft-x-ray images at 257 eV were quite uniform and featureless. In contrast, the hard-x-ray images in the energy range of >2 kev were highly nonuniform with numerous features of size 150 μm. copyright 1998 Optical Society of America

Electric fields, electron production, and electron motion at the stripper foil in the Los Alamos Proton Storage Ring

International Nuclear Information System (INIS)

Plum, M.

1995-01-01

The beam instability at the Los Alamos Proton Storage Ring (PSR) most likely involves coupled oscillations between electrons and protons. For this instability to occur, there must be a strong source of electrons. Investigation of the various sources of electrons in the PSR had begun. Copious electron production is expected in the injection section because this section contains the stripper foil. This foil is mounted near the center of the beam pipe, and both circulating and injected protons pass through it, thus allowing ample opportunity for electron production. This paper discusses various mechanisms for electron production, beam-induced electric fields, and electron motion in the vicinity of the foil

A new method for designing dual foil electron beam forming systems. II. Feasibility of practical implementation of the method

International Nuclear Information System (INIS)

Adrich, Przemysław

2016-01-01

In Part I of this work a new method for designing dual foil electron beam forming systems was introduced. In this method, an optimal configuration of the dual foil system is found by means of a systematic, automatized scan of system performance in function of its parameters. At each point of the scan, Monte Carlo method is used to calculate the off-axis dose profile in water taking into account detailed and complete geometry of the system. The new method, while being computationally intensive, minimizes the involvement of the designer. In this Part II paper, feasibility of practical implementation of the new method is demonstrated. For this, a prototype software tools were developed and applied to solve a real life design problem. It is demonstrated that system optimization can be completed within few hours time using rather moderate computing resources. It is also demonstrated that, perhaps for the first time, the designer can gain deep insight into system behavior, such that the construction can be simultaneously optimized in respect to a number of functional characteristics besides the flatness of the off-axis dose profile. In the presented example, the system is optimized in respect to both, flatness of the off-axis dose profile and the beam transmission. A number of practical issues related to application of the new method as well as its possible extensions are discussed.

The structure of neutron-rich nuclei explored via in-beam gamma-ray spectroscopy of fast beams

International Nuclear Information System (INIS)

Glasmacher, T.; Campbell, C.M.; Church, J.A.; Dinca, D.C.; Hansen, P.G.; Olliver, H.; Perry, B.C.; Sherrill, B.M.; Terry, J.R.; Bazin, D.; Enders, J.; Gade, A.; Hu, Z.; Mueller, W.F.

2003-01-01

In-beam gamma-ray spectroscopy with fast exotic beams provides an efficient tool to study bound states in exotic neutron-rich nuclei. Specialized experimental techniques have been developed and explore different aspects of nuclear structure. Inelastic scattering experiments with γ-ray detection can measure the response of exotic nuclei to electromagnetic (Coulomb excitation with a heavy target) or hadronic probes (proton scattering with hydrogen target). In-beam fragmentation populates higher-lying bound states to establish levels. Single- and two-nucleon knockout reactions allow for detailed wavefunction spectroscopy of individual levels and for the measurement of spectroscopic factors. Experimental programs employing these techniques are now underway at all projectile-fragmentation facilities around the world. Here we report on several successful in-beam gamma-ray spectroscopy experiments that have been performed at the Coupled Cyclotron Facility at Michigan State University with an emphasis on elucidating the evolution of nuclear structure around neutron numbers N=16, N=20, and N=28 in the π(sd) shell. (orig.)

Generation of an intense ion beam by a pinched relativistic electron beam

International Nuclear Information System (INIS)

Gilad, P.; Zinamon, Z.

1976-01-01

The pinched electron beam of a pulsed electron accelerator is used to generate an intense beam of ions. A foil anode and vacuum drift tube are used. The space charge field of the pinched beam in the tube accelerates ions from the foil anode. Ion currents of 10 kA at a density of 5kA/cm 2 with pulse length of 50 ns are obtained using a 5 kJ, 450 kV, 3 Ω diode. (author)

Spot size dependence of laser accelerated protons in thin multi-ion foils

International Nuclear Information System (INIS)

Liu, Tung-Chang; Shao, Xi; Liu, Chuan-Sheng; Eliasson, Bengt; Wang, Jyhpyng; Chen, Shih-Hung

2014-01-01

We present a numerical study of the effect of the laser spot size of a circularly polarized laser beam on the energy of quasi-monoenergetic protons in laser proton acceleration using a thin carbon-hydrogen foil. The used proton acceleration scheme is a combination of laser radiation pressure and shielded Coulomb repulsion due to the carbon ions. We observe that the spot size plays a crucial role in determining the net charge of the electron-shielded carbon ion foil and consequently the efficiency of proton acceleration. Using a laser pulse with fixed input energy and pulse length impinging on a carbon-hydrogen foil, a laser beam with smaller spot sizes can generate higher energy but fewer quasi-monoenergetic protons. We studied the scaling of the proton energy with respect to the laser spot size and obtained an optimal spot size for maximum proton energy flux. Using the optimal spot size, we can generate an 80 MeV quasi-monoenergetic proton beam containing more than 10 8 protons using a laser beam with power 250 TW and energy 10 J and a target of thickness 0.15 wavelength and 49 critical density made of 90% carbon and 10% hydrogen

Nanodiamond Foils for H- Stripping to Support the Spallation Neutron Source (SNS) and Related Applications

Energy Technology Data Exchange (ETDEWEB)

Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL; Harris, Gary [Howard University; Piazza, Fabrice [Pontifica Universidad Catolica Madre y Maestra, Dominican Republic

2013-01-01

Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a single nanodiamond foil about the size of a postage stamp is critical to the entire operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control over film thickness. The results are discussed in the light of development

The transmission of fast molecular ions through thin foils

International Nuclear Information System (INIS)

Pietsch, W.J.; Gemmell, D.S.; Cooney, P.J.; Kanter, E.P.; Kurath, D.; Ratkowski, A.J.; Vager, Z.; Zabransky, B.J.

1980-01-01

We present new results on the transmission of fast molecular ions through thin foils and propose a mechanism for the transmission process. The main feature of the postulated mechanism is that a finite fraction of the incident molecular beam does not undergo a strong Coulomb explosion while traversing the foil. Because the emerging fragments are at large internuclear separations, there is an enhanced probability for the formation of bound, long-range, excited electronic states following electron capture at the rear surface of the target. (orig.)

BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

International Nuclear Information System (INIS)

Bonomo, F.; Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D.; Barbisan, M.; Pasqualotto, R.; Serianni, G.; Cristofaro, S.

2015-01-01

The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H α light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H α spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region

RFQ beam cooler and buncher for collinear laser spectroscopy of rare isotopes

Science.gov (United States)

Barquest, B. R.; Bollen, G.; Mantica, P. F.; Minamisono, K.; Ringle, R.; Schwarz, S.; Sumithrarachchi, C. S.

2017-09-01

A radiofrequency quadrupole (RFQ) ion beam cooler and buncher has been developed to deliver bunched beams with low transverse emittance, energy spread, and time spread to the BECOLA collinear laser spectroscopy system at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The beam cooler and buncher contains new features which enhance performance, especially for high count rate beams, as well as simplifying construction, maintenance, and operation. The transverse emittance, energy spread, and time spread of the bunched beam, as well as buncher efficiency are reported, showcasing the capabilities of the BECOLA facility to perform collinear laser spectroscopy measurements with bunched rare isotope beams at NSCL and at the future Facility for Rare Isotope Beams (FRIB).

Proceedings of the 3rd US-Japan Workshop on Plasma Polarization Spectroscopy

International Nuclear Information System (INIS)

Beiersdorfer, P; Flyimoto, T

2002-01-01

The third US-Japan Workshop on Plasma Polarization Spectroscopy was held at the Lawrence Livermore National Laboratory in Livermore, California, on June 18-21, 2001. The talks presented at this workshop are summarized in these proceedings. The papers cover both experimental investigation and applications of plasma polarization spectroscopy as well as the theoretical foundation and formalisms to understand and describe the polarization phenomena. The papers give an overview of the history of plasma polarization spectroscopy, derive the formal aspects of polarization spectroscopy, including the effects of electric and magnetic fields, discuss spectra perturbed by intense microwave fields, charge exchange, and dielectronic recombination, and present calculations of various collisional excitation and ionization cross sections and the modeling of plasma polarization spectroscopy phenomena. Experimental results are given from the WT-3 tokamak, the MST reverse field pinch, the Large Helical Device, the GAMMA 10 mirror machine, the Nevada Terrawatt Facility, the Livermore EBIT-II electron beam ion trap, and beam-foil spectroscopy. In addition, results were presented from studies of several laser-produced plasma experiments and new instrumental techniques were demonstrated

Active beam spectroscopy for ITER

International Nuclear Information System (INIS)

Von Hellermann, M.; Giroud, C.; Jaspers, R.; Hawkes, N.C.; Mullane, M.O.; Zastrow, K.D.; Krasilnikov, A.; Tugarinov, S.; Lotte, P.; Malaquias, A.; Rachlew, E.

2003-01-01

The latest status of 'Active Beam' related spectroscopy aspects as part of the ITER diagnostic scenario is presented. A key issue of the proposed scheme is based on the concept that in order to achieve the ultimate goal of global data consistency, all particles involved, that is, intrinsic and seeded impurity ions as well as helium ash ions and bulk plasma ions and also the plasma background data (e.g. magnetic and electric fields, electron density and temperature profiles) need to be addressed. A further sensible step in this direction is the decision of exploiting both a dedicated low-energy, low-power diagnostic beam (DNB, 2.2 MW 100 keV/amu) as well as the high-power, high-energy heating beams (HNB, 17 MW 500 keV/amu) for maximum diagnostic information. The authors report some new aspects referring to the use of DNB for motional Stark effect (MSE) where the main idea is to treat both beams (HNB and DNB) as potential diagnostic tools with complementary roles. The equatorial ports for the DNB promise excellent spatial resolution, however, the angles are less favourable for a polarimetric MSE exploitation. HNB can be used as probe beam for diagnosing slowing-down fusion alpha with a birth energy of 3,5 MeV

Resonance effects of transition radiation emitted from thin foil stacks using electron beam

Energy Technology Data Exchange (ETDEWEB)

Awata, Takaaki; Yajima, Kazuaki; Tanaka, Takashi [Kyoto Univ. (Japan). Faculty of Engineering; and others

1997-03-01

Transition Radiation(TR) X rays are expected to be a high brilliant X-ray source because the interference among TR X rays emitted from many thin foils placed periodically in vacuum can increase their intensity and make them quasi-monochromatic. In order to study the interference (resonance) effects of TR, we measured the energy spectra of TR for several sets of thin-foil stacks at various emission angles. It was found that the resonance effects of TR are classified into intrafoil and interfoil resonances and the intensity of TR X rays increases nonlinearly with increasing foil number, attributing to the interfoil resonance. It became evident that the brilliance of TR is as high as that of SR. (author)

Charge-state-distributions of foil-excited heavy Rydberg atoms

International Nuclear Information System (INIS)

Faibis, A.; Kanter, E.P.; Koenig, W.; Zabransky, B.J.

1985-01-01

Studies of foil-excited fast (MeV/amu) heavy ions have demonstrated large yields of high Rydberg atoms formed in such beams. Further experiments have suggested a strong target-thickness dependence of the yields of such atoms. These results have been puzzling in view of the supposed short mean free paths of such atoms in solids. In an effort to better understand these results, the authors have measured the yields of Rydberg atoms (napprox.100-200) in foil-excited 32 S ions at an incident energy of 125 MeV

Scrape-off layer-induced beam density fluctuations and their effect on beam emission spectroscopy

Science.gov (United States)

Moulton, D.; Marandet, Y.; Tamain, P.; Dif-Pradalier, G.

2015-07-01

A statistical model is presented to calculate the magnitude of beam density fluctuations generated by a turbulent scrape-off layer (SOL). It is shown that the SOL can induce neutral beam density fluctuations of a similar magnitude to the plasma density fluctuations in the core, potentially corrupting beam emission spectroscopy measurements. The degree of corruption is quantified by combining simulations of beam and plasma density fluctuations inside a simulated measurement window. A change in pitch angle from the separatrix to the measurement window is found to reduce the effect of beam fluctuations, whose largest effect is to significantly reduce the measured correlation time.

On-line spectroscopy with thermal atomic beams

International Nuclear Information System (INIS)

Thibault, C.; Guimbal, P.; Klapisch, R.; Saint Simon, M. de; Serre, J.M.; Touchard, F.; Duong, H.T.; Jacquinot, P.; Juncar, P.

1981-01-01

On-line high resolution laser spectroscopy experiments have been performed in which the light from a cw tunable dye laser interacts at right angles with a thermal atomic beam. sup(76-98)Rb, sup(118-145)Cs and sup(208-213)Fr have been studied using the ionic beam delivered by the ISOLDE on-line mass separator at CERN while sup(20-31)Na and sup(38-47)K have been studied by setting the apparaturs directly on-line with the PS 20 GeV proton beam. The principle of the method is briefly explained and some results concerning nuclear structure are given. (orig.)

Analysis of multiple-foil XRL targets using x-ray spectroscopy

International Nuclear Information System (INIS)

Wang, J.; Boehly, T.; Yaakobi, B.; Epstein, R.; Meyerhofer, D.; Richardson, M.C.; Russotto, M.; Soures, J.M.

1989-01-01

The multiple-foil collisional excitation x-ray laser targets proposed by LLE have been studied spectroscopically. Using spatially resolved 3d-2p x-ray spectra, the authors compare the temperatures and densities obtained in single- and double-foil geometries. They use the ratio of the dipole transitions to the electric quadrupole transitions in the Neon-like species as a density diagnostic. A non-LTE average-ion atomic physics model is used to describe the ionization process and a relativistic atomic physics code is used for calculation of the level energies, populations, and gain calculations. They support their claims that the double-vfoils provide higher densities and in some cases concave density profiles. The XUV spectra in the range of 20-300 A show the effect of target geometry and incident laser intensity on the lasing lines and the ionization balance

High quality graphene synthesized by atmospheric pressure CVD on copper foil

OpenAIRE

Trinsoutrot, Pierre; Rabot, Caroline; Vergnes, Hugues; Delamoreanu, Alexandru; Zenasni, Aziz; Caussat, Brigitte

2013-01-01

International audience; Graphene was synthesized at 1000 °C by Atmospheric Pressure Chemical Vapor Deposition on copper foil from methane diluted in argon and hydrogen. The influence of the main synthesis parameters was studied on 2 × 2 cm2 foils in order to obtain continuous monolayer graphenewithout crystalline defect. The uniformity, crystal quality and number of layers of graphenewere analyzed by Raman spectroscopy and Scanning Electronic Microscopy. First, an increase of the annealing pr...

Acceleration of polyethelene foils by laser driven ablation

International Nuclear Information System (INIS)

Ahlstrom, H.G.; Burginyon, G.A.; Haas, R.A.

1974-01-01

The production of thermonuclear energy, by laser driven implosion of spherical DT shells, with achievable laser technology, requires the development of an efficient and stable implosion. Certain aspects of the acceleration of the spherical shells can be studied experimentally by irradiating thin, 5 to 25 μm, polyethelene foils. The results of foil acceleration experiments performed using a Nd:YAG-Glass laser capable of producing 150 J, 1 nsec pulses will be discussed. The dynamics of the accelerated foil, the ion blow off, high energy electron spectrum (6 to 180 keV), x-ray spectrum (1 to 150 keV) the spatial distribution of the x-ray emission, the laser beam focal spot energy distribution, the laser temporal pulse shape and spectrum for reflected and transmitted radiation have all been measured simultaneously. The results of these measurements are compared with detailed numerical simulations. (U.S.)

Monte Carlo simulation of the scattering foil for EB food processing facility

International Nuclear Information System (INIS)

Petwal, V.C.; Pramod, R.; Soni, H.C.

2003-01-01

The electron beam coming out from accelerator window has diameter of few mm, and posses Gaussian distribution of electrons within its envelope. When such electron beam with 10 MeV energy and 1 kW average power passes through a vacuum isolating window and is allowed to fall on a product, the dose distribution of each beam pulse in side the product is very narrow. At 10 cm away from window the FWHM of dose profile is few cm with peak dose rate of the order kGy/pulse. In order to use this beam to process onion and potato in accordance with the stipulated requirement of total delivered dose and dose uniformity, the dose profile from each pulse must be modified. In present study the modification/flattening of the dose profile of each pulse is achieved by introducing scattering foil in the path of electron beam. The optimization of the scattering foil and resulting dose distributions simulated with MCNP (Monte Carlo Code for N Particle) is presented in the paper. (author)

Direct growth of hexagonal boron nitride/graphene heterostructures on cobalt foil substrates by plasma-assisted molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhongguang; Khanaki, Alireza; Tian, Hao; Zheng, Renjing; Suja, Mohammad; Liu, Jianlin, E-mail: jianlin@ece.ucr.edu [Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521 (United States); Zheng, Jian-Guo [Irvine Materials Research Institute, University of California, Irvine, California 92697-2800 (United States)

2016-07-25

Graphene/hexagonal boron nitride (G/h-BN) heterostructures have attracted a great deal of attention because of their exceptional properties and wide variety of potential applications in nanoelectronics. However, direct growth of large-area, high-quality, and stacked structures in a controllable and scalable way remains challenging. In this work, we demonstrate the synthesis of h-BN/graphene (h-BN/G) heterostructures on cobalt (Co) foil by sequential deposition of graphene and h-BN layers using plasma-assisted molecular beam epitaxy. It is found that the coverage of h-BN layers can be readily controlled on the epitaxial graphene by growth time. Large-area, uniform-quality, and multi-layer h-BN films on thin graphite layers were achieved. Based on an h-BN (5–6 nm)/G (26–27 nm) heterostructure, capacitor devices with Co(foil)/G/h-BN/Co(contact) configuration were fabricated to evaluate the dielectric properties of h-BN. The measured breakdown electric field showed a high value of ∼2.5–3.2 MV/cm. Both I-V and C-V characteristics indicate that the epitaxial h-BN film has good insulating characteristics.

Determination of cross sections of nuclear reactions to use Al as monitoring foil in heavy ion irradiation with 20Ne projectile

International Nuclear Information System (INIS)

Chowdhury, D.P.; Datta, J.; Guin, R.; Verma, R.

2009-01-01

The beam current is generally accurately measured using monitoring foils during the irradiation of thick samples by high energy ion beams. The cross sections of many nuclear reactions induced by light particles are available in literature for use as monitoring foil. However, such cross sections of heavy ion induced reactions are not reported much for their use in applied works. We have determined cross sections of two nuclear reactions, 27 Al ( 20 Ne,2p2n) 43 Sc and 27 Al ( 20 Ne, 2pn) 44m Sc, to use Al as monitoring foil for the irradiation with 20 Ne heavy ion beam. (author)

Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils

International Nuclear Information System (INIS)

Allen, M; Patel, P; Mackinnon, A; Price, D; Wilks, S; Morse, E

2004-01-01

Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10 20 W/cm 2 producing proton beams with a total yield of ∼ 10 11 and maximum proton energy of > 9 MeV. Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text

Relative measurements of fast neutron contamination in 18-MV photon beams from two linear accelerators and a betatron

International Nuclear Information System (INIS)

Gur, D.; Bukovitz, A.G.; Rosen, J.C.; Holmes, B.G.

1979-01-01

Fast neutron contamination in photon beams in the 20 MV range have been reported in recent years. In order to determine if the variations were due mainly to differences in measurement procedures, or inherent in the design of the accelerators, three different 18-MV (BJR) photon beams were compared using identical analytical techniques. The units studied were a Philips SL/75-20 and a Siemens Mevatron-20 linear accelerators and a Schimadzu betatron. Gamma spectroscopy of an activated aluminum foil was the method used. By comparing the relative amounts of neutron contamination, errors associated with absolute measurements such as detector efficiency and differences in activation foils were eliminated. Fast neutron contaminations per rad of x rays in a ratio of 6.7:3.7:1 were found for the Philips, Schimadzu and Siemens accelerators, respectively

Electrochemical etching of a niobium foil in methanolic HF for electrolytic capacitor

International Nuclear Information System (INIS)

Kim, Kyungmin; Park, Jiyoung; Cha, Gihoon; Yoo, Jeong Eun; Choi, Jinsub

2013-01-01

Electrochemical etching of niobium foil in order to enlarge the surface area for the application in electrolytic capacitor was carried out in a methanolic electrolyte. We found that the pit density and depth are not linearly proportional to concentration of HF and applied potential: there is the optimal concentration of HF at each applied potential. The optimal etching condition was obtained at 50 V in 0.99 vol.% HF, which exhibited the capacitance of 350 μF cm −2 . Pit density and depth of pits on electrochemical etched Nb foil under different conditions were counted from SEM images and electrochemical impedance spectroscopy (EIS) of the etched Nb foils was carried out for the capacitance measurement. Equivalent circuit model showing less than 5% error was suggested for applying to the etched niobium foil. - Highlights: • Surface enlargement of Nb foil can be achieved by electrochemical etching in methanolic HF. • Electrolytic capacitor of etched niobium foil exhibits a capacitance of 350 μF cm −2 . • The method provides a way of developing commercially viable process

Plasma heating by relativistic electron beams: correlations between experiment and theory

International Nuclear Information System (INIS)

Thode, L.E.; Godfrey, B.B.

1975-01-01

The streaming instability is the primary heating mechanism in most, if not all, experiments in which the beam is injected into partially or fully ionized gas. In plasma heating experiments, the relativistic beam must traverse an anode foil before interacting with the plasma. The linear theory for such a scattered beam is discussed, including a criterion for the onset of the kinetic interaction. A nonlinear model of the two-stream instability for a scattered beam is developed. Using this model, data from ten experiments are unfolded to obtain the following correlations: (i) for a fixed anode foil, the dependence of the plasma heating on the beam-to-plasma density ratio is due to anode foil scattering, (ii) for a fixed beam-to-plasma density ratio, the predicted change in the magnitude of plasma heating as a function of the anode foil is in agreement with experiment, and (iii) the plasma heating tentatively appears to be proportional to the beam kinetic energy density and beam pulse length. For a fixed anode foil, theory also predicts that the energy deposition is improved by increasing the beam electron energy γmc 2 . Presently, no experiment has been performed to confirm this aspect of the theory

Study of electron beam effects on surfaces using x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS)

International Nuclear Information System (INIS)

Gettings, M.; Coad, J.P.

1976-02-01

Discrepancies in the surface analyses of oxidised or heavily contaminated materials have been observed between X-ray Photoelectron Spectroscopy (XPS) and techniques using electron beams (primarily Auger Electron Spectroscopy (AES)). These discrepancies can be ascribed to the influence of the primary electron beam and to illustrate the various types of electron effects different materials were analysed using XPS and Secondary Ion Mass Spectroscopy (SIMS) before and after large area electron bombardment. The materials used included chrome and stainless steels, nickel, platinum, glass and brass. (author)

Beam-transport system for high-resolution heavy-ion spectroscopy

International Nuclear Information System (INIS)

Roussel, P.; Kashy, E.

1980-01-01

A method is given to adjust a beam-transport system to the requirements of high-energy resolution heavy-ion spectroscopy. The results of a test experiment performed on a MP tandem with a 12 C beam are shown. A drastic improvement in energy resolution is obtained for a kinematical factor K=1/p dp/dtheta=0.12 [fr

Laser spectroscopy of radioactive beams

International Nuclear Information System (INIS)

Otten, E.W.

1983-01-01

The problem of using the laser spectroscopy in investigations radioactive beams is considered. The main attention is payed to the isotope shift of nuclear charge radii delta 2 >. The general trend of delta 2 > is discussed. Predictions for delta>r 2 < in the framework of the droplet model are given. It is noted that two parameter interpretation of the isotope shift based on the droplet model works the better, the further the distance spans and the clearer the nuclear structure is

Modelling Accumulator Stripper Foil Heating for ESSNUSB Facility

CERN Document Server

Martini, Michel

2015-01-01

It is proposed to use the 2.0 GeV, 5 MW proton linac, 2.86 ms long pulses at 14 Hz of the European Spallation Source [1], [2] being built in Lund, Sweden to deliver, alternately with the spallation neutron production a very intense neutrino beam to enable the discovery of leptonic CP violation. To this end the linac would be upgraded to supply, in addition to the 2.86 ms long proton pulses at 14 Hz, four 0.72 ms H short pulses at 70 Hz for neutrino production. Because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production will need to be compressed to a few s with the aid of an accumulator ring. Charge exchange injection of an H- beam from the linac will be used, the linac delivering 1.1E15 H- per pulse. This paper is about stripping foil heating considerations, emphasizing the detailed evaluation of the foil temperature over the multiple ring re-fills

Thrust augmentation in tandem flapping foils by foil-wake interaction

Science.gov (United States)

Anderson, Erik; Lauder, George

2006-11-01

Propulsion by pitching and heaving airfoils and hydrofoils has been a focus of much research in the field of biologically inspired propulsion. Organisms that use this sort of propulsion are self-propelled, so it is difficult to use standard experimental metrics such as thrust and drag to characterize performance. We have constructed a flapping foil robot mounted in a flume on air-bearings that allows for the determination of self-propelled speed as a metric of performance. We have used a pair of these robots to examine the impact of an upstream flapping foil on a downstream flapping foil as might apply to tandem fins of a swimming organism or in-line swimming of schooling organisms. Self-propelled speed and a force transducer confirmed significant thrust augmentation for particular foil-to-foil spacings, phase differences, and flapping frequencies. Flow visualization shows the mechanism to be related to the effective angle of attack of the downstream foil due to the structure of the wake of the upstream foil. This confirms recent computational work and the hypotheses by early investigators of fish fluid dynamics.

Physics with fast molecular-ion beams. Proceedings of workshop held at Argonne National Laboratory, August 20-21, 1979

International Nuclear Information System (INIS)

Gemmell, D.S.

1979-01-01

The Workshop on Physics with Fast Molecular-Ion Beams was held in the Physics Division, Argonne National Laboratory on August 20 and 21, 1979. The meeting brought together representatives from several groups studying the interactions of fast (MeV) molecular-ion beams with matter. By keeping the Workshop program sharply focussed on current work related to the interactions of fast molecular ions, it was made possible for the participants to engage in vigorous and detailed discussions concerning such specialized topics as molecular-ion dissociation and transmission, wake effects, ionic charge states, cluster stopping powers, beam-foil spectroscopy, electron-emissions studies with molecular-ion beams, and molecular-ion structure determinations

Transition radiation electron beam diagnostic study at ATF

International Nuclear Information System (INIS)

Qiu, X.Z.; Wang, X.J.; Batchelor, K.; Ben-Zvi, I.

1995-01-01

Recently we have started a program to develop transition radiation based electron beam diagnostics at the Accelerator Test Facility at Brookhaven National Laboratory. In this paper, we will discuss a technique to estimate the lower limit in electron beam divergence measurement with single foil transition radiation and two-foil transition radiation interferometer. Preliminary experimental data from 4.5 MeV electron beam will be presented

Search for Rayleigh-Taylor instability in laser irradiated layered thin foil targets

International Nuclear Information System (INIS)

Kilkenny, J.D.; Hares, J.D.; Rumsby, P.T.

1980-01-01

An experiment to measure the Rayleigh-Taylor instability at the vacuum-ablation surface of laser irradiated layered targets by time resolved x-ray spectroscopy is described. The time taken to burn through a layer of material is measured to be the same for massive targets as for thin foil accelerating targets. It is inferred that the thin foil targets might be Rayleigh-Taylor stable despite the values of γtauapproximately equal to15 calculated from classical theory. (author)

Hard X-ray emission spectroscopy with pink beam

Energy Technology Data Exchange (ETDEWEB)

Kvashnina, Kristina O.; Rossberg, Andre; Exner, Joerg; Scheinost, Andreas C. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Molecular Structures

2017-06-01

Valence-band X-ray emission spectroscopy (XES) with a ''pink beam'', i.e. a beam with large energy bandwidth produced by a double-multilayer monochromator, is introduced here to overcome the weak count rate of monochromatic beams produced by conventional double-crystal monochromators. Our results demonstrate that - in spite of the large bandwidth in the order of 100 eV - the high spectral resolution of the Johann-type spectrometer is maintained, while the two orders of magnitude higher flux greatly reduces the required counting time. The short working distance Johann-type X-ray emission spectrometer and multilayer monochromator is available at ROBL.

100-MeV proton beam intensity measurement by Au activation analysis using {sup 197}Au(p, pn){sup 196}Au and {sup 197}Au(p, p3n){sup 194}Au reactions

Energy Technology Data Exchange (ETDEWEB)

Mokhtari Oranj, Leila [Division of Advanced Nuclear Engineering, POSTECH, Pohang 37673 (Korea, Republic of); Jung, Nam-Suk; Oh, Joo-Hee [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of); Lee, Hee-Seock, E-mail: lee@postech.ac.kr [Pohang Accelerator Laboratory, POSTECH, Pohang 37673 (Korea, Republic of)

2016-05-15

The proton beam intensity of a 100-MeV proton linac at the Korea Multi-purpose Accelerator Complex (KOMAC) was measured by an Au activation analysis using {sup 197}Au(p, pn){sup 196}Au and {sup 197}Au(p, p3n){sup 194}Au reactions to determine the accuracy and precision of beam intensity measurement using Gafchromic film dosimetry method. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of Au, Al foils and Pb plates. The yields of produced radio-nuclei in Au foils were obtained by gamma-ray spectroscopy. The FLUKA code was employed to calculate the energy spectrum of protons onto the front surface of Au foils located at three different depth points of the target and also to investigate the condition of incident beam on the target. A good agreement was found between the beam intensity measurements using the activation analysis method at three different depth points of the target. An excellent agreement was also observed between the beam intensity measurements using the Au activation analysis method and the dosimetry method using Gafchromic film.

Overview of in-beam gamma-ray spectroscopy at the RIBF

Energy Technology Data Exchange (ETDEWEB)

Doornenbal, Pieter [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

2016-07-07

At the Radioactive Isotope Beam Factory stable primary beams are accelerated up to 345 MeV/u and incident on a primary target to produce cocktail secondary beams with the fragment separator BigRIPS ranging from the lightest nuclei up to the lead region. For in-beam γ-ray spectroscopy, the secondary beams impinge on a reaction target at energies between 100 and 300 MeV/u. Reaction residues are identified with the ZeroDegree spectrometer and γ-rays detected with the NaI(Tl) based DALI2 array. This conference paper outlines the experimental setup and presents recent exemplary results.

Dose reader of dosimetric foil; Czytnik dawki folii dozymetrycznej

Energy Technology Data Exchange (ETDEWEB)

Machaj, B.; Strzalkowski, J.; Smolko, K.

1997-12-31

Read out the absorbance of a dosimetric foil is accomplished by two beam spectrophotometer. Such a solution makes possible the compensation of light source instabilities and ensures higher stability of the dose reader. The error of absorbance measurement caused by the instabilities does not exceed 0.0004 A. (author). 3 refs, 3 figs.

Comparison between bulk and thin foil ion irradiation of ultra high purity Fe

Energy Technology Data Exchange (ETDEWEB)

Prokhodtseva, A., E-mail: anna.prokhodtseva@psi.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland); Décamps, B. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS-IN2P3-Univ. Paris-Sud 11, UMR 8609, Bât. 108, 91405 Orsay (France); Schäublin, R. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland)

2013-11-15

Accumulation of radiation damage in ultra high purity iron under self ion irradiation without and with simultaneous He implantation was investigated in bulk and thin foil form to assess, on the one hand, the effect of free surfaces and, on the other hand, the influence of He. Specimens were irradiated at room temperature to a dose of 0.8 dpa and ∼900 appm He content. We found in thin foils after irradiation with single beam a majority of a{sub 0} 〈1 0 0〉 type loops, while in the presence of He it is the ½ a{sub 0} 〈1 1 1〉 type loops that prevail. In single beam irradiated bulk samples most of the loops are of ½ a{sub 0} 〈1 1 1〉 type. In both bulk and thin foils density of defects visible in transmission electron microscope is considerably higher when He is implanted with prevailing ½ a{sub 0} 〈1 1 1〉 dislocation loops, indicating that He stabilizes them.

Temperature-dependent Raman spectroscopy studies of the interface coupling effect of monolayer ReSe2 single crystals on Au foils

Science.gov (United States)

Jiang, Shaolong; Zhao, Liyun; Shi, Yuping; Xie, Chunyu; Zhang, Na; Zhang, Zhepeng; Huan, Yahuan; Yang, Pengfei; Hong, Min; Zhou, Xiebo; Shi, Jianping; Zhang, Qing; Zhang, Yanfeng

2018-05-01

Rhenium diselenide (ReSe2), which bears in-plane anisotropic optical and electrical properties, is of considerable interest for its excellent applications in novel devices, such as polarization-sensitive photodetectors and integrated polarization-controllers. However, great challenges to date in the controllable synthesis of high-quality ReSe2 have hindered its in-depth investigations and practical applications. Herein, we report a feasible synthesis of monolayer single-crystal ReSe2 flakes on the Au foil substrate by using a chemical vapor deposition route. Particularly, we focus on the temperature-dependent Raman spectroscopy investigations of monolayer ReSe2 grown on Au foils, which present concurrent red shifts of Eg-like and Ag-like modes with increasing measurement temperature from 77–290 K. Linear temperature dependences of both modes are revealed and explained from the anharmonic vibration of the ReSe2 lattice. More importantly, the strong interaction of ReSe2 with Au, with respect to that with SiO2/Si, is further confirmed by temperature-dependent Raman characterization. This work is thus proposed to shed light on the optical and thermal properties of such anisotropic two-dimensional three-atom-thick materials.

Laser spectroscopy of relativistic beams of H- and H

International Nuclear Information System (INIS)

Smith, W.W.; Tang, C.Y.; Harris, P.G.; Mohagheghi, A.H.; Bryant, H.C.; Reeder, R.A.; Toutounchi, H.; Sharifian, H.

1989-01-01

Laser spectroscopy on near-light velocity H- ions and H atoms has been carried out at the Los Alamos Meson Physics Facility using a variety of fixed frequency lasers intersecting accelerated beams at variable angles. Beam energies up to 800 MeV (v/c) = 0.84 make possible an unusually wide tuning range at modestly high resolution. A dedicated beam line, the High Resolution Atomic Beam (HIRAB), also makes possible Stark effect and field ionization studies in the multi-megavolt/cm range. Preliminary results on multiphoton detachment of fast H-ions using a pulsed CO 2 laser focussed to ∼10 11 W/cm 2 over a factor 10 photon energy range (CM frame) are presented in this paper

Angular dependence of imprinting levels in laser-target interactions on planar CH foils

International Nuclear Information System (INIS)

Smalyuk, V.A.; Goncharov, V.N.; Boehly, T.R.; Delettrez, J.A.; Li, D.Y.; Marozas, J.A.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

2005-01-01

Imprinting of laser-beam modulations at various angles of incidence is measured for the first time in planar CH foils. The imprinted target modulations were seeded by special probe beams at a spatial wavelength of 60 μm and subsequently amplified by five drive beams. The measured imprint efficiency decreases by a factor of 3 as the angle of incidence of the probe beam is increased from 20 deg. to 60 deg., as predicted by theoretical modeling. The imprinting is very sensitive to the relative arrival time of the probe and drive beams

Thin Foil Acceleration Method for Measuring the Unloading Isentropes of Shock-Compressed Matter

International Nuclear Information System (INIS)

Asay, J.R.; Chhabildas, L.C.; Fortov, V.E.; Kanel, G.I.; Khishchenko, K.V.; Lomonosov, I.V.; Mehlhorn, T.; Razorenov, S.V.; Utkin, A.V.

1999-01-01

This work has been performed as part of the search for possible ways to utilize the capabilities of laser and particle beams techniques in shock wave and equation of state physics. The peculiarity of these techniques is that we have to deal with micron-thick targets and not well reproducible incident shock wave parameters, so all measurements should be of a high resolution and be done in one shot. Besides the Hugoniots, the experimental basis for creating the equations of state includes isentropes corresponding to unloading of shock-compressed matter. Experimental isentrope data are most important in the region of vaporization. With guns or explosive facilities, the unloading isentrope is recovered from a series of experiments where the shock wave parameters in plates of standard low-impedance materials placed behind the sample are measured [1,2]. The specific internal energy and specific volume are calculated from the measured p(u) release curve which corresponds to the Riemann integral. This way is not quite suitable for experiments with beam techniques where the incident shock waves are not well reproducible. The thick foil method [3] provides a few experimental points on the isentrope in one shot. When a higher shock impedance foil is placed on the surface of the material studied, the release phase occurs by steps, whose durations correspond to that for the shock wave to go back and forth in the foil. The velocity during the different steps, connected with the knowledge of the Hugoniot of the foil, allows us to determine a few points on the isentropic unloading curve. However, the method becomes insensitive when the low pressure range of vaporization is reached in the course of the unloading. The isentrope in this region can be measured by recording the smooth acceleration of a thin witness plate foil. With the mass of the foil known, measurements of the foil acceleration will give us the vapor pressure

Proceeding of the workshop on gamma-ray spectroscopy utilizing heavy-ion, photon and RI beams

Energy Technology Data Exchange (ETDEWEB)

Oshima, Masumi; Sugita, Michiaki; Hayakawa, Takehito [eds.

1998-03-01

Three time since 1992, we have held the symposia entitled `Joint Spectroscopy Experiments Utilizing JAERI Tandem-Booster Accelerator` at the Tokai Research Establishment. In the symposia, we have mainly discussed the plans of experiments to be done in this joint program. The joint program started in 1994. Several experiments have been made since and some new results have already come up. This symposium `Gamma-ray Spectroscopy utilizing heavy-ion, Photon and RI beams` was held at Tokai Research Establishment of JAERI. Because this symposium is the first occasion after the program started, the first purpose of the symposium is to present and discuss the experimental results so far obtained using the JAERI Tandem-Booster. The second purpose of the symposium is to discuss new possibilities of gamma-ray spectroscopy using new resources such as RI-beam and Photon-beam. The participants from RIKEN, Tohoku University and JAERI Neutron Science Research Center presented the future plans of experiments with RI-beam at each facility. Compared with these nuclear beams, photon beam provides a completely new tool for the {gamma}-ray spectroscopy, which is achieved by inverse Compton scattering between high-energy electron and laser beams. The 23 of the presented papers are indexed individually. (J.P.N.)

Development of nanodiamond foils for H- stripping to Support the Spallation Neutron Source (SNS) using hot filament chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL

2014-01-01

Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a small foil about the size of a postage stamp is critical to the operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control film thickness. The results are discussed in the light of development of nanodiamond foils that

Beam heating of target foils

International Nuclear Information System (INIS)

Corwin, W.C.

1975-01-01

A target rotator, built to reduce the effects of beam spot heating, is fully adjustable, holds three targets, is chamber independent, and takes up limited space. The expected temperature rise in the target is calculated from the Stefan--Boltzmann law

In-beam spectroscopy of 253,254No

International Nuclear Information System (INIS)

Herzberg, R.D.; Amzal, N.; Bastin, J.E.; Brew, P.M.T.; Butler, P.A.; Chewter, A.J.C.; Hammond, N.J.; Humphreys, R.D.; Jones, G.D.; Becker, F.; Hauschild, K.; Houry, M.; Huerstel, A.; Cocks, J.F.C.; Dorvaux, O.; Greenlees, P.T.; Eskola, K.; Gerl, J.; Hessberger, F.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.; Kankaanpaeae, H.; Kettunen, H.; Khoo, T.L.; Korten, W.; Kuusiniemi, P.; Le Coz, Y.; Leino, M.; Leppaenen, C.J.; Lister, A.P.; Lucas, R.; Muikku, M.; Nieminen, P.; Page, R.D.; Page, T.; Rahkila, P.; Reiter, P.; Schlegel, Ch.; Scholey, C.; Sletten, G.; Stezowski, O.; Theisen, Ch.; Trzaska, W.H.; Uusitalo, J.; Wollersheim, H.J.

2002-01-01

In-beam conversion electron spectroscopy experiments have been performed on the transfermium nuclei 253, 254 No using the conversion electron spectrometer SACRED in nearly collinear geometry in conjunction with the gas-filled separator RITU at the University of Jyvaeskylae. The experimental setup is discussed and the spectra are compared to Monte Carlo simulations. The implications for the ground-state configuration of 253 No are discussed. (orig.)

Combined in-beam gamma-ray and conversion electron spectroscopy with radioactive ion beams

Directory of Open Access Journals (Sweden)

Konki J.

2013-12-01

Full Text Available In-beam gamma-ray and electron spectroscopy have been widely used as tools to study the broad variety of phenomena in nuclear structure. The SPEDE spectrometer is a new device to be used in conjunction with the MINIBALL germanium detector array to enable the detection of internal conversion electrons in coincidence with gamma rays from de-exciting nuclei in radioactive ion beam experiments at the upcoming HIE-ISOLDE facility at CERN, Switzerland. Geant4 simulations were carried out in order to optimise the design and segmentation of the silicon detector to achieve good energy resolution and performance.

Post-foil interaction in foil-induced molecular dissociation

International Nuclear Information System (INIS)

Faibis, A.; Kanter, E.P.; Koenig, W.; Plesser, I.; Vager, Z.

1985-01-01

The authors have investigated the foil-induced dissociation of 175- 250- keV/amu CH + , NH + , and OH + , FH + and NeH + ions by coincident detection of the fragment atoms. The dissociation energies corresponding to in-foil and post-foil interactions were deduced from the measured relative flight times of the fragment pairs to a set of detectors downstream from the target. The authors considered final states consisting of a) a proton and a heavy-ion and, b) a hydrogen atom and a heavy-ion. Surprisingly, in both cases the energy released in the post-target interaction shows a similar linear increase with the charge state of the heavy partner

Production of thin carbon stripper foils using heated-substrates in a cathodic arc deposition system

International Nuclear Information System (INIS)

Merchant, A.R.; Lobanov, N.; Elliman, R.G.; Ophel, T.R.; Rode, A.; Weisser, D.C.; Turkentine, R.B.

1998-01-01

The lifetime of carbon stripper foil can have a marked impact on the successful running of a beam line. Standard techniques for production of carbon stripper foils include evaporation of carbon (ec) and laser-pulsed ablation (Ipa). Recent work by a using Ipa has been successful in substantially increasing the lifetime of a very thin foil. The suspected mechanism for the increased lifetime of the foil is that the amorphous carbon foil is density-matched to that of graphite (around 2.26g/cc). In this work, we attempt to reproduce this result by producing carbon stripper foils with a mass-density similar to graphite using a cathodic arc deposition system. The cathodic arc is well known for the production of tetrahedral amorphous carbon: a high density, high stress form of carbon with over 90% sp 3 -like bonds; to reduce the density of the carbon and promote more graphitic structure, a high bias was initially attempted but this proved unsuccessful. Another method is to use a heated-substrate holder to reduce compressive stress within the deposited film. The performance of the density-matched carbon stripper foils and the implications for future production of high-quality carbon stripper foils in our laboratory will be discussed. (authors)

Time-resolved plasma spectroscopy of thin foils heated by a relativistic-intensity short-pulse laser

International Nuclear Information System (INIS)

Audebert, P.; Gauthier, J.-C.; Shepherd, R.; Fournier, K.B.; Price, D.; Lee, R.W.; Springer, P.; Peyrusse, O.; Klein, L.

2002-01-01

Time-resolved K-shell x-ray spectra are recorded from sub-100 nm aluminum foils irradiated by 150-fs laser pulses at relativistic intensities of Iλ 2 =2x10 18 W μm 2 /cm 2 . The thermal penetration depth is greater than the foil thickness in these targets so that uniform heating takes place at constant density before hydrodynamic motion occurs. The high-contrast, high-intensity laser pulse, broad spectral band, and short time resolution utilized in this experiment permit a simplified interpretation of the dynamical evolution of the radiating matter. The observed spectrum displays two distinct phases. At early time, ≤500 fs after detecting target emission, a broad quasicontinuous spectral feature with strong satellite emission from multiply excited levels is seen. At a later time, the He-like resonance line emission is dominant. The time-integrated data is in accord with previous studies with time resolution greater than 1 ps. The early time satellite emission is shown to be a signature of an initial large area, high density, low-temperature plasma created in the foil by fast electrons accelerated by the intense radiation field in the laser spot. We conclude that, because of this early time phenomenon and contrary to previous predictions, a short, high-intensity laser pulse incident on a thin foil does not create a uniform hot and dense plasma. The heating mechanism has been studied as a function of foil thickness, laser pulse length, and intensity. In addition, the spectra are found to be in broad agreement with a hydrodynamic expansion code postprocessed by a collisional-radiative model based on superconfiguration average rates and on the unresolved transition array formalism

Development of a high current 60 keV neutral lithium beam injector for beam emission spectroscopy measurements on fusion experiments

Science.gov (United States)

Anda, G.; Dunai, D.; Lampert, M.; Krizsanóczi, T.; Németh, J.; Bató, S.; Nam, Y. U.; Hu, G. H.; Zoletnik, S.

2018-01-01

A 60 keV neutral lithium beam system was designed and built up for beam emission spectroscopy measurement of edge plasma on the KSTAR and EAST tokamaks. The electron density profile and its fluctuation can be measured using the accelerated lithium beam-based emission spectroscopy system. A thermionic ion source was developed with a SiC heater to emit around 4-5 mA ion current from a 14 mm diameter surface. The ion optic is following the 2 step design used on other devices with small modifications to reach about 2-3 cm beam diameter in the plasma at about 4 m from the ion source. A newly developed recirculating sodium vapour neutralizer neutralizes the accelerated ion beam at around 260-280 °C even during long (manipulation techniques are applied to allow optimization, aiming, cleaning, and beam modulation. The maximum 60 keV beam energy with 4 mA ion current was successfully reached at KSTAR and at EAST. Combined with an efficient observation system, the Li-beam diagnostic enables the measurement of the density profile and fluctuations on the plasma turbulence time scale.

Study of the nuclear structure far from stability: Coulomb excitation of neutron-rich Rb isotopes around N=60; Production of nuclear spin polarized beams using the tilted foils technique

International Nuclear Information System (INIS)

Sotty, C.

2013-01-01

The underlying structure in the region A ∼ 100, N ∼ 60 has been under intensive and extensive investigation, mainly by β-decay and γ-ray spectroscopy from fission processes. Around N ∼ 60, by adding just few neutrons, protons a rapid shape change occurs from spherical-like to well deformed g.s. shape. Shape coexistence has been observed in the Sr and Zr nuclei, and is expected to take place in the whole region. The mechanisms involved in the appearance of the deformation is not well understood. The interplay between down-sloping and up-sloping neutron Nilsson orbital is evoked as one of the main reasons for the sudden shape change. However, a clear identification of the active proton and neutron orbitals was still on-going. For that purpose, the neutron rich 93;95;97;99 Rb isotopes have been studied by Coulomb excitation at CERN (ISOLDE) using the REX-ISOLDE post-accelerator and the MINIBALL setup. The completely unknown structures of 97;99 Rb have been populated and observed. Prompt γ-ray coincidences of low-lying states have been observed and time-correlated in order to build level schemes. The associated transition strengths have been extracted with the GOSIA code. The observed matrix elements of the electromagnetic operator constituted new inputs of further theoretical calculations giving new insight on the involved orbitals. The sensitivity of such experiment can be increased using nuclear spin polarized radioactive ion beam. For that purpose the Tilted Foils Technique (TFT) of polarization has been investigated at CERN. This technique consists to spin polarize the ion beam, passing through thin foils tilted at an oblique angle with respect to the beam direction. The initially obtained atomic polarization is transferred to the nucleus by hyperfine interaction. This technique does not depend on the chemical nature of the element. Short lived nuclei can be polarized in-flight without any need to be stopped in a catcher. It opens up the possibility to

Foil-less plasma-filled diode for HPM generator

International Nuclear Information System (INIS)

Eltchaninov, A A; Kovalchuk, B M; Kurkan, I K; Zherlitsyn, A A

2014-01-01

Plasma-filled diode regarded as perspective source of electron beam feeding HPM generator of GW power level, comparing to conventional explosive emission vacuum diode. Electron beam generation occurs in plasma double layer, where plasma boundary plays as an anode. It allows cancelling the usage of anode foils or grids in HPM generators with the virtual cathode, which could limit its life time to few shots. The presence of ions in the e-beam drift space could raise the limiting current for a drift space, but it could affect to microwave generation also. Sectioned plasma-filled diode with beam current of about 100 kA, electron beam energy of about 0.5 MV and beam current density of 1-10 kA/cm 2 was realized. Cylindrical transport channel with the diameter of 200 mm and the length of about 30 cm was attached to the diode. Beam current measurements in a drift space were performed. Computer simulations of electron beam transport with the presence of ions were carried out with the 2.5D axisymmetric version of PiC-code KARAT. Obtained results would help optimizing electrodynamic system of HPM generator subjected to the presence of ions

Vacuum-to-air interface for the advanced test accelerator beam director

International Nuclear Information System (INIS)

Cruz, G.E.; Edwards, W.F.; Kavanagh, D.P.; Addis, R.B.; Weiss, W.C.; Livenspargar, C.M.

1986-01-01

A vacuum-to-air transition was created to facilitate the Lawrence Livermore National Laboratory's Advanced Test Accelerator (ATA) electron beam 1-Hz pulse rate. It is necessary that a pulsed particle beam go from a region at 10 -6 torr through a 1-cm-diam maximum aperture into a region at 760 torr. This must be accomplished without the use of windows or solid barriers. Two tests will be conducted on the vacuum-to-air interface. The first determines pressure profiles through 1.0-mm- and 10.0-mm-diam orifices. The second test employs an expendable foil and foil advancement mechanism. In this paper, the experimental results of the orifice test are presented and the analytical results are compared with the empirical results. The foil advancement test will be documented after the test is completed. The mechanism serves both as an orifice and as a fast-acting vacuum valve. In operation, the electron beam penetrates the thin foil, thereby creating an aperture of minimum geometry. During the balance of the pulse cycle, after the beam duration, the foil is advanced to seal the opening and recover the almost negligible loss in vacuum

Gamma spectroscopy: from steady beams to radioactive beams

International Nuclear Information System (INIS)

Stezowski, O.

2008-06-01

The author gives an overview of his research works in the field of gamma spectroscopy. First, he recalls some results of experiments performed for the study of peculiar structures associated with different modes of nucleus rotation, and notably in the case of collective rotation of deformed and even super-deformed nuclei. Then, he details tools and methods used to experimentally determine the level scheme. The main characteristics of steady and radioactive beams are briefly presented, and their complementarities and differences are highlighted. Specific spectrometers and sensors are described. In a last chapter, the author discusses several research projects he is involved in, and more particularly the 'gamma tracking' which is the fundamental principle for gamma multi-sensors of the next generations

Determination of low-energy ion-induced electron yields from thin carbon foils

International Nuclear Information System (INIS)

Allegrini, Frederic; Wimmer-Schweingruber, Robert F.; Wurz, Peter; Bochsler, Peter

2003-01-01

Ion beams crossing thin carbon foils can cause electron emission from the entrance and exit surface. Thin carbon foils are used in various types of time-of-flight (TOF) mass spectrometers to produce start pulses for TOF measurements. The yield of emitted electrons depends, among other parameters, on the energy of the incoming ion and its mass, and it has been experimentally determined for a few projectile elements. The electron emission yield is of great importance for deriving abundance ratios of elements and isotopes in space plasmas using TOF mass spectrometers. We have developed a detector for measuring ion-induced electron yields, and we have extended the electron yield measurements for oxygen to energies relevant for solar wind research. We also present first measurements of the carbon foil electron emission yield for argon and iron in the solar wind energy range

Nanocomposite of polystyrene foil grafted with metallaboranes for antimicrobial activity

Science.gov (United States)

Benkocká, Monika; Kolářová, Kateřina; Matoušek, Jindřich; Semerádtová, Alena; Šícha, Václav; Kolská, Zdeňka

2018-05-01

The surface of polystyrene foil (PS) was chemically modified. Firstly, the surface was pre-treated with Piranha solution. The activated surface was grafted by selected amino-compounds (cysteamine, ethylenediamine or chitosan) and/or subsequently grafted with five members of inorganic metallaboranes. Selected surface properties were studied by using various methods in order to indicate significant changes before and after individual modification steps of polymer foil. Elemental composition of surface was conducted by using X-ray photoelectron spectroscopy, chemistry and polarity by infrared spectroscopy and by electrokinetic analysis, wettability by goniometry, surface morphology by atomic force microscopy. Antimicrobial tests were performed on individual samples in order to confirm antimicrobial impact. Our results show slight antibacterial activity of PS modified with SK5 for Escherichia coli in comparison with the rest of the tested borane. On the other hand molecules of all tested metallaboranes could easier pierce through bacterial cell of Staphylococcus epidermidis due to absence of outer membrane (phospholipid bilayer). Some borane grafted on PS surface embodies the strong activity for Staphylococcus epidermidis and also for Desmodesmus quadricauda growth inhibition.

Use of molecular ion beams from a tandem accelerator

International Nuclear Information System (INIS)

Faibis, A.; Goldring, G.; Hass, M.; Kaim, R.; Plesser, I.; Vager, Z.

1981-01-01

A large variety of positive molecular ion beams can be produced by gaseous charge exchange in the terminal of a tandem accelerator. After acceleration the molecules are usually dissociated by passage through a thin foil. Measurements of the break-up products provide a way to study both the structure of incident ions and the effects of electronic potentials on the internuclear interaction inside the foil. Beam intensities of a few picoamperes are quite adequate for these measurements, and the relatively high energy obtained by use of a tandem accelerator has the advantage of minimizing multiple scattering effects in the foil. The main difficulty in using the molecular beams lies in the large magnetic rigidity of singly-charged heavy molecular ions

Process for anodizing aluminum foil

International Nuclear Information System (INIS)

Ball, J.A.; Scott, J.W.

1984-01-01

In an integrated process for the anodization of aluminum foil for electrolytic capacitors including the formation of a hydrous oxide layer on the foil prior to anodization and stabilization of the foil in alkaline borax baths during anodization, the foil is electrochemically anodized in an aqueous solution of boric acid and 2 to 50 ppm phosphate having a pH of 4.0 to 6.0. The anodization is interrupted for stabilization by passing the foil through a bath containing the borax solution having a pH of 8.5 to 9.5 and a temperature above 80 0 C. and then reanodizing the foil. The process is useful in anodizing foil to a voltage of up to 760 V

Beam Cooling with ionisation losses

CERN Document Server

Rubbia, Carlo; Kadi, Y; Vlachoudis, V

2006-01-01

A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady configuration in which ionisation losses are recovered at each turn by a RF-cavity. For a uniform target "foil" the longitudinal momentum spread diverges exponentially since faster (slower) particles ionise less (more) than the average. In order to "cool" also longitudinally, a chromaticity has to be introduced with a wedge shaped "foil". Multiple scattering and straggling are then "cooled" in all three dimensions, with a method similar to the one of synchrotron cooling, but valid for low energy ions. Particles then stably circulate in the beam indefinitely, until they undergo for instance nuclear processes in the thin target foil. This new method is under consideration for the nuclear production of a few MeV/A ion beams. Simple reactions, for instance Li 7 + D Li 8 + p, are more ...

Neutral hydrogen from the foil-induced dissociation of 4HeH+, 3HeH+, and H2+

International Nuclear Information System (INIS)

Cooney, P.J.; Gemmell, D.S.; Kanter, E.P.; Pietsch, W.J.; Zabransky, B.J.

1979-01-01

High resolution energy spectra and angular distributions of H 0 from the dissociation of 4 HeH + , 3 HeH + , and H 2 + in thin carbon foils are presented for incident ion energies ranging from 170 to 1800 keV/amu. For the range of dwell times inside the target foils studied (about 1 to 10 fsec), the dominant mechanism for such dissociation is the Coulomb explosion of the ions inside the target followed by electron capture near the rear surface of the foil. At the shortest of these dwell times, the yield of H 0 for incident ions oriented perpendicular to the beam relative to that for ions aligned with the beam is a factor of two greater than at longer dwell times. These data indicate that, for ion fragments which emerge from the rear surface of the target within a few angstroms of one another, those in the perpendicular orientation have a greater electron capture probability than those emerging in other orientations. 9 references

Beam-foil spectroscopy at Argonne National Laboratory

International Nuclear Information System (INIS)

Berry, H.G.

1981-01-01

We have completed a set of precision wavelength measurements of the transitions 1s2s 3 S 1 - 1s2p 3 P 0 2 of the helium-like ions of silicon, sulfur, and chlorine. We have calculated the wavelengths of these transitions for Z = 2-50 using a nonrelativisitc 1/Z expansion, one-electron Dirac energies, plus relativistic corrections in first-order perturbation theory, plus one-electron QED or Lamb-shift corrections. By comparisons of measurements of Z = 4-26 and theory, we find a discrepancy which is approximately 0.015 Z 3 cm - 1 . We have shown that this arises from a first-order screening correction to the one-electron Lamb shift and we have obtained an ab initio estimate of the correction

Influence of micromachined targets on laser accelerated proton beam profiles

Science.gov (United States)

Dalui, Malay; Permogorov, Alexander; Pahl, Hannes; Persson, Anders; Wahlström, Claes-Göran

2018-03-01

High intensity laser-driven proton acceleration from micromachined targets is studied experimentally in the target-normal-sheath-acceleration regime. Conical pits are created on the front surface of flat aluminium foils of initial thickness 12.5 and 3 μm using series of low energy pulses (0.5-2.5 μJ). Proton acceleration from such micromachined targets is compared with flat foils of equivalent thickness at a laser intensity of 7 × 1019 W cm-2. The maximum proton energy obtained from targets machined from 12.5 μm thick foils is found to be slightly lower than that of flat foils of equivalent remaining thickness, and the angular divergence of the proton beam is observed to increase as the depth of the pit approaches the foil thickness. Targets machined from 3 μm thick foils, on the other hand, show evidence of increasing the maximum proton energy when the depths of the structures are small. Furthermore, shallow pits on 3 μm thick foils are found to be efficient in reducing the proton beam divergence by a factor of up to three compared to that obtained from flat foils, while maintaining the maximum proton energy.

Tungsten foil laminate for structural divertor applications – Analyses and characterisation of tungsten foil

International Nuclear Information System (INIS)

Reiser, Jens; Rieth, Michael; Dafferner, Bernhard; Hoffmann, Andreas; Yi Xiaoou; Armstrong, David E.J.

2012-01-01

It has been attempted for several years to synthesise a tungsten material with a low brittle-to-ductile transition temperature and a high fracture toughness that can be used for structural parts. It was shown in our previous work that tungsten foil is ductile at room temperature and that this ductility can be transformed to bulk by synthesising a tungsten laminate. In this work we want to focus on tungsten foil and assess the microstructure as well as the mechanical properties of the foil. The assessment of the microstructure of 0.1 mm tungsten foil will be performed using electron microscopy. It will be shown that the grains of the tungsten foil have a dimension of 0.5 μm × 3 μm × 15 μm and a clear texture in (1 0 0) 〈0 1 1〉. This texture becomes even more pronounced by annealing. Three-point-bending tests with tungsten foil, as-received, will define the barriers: ductile at room temperature and brittle in liquid nitrogen (−196 °C). This shows that the ductility is a thermally activated process. Recrystallised tungsten foil (annealed for 1 h/2700 °C) shows ductile material behaviour at 200 °C. The paper closes with a discussion on the reasons of the ductility of 0.1 mm tungsten foil. These might be the ultra fine grained (UFG) microstructure or, in other words, a nano microstructure (see tungsten foil as-received), the high amount of mobile edge dislocations, and/or the foil effect, which means that dislocations can move to the surface and are annihilated (see tungsten foil recrystallised).

Use of Kelvin probe force microscopy for identification of CVD grown graphene flakes on copper foil

Science.gov (United States)

Kumar, Rakesh; Mehta, B. R.; Kanjilal, D.

2017-05-01

Graphene flakes have been grown by chemical vapour deposition (CVD) method on Cu foils. The obtained graphene flakes have been characterized by optical microscopy, field emission scanning electron microscopy, Kelvin probe force microscopy (KPFM) and Raman spectroscopy. The graphene flakes grown on Cu foil comprise mainly single layer graphene and confirm that the nucleation for graphene growth starts very quickly. Moreover, KPFM has been found to be a valuable technique to differentiate between covered and uncovered portion of Cu foil by graphene flakes deposited for shorter duration. The results show that KPFM can be a very useful technique in understanding the mechanism of graphene growth.

Correlative Raman spectroscopy and focused ion beam for targeted phase boundary analysis of titania polymorphs

Energy Technology Data Exchange (ETDEWEB)

Mangum, John S.; Chan, Lisa H.; Schmidt, Ute; Garten, Lauren M.; Ginley, David S.; Gorman, Brian P.

2018-05-01

Site-specific preparation of specimens using focused ion beam instruments for transmission electron microscopy is at the forefront of targeting regions of interest for nanoscale characterization. Typical methods of pinpointing desired features include electron backscatter diffraction for differentiating crystal structures and energy-dispersive X-Ray spectroscopy for probing compositional variations. Yet there are situations, notably in the titanium dioxide system, where these techniques can fail. Differentiating between the brookite and anatase polymorphs of titania is either excessively laborious or impossible with the aforementioned techniques. However, due to differences in bonding structure, Raman spectroscopy serves as an ideal candidate for polymorph differentiation. In this work, a correlative approach utilizing Raman spectroscopy for targeted focused ion beam specimen preparation was employed. Dark field imaging and diffraction in the transmission electron microscope confirmed the region of interest located via Raman spectroscopy and demonstrated the validity of this new method. Correlative Raman spectroscopy, scanning electron microscopy, and focused ion beam is shown to be a promising new technique for identifying site-specific preparation of nanoscale specimens in cases where conventional approaches do not suffice.

Condensed matter physics with radioactive ion beams

International Nuclear Information System (INIS)

Haas, H.

1996-01-01

An overview of the present uses of radioactive ion beams from ISOLDE for condensed matter research is presented. As simple examples of such work, tracer studies of diffusion processes with radioisotopes and blocking/channeling measurements of emitted particles for lattice location are discussed. Especially the application of nuclear hyperfine interaction techniques such as PAC or Moessbauer spectroscopy has become a powerful tool to study local electronic and structural properties at impurities. Recently, interesting information on impurity properties in semiconductors has been obtained using all these methods. The extreme sensitivity of nuclear techniques makes them also well suited for investigations of surfaces, interfaces, and biomolecules. Some ideas for future uses of high energy radioactive ion beams beyond the scope of the present projects are outlined: the study of diffusion in highly immiscible systems by deep implantation, nuclear polarization with the tilted-foil technique, and transmutation doping of wide-bandgap semiconductors. (orig.)

Photoelectron spectroscopy of supersonic molecular beams

International Nuclear Information System (INIS)

Pollard, J.E.

1982-05-01

A new technique for performing high resolution molecular photoelectron spectroscopy is described, beginning with its conceptual development, through the construction of a prototypal apparatus, to the initial applications on a particularly favorable molecular system. The distinguishing features of this technique are: (1) the introduction of the sample in the form of a collimated supersonic molecular beam; and (2) the use of an electrostatic deflection energy analyzer which is carefully optimized in terms of sensitivity and resolution. This combination makes it possible to obtain photoelectron spectra at a new level of detail for many small molecules. Three experiments are described which rely on the capability to perform rotationally-resolved photoelectron spectroscopy on the hydrogen molecule and its isotopes. The first is a measurement of the ionic vibrational and rotational spectroscopic constants and the vibrationally-selected photoionization cross sections. The second is a determination of the photoelectron asymmetry parameter, β, for selected rotational transitions. The third is an investigation of the rotational relaxation in a free jet expansion, using photoelectron spectroscopy as a probe of the rotational state population distributions. In the closing chapter an assessment is made of the successes and limitations of the technique, and an indication is given of areas for further improvement in future spectrometers

High resolution laser spectroscopy as a diagnostic tool in beams

International Nuclear Information System (INIS)

Bergmann, K.; Hefter, U.; Hering, P.

1977-01-01

The combination of high resolution laser spectroscopy with the technique of molecular beams allows a very detailed beam research since molecules or atoms in specific quantum states can be sampled yielding previously unavailable sources of data. In these experiments a Na/Na 2 beam emerges from a 0.2 mm nozzle and is collimated by a 2 mm wide slit 50 cm downstream. To probe the molecules a single mode Ar + -laser was used which can be tuned within the gain profile of the laser line (8 GHz) to several transitions between specific levels in the ground state and second electronically excited state of the Na 2 molecule. (Auth.)

Investigation of the reversible sodiation of Sn foil by ex-situ X-ray diffractometry and Mössbauer effect spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Du, Zhijia [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Dunlap, R.A. [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Institute for Research in Materials, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); College of Sustainability, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Obrovac, M.N., E-mail: mobrovac@dal.ca [Department of Physics and Atmospheric Science, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Institute for Research in Materials, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Chemistry, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia B3H 4R2 (Canada)

2014-12-25

Highlights: • Mössbauer spectra of all phases formed during sodiation measured for the first time. • Center shifts correlated with metallurgically prepared samples. • Center shift correlated with Na content in Na–Sn. - Abstract: The reversible sodiation of Sn foil was investigated using ex-situ X-ray diffractometry (XRD) and Mössbauer effect spectroscopy. The measured voltage profile indicated that the sodiation process of Sn foil proceeded in three stages. Ex-situ XRD patterns demonstrated that Na{sub 4}Sn{sub 4}, Na{sub 5}Sn{sub 2} and Na{sub 15}Sn{sub 4} phases were formed at the end of each discharge plateau. Na{sub 5}Sn{sub 2}, Na{sub 4}Sn{sub 4} and β-Sn were formed at the end of each charge plateau. Three single-phase alloys, Na{sub 4}Sn{sub 4}, Na{sub 9}Sn{sub 4} and Na{sub 15}Sn{sub 4}, were prepared by annealing stoichiometric ratios of Na and Sn. The Mössbauer spectra of ex-situ samples at the end of each discharge plateau were collected and compared with the Mössbauer spectra of the three single phase alloys. The measured parameters for the Mössbauer effect spectra were consistent with an analysis of the crystal structures. The center shift became less positive with an increase of the sodium content in Na–Sn phases and this was shown to be a useful indicator of the degree of sodiation of Sn electrodes.

Beam-foil lifetime measurements for some 5d10 nl and 5d96s6p levels of Pb IV

International Nuclear Information System (INIS)

Pinnington, E.H.; Ansbacher, W.; Tauheed, A.; Kernahan, J.A.

1991-01-01

The beam-foil technique was used to measure the lifetimes of the 5d 10 5f, 5g, 6d, 6h, 7p, 7d, 8s and 5d 9 6s6p (2) 0 , (3) 0 , (6) 0 , (14) 0 , (17) 0 levels of Pb IV. Correlated decay-curve analyses were used to correct for the effects of cascading in the case of the 5d 10 5f, 5g, 6d, and 7p levels. The numerical Coulomb approximation was used to calculate comparison values for the 5d 10 nl levels. The need for a more rigorous calculation for specific levels is discussed. (12 refs., fig., tab.)

Relative excitation functions for singly-excited and core-excited levels of S V--S IX populated by the beam-foil interaction

International Nuclear Information System (INIS)

Moenke, D.; Bengtsson, P.; Engstroem, L.; Hutton, R.; Jupen, C.; Kirm, M.; Westerlind, M.

1994-01-01

We have investigated the relative excitation functions for low-lying singly excited and low-lying core-excited levels in S V (S 4+ ) to S IX (S 8+ ) after beam-foil excitation using ions in the energy range 2--10 MeV. The spectral line intensities have been normalized to the same number of particles at each ion energy and corrections for the level lifetimes have been made. The overall accuracy of the measured relative excitation function at each energy and charge state is estimated to be better than 2%. A comparison of the relative excitation functions for singly excited and core-excited lines shows a difference in S VII, but not in S VI

A beam profile monitor for small electron beams

International Nuclear Information System (INIS)

Norem, J.

1991-01-01

Measurement of beam properties at the foci of high energy linacs is difficult due to the small size of the waists in proposed and existing accelerators (1 nm -2 μm). This article considers the use of bremsstrahlung radiation from thin foils to measure the size and phase space density these beams using nonimaging optics. The components of the system are described, and the ultimate resolution, evaluated theoretically for the case of the Final Focus Test Beam (FFTB) at Stanford Linear Accelerator Center, is a few nm

Relative level populations in S VI after beam-foil excitation, obtained from ANDC analyses of measured decay curves

International Nuclear Information System (INIS)

Engstroem, L.

1983-01-01

This paper reports the relative population of the levels 3p, 3d, 4d, 5d, 4f, 5g, 6g, 6h, 7h, 7i, 8i and 8k in Na-like sulfur, S VI, after beam-foil excitation at an energy of 3 MeV. For the first time the ANDC technique has been used to obtain the relative efficiency calibration of the detection system at discrete points in the wavelength interval 400-5000 A, from the analyses of measured decay curves. The advantages and limitations of this method are discussed. The populations obtained with this new technique are compared to previous measurements in multiply ionized atoms. The preferential population of the 3p and 3d levels observed in other Na-like ions is now accurately established. For the higher lying levels an almost constant population is observed. (Auth.)

Beam Characterization at the Neutron Radiography Facility

Energy Technology Data Exchange (ETDEWEB)

Sarah Morgan; Jeffrey King

2013-01-01

The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

Tandem accelerator transmission and life measurement of 50 keV/amu Au ions using stripper foil made by INS

Energy Technology Data Exchange (ETDEWEB)

Ishii, Satoshi; Takahashi, Tsutomu; Shima, Kunihiro [Tsukuba Univ., Ibaraki (Japan). Tandem Accelerator Center; Sugai, Isamu; Oyaizu, Mitsuhiro

1996-12-01

The role of stripper foil is the charge exchange of ions. The thickness for attaining equilibrium in charge exchange becomes thinner as ions become lower speed and heavier. Accordingly, for the stripper foil, thin foil thickness is demanded in addition to the demand of long life. The stripper foil made by INS, University of Tokyo, is recognized as its long life. In the 12 UD PELETRON tandem accelerator in University of Tsukuba, in order to meet the demand of users to use heavy ions, the use of long life stripper foil has become urgent necessity. Therefore, as for the foil made by INS, the life by Au ion irradiation and the Au ion transmission were measured four times. As to the features of the test of this time, irradiation was carried out under the severe condition for the foil of low speed Au ions, and the change of beam transmission with time lapse was observed in addition to the life. The method of measurement is explained. The preparation of foils and the determination of their thickness are reported. As the results, the lifetime of the foils made by INS and the thickness dependence and time dependence or dose dependence of the transmission of low speed, heavy Au-197 ions are described. (K.I.)

A beam profile monitor for small electron beams

International Nuclear Information System (INIS)

Norem, J.

1991-01-01

Measurement of beam properties at the foci of high energy linacs is difficult due to the small size of the waists in proposed and existing accelerators (1 nm - 2 μ). This paper considers the use of bremsstrahlung radiation from thin foils to measure the size and phase space density these beams using nonimaging optics. The components of the system are described, and the ultimate resolution, evaluated theoretically for the case of the Final Focus Test Beam at Stanford Linear Accelerator Center, is a few nm. 13 refs., 4 figs. 1 tab

Tilted-foil polarisation and magnetic moments of mirror nuclei at ISOLDE

CERN Multimedia

Bordeanu, C; Thundiyamkulathu Baby, L; Lindroos, M

2002-01-01

We report here on the first measurement in an experimental program initiated at the ISOLDE facility at CERN for the measurement of magnetic moments of short-lived radionuclides. The 60~keV ISOLDE beam from the GPS separator is boosted in energy by a 200~kV high-voltage platform, on which the whole experiment is mounted, in order to achieve sufficiently high energy for transmission through the foils of a tilted-foil setup. The 520~keV $^{23}$Mg(2$^+$) nuclei are polarized by the tilted foil technique and the resulting 0$^o$ - 180$^o$ $\\beta$- asymmetry is monitored as a function of the frequency of an rf-applied perturbing magnetic field in an NMR setup.\\\\ In this experiment, earlier asymmetry measurements were confirmed and an NMR resonance was observed, corresponding to a preliminary value of the magnetic moment of 0.533(6) n.m., in agreement with a previous measurement. The measured asymmetry as function of NMR frequency and the fitted resonance curve are presented in the figure. During the e...

Atomic data for beam-stimulated plasma spectroscopy in fusion plasmas

International Nuclear Information System (INIS)

Marchuk, O.; Biel, W.; Schlummer, T.; Ralchenko, Yu.; Schultz, D. R.

2013-01-01

Injection of high energy atoms into a confined plasma volume is an established diagnostic technique in fusion research. This method strongly depends on the quality of atomic data for charge-exchange recombination spectroscopy (CXRS), motional Stark effect (MSE) and beam-emission spectroscopy (BES). We present some examples of atomic data for CXRS and review the current status of collisional data for parabolic states of hydrogen atoms that are used for accurate MSE modeling. It is shown that the collisional data require knowledge of the excitation density matrix including the off-diagonal matrix elements. The new datasets for transitions between parabolic states are used in an extended collisional-radiative model. The ratios between the σ- and π-components and the beam-emission rate coefficients are calculated in a quasi-steady state approximation. Good agreement with the experimental data from JET is found which points out to strong deviations from the statistical distribution for magnetic sublevels

Chromic acid anodizing of aluminum foil

Science.gov (United States)

Dursch, H.

1988-01-01

The success of the Space Station graphite/epoxy truss structure depends on its ability to endure long-term exposure to the LEO environment, primarily the effects of atomic oxygen and the temperture cycling resulting from the 94 minute orbit. This report describes the development and evaluation of chromic acid anodized (CAA) aluminum foil as protective coatings for these composite tubes. Included are: development of solar absorptance and thermal emittance properties required of Al foil and development of CAA parameters to achieve these optical properties; developing techniques to CAA 25 ft lengths of Al foil; developing bonding processes for wrapping the Al foil to graphite/epoxy tubes; and atomic oxygen testing of the CAA Al foil. Two specifications were developed and are included in the report: Chromic Acid Anodizing of Aluminum Foil Process Specification and Bonding of Anodized Aluminum Foil to Graphite/Epoxy Tubes. Results show that CAA Al foil provides and excellent protective and thermal control coating for the Space Station truss structure.

Precision atomic beam density characterization by diode laser absorption spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Oxley, Paul; Wihbey, Joseph [Physics Department, The College of the Holy Cross, Worcester, Massachusetts 01610 (United States)

2016-09-15

We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10{sup −5} are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 10{sup 4} atoms cm{sup −3}. The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

Precision atomic beam density characterization by diode laser absorption spectroscopy

International Nuclear Information System (INIS)

Oxley, Paul; Wihbey, Joseph

2016-01-01

We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10 −5 are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 10 4 atoms cm −3 . The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

Precision atomic beam density characterization by diode laser absorption spectroscopy.

Science.gov (United States)

Oxley, Paul; Wihbey, Joseph

2016-09-01

We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10 -5 are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 10 4 atoms cm -3 . The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

Spectroscopy Division progress report for January 1987 - December 1988

International Nuclear Information System (INIS)

Dixit, R.M.

1989-01-01

During the period January 1987 - December 1988, the Spectroscopy Division has carried out research and development in many areas of analytical spectroscopy, atomic spectra and spectra of diatomic and polyatomic molecules. The Division has acquired an ICP spectrometer and an excimer laser pumped dye laser during this period and they have been used very fruitfully for research and development. Research in high resolution atomic spectroscopy has continued to flourish. Beam foil spectroscopy and spectroscopy of low energy plasma focus sources have been put on a firm foundation. Setting up of new experimental systems for solid state spectral studies at liquid helium temperatures have been started. A good amount of theoretical work in forbidden transitions, has been carried out. Diode laser spectroscopy has been used for high precision intensity and frequency measurements. Service facilities like quality control analysis of nuclear materials and supply of optical components and thin film devices have performed with maximum efficiency. The electronics and instrumentation group has developed several facilities for various experimental set ups. Brief description of all these and other activities of the Division are given in the present progress report. A list of publications and a divisional staff chart are also given. (author). figs., tabs

Tungsten foil laminate for structural divertor applications - Joining of tungsten foils

Science.gov (United States)

Reiser, Jens; Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan; Mrotzek, Tobias; Hoffmann, Andreas; Armstrong, D. E. J.; Yi, Xiaoou

2013-05-01

This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

In-beam gamma spectroscopy of /sup 82/Sr

CERN Document Server

Dewald, A; Gelberg, A; Kaup, U; Von Brentano, P; Zell, K O

1981-01-01

The excited levels of /sup 82/Sr have been investigated by means of in-beam gamma-ray spectroscopy via the reactions /sup 72/Ge(/sup 12/C, 2n), /sup 66/Zn(/sup 19/F, p2n), and /sup 79/Br(/sup 6/Li, 3n). Lifetimes of excited states were measured by the recoil distance method. Excitation energies and B(E2) values have been compared with calculations using the Interacting Boson Model. (19 refs).

Recent progress in the studies of atomic spectra and transition probabilities by beam-foil spectroscopy

International Nuclear Information System (INIS)

Martinson, I.

1982-01-01

A review is given of recent studies of atomic structure (in particular atomic spectra, energy levels and transition probabilities) using fast beams from ion accelerators. Thanks to improved spectral resolution detailed and quite accurate studies of energy levels are now possible, a number of such results will be discussed. The non-autoionizing, multiply excited levels in atoms and ions (including negative ions) are being vigorously investigated at present, some new results will be reported. The accuracy in lifetime determinations continues to improve, and several new ways for reduction of cascading effects have been developed. Some selected examples of recent progress in lifetime measurements are also included. (orig.)

Ion beam nanopatterning and micro-Raman spectroscopy analysis on HOPG for testing FIB performances

International Nuclear Information System (INIS)

Archanjo, B.S.; Maciel, I.O.; Martins Ferreira, E.H.; Peripolli, S.B.; Damasceno, J.C.; Achete, C.A.; Jorio, A.

2011-01-01

This work reports Ga + focused ion beam nanopatterning to create amorphous defects with periodic square arrays in highly oriented pyrolytic graphite and the use of Raman spectroscopy as a new protocol to test and compare progresses in ion beam optics, for low fluence bombardment or fast writing speed. This can be ultimately used as a metrological tool for comparing different FIB machines and can contribute to Focused Ion Beam (FIB) development in general for tailoring nanostructures with higher precision. In order to do that, the amount of ion at each spot was varied from about 10 6 down to roughly 1 ion per dot. These defects were also analyzed by using high resolution scanning electron microscopy and atomic force microscopy. The sensitivities of these techniques were compared and a geometrical model is proposed for micro-Raman spectroscopy in which the intensity of the defect induced D band, for a fixed ion dose, is associated with the diameter of the ion beam. In addition, the lateral increase in the bombarded spot due to the cascade effect of the ions on graphite surface was extracted from this model. A semi-quantitative analysis of the distribution of ions at low doses per dot or high writing speed for soft modification of materials is discussed. -- Highlights: → Highly oriented pyrolytic graphite surface is bombarded using a focused ion beam. → Raman spectroscopy is used to propose a new protocol to test focused ion beam optics. → Scattering diameter of the ions on HOPG surface is experimentally obtained. → Optical limitations of the ion column in fast writing speed are discussed. → Small level of modifications is considered for changing graphene conductive properties.

Implants with 32P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology

International Nuclear Information System (INIS)

Assmann, Walter; Becker, Ricarda; Otto, Henrike

2013-01-01

For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting 32 P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of 32 P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the 32 P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of 32 P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated 32 P-foils could extend essentially the application possibilities of LDR-brachytherapy. (orig.)

Electron beam effects in auger electron spectroscopy and scanning electron microscopy

International Nuclear Information System (INIS)

Fontaine, J.M.; Duraud, J.P.; Le Gressus, C.

1979-01-01

Electron beam effects on Si(100) and 5% Fe/Cr alloy samples have been studied by measurements of the secondary electron yield delta, determination of the surface composition by Auger electron spectroscopy and imaging with scanning electron microscopy. Variations of delta as a function of the accelerating voltage Esub(p) (0.5 -9 Torr has no effect on technological samples covered with their reaction layers; the sensitivities to the beam depend rather on the earlier mechanical, thermal and chemical treatment of the surfaces. (author)

Beam foil spectroscopy of N = 3 to N = 2 transitions in highly stripped heavy ions. Revision 1

International Nuclear Information System (INIS)

Dietrich, D.D.; Chandler, G.A.; Egan, P.O.; Ziock, K.P.; Mokler, P.H.; Reusch, S.; Hoffmann, D.H.H.

1986-09-01

The spectroscopy of very highly ionized atoms provides an important testing ground for multi-electron atomic theory. We report preliminary experimental results on the n = 3 → 2 spectra of Bi +73 and A +69 obtained at the GSI UNILAC accelerator. 19 refs., 4 figs

Dynamics of laser-driven proton beam focusing and transport into solid density matter

Science.gov (United States)

Kim, J.; McGuffey, C.; Beg, F.; Wei, M.; Mariscal, D.; Chen, S.; Fuchs, J.

2016-10-01

Isochoric heating and local energy deposition capabilities make intense proton beams appealing for studying high energy density physics and the Fast Ignition of inertial confinement fusion. To study proton beam focusing that results in high beam density, experiments have been conducted using different target geometries irradiated by a kilojoule, 10 ps pulse of the OMEGA EP laser. The beam focus was measured by imaging beam-induced Cu K-alpha emission on a Cu foil that was positioned at a fixed distance. Compared to a free target, structured targets having shapes of wedge and cone show a brighter and narrower K-alpha radiation emission spot on a Cu foil indicating higher beam focusability. Experimentally observed images with proton radiography demonstrate the existence of transverse fields on the structures. Full-scale simulations including the contribution of a long pulse duration of the laser confirm that such fields can be caused by hot electrons moving through the structures. The simulated fields are strong enough to reflect the diverging main proton beam and pinch a transverse probe beam. Detailed simulation results including the beam focusing and transport of the focused intense proton beam in Cu foil will be presented. This work was supported by the National Laser User Facility Program through Award DE-NA0002034.

Spectroscopy Division : Progress report for Oct 1979 - Dec 1980

International Nuclear Information System (INIS)

Saksena, G.D.; Naik, R.C.

1981-01-01

An account of the activities, with an individual summary of each, of the Spectroscopy Division of the Bhabha Atomic Research Centre (BARC), Bombay, for the period from October 1979 to December 1980 is given. The activities of the Division are mainly concerned with: (1) spectrochemical analysis of nuclear fuels, reactor materials, mineral samples, environmental samples, biological samples, and other samples by methods of optical emission spectroscopy, electron spectroscopy, and X-ray fluorescence spectroscopy, (2) research and development primarily in the field of high resolution atomic and molecular spectroscopy, and (3) design and fabrication of high precision optical instruments and electronic components for other Divisions of BARC and other constituent units of the Department of Atomic Energy. During the report period, the following were fabricated: a monochromator using a concave holographic grating, a holographic grating spectrograph, a core viewing system for the Fast Breeder Test Reactor now under construction at Kalpakkam, a critical angle refractometer for heavy water analysis in the Rajasthan Atomic Power Station, electronic equipment like frequency divider amplifier, lock-in-voltmeter, analog ratio meter etc. required for laser spectroscopy. Lists of the staff members, their publications during the report period, educational and training activities of the Division are also given. Two feature articles, one dealing with beam foil spectroscopy and the other with monochromatization of synchrotron radiation, are also included. (M.G.B.)

Development of surface perturbation target and thin silicon foil target used to research Rayleigh-Taylor instability in inertial confinement fusion experiment

International Nuclear Information System (INIS)

Zhou Bin; Sun Qi; Huang Yaodong; Shen Jun; Wu Guangming; Wang Jue

2004-01-01

The developments of the surface perturbation target and the thin silicon foil target used to research Rayleigh-Taylor instability in the resolved experiments of Inertial Confinement Fusion (ICF) are carried out. Based on the laser interference process combined with the figure-transfer process, the surface perturbation target with sine modulated perturbation is gotten, the wavelength is in the range of 20-100 μm and the amplitude is several micrometers. The thin silicon foil within the thickness about 3-4 μm is prepared by semiconductor process together with heavy-doped self-stop etching. Combined with ion beam etching, the check or the stripe patterns are transferred to the surface of thin silicon foils, and then the silicon grating foil is obtained

Tungsten foil laminate for structural divertor applications – Joining of tungsten foils

Energy Technology Data Exchange (ETDEWEB)

Reiser, Jens, E-mail: jens.reiser@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM-AWP) (Germany); Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM-AWP) (Germany); Mrotzek, Tobias; Hoffmann, Andreas [PLANSEE SE, Reutte (Austria); Armstrong, D.E.J.; Yi, Xiaoou [University of Oxford, Department of Materials (United Kingdom)

2013-05-15

This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.

Ultra high vacuum system of the 3 MeV electron beam accelerator

International Nuclear Information System (INIS)

Puthran, G.P.; Jayaprakash, D.; Mishra, R.L.; Ghodke, S.R.; Majumder, R.; Mittal, K.C.; Sethi, R.C.

2003-01-01

Full text: A 3 MeV electron beam accelerator is coming up at the electron beam centre, Kharghar, Navi Mumbai. A vacuum of the order of 1x10 -7 mbar is desired in the beam line of the accelerator. The UHV system is spread over a height of 6 meters. The total surface area exposed to vacuum is 65,000 cm 2 and the volume is 200 litres. Distributed pumping is planned, to avoid undesirable vacuum gradient between any two sections of the beam-line. The electron beam is scanned in an area of 6 cms x 100 cms and it comes out of the scan-horn through a titanium foil of 50 micron thick. Hence the vacuum system is designed in such a way that, in the event of foil rupture during beam extraction, the electron gun, accelerating column and the pumps can be protected from sudden air rush. The vacuum in the beam-line can also be maintained in this condition. After changing the foil, scan-horn area can be separately pumped to bring the vacuum level as desired and can be opened to the beam-line. The design, vacuum pumping scheme and the safety aspects are discussed in this paper

Mock-up experiment at Birmingham University for BNCT project of Osaka University – Neutron flux measurement with gold foil

International Nuclear Information System (INIS)

Tamaki, S.; Sakai, M.; Yoshihashi, S.; Manabe, M.; Zushi, N.; Murata, I.; Hoashi, E.; Kato, I.; Kuri, S.; Oshiro, S.; Nagasaki, M.; Horiike, H.

2015-01-01

Mock-up experiment for development of accelerator based neutron source for Osaka University BNCT project was carried out at Birmingham University, UK. In this paper, spatial distribution of neutron flux intensity was evaluated by foil activation method. Validity of the design code system was confirmed by comparing measured gold foil activities with calculations. As a result, it was found that the epi-thermal neutron beam was well collimated by our neutron moderator assembly. Also, the design accuracy was evaluated to have less than 20% error. - Highlights: • Accelerator based neutron source for BNCT is being developed in Osaka University. • Mock-up experiment was carried out at Birmingham University, UK. • Neutronics performance of our assembly was evaluated from gold foil activation. • Gold foil activation was determined by using HPGe detectors. • Validity of the neutronics design code system was confirmed.

Using Rutherford Backscattering Spectroscopy to Characterize Targets for MTW

Science.gov (United States)

Brown, Gunnar; Stockler, Barak; Ward, Ryan; Freeman, Charlie; Padalino, Stephen; Stillman, Collin; Ivancic, Steven; Reagan, S. P.; Sangster, T. C.

2017-10-01

A study is underway to determine the composition and thickness of targets used at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) using Rutherford backscattering spectroscopy (RBS). In RBS, an ion beam is incident on a sample and the scattered ions are detected with a surface barrier detector. The resulting energy spectra of the scattered ions can be analyzed to determine important parameters of the target including elemental composition and thickness. Proton, helium and deuterium beams from the 1.7 MV Pelletron accelerator at SUNY Geneseo have been used to characterize several different targets for MTW, including CH and aluminum foils of varying thickness. RBS spectra were also obtained for a cylindrical iron buried-layer target with aluminum dopant which was mounted on a silicon carbide stalk. The computer program SIMNRA is used to analyze the spectra. This work was funded in part by a Grant from the DOE through the Laboratory for Laser Energetics.

Spallation Neutron Source SNS Diamond Stripper Foil Development

International Nuclear Information System (INIS)

Shaw, Robert W.; Plum, Michael A.; Wilson, Leslie L.; Feigerle, Charles S.; Borden, Michael J.; Irie, Y.; Sugai, I.; Takagi, A.

2007-01-01

Diamond stripping foils are under development for the SNS. Freestanding, flat 300 to 500 (micro)g/cm 2 foils as large as 17 x 25 mm 2 have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 15 (micro)C of protons, approximately 64% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 C of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (640 keV H - ) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.

Low-energy foil aberration corrector

International Nuclear Information System (INIS)

Aken, R.H. van; Hagen, C.W.; Barth, J.E.; Kruit, P.

2002-01-01

A spherical and chromatic aberration corrector for electron microscopes is proposed, consisting of a thin foil sandwiched between two apertures. The electrons are retarded at the foil to almost zero energy, so that they can travel ballistically through the foil. It is shown that such a low-voltage corrector has a negative spherical aberration for not too large distances between aperture and foil, as well as a negative chromatic aberration. For various distances the third- and fifth-order spherical aberration coefficients and the first- and second-order chromatic aberration coefficients are calculated using ray tracing. Provided that the foils have sufficient electron transmission the corrector is able to correct the third-order spherical aberration and the first-order chromatic aberration of a typical low-voltage scanning electron microscope. Preliminary results show that the fifth-order spherical aberration and the second-order chromatic aberration can be kept sufficiently low

'Beam-emission spectroscopy' diagnostics also measure edge fast-ion light

International Nuclear Information System (INIS)

Heidbrink, W W; Bortolon, A; McKee, G R; Smith, D R

2011-01-01

Beam-emission spectroscopy (BES) diagnostics normally detect fluctuations in the light emitted by an injected neutral beam. Under some circumstances, however, light from fast ions that charge exchange in the high neutral-density region at the edge of the plasma make appreciable contributions to the BES signals. This 'passive' fast-ion D α (FIDA) light appears in BES signals from both the DIII-D tokamak and the National Spherical Torus Experiment (NSTX). One type of passive FIDA light is associated with classical orbits that traverse the edge. Another type is caused by instabilities that expel fast ions from the core; this light can complicate measurement of the instability eigenfunction.

Study on lifetime of C stripping foils

International Nuclear Information System (INIS)

Zhang Hongbin; Lu Ziwei; Zhao Yongtao; Li Zhankui; Xu Hushan; Xiao Guoqing; Wang Yuyu; Zhang Ling; Li Longcai; Fang Yan

2007-01-01

The carbon stripping foils can be prepared with the AC and DC arc discharge methods, or even sandwiched with AC-DC alternative layers. The lifetime of the carbon stripping foils of 19 μg/cm 2 prepared with different methods and/or structures was measured. The factors affecting the bombarding lifetime of the carbon stripping foils, especially the method of the foil preparation and the structure of the carbon stripping foils, were discussed. It is observed that the foils prepared with the DC arc discharge method have a longer bombarding lifetime than those prepared with the AC arc discharge method. (authors)

Non-destructive Quantitative Phase Analysis and Microstructural Characterization of Zirconium Coated U-10Mo Fuel Foils via Neutron Diffraction

Energy Technology Data Exchange (ETDEWEB)

Cummins, Dustin Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogel, Sven C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollis, Kendall Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-10-18

This report uses neutron diffraction to investigate the crystal phase composition of uranium-molybdenum alloy foils (U-10Mo) for the CONVERT MP-1 Reactor Conversion Project, and determines the effect on alpha-uranium contamination following the deposition of a Zr metal diffusion layer by various methods: plasma spray deposition of Zr powders at LANL and hot co-rolling with Zr foils at BWXT. In summary, there is minimal decomposition of the gamma phase U-10Mo foil to alpha phase contamination following both plasma spraying and hot co-rolling. The average unit cell volume, i.e. lattice spacing, of the Zr layer can be mathematically extracted from the diffraction data; co-rolled Zr matches well with literature values of bulk Zr, while plasma sprayed Zr shows a slight increase in the lattice spacing, indicative of interstitial oxygen in the lattice. Neutron diffraction is a beneficial alternative to conventional methods of phase composition, i.e. x ray diffraction (XRD) and destructive metallography. XRD has minimal penetration depth in high atomic number materials, particularly uranium, and can only probe the first few microns of the fuel plate; neutrons pass completely through the foil, allowing for bulk analysis of the foil composition and no issues with addition of cladding layers, as in the final, aluminum-clad reactor fuel plates. Destructive metallography requires skilled technicians, cutting of the foil into small sections, hazardous etching conditions, long polishing and microscopy times, etc.; the neutron diffraction system has an automated sample loader and can fit larger foils, so there is minimal analysis preparation; the total spectrum acquisition time is ~ 1 hour per sample. The neutron diffraction results are limited by spectra refinement/calculation times and the availability of the neutron beam source. In the case of LANSCE at Los Alamos, the beam operates ~50% of the year. Following the lessons learned from these preliminary results, optimizations to

Non-destructive Quantitative Phase Analysis and Microstructural Characterization of Zirconium Coated U-10Mo Fuel Foils via Neutron Diffraction

International Nuclear Information System (INIS)

Cummins, Dustin Ray; Vogel, Sven C.; Hollis, Kendall Jon; Brown, Donald William; Dombrowski, David E.

2016-01-01

This report uses neutron diffraction to investigate the crystal phase composition of uranium-molybdenum alloy foils (U-10Mo) for the CONVERT MP-1 Reactor Conversion Project, and determines the effect on alpha-uranium contamination following the deposition of a Zr metal diffusion layer by various methods: plasma spray deposition of Zr powders at LANL and hot co-rolling with Zr foils at BWXT. In summary, there is minimal decomposition of the gamma phase U-10Mo foil to alpha phase contamination following both plasma spraying and hot co-rolling. The average unit cell volume, i.e. lattice spacing, of the Zr layer can be mathematically extracted from the diffraction data; co-rolled Zr matches well with literature values of bulk Zr, while plasma sprayed Zr shows a slight increase in the lattice spacing, indicative of interstitial oxygen in the lattice. Neutron diffraction is a beneficial alternative to conventional methods of phase composition, i.e. x ray diffraction (XRD) and destructive metallography. XRD has minimal penetration depth in high atomic number materials, particularly uranium, and can only probe the first few microns of the fuel plate; neutrons pass completely through the foil, allowing for bulk analysis of the foil composition and no issues with addition of cladding layers, as in the final, aluminum-clad reactor fuel plates. Destructive metallography requires skilled technicians, cutting of the foil into small sections, hazardous etching conditions, long polishing and microscopy times, etc.; the neutron diffraction system has an automated sample loader and can fit larger foils, so there is minimal analysis preparation; the total spectrum acquisition time is ~ 1 hour per sample. The neutron diffraction results are limited by spectra refinement/calculation times and the availability of the neutron beam source. In the case of LANSCE at Los Alamos, the beam operates ~50% of the year. Following the lessons learned from these preliminary results, optimizations to

High resolution, position sensitive detector for energetic particle beams

International Nuclear Information System (INIS)

Marsh, E.P.; Strathman, M.D.; Reed, D.A.; Odom, R.W.; Morse, D.H.; Pontau, A.E.

1993-01-01

The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10 10 ), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented. (orig.)

Spatial resolution test of a beam diagnostic system for DESIREE

Science.gov (United States)

Das, Susanta; Kallberg, A.

2010-11-01

A diagnostic system based on the observation of low energy ( ˜ 10 eV) secondary electrons (SE) produced by a beam, striking a metallic foil has been built to monitor and to cover the wide range of beam intensities and energies for Double ElectroStatic Ion Ring ExpEriment [1,2].The system consists of a Faraday cup to measure the beam current, a collimator with circular apertures of different diameters to measure the spatial resolution of the system, a beam profile monitoring system (BPMS), and a control unit. The BPMS, in turn, consists of an aluminim (Al) foil, a grid placed in front of the Al foil to accelerate the SE, position sensitive MCP, fluorescent screen, and a CCD camera to capture the images. The collimator contains a set of circular holes of different diameters and separations (d) between them. The collimator cuts out from the beam areas equal to the holes with separation d mm between the beams centers and creates well separated (distinguishable) narrow beams of approximately same intensity close to each other. A 10 keV proton beam was used. The spatial resolution of the system was tested for different Al plate and MCP voltages and resolution of better than 2 mm was achieved. Ref.: 1. K. Kruglov {et al}., NIM A 441 (2000) 595; 701 (2002) 193c, 2. MSL and Atomic Physics, Stockholm Univ.(www.msl.se, http://www.atom.physto.se/Cederquist/desiree/web/hc.html).

Beam line design for synchrotron spectroscopy in the VUV

Energy Technology Data Exchange (ETDEWEB)

Howells, M R

1980-01-01

The character of the radiation source provided by an electron storage ring is briefly reviewed from the point of view of utilization for VUV spectroscopy. The design of beam line components is then considered with special reference to the problems of contamination of optical surfaces and vacuum protection. The issues involved in designing mirrors for use with storage rings are considered with emphasis on the questions of power dissipation, image quality and materials selection.

Beam line design for synchrotron spectroscopy in the VUV

International Nuclear Information System (INIS)

Howells, M.R.

1980-01-01

The character of the radiation source provided by an electron storage ring is briefly reviewed from the point of view of utilization for VUV spectroscopy. The design of beam line components is then considered with special reference to the problems of contamination of optical surfaces and vacuum protection. The issues involved in designing mirrors for use with storage rings are considered with emphasis on the questions of power dissipation, image quality and materials selection

New intensifier foils in roentgenologic diagnostics

Energy Technology Data Exchange (ETDEWEB)

Beyer, H K; Schulze, B

1981-09-01

The main components of the foils are the carrier layer and the luminescent layer, which are in direct contact through an adhesive layer. Carrier layer and adhesive layer absorb and reflect parts of the light. In order to reduce this effect, modern foils are slightly dyed, mostly in the complementary colour of the emitted light. The luminescent layer is attached to the carrier layer by means of a binder. The mean binder content of the luminescent layer is about 10% of the weight of the luminescent material. The particle or crystal range between 5 and 10 ..mu..m. The luminescent layer thickness varies between 0.1 and 0.5 mm, according to the intensification. The imposing with luminescents consequently increases from 20 up to 100 mg/cm/sup 2/. In most cases the luminescent layer is protected by a thin layer (10 to 20 ..mu..m thick) of a very resistant and well-transparent synthetic resin. A foil combination consists of a front and a rear foil, the rear foil often providing a higher degree of intensification than the front foil. Foil quality is mainly defined by the intensification factor, quality on its part is characterized by the modulation transmission function and by the particle structure of the luminescent layer. Quality indicators are also the durability of the foils and the steadiness of the crystal arrangement in the luminescent layer. The representation quality is deteriorated also by the irregular blackening of the roentgen film, resulting from the statistic fluctuations of the roentgen quantums, which are absorbed in the luminescent layer. This unfavourable feature, termed quantum noise, increases with decreasing irradiation intensity, with increasing film gradation, and with increasing sensivity of the film-foil-system. Moreover, an optimal image quality is only possible when film and foil are in good contact conditions (in the cassette).

Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

CERN Document Server

Krieger, A.; Catherall, R.; Hochschulz, F.; Kramer, J.; Neugart, R.; Rosendahl, S.; Schipper, J.; Siesling, E.; Weinheimer, Ch.; Yordanov, D.T.; Nortershauser, W.

2011-01-01

A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the highvoltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequencycomb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.

Computational modeling of plasma-flow switched foil implosions

International Nuclear Information System (INIS)

Lindemuth, I.R.

1985-01-01

A ''plasma-flow'', or ''commutator'', switch has been proposed as a means of achieving high dI/dt in a radially imploding metallic foil plasma. In this concept, an axially moving foil provides the initial coaxial gun discharge path for the prime power source and provides and ''integral'' inductive storage of magnetic energy. As the axially moving foil reaches the end of the coaxial gun, a radially imploding load foil is switched into the circuit. The authors have begun two-dimensional computer modeling of the two-foil implosion system. They use a magnetohydrodynamic (MHD) model which includes tabulated state and transport properties of the metallic foil material. Moving numerical grids are used to achieve adequate resolution of the moving foils. A variety of radiation models are used to compute the radiation generated when the imploding load foil converges on axis. These computations are attempting to examine the interaction of the switching foil with the load foil. In particular, they examine the relationship between foil placement and implosion quality

Reduction of angular divergence of laser-driven ion beams during their acceleration and transport

Science.gov (United States)

Zakova, M.; Pšikal, Jan; Margarone, Daniele; Maggiore, Mario; Korn, G.

2015-05-01

Laser plasma physics is a field of big interest because of its implications in basic science, fast ignition, medicine (i.e. hadrontherapy), astrophysics, material science, particle acceleration etc. 100-MeV class protons accelerated from the interaction of a short laser pulse with a thin target have been demonstrated. With continuing development of laser technology, greater and greater energies are expected, therefore projects focusing on various applications are being formed, e.g. ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration). One of the main characteristic and crucial disadvantage of ion beams accelerated by ultra-short intense laser pulses is their large divergence, not suitable for the most of applications. In this paper two ways how to decrease beam divergence are proposed. Firstly, impact of different design of targets on beam divergence is studied by using 2D Particlein-cell simulations (PIC). Namely, various types of targets include at foils, curved foil and foils with diverse microstructures. Obtained results show that well-designed microstructures, i.e. a hole in the center of the target, can produce proton beam with the lowest divergence. Moreover, the particle beam accelerated from a curved foil has lower divergence compared to the beam from a flat foil. Secondly, another proposed method for the divergence reduction is using of a magnetic solenoid. The trajectories of the laser accelerated particles passing through the solenoid are modeled in a simple Matlab program. Results from PIC simulations are used as input in the program. The divergence is controlled by optimizing the magnetic field inside the solenoid and installing an aperture in front of the device.

Monte Carlo transport of electrons and positrons through thin foils

International Nuclear Information System (INIS)

Legarda, F.; Idoeta, R.

2000-01-01

In the different measurements made with electrons traversing matter it becomes useful the knowledge of its transmission through that medium, their paths and their angular distribution through matter so as to process and get information about the traversed medium and to improve and innovate the techniques that employ electrons, as medical applications or materials irradiation. This work presents a simulation of the transport of beams of electrons and positrons through thin foils using an analog Monte Carlo code that simulates in a detailed way every electron movement or interaction in matter. As those particles penetrate thin absorbers it has been assumed that they interact with matter only through elastic scattering, with negligible energy loss. This type of interaction has been described quite precisely because its angular form influences very much the angular distribution of electrons and positrons in matter. With this code it has been calculated the number of particles, with energies between 100 and 3000 keV, that are transmitted through different media of various thicknesses as well as its angular distribution, showing a good agreement with experimental data. The discrepancies are less than 5% for thicknesses lower than about 30% of the corresponding range in the tested material. As elastic scattering is very anisotropic, angular distributions resemble a collimated incident beam for very thin foils becoming slowly more isotropic when absorber thickness is increased. (author)

Lifetimes of carbon foils deposited on etched substrates

International Nuclear Information System (INIS)

Stoner, J.O. Jr.; Bashkin, S.; Hartog, P.D.; Thomas, G.; Yntema, J.L.

1981-01-01

The methods currently in use for producing long-lived carbon foils are listed. The possible common factors which are important in making long lasting foils are a) making a strong, coherent, continuous layer, b) making a foil slack, loose, or baggy, and c) making a foil whose molecular structure minimizes shrinkage. The behavior of foils deposited on etched substrates is compared with foils deposited upon conventional microscope slides

Hyaluronan-lecithin foils and their properties

International Nuclear Information System (INIS)

BiaIopiotrowicz, Tomasz; Janczuk, BronisIaw; Fiedorowicz, Maciej; Khachatryan, Gohar; Tomasik, Piotr; Bakos, Dusan

2006-01-01

Thin, elastic foils of good resistance to the air exposure, patented as wound healing aids, were prepared by evaporation of a blend of lecithin (L) and sodium hyaluronan (H) taken under varying proportions. The contact angle for water, glycerol, formamide, ethylene glycol and diiodomethane, was determined for these foils. The contact angle was correlated against the H:L foil composition. For all liquids but formamide the highest contact angle was noted for the H:L = 2:1 (g g -1 ) ratio. The contact angles provided estimation of the work of adhesion. At the same L:H ratio the work of adhesion was the lowest. It was suggested that lecithin cross-linked hyaluronan. Since the work of adhesion of the studied liquids was similar to that of diiodomethane, it could be concluded that almost all functional groups on the foil surface were completely blocked. Perhaps, at H:L = 2:1 (g g -1 ) a stoichiometric complex of hyaluronic acid with lecithin was formed, and polar functional groups from both reagents were involved. Foils seem to be electrostatic complexes of H with L. Foils with the H:L equal to 2:1 exhibited specific properties confirmed by the IR reflectance spectra of the foils. The thermogravimetry (TG/DTG) also revealed unique thermal behaviour confirming other specific properties of the foil of this composition. For the same ratio a thorough inspection of the scanning electron micrographs (SEM) revealed few irregularly distributed perforations of 1-2 μm in diameter seen as black points, which can be recognized as pores. Properties of the foils determined in the contact angle measurements are nicely backed by the results from thermogravimetric and scanning electron microscopic studies

[Implants with 32P-foils for LDR-brachytherapy of benign stenosis in urology and gastroenterology].

Science.gov (United States)

Assmann, Walter; Becker, Ricarda; Otto, Henrike; Bader, Markus; Clemente, Lucas; Reinhardt, Sabine; Schäfer, Claus; Schirra, Jörg; Uschold, Stephanie; Welzmüller, Andreas; Sroka, Ronald

2013-02-01

For LDR-brachytherapy, a limited number of implant geometries and materials are available. To avoid wound healing related hyper-proliferation (stenosis, keloids) a novel radioactive foil system was developed based on beta emitting (32)P, which can be easily integrated in existing implants such as urethral catheters or bile duct stents. As substrate material for these foils PEEK (polyetherethercetone) was chosen because of its radiation hardness during neutron activation of (32)P. The activity was determined by liquid scintillation counting and gamma spectroscopy, dose distributions were measured with scintillation detectors and radiochromic films. The correlation between activity and dose was checked by Monte-Carlo-simulations (Geant4). Prototypes of the (32)P-implants have shown in wash-out tests the required tightness for sealed radioactive sources. In animal tests on urethra and bile duct, the uncomplicated and save application of (32)P-foils mounted on standard implants has been demonstrated, which is almost unchanged due to the simple radiation protection with plexiglass. This concept of radioactive implants with integrated (32)P-foils could extend essentially the application possibilities of LDR-brachytherapy. Copyright © 2012. Published by Elsevier GmbH.

Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Krieger, A., E-mail: kriegea@uni-mainz.d [Institut fuer Kernchemie, Johannes Gutenberg, Universitaet Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz (Germany); Geppert, Ch. [Institut fuer Kernchemie, Johannes Gutenberg, Universitaet Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Catherall, R. [CERN, CH-1211 Geneve 23 (Switzerland); Hochschulz, F. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Kraemer, J.; Neugart, R. [Institut fuer Kernchemie, Johannes Gutenberg, Universitaet Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz (Germany); Rosendahl, S. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Schipper, J.; Siesling, E. [CERN, CH-1211 Geneve 23 (Switzerland); Weinheimer, Ch. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Yordanov, D.T. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Noertershaeuser, W. [Institut fuer Kernchemie, Johannes Gutenberg, Universitaet Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany)

2011-03-11

A high-voltage divider with accuracy at the ppm level and collinear laser spectroscopy were used to calibrate the high-voltage installation at the radioactive ion beam facility ISOLDE at CERN. The accurate knowledge of this voltage is particularly important for collinear laser spectroscopy measurements. Beam velocity measurements using frequency-comb based collinear laser spectroscopy agree with the new calibration. Applying this, one obtains consistent results for isotope shifts of stable magnesium isotopes measured using collinear spectroscopy and laser spectroscopy on laser-cooled ions in a trap. The long-term stability and the transient behavior during recovery from a voltage dropout were investigated for the different power supplies currently applied at ISOLDE.

The Anomalous Currents In The Front Foils of the JET Lost Alpha Diagnostic KA-2

International Nuclear Information System (INIS)

Cecil, F.E.; Kiptily, V.; Salmi, A.; Horton, A.; Fullard, K.; Murari, A.; Darrow, D.; Hill, K.

2011-01-01

We have examined the observed currents in the front foils of the JET Faraday cup lost alpha particle diagnostic KA-2. In particular, we have sought to understand the currents during Ohmic plasmas for which the ion flux at the detectors was initially assumed to be negligible. We have considered two sources of this current: plasma ions (both deuterium and impurity) in the vicinity of the detector (including charge exchange neutrals) and photoemission from scattered UV radiation. Based upon modeling and empirical observation, the latter source appears most likely and, moreover, seems to be applicable to the currents in the front foil during ELMy H-mode plasmas. A very thin gold or nickel foil attached to the present detector aperture is proposed as a solution to this problem, and realistic calculations of expected fluxes of lost energetic neutral beam ions during TF ripple experiments are presented as justification of this proposed solution.

The Anomalous Currents In The Front Foils of the JET Lost Alpha Diagnostic KA-2

Energy Technology Data Exchange (ETDEWEB)

Cecil, F. E.; Kiptily, V.; Salmi, A.; Horton, A.; Fullard, K.; Murari, A.; Darrow, D.; Hill, K.

2011-05-04

We have examined the observed currents in the front foils of the JET Faraday cup lost alpha particle diagnostic KA-2. In particular, we have sought to understand the currents during Ohmic plasmas for which the ion flux at the detectors was initially assumed to be negligible. We have considered two sources of this current: plasma ions both deuterium and impurity in the vicinity of the detector including charge exchange neutrals and photoemission from scattered UV radiation. Based upon modeling and empirical observation, the latter source appears most likely and, moreover, seems to be applicable to the currents in the front foil during ELMy H-mode plasmas. A very thin gold or nickel foil attached to the present detector aperture is proposed as a solution to this problem, and realistic calculations of expected fluxes of lost energetic neutral beam ions during TF ripple experiments are presented as justification of this proposed solution.

High resolution, position sensitive detector for energetic particle beams

Energy Technology Data Exchange (ETDEWEB)

Marsh, E P [Charles Evans and Associates, Redwood City, CA (United States); Strathman, M D [Charles Evans and Associates, Redwood City, CA (United States); Reed, D A [Charles Evans and Associates, Redwood City, CA (United States); Odom, R W [Charles Evans and Associates, Redwood City, CA (United States); Morse, D H [Sandia National Labs., Livermore, CA (United States); Pontau, A E [Sandia National Labs., Livermore, CA (United States)

1993-05-01

The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10[sup 10]), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 [mu]m for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 [mu]m) with an image resolution of better than 0.5 [mu]m has since been developed and its design is presented. (orig.)

High-resolution electron collision spectroscopy with multicharged ions in merged beams

Energy Technology Data Exchange (ETDEWEB)

Lestinsky, M.

2007-04-18

The Heidelberg ion storage ring Tsr is currently the only ring equipped with two independent devices for the collinear merging of a cold electron beam with stored ions. This greatly improves the potential of electron-ion collision experiments, as the ion beam can be cooled with one electron beam, while the other one is used as a dedicated target for energy-resolved electron collision processes, such as recombination. The work describes the implementation of this system for rst electron collision spectroscopy experiments. A detection system has been realized including an ion detector and specroscopic beam-control software and instrumentation. Moreover, in order to improve the spectroscopic resolution systematical studies of intrinsic relaxation processes in the electron beam have been carried out. These include the dependence on the electron beam density, the magnetic guiding eld strength, and the acceleration geometry. The recombination measurements on low-lying resonances in lithiumlike Sc{sup 18+} yield a high-precision measurement of the 2s-2p{sub 3/2} transition energy in this system. Operation of the two-electron-beam setup at high collision energy ({approx}1000 eV) is established using resonances of hydrogenlike Mg{sup 11+}, while the unique possibility of modifying the beam-merging geometry con rms its importance for the electron-ion recombination rate at lowest relative energy, as demonstrated on F{sup 6+}. (orig.)

High-resolution electron collision spectroscopy with multicharged ions in merged beams

International Nuclear Information System (INIS)

Lestinsky, M.

2007-01-01

The Heidelberg ion storage ring Tsr is currently the only ring equipped with two independent devices for the collinear merging of a cold electron beam with stored ions. This greatly improves the potential of electron-ion collision experiments, as the ion beam can be cooled with one electron beam, while the other one is used as a dedicated target for energy-resolved electron collision processes, such as recombination. The work describes the implementation of this system for rst electron collision spectroscopy experiments. A detection system has been realized including an ion detector and specroscopic beam-control software and instrumentation. Moreover, in order to improve the spectroscopic resolution systematical studies of intrinsic relaxation processes in the electron beam have been carried out. These include the dependence on the electron beam density, the magnetic guiding eld strength, and the acceleration geometry. The recombination measurements on low-lying resonances in lithiumlike Sc 18+ yield a high-precision measurement of the 2s-2p 3/2 transition energy in this system. Operation of the two-electron-beam setup at high collision energy (∼1000 eV) is established using resonances of hydrogenlike Mg 11+ , while the unique possibility of modifying the beam-merging geometry con rms its importance for the electron-ion recombination rate at lowest relative energy, as demonstrated on F 6+ . (orig.)

Mechanical design of the two dimensional beam emission spectroscopy diagnostics on mast

Energy Technology Data Exchange (ETDEWEB)

Kiss, Istvan Gabor, E-mail: kiss.istvan.gabor@rmki.kfki.hu [Association EURATOM, KFKI-RMKI, P.O. Box 49, H-1525 Budapest (Hungary); Meszaros, Botond; Dunai, Daniel; Zoletnik, Sandor; Krizsanoczi, Tibor [Association EURATOM, KFKI-RMKI, P.O. Box 49, H-1525 Budapest (Hungary); Field, Anthony R.; Gaffka, Rob [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

2011-10-15

A two dimensional beam emission spectroscopy (BES) system optimized for density turbulence measurements has recently been installed on the MAST tokamak. This system observes the emission of a Deuterium heating beam using a rotatable mirror to view from the plasma centre to the outboard edge (0.7-1.5 m), although the optics is optimized for core region (1.2 m). The beam is imaged onto a 4x8 pixel Avalanche Photodiode (APD) array detector, enabling measurements with 1 MHz bandwidth at photon-flux level of few times 10{sup 11} photons/s. This article will present the mechanical design of MAST BES equipment with special emphasis on its in-vessel components.

Ion movie camera for particle-beam-fusion experiments

International Nuclear Information System (INIS)

Stygar, W.A.; Mix, L.P.; Leeper, R.J.; Maenchen, J.; Wenger, D.F.; Mattson, C.R.; Muron, D.J.

1992-01-01

A camera with a 3 ns time resolution and a continuous (>100 ns) record length has been developed to image a 10 12 --10 13 W/cm 2 ion beam for inertial-confinement-fusion experiments. A thin gold Rutherford-scattering foil placed in the path of the beam scatters ions into the camera. The foil is in a near-optimized scattering geometry and reduces the beam intensity∼seven orders of magnitude. The scattered ions are pinhole imaged onto a 2D array of 39 p-i-n diode detectors; outputs are recorded on LeCroy 6880 transient-waveform digitizers. The waveforms are analyzed and combined to produce a 39-pixel movie which can be displayed on an image processor to provide time-resolved horizontal- and vertical-focusing information

An efficient fabrication of vertically aligned carbon nanotubes on flexible aluminum foils by catalyst-supported chemical vapor deposition

International Nuclear Information System (INIS)

Yoshikawa, Naoki; Kishi, Naoki; Sugai, Toshiki; Shinohara, Hisanori; Asari, Takuma; Hayashi, Shigeo

2008-01-01

An efficient and versatile growth of thin-layer carbon nanotubes on a flexible aluminum foil (for kitchen use) by catalyst-supported chemical vapor deposition is reported. The aluminum foil used in the present experiment is commercially available for kitchen use. The electron-beam vapor deposition and dip-coating have been used for preparing catalysts on the aluminum foil. Vertically aligned thin-layer CNTs with typical diameters of 2.5-6.0 nm and lengths up to 90 μm are obtained when ethanol is used in combination with Fe and Co catalyst particles at a growth temperature of around 650 deg. C under an Ar/H 2 gas flow. Thermo-gravimetric analyses together with HR-TEM observations indicate that the purity of the CNTs synthesized by the current technique is very high

Experiments with activated metal foils

Energy Technology Data Exchange (ETDEWEB)

Malati, M A [Medway and Maidstone Coll. of Tech., Chatham (UK)

1978-09-01

Experiments based on the activation of metal foils by slow neutron bombardment which can be used to demonstrate various aspects of artificial radioactivity are described and discussed. Suitable neutron sources and foils are considered.

Thermal analysis of injection beam dump of high-intensity rapid-cycling synchrotron in J-PARC

Science.gov (United States)

Kamiya, J.; Saha, P. K.; Yamamoto, K.; Kinsho, M.; Nihei, T.

2017-10-01

The beam dump at the beam injection area in the J-PARC 3-GeV rapid cycling synchrotron (RCS) accepts beams that pass through the charge exchange foil without ideal electron stripping during the multi-turn beam injection. The injection beam dump consists of the beam pipe, beam stopper, radiation shield, and cooling mechanism. The ideal beam power into the injection beam dump is 400 W in the case of design RCS extraction beam power of 1 MW with a healthy foil, which has 99.7 % charge stripping efficiency. On the other hand, as a radiation generator, the RCS is permitted to be operated with maximum average beam power of 4 kW into the injection beam dump based on the radiation shielding calculation, in consideration of lower charge stripping efficiency due to the foil deterioration. In this research, to evaluate the health of the RCS injection beam dump system from the perspective of the heat generation, a thermal analysis was performed based on the actual configuration with sufficiently large region, including the surrounding concrete and soil. The calculated temperature and heat flux density distribution showed the validity of the mesh spacing and model range. The calculation result showed that the dumped 4 kW beam causes the temperature to increase up to 330, 400, and 140 °C at the beam pipe, beam stopper, and radiation shield, respectively. Although these high temperatures induce stress in the constituent materials, the calculated stress values were lower than the ultimate tensile strength of each material. Transient temperature analysis of the beam stopper, which simulated the sudden break of the charge stripper foil, demonstrated that one bunched beam pulse with the maximum beam power does not lead to a serious rise in the temperature of the beam stopper. Furthermore, from the measured outgassing rate of stainless steel at high temperature, the rise in beam line pressure due to additive outgassing from the heated beam pipe was estimated to have a negligible

Nuclear spin polarized alkali beams (Li and Na): Production and acceleration

International Nuclear Information System (INIS)

Jaensch, H.; Becker, K.; Blatt, K.; Leucker, H.; Fick, D.

1987-01-01

Recent improvements of the Heidelberg source for polarized heavy ions (PSI) are described. By means of optical pumping in combination with the existing multipole separation magnet the beam figure of merit (polarization 2 x intensity) was doubled. 7 Li and 23 Na atomic beams can now be produced in pure hyperfine magnetic substates. Fast switching of the polarization is achieved by an adiabatic medium field transition. The hyperfine magnetic substate population is determined by laser-induced fluorescence spectroscopy. In routine operation atomic beams with nuclear polarization p α ≥0.85 (α=z, zz) are obtained. The acceleration of polarized 23 Na - ions by a 12 MV tandem accelerator introduces a new problem: the energy at the terminal stripper foil is not sufficient to produce a usable yield of naked ions. For partially stripped ions hyperfine interaction of the remaining electrons with the nuclear spin reduces the nuclear polarization. Using in addition the Heidelberg postaccelerator 23 Na 9+ beams of energies between 49 and 184 MeV were obtained with an alignment on target of P zz ≅0.45. 7 Li beams have also been accelerated up to 45 MeV with an alignment of P zz =0.69. (orig.)

Evaluation of two-beam spectroscopy as a plasma diagnostic

International Nuclear Information System (INIS)

Billard, B.D.

1980-04-01

A two-beam spectroscopy (TBS) system is evaluated theoretically and experimentally. This new spectroscopic technique uses correlations between components of emitted light separated by a small difference in angle of propagation. It is thus a non-perturbing plasma diagnostic which is shown to provide local (as opposed to line-of-sight averaged) information about fluctuations in the density of light sources within a plasma - information not obtainable by the usual spectroscopic methods. The present design is an improvement on earlier systems proposed in a thesis by Rostler

In situ micro-focused X-ray beam characterization with a lensless camera using a hybrid pixel detector

International Nuclear Information System (INIS)

Kachatkou, Anton; Marchal, Julien; Silfhout, Roelof van

2014-01-01

Position and size measurements of a micro-focused X-ray beam, using an X-ray beam imaging device based on a lensless camera that collects radiation scattered from a thin foil placed in the path of the beam at an oblique angle, are reported. Results of studies on micro-focused X-ray beam diagnostics using an X-ray beam imaging (XBI) instrument based on the idea of recording radiation scattered from a thin foil of a low-Z material with a lensless camera are reported. The XBI instrument captures magnified images of the scattering region within the foil as illuminated by the incident beam. These images contain information about beam size, beam position and beam intensity that is extracted during dedicated signal processing steps. In this work the use of the device with beams for which the beam size is significantly smaller than that of a single detector pixel is explored. The performance of the XBI device equipped with a state-of-the-art hybrid pixel X-ray imaging sensor is analysed. Compared with traditional methods such as slit edge or wire scanners, the XBI micro-focused beam characterization is significantly faster and does not interfere with on-going experiments. The challenges associated with measuring micrometre-sized beams are described and ways of optimizing the resolution of beam position and size measurements of the XBI instrument are discussed

Synchronization of streak and framing camera measurements of an intense relativistic electron beam propagating through gas

International Nuclear Information System (INIS)

Weidman, D.J.; Murphy, D.P.; Myers, M.C.; Meger, R.A.

1994-01-01

The expansion of the radius of a 5 MeV, 20 kA, 40 ns electron beam from SuperIBEX during propagation through gas is being measured. The beam is generated, conditions, equilibrated, and then passed through a thin foil that produces Cherenkov light, which is recorded by a streak camera. At a second location, the beam hits another Cherenkov emitter, which is viewed by a framing camera. Measurements at these two locations can provide a time-resolved measure of the beam expansion. The two measurements, however, must be synchronized with each other, because the beam radius is not constant throughout the pulse due to variations in beam current and energy. To correlate the timing of the two diagnostics, several shots have been taken with both diagnostics viewing Cherenkov light from the same foil. Experimental measurements of the Cherenkov light from one foil viewed by both diagnostics will be presented to demonstrate the feasibility of correlating the diagnostics with each other. Streak camera data showing the optical fiducial, as well as the final correlation of the two diagnostics, will also be presented. Preliminary beam radius measurements from Cherenkov light measured at two locations will be shown

Foil fabrication for the ROMANO event. Revision 1

International Nuclear Information System (INIS)

Romo, J.G. Jr.; Weed, J.W.; Griggs, G.E.; Brown, T.G.; Tassano, P.L.

1984-01-01

The Vacuum Processes Lab (VPL), of LLNL's M.E. Dept. - Material Fabrication Division (MFD), conducted various vacuum related support activities for the ROMANO nuclear physics experiment. This report focuses on the foil fabrication activities carried out between July and November 1983 for the ROMANO event. Other vacuum related activities for ROMANO, such as outgassing tests of materials, are covered in separate documentation. VPL was asked to provide 270 coated Parylene foils for the ROMANO event. However, due to the developmental nature of some of the procedures, approximately 400 coated foils were processed. In addition, VPL interacted with MFD's Plastics Shop to help supply Parylene substrates to other organizations (i.e., LBL and commercial vendors) which had also been asked to provide coated foils for ROMANO. The purposes of this report are (A) to document the processes developed and the techniques used to produce the foils, and (B) to suggest future directions. The report is divided into four sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, (3) calibration foil fabrication, and (4) foil and substrate inspections

Characterization of beryllium foil produced by hot rolling

International Nuclear Information System (INIS)

Wittenauer, J.; Nieh, T.G.; Waychunas, G.

1992-01-01

Beryllium foil is important for a number of aerospace applications including honeycomb structures and metal-matrix composites. In this study, a method of producing beryllium foil directly from powder or flake is demonstrated. A variety of foils were produced in the thickness range 90-300 μm, free from defects such as pinholes and excessive surface roughness, and exhibiting sufficient formability for honeycomb manufacture. Foil produced directly from powder or flake exhibits crystallographic texture, microstructure, and formability equivalent to foil produced from more massive precursors. (Author)

Monitoring the degradation of partly decomposable plastic foils

Directory of Open Access Journals (Sweden)

Rétháti Gabriella

2014-11-01

Full Text Available We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE, MDPE containing pro-oxydative additives (238, 242 and MDPE with pro-oxydative additives and thermoplastic starch (297 in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.

Particle velocity measurements in laser irradiated foils using ORVIS

International Nuclear Information System (INIS)

Sheffield, S.A.; Fisk, G.A.

1983-01-01

Aluminum foils from 2- to 200-μm thick have been subjected to a Nd:YAG laser pulse of low irradiance (10 9 W/cm 2 , approx. 10 ns pulse) to produce laser-driven shocks in the foils. The particle velocity history of the foil side opposite the laser deposition was monitored with nanosecond resolution by a velocity interferometer system called ORVIS. These histories indicate a shock reverberation process accelerates the foil. Peak foil velocities can be adequately calculated using a ricket propulsion model developed from experiments at much higher irradiances. A velocity of 1 km/s was developed in a 2-μm-thick free foil in a time of 50 ns. Water-confined foils attained peak particle velocities about three times higher than those of free foils

Collodion-reinforcement and plasma-cleaning of target foils

Science.gov (United States)

Stoner, John O.

2002-03-01

The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed.

Collodion-reinforcement and plasma-cleaning of target foils

International Nuclear Information System (INIS)

Stoner, John O.

2002-01-01

The preparation of evaporated target foils can often be facilitated by use of collodion coatings either on the substrate sides or on the exterior surfaces of the foils. Later, such coatings must usually be removed. Cleaning of a foil is necessary if thin layers of adhesives have crept onto the foil. Removal and/or cleaning can often be done satisfactorily with an oxygen plasma. Apparatus and procedures used for this are described. Foils that were cleaned successfully, and some that were incompatible with the cleaning process are listed

Multiphoton Ionization Detection in Collinear Laser Spectroscopy of Isolde Beams

CERN Multimedia

2002-01-01

The experiments using the multiphoton ionization technique have been continued in the beginning of 1990 with stable beam tests on the modified apparatus and with another radioactive beam time on Yb. Higher laser power and an increased vacuum in the ionization region (see figure) yielded a further gain in sensitivity, mainly due to the better suppression of the background ions produced in rest gas collisions. For even Yb isotopes we have now reached a detection efficiency of $\\epsilon$~=~1~x~10$^{-5}$ ions per incoming atom at a background count rate of 30~ions from a beam of 5~x~10$^9$. This sensitivity was high enough for spectroscopy on $^{157}$Yb, where the typical ISOLDE yield of 5~x~10$^7$Yb ions is covered by an isobaric contamination of more than 10$^{10}$ ions. Measurements have also been performed on $^{175}$Yb. These give the first precise value for the magnetic moment of this isotope, $\\mu$~=~0.766(8)$ mu _{N} $, which agrees rather well with the magnetic moment of the isotone $^{177}$Hf. The isoto...

Efficient electron beam deposition for repetitively pulsed krypton fluoride lasers

International Nuclear Information System (INIS)

Hegeler, F.; Myers, M.C.; Friedman, M.; Sethian, J.D.; Swanekamp, S.B.; Rose, D.V.; Welch, D.R.

2002-01-01

We have demonstrated that we can significantly increase the electron beam transmission efficiency through a pressure foil structure (hibachi) by segmenting the beam into strips to miss the hibachi support ribs. In order to increase the electron beam transmission, the cathode strips are adjusted to compensate for beam rotation and pinching. The beam propagation through the hibachi has been both measured and simulated with 1-D and 3-D codes

Positron beam lifetime spectroscopy of atomic scale defect distributions in bulk and microscopic volumes

International Nuclear Information System (INIS)

Howell, R.H.; Cowan, T.E.; Hartley, J.; Sterne, P.; Brown, B.

1996-05-01

We are developing a defect analysis capability based on two positron beam lifetime spectrometers: the first is based on a 3 MeV electrostatic accelerator and the second on our high current linac beam. The high energy beam lifetime spectrometer is operational and positron lifetime analysis is performed with a 3 MeV positron beam on thick samples. It is being used for bulk sample analysis and analysis of samples encapsulated in controlled environments for insitu measurements. A second, low energy, microscopically focused, pulsed positron beam for defect analysis by positron lifetime spectroscopies is under development at the LLNL high current positron source. This beam will enable defect specific, 3-D maps of defect concentration with sub-micron location resolution and when coupled with first principles calculations of defect specific positron lifetimes it will enable new levels of defect concentration mapping and defect identification

Radiation lifetimes and failure mechanisms of carbon stripper foils

International Nuclear Information System (INIS)

Auble, R.L.

1981-01-01

Measurements of lifetimes of thin carbon foils under heavy-ion irradiation are compiled and recent advances in stripper foil technology are reviewed. The impact of recent foil lifetime improvements, many by more than an order of magnitude, on heavy-ion electrostatic accelerators is discussed. Foil inhomogeneities, particularly those caused by sputtering are suggested to be a prime factor in usable foil lifetimes

Study of graphene growth on copper foil by pulsed laser deposition at reduced temperature

Science.gov (United States)

Abd Elhamid, Abd Elhamid M.; Hafez, Mohamed A.; Aboulfotouh, Abdelnaser M.; Azzouz, Iftitan M.

2017-01-01

Graphene has been successfully grown on commercial copper foil at low temperature of 500 °C by pulsed laser deposition (PLD). X-ray diffraction patterns showed that films have been grown in the presence of Cu(111) and Cu(200) facets. Raman spectroscopy was utilized to study the effects of temperature, surface structure, and cooling rate on the graphene growth. Raman spectra indicate that the synthesis of graphene layers rely on the surface quality of the Cu substrate together with the proper cooling profile coupled with graphene growth temperature. PLD-grown graphene film on Cu has been verified by transmission electron microscopy. Surface mediated growth of graphene on Cu foil substrate revealed to have a favorable catalytic effect. High growth rate of graphene and less defects can be derived using fast cooling rate.

Densities of carbon foils

International Nuclear Information System (INIS)

Stoner, J.O. Jr.

1991-01-01

The densities of arc-evaporated carbon target foils have been measured by several methods. The density depends upon the method used to measure it; for the same surface density, values obtained by different measurement techniques may differ by fifty percent or more. The most reliable density measurements are by flotation, yielding a density of 2.01±0.03 g cm -3 , and interferometric step height with the surface density known from auxiliary measurements, yielding a density of 2.61±0.4 g cm -3 . The difference between these density values mayy be due in part to the compressive stresses that carbon films have while still on their substrates, uncertainties in the optical calibration of surface densities of carbon foils, and systematic errors in step-height measurements. Mechanical thickness measurements by micrometer caliper are unreliable due to nonplanarity of these foils. (orig.)

Characterization of U-Mo Foils for AFIP-7

Energy Technology Data Exchange (ETDEWEB)

Edwards, Danny J.; Ermi, Ruby M.; Schemer-Kohrn, Alan L.; Overman, Nicole R.; Henager, Charles H.; Burkes, Douglas; Senor, David J.

2012-11-07

Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains.

Measurement of Moments and Radii of Light Nuclei by Collinear Fast-Beam Laser Spectroscopy and $\\beta$-NMR Spectroscopy

CERN Multimedia

Marinova, K P

2002-01-01

Nuclear Moments and radii of light unstable isotopes are investigated by applying different high-sensitivity and high-resolution techniques based on collinear fast-beam laser spectroscopy. A study of nuclear structure in the sd shell is performed on neon isotopes in the extended chain of $^{17-28}$Ne, in particular on the proton-halo candidate $^{17}$Ne. Measurements of hyperfine structure and isotope shift have become possible by introducing an ultra-sensitive non-optical detection method which is based on optical pumping, state-selective collisional ionization and $\\beta$-activity counting. The small effect of nuclear radii on the optical isotope shifts of light elements requires very accurate measurements. The errors are dominated by uncertainties of the Doppler shifts which are conventionally determined from precisely measured acceleration voltages. These uncertainties are removed by measuring the beam energy with simultaneous excitation of two optical lines in parallel / antiparallel beam configuration. ...

Numerical and experimental investigation of bump foil mechanical behaviour

DEFF Research Database (Denmark)

Larsen, Jon Steffen; Cerda Varela, Alejandro Javier; Santos, Ilmar

2014-01-01

Corrugated foils are utilized in air foil bearings to introduce compliance and damping thus accurate mathematical predictions are important. A corrugated foil behaviour is investigated experimentally as well as theoretically. The experimental investigation is performed by compressing the foil...

FOIL ELEMENT FOR NUCLEAR REACTOR

Science.gov (United States)

Noland, R.A.; Walker, D.E.; Spinrad, B.I.

1963-07-16

A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

Sub-Doppler spectroscopy

International Nuclear Information System (INIS)

Hansch, T.W.

1983-01-01

This chapter examines Doppler-free saturation spectroscopy, tunable cw sources, and Doppler-free two-photon spectroscopy. Discusses saturation spectroscopy; continuous wave saturation spectroscopy in the ultraviolet; and two-photon spectroscopy of atomic hydrogen 1S-2S. Focuses on Doppler-free laser spectroscopy of gaseous samples. Explains that in saturation spectroscopy, a monochromatic laser beam ''labels'' a group of atoms within a narrow range of axial velocities through excitation or optical pumping, and a Doppler-free spectrum of these selected atoms is observed with a second, counterpropagating beam. Notes that in two-photon spectroscopy it is possible to record Doppler-free spectra without any need for velocity selection by excitation with two counterpropagating laser beams whose first order Doppler shifts cancel

Nuclear target foil fabrication for the Romano Event

International Nuclear Information System (INIS)

Weed, J.W.; Romo, J.G. Jr.; Griggs, G.E.

1984-01-01

The Vacuum Processes Lab, of LLNL's M.E. Dept. - Material Fabrication Division, was requested to provide 250 coated Parylene target foils for a nuclear physics experiment titled the ROMANO Event. Due to the developmental nature of some of the fabrication procedures, approximately 400 coated foils were produced to satisfy the event's needs. The foils were used in the experiment as subkilovolt x-ray, narrow band pass filters, and wide band ultraviolet filters. This paper is divided into three sections describing: (1) nuclear target foil fabrication, (2) Parylene substrate preparation and production, and (3) foil and substrate inspections

Technical Development Path for Gas Foil Bearings

Science.gov (United States)

Dellacorte, Christopher

2016-01-01

Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

Radioactivity analysis in niobium activation foils

Energy Technology Data Exchange (ETDEWEB)

Mueller, G.E.

1995-06-01

The motivation for this study was to measure and analyze the activity of six (6) niobium (Nb) foils (the x-rays from an internal transition in Nb-93m) and apply this information with previously obtained activation foil data. The niobium data was used to determine the epithermal to MeV range for the neutron spectrum and fluence. The foil activation data was re-evaluated in a spectrum analysis code (STAY`SL) to provide new estimates of the exposure at the Los Alamos Spallation Radiation Effect Facility (LASREF). The activity of the niobium foils was measured and analyzed at the University of Missouri-Columbia (UMC) under the direction of Professor William Miller. The spectrum analysis was performed at the University of Missouri-Rolla (UMR) by Professor Gary Mueller.

Intra-pulse transition between ion acceleration mechanisms in intense laser-foil interactions

Energy Technology Data Exchange (ETDEWEB)

Padda, H.; King, M.; Gray, R. J.; Powell, H. W.; Gonzalez-Izquierdo, B.; Wilson, R.; Dance, R. J.; MacLellan, D. A.; Butler, N. M. H.; Capdessus, R.; McKenna, P., E-mail: paul.mckenna@strath.ac.uk [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Stockhausen, L. C. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja s/n. 37185 Villamayor, Salamanca (Spain); Carroll, D. C. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Yuan, X. H. [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Borghesi, M. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Neely, D. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom)

2016-06-15

Multiple ion acceleration mechanisms can occur when an ultrathin foil is irradiated with an intense laser pulse, with the dominant mechanism changing over the course of the interaction. Measurement of the spatial-intensity distribution of the beam of energetic protons is used to investigate the transition from radiation pressure acceleration to transparency-driven processes. It is shown numerically that radiation pressure drives an increased expansion of the target ions within the spatial extent of the laser focal spot, which induces a radial deflection of relatively low energy sheath-accelerated protons to form an annular distribution. Through variation of the target foil thickness, the opening angle of the ring is shown to be correlated to the point in time transparency occurs during the interaction and is maximized when it occurs at the peak of the laser intensity profile. Corresponding experimental measurements of the ring size variation with target thickness exhibit the same trends and provide insight into the intra-pulse laser-plasma evolution.

Generation of subnanosecond electron beams in air at atmospheric pressure

Science.gov (United States)

Kostyrya, I. D.; Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Lomaev, M. I.; Rybka, D. V.

2009-11-01

Optimum conditions for the generation of runaway electron beams with maximum current amplitudes and densities in nanosecond pulsed discharges in air at atmospheric pressure are determined. A supershort avalanche electron beam (SAEB) with a current amplitude of ˜30 A, a current density of ˜20 A/cm2, and a pulse full width at half maximum (FWHM) of ˜100 ps has been observed behind the output foil of an air-filled diode. It is shown that the position of the SAEB current maximum relative to the voltage pulse front exhibits a time shift that varies when the small-size collector is moved over the foil surface.

The use of electron beam in RIA R and D

International Nuclear Information System (INIS)

Gomes, Itacil C.; Nolen, Jerry; Reed, Claude

2004-01-01

This paper discusses two electron beam applications for the RIA (Rare Isotope Accelerator) R and D. The first is for simulating energy deposition of heavy ions on lithium jets. The peak energy deposition for a 400-kW uranium beam will be 4 MW/cm 3 . Calculations have shown that a 1-MeV electron beam with 40mA of current has a peak energy deposition about 4 MW/cm 3 making it suitable to mimic the thermal response of lithium jet at that uranium beam heat load. The second application of electron beams for RIA R and D, discussed in this paper, is the use of low energy electron beam as a diagnosis tool for on-line monitoring of thickness variations of thin foils or thin jets. Thin foils can be corroded and jets might experience instabilities that can compromise their functionality. Low energy electron beams can be used to detect any change in thickness enabling a continuous on-line monitoring of the thin film being monitored. Calculations have indicated that variations in lithium jet thicknesses at the micron level can easily be detected

High precision electron beam diagnostic system for high current long pulse beams

International Nuclear Information System (INIS)

Chen, Y J; Fessenden, T; Holmes, C; Nelson, S D; Selchow, N.

1999-01-01

As part of the effort to develop a multi-axis electron beam transport system using stripline kicker technology for DARHT II applications, it is necessary to precisely determine the position and extent of long high energy beams (6-40 MeV, 1-4 kA, 2 microseconds) for accurate position control. The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (<20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt measurements performed using capacitive pick-off probes. Likewise, transmission line traveling wave probes have problems with multi-bounce effects due to these longer pulse widths. Finally, the high energy densities experienced in these applications distort typical foil beam position measurements

Experimental atomic and molecular physics research

International Nuclear Information System (INIS)

Anon.

1980-01-01

The Atomic Physics research in the Physics Division consists of five ongoing experimental programs: dissociation and other interactions of energetic molecular ions in solid and gaseous targets; beam-foil research and collision dynamics of heavy ions; photoionization-photoelectron research; spectroscopy of free atoms and molecules, high precision laser-rf double-resonance spectroscopy with atomic and molecular beams; and Moessbauer effect research

On the use of Indium ({sup 115}In) activation foils for the study of neutron radiation field surrounding a not shielded cyclotron; Sobre o uso de folhas de ativacao de Indio ({sup 115}In) para o estudo do campo de radiacao neutronica ao redor de um ciclotron nao blindado

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, Adriana, E-mail: amgr@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencia e Tecnologia das Radiacoes, Minerais e Materiais; Rodrigues, Sergio Luiz Moreira; Andrade, Ricardo Severino [Centro de Desenvolvimento da Tecnologia Nuclear (SECPRA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Pesquisa e Producao de Radiofarmacos; Lacerda, Marco Aurelio de Sousa [Centro de Desenvolvimento da Tecnologia Nuclear (SEPRA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Protecao Radiologica; Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (SERAS/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico das Radiacoes Aplicadas a Saude

2011-10-26

Use activation foils of {sup 115}In were evaluated for study of neutron radiation field surrounding a non shielded 16.5 MeV cyclotron, during the production of fluorine-18. Two foils of {sup 115}In were used which were exposed to the neutron flux of target-chamber of the GEPETtrace-8 of CDTN/CNEN, Brazil. The first foil were positioned in front of cyclotron beam, and the second one in the diametral opposed position to the beam. It was possible to distinguish for the first foil the 417 keV photo peaks, attributed to the thermal and the 417 keV neutrons attributed to the fast neutrons. On the second foil it was only distinguished the 417 keV photopeak. The results had shown that it is possible to evaluate the fast and thermal neutron fraction surrounding the cyclotron by using indium foils. However, the short half life of the {sup 115}In makes unviable the simultaneous irradiation of a great number of foils

Progress towards antihydrogen hyperfine spectroscopy in a beam

Energy Technology Data Exchange (ETDEWEB)

Widmann, Eberhard [Stefan Meyer Institute for Subatomic Physics, Vienna (Austria); Collaboration: ASACUSA CUSP collaboration

2014-07-01

The spectroscopy of antihydrogen promises one of the most precise tests of CPT symmetry. The ASACUSA CUSP collaboration at the Antiproton Decelerator of CERN is preparing an experiment to measure the ground-state hyperfine structure GS-HFS of antihydrogen, since this quantity is one of the most precisely determined transitions in ordinary hydrogen (relative accuracy ∝10{sup -12}). The experiment uses a Rabi-type atomic beam apparatus consisting of a source of spin-polarized antihydrogen (a so-called cusp trap), a microwave cavity to induce a spin flip, a superconducting sextuple magnet for spin analysis, and an antihydrogen detector. In this configuration, a relative accuracy of better than 10{sup -6} can be obtained. This precision will already allow to be sensitive to finite size effects of the antiproton, provided its magnetic moment will measured to higher precision, which is in progress by two collaborations at the AD. The recent progress in producing a beam of antihydrogen atoms and in the development of the apparatus as well as ways to further improve the accuracy by using the Ramsey method of separated oscillatory fields are presented.

Reble, a radially converging electron beam accelerator

International Nuclear Information System (INIS)

Ramirez, J.J.; Prestwich, K.R.

1976-01-01

The Reble accelerator at Sandia Laboratories is described. This accelerator was developed to provide an experimental source for studying the relevant diode physics, beam propagation, beam energy deposition in a gas using a radially converging e-beam. The nominal parameters for Reble are 1 MV, 200 kA, 20 ns e-beam pulse. The anode and cathode are concentric cylinders with the anode as the inner cylinder. The radial beam can be propagated through the thin foil anode into the laser gas volume. The design and performance of the various components of the accelerator are presented

Direct synthesis of RGO/Cu{sub 2}O composite films on Cu foil for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Dong, Xiangmao; Wang, Kun [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhao, Chongjun, E-mail: chongjunzhao@ecust.edu.cn [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Qian, Xiuzhen [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Shi [School of Information Engineering, Wuhan University of Technology, Wuhan 430070 (China); Li, Zhen, E-mail: zhenl@uow.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Liu, Huakun; Dou, Shixue [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia)

2014-02-15

Graphical abstract: RGO/Cu{sub 2}O/Cu composites were synthesized by simple hydrothermal treatment of copper foils with graphene oxide, in which the reduction of graphene oxide and the formation of Cu{sub 2}O nanoparticles simultaneously happened in one-pot reaction. These composites can be directly used as electrodes of supercapacitors with the highest specific capacitance of 98.5 F/g at 1 A g{sup −1}, which is much better than that of CuO or Cu{sub 2}O electrodes. -- Highlights: • The RGO/Cu{sub 2}O/Cu composites were obtained by a friendly method in one step. • Improved capacitance performance is realized by the hydrothermal treatment of graphene oxides with Cu foils. • RGO/Cu{sub 2}O/Cu-200 composites exhibit the largest specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1}. -- Abstract: Reduced graphene oxide/cuprous oxide (RGO/Cu{sub 2}O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu{sub 2}O and reduction of GO, in which Cu{sub 2}O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu{sub 2}O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry (EIS) in 1 M KOH aqueous solution. A specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1} was obtained, which is much higher than that of pure Cu{sub 2}O prepared under the same conditions, due to the presence of RGO.

The PRESPEC liquid-hydrogen target for in-beam gamma spectroscopy of exotic nuclei at GSI

International Nuclear Information System (INIS)

Louchart, C.; Gheller, J.M.; Chesny, Ph.; Authelet, G.; Rousse, J.Y.; Obertelli, A.; Boutachkov, P.; Pietri, S.; Ameil, F.; Audirac, L.; Corsi, A.; Dombradi, Z.; Gerl, J.; Gillibert, A.; Korten, W.; Mailleret, C.; Merchan, E.; Nociforo, C.; Pietralla, N.; Ralet, D.

2014-01-01

We report on a new liquid hydrogen and deuterium target dedicated to in-beam γ spectroscopy experiments in inverse kinematics at relativistic incident energies at GSI/FAIR. Target thicknesses from 10 to 80 mm can be achieved for an effective diameter of 60 mm. The target-cell and entrance window are maded of 200μm thick Mylar. The design has the advantage of being free of absorbing material at forward angles and 90°, allowing the detection of photons in a wide angular range. A commissioning experiment with a 54 Cr beam at 130 MeV/nucleon has been performed at GSI, using the Rare Isotopes INvestigation at GSI (RISING) detectors. The target has been shown to behave as expected and is ready for experiments at fragmentation Radioactive-Ion Beam Facilities. -- Highlights: • We report on a new liquid hydrogen target for gamma spectroscopy experiments at FAIR. • A commissioning experiment has been performed at GSI, using the RISING detectors. • The target behaves as expected and is ready for experiments

Cascaded two-photon spectroscopy of Yb atoms with a transportable effusive atomic beam apparatus

International Nuclear Information System (INIS)

Song, Minsoo; Yoon, Tai Hyun

2013-01-01

We present a transportable effusive atomic beam apparatus for cascaded two-photon spectroscopy of the dipole-forbidden transition (6s 2 1 S 0 ↔ 6s7s 1 S 0 ) of Yb atoms. An ohmic-heating effusive oven is designed to have a reservoir volume of 1.6 cm 3 and a high degree of atomic beam collimation angle of 30 mrad. The new atomic beam apparatus allows us to detect the spontaneously cascaded two-photons from the 6s7s 1 S 0 state via the intercombination 6s6p 3 P 1 state with a high signal-to-noise ratio even at the temperature of 340 °C. This is made possible in our apparatus because of the enhanced atomic beam flux and superior detection solid angle.

High power beam profile monitor with optical transition radiation

International Nuclear Information System (INIS)

Denard, J.C.; Piot, P.; Capek, K.; Feldl, E.

1997-01-01

A simple monitor has been built to measure the profile of the high power beam (800 kW) delivered by the CEBAF accelerator at Jefferson Lab. The monitor uses the optical part of the forward transition radiation emitted from a thin carbon foil. The small beam size to be measured, about 100 μm, is challenging not only for the power density involved but also for the resolution the instrument must achieve. An important part of the beam instrumentation community believes the radiation being emitted into a cone of characteristic angle 1/γ is originated from a region of transverse dimension roughly λγ; thus the apparent size of the source of transition radiation would become very large for highly relativistic particles. This monitor measures 100 μm beam sizes that are much smaller than the 3.2 mm λγ limit; it confirms the statement of Rule and Fiorito that optical transition radiation can be used to image small beams at high energy. The present paper describes the instrument and its performance. The authors tested the foil in, up to 180 μA of CW beam without causing noticeable beam loss, even at 800 MeV, the lowest CEBAF energy

Measurements of Electron Transport in Foils Irradiated with a Picosecond Time Scale Laser Pulse

International Nuclear Information System (INIS)

Brown, C. R. D.; Hoarty, D. J.; James, S. F.; Swatton, D.; Hughes, S. J.; Morton, J. W.; Guymer, T. M.; Hill, M. P.; Chapman, D. A.; Andrew, J. E.; Comley, A. J.; Shepherd, R.; Dunn, J.; Chen, H.; Schneider, M.; Brown, G.; Beiersdorfer, P.; Emig, J.

2011-01-01

The heating of solid foils by a picosecond time scale laser pulse has been studied by using x-ray emission spectroscopy. The target material was plastic foil with a buried layer of a spectroscopic tracer material. The laser pulse length was either 0.5 or 2 ps, which resulted in a laser irradiance that varied over the range 10 16 -10 19 W/cm 2 . Time-resolved measurements of the buried layer emission spectra using an ultrafast x-ray streak camera were used to infer the density and temperature conditions as a function of laser parameters and depth of the buried layer. Comparison of the data to different models of electron transport showed that they are consistent with a model of electron transport that predicts the bulk of the target heating is due to return currents.

Electron beam cladding of titanium on stainless steel plate

International Nuclear Information System (INIS)

Tomie, Michio; Abe, Nobuyuki; Yamada, Masanori; Noguchi, Shuichi.

1990-01-01

Fundamental characteristics of electron beam cladding was investigated. Titanium foil of 0.2mm thickness was cladded on stainless steel plate of 3mm thickness by scanning electron beam. Surface roughness and cladded layer were analyzed by surface roughness tester, microscope, scanning electron microscope and electron probe micro analyzer. Electron beam conditions were discussed for these fundamental characteristics. It is found that the energy density of the electron beam is one of the most important factor for cladding. (author)

Microfabricated Segmented-Involute-Foil Regenerator for Stirling Engines

Science.gov (United States)

Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Qiu, Songgang; Wood, Gary; Kelly, Kevin; McLean, Jeffrey

2010-01-01

An involute-foil regenerator was designed, microfabricated, and tested in an oscillating-flow test rig. The concept consists of stacked involute-foil nickel disks (see figure) microfabricated via a lithographic process. Test results yielded a performance of about twice that of the 90-percent random-fiber currently used in small Stirling converters. The segmented nature of the involute- foil in both the axial and radial directions increases the strength of the structure relative to wrapped foils. In addition, relative to random-fiber regenerators, the involute-foil has a reduced pressure drop, and is expected to be less susceptible to the release of metal fragments into the working space, thus increasing reliability. The prototype nickel involute-foil regenerator was adequate for testing in an engine with a 650 C hot-end temperature. This is lower than that required by larger engines, and high-temperature alloys are not suited for the lithographic microfabrication approach.

Properties of polymer foils used as solid-state track detectors

International Nuclear Information System (INIS)

Spurny, F.

1973-05-01

Polymer foils were studied with a view to their application as solid-state alpha track detectors. The detection efficiency was determined as was its alpha energy dependence and the quality of the surface and the natural background of the foils were evaluated. The kinetics of etching was studied in three selected type of foils. Characteristic constants for the selected foils and methods of etching were calculated. The possible applications of the foils as track detectors are discussed and the effect is dealt with of the selected foil and of the method of chemical etching on the foil applicability in nuclear sciences, especially in fast neutron dosimetry and in alpha spectrometry. (author)

Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

CERN Document Server

Andreyev, Andrei

2013-01-01

Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

A Microfabricated Involute-Foil Regenerator for Stirling Engines

Science.gov (United States)

Tew, Roy; Ibrahim, Mounir; Danila, Daniel; Simon, Terrence; Mantell, Susan; Sun, Liyong; Gedeon, David; Kelly, Kevin; McLean, Jeffrey; Qiu, Songgang

2007-01-01

A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C

The affect of erbium hydride on the conversion efficience to accelerated protons from ultra-shsort pulse laser irradiated foils

Energy Technology Data Exchange (ETDEWEB)

Offermann, Dustin Theodore [The Ohio State Univ., Columbus, OH (United States)

2008-01-01

This thesis work explores, experimentally, the potential gains in the conversion efficiency from ultra-intense laser light to proton beams using erbium hydride coatings. For years, it has been known that contaminants at the rear surface of an ultra-intense laser irradiated thin foil will be accelerated to multi-MeV. Inertial Confinement Fusion fast ignition using proton beams as the igniter source requires of about 10¹⁶ protons with an average energy of about 3MeV. This is far more than the 10¹² protons available in the contaminant layer. Target designs must include some form of a hydrogen rich coating that can be made thick enough to support the beam requirements of fast ignition. Work with computer simulations of thin foils suggest the atomic mass of the non-hydrogen atoms in the surface layer has a strong affect on the conversion efficiency to protons. For example, the 167amu erbium atoms will take less energy away from the proton beam than a coating using carbon with a mass of 12amu. A pure hydrogen coating would be ideal, but technologically is not feasible at this time. In the experiments performed for my thesis, ErH₃ coatings on 5 μm gold foils are compared with typical contaminants which are approximately equivalent to CH_1.7. It will be shown that there was a factor of 1.25 ± 0.19 improvement in the conversion efficiency for protons above 3MeV using erbium hydride using the Callisto laser. Callisto is a 10J per pulse, 800nm wavelength laser with a pulse duration of 200fs and can be focused to a peak intensity of about 5 x 10¹⁹W/cm². The total number of protons from either target type was on the order of 10¹⁰. Furthermore, the same experiment was performed on the Titan laser, which has a 500fs pulse duration, 150J of energy and can be focused to about 3 x 10²⁰ W/cm². In this experiment 10¹² protons were seen from both erbium hydride and

In-beam measurement of the hydrogen hyperfine splitting and prospects for antihydrogen spectroscopy.

Science.gov (United States)

Diermaier, M; Jepsen, C B; Kolbinger, B; Malbrunot, C; Massiczek, O; Sauerzopf, C; Simon, M C; Zmeskal, J; Widmann, E

2017-06-12

Antihydrogen, the lightest atom consisting purely of antimatter, is an ideal laboratory to study the CPT symmetry by comparison with hydrogen. With respect to absolute precision, transitions within the ground-state hyperfine structure (GS-HFS) are most appealing by virtue of their small energy separation. ASACUSA proposed employing a beam of cold antihydrogen atoms in a Rabi-type experiment, to determine the GS-HFS in a field-free region. Here we present a measurement of the zero-field hydrogen GS-HFS using the spectroscopy apparatus of ASACUSA's antihydrogen experiment. The measured value of ν HF =1,420,405,748.4(3.4) (1.6) Hz with a relative precision of 2.7 × 10 -9 constitutes the most precise determination of this quantity in a beam and verifies the developed spectroscopy methods for the antihydrogen HFS experiment to the p.p.b. level. Together with the recently presented observation of antihydrogen atoms 2.7 m downstream of the production region, the prerequisites for a measurement with antihydrogen are now available within the ASACUSA collaboration.

Quantitative damage and detwinning analysis of nanotwinned copper foil under cyclic loading

International Nuclear Information System (INIS)

Yoo, Byung-Gil; Boles, Steven T.; Liu, Y.; Zhang, X.; Schwaiger, Ruth; Eberl, Christoph; Kraft, Oliver

2014-01-01

High-purity Cu samples containing parallel columns of highly aligned nanotwins with median spacing of ∼25 nm were subjected to tension–compression cyclic loading by a high-throughput cyclic testing method. The methodology utilizes gradients in surface strain amplitude of a vibrating cantilever: one along the beam axis, with decreasing strain from the fixed to the free end of the beam, and the other through the foil thickness with decreasing strain from the surface to the neutral axis. Systematic microstructural investigations indicate that nanotwins are not stable under cyclic loading and that the applied strain amplitude has a strong influence on the resulting twin structure. In the highly stressed regions the detwinning process produces a twin free microstructure, allowing for subsequent extrusion and crack formation, and introduces fatal defects into structural parts

Cryostat with Foil and MLI

Energy Technology Data Exchange (ETDEWEB)

Hwang, Peter K.F.; Gung, Chen-yu

2005-10-06

Induction cores are used to accelerate heavy ion beam array, which are built around the outer diameter of the cryostat housing the superconducting quadruple array. Compact cryostat is highly desirable to reduce the cost of the induction cores. Recent experiences in fabrication of a cryostat for single beam transport revealed that it is possible to reduce the spacing in the cryostat vacuum jacket by using low-emissivity thermal insulation material instead of conventional MLI. However, it is labor-intensive to install the new type of insulation as compared with using MLI. It is promising to build a cost-effective compact cryostat for quadruple magnet array for heavy ion beam array transport by using low-emissivity material combined with conventional MLI as radiation insulation. A matrix of insulation designs and tests will be performed as the feasibility study and for the selection of the optimal thermal insulation as the Phase I work. The selected mixed insulation will be used to build prototype compact cryostats in the Phase II project, which are aiming for housing quadruple doublet array. In this STTR phase I study, a small cryostat has been designed and built to perform calorimetric characterization of the heat load in a liquid helium vessel insulated with a vacuum layer with a nominal clearance of 3.5 mm. The vacuum clearance resembled that used in the warm-bore beam tube region in a prototype cryostat previously built for the heavy ion beam transport experiment. The vacuum clearance was geometrically restricted with a heater shell with the temperature controlled at near 300 K. Various combinations of radiation and thermal shields were installed in the tight vacuum clearance for heat load measurements. The measured heat loads are reported and compared with previous test result using a compact vacuum layer. Further developments of the thermal insulations used in the present study are discussed. The compact cryostat with foil and MLI insulation may be used in the

Gamma-Ray Spectroscopy at TRIUMF-ISAC: the New Frontier of Radioactive Ion Beam Research

Science.gov (United States)

Ball, G. C.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Becker, J. A.; Bricault, P.; Brown, N.; Chan, S.; Churchman, R.; Colosimo, S.; Coombes, H.; Cross, D.; Demand, G.; Drake, T. E.; Dombsky, M.; Ettenauer, S.; Finlay, P.; Furse, D.; Garnsworthy, A.; Garrett, P. E.; Green, K. L.; Grinyer, G. F.; Hyland, B.; Hackman, G.; Kanungo, R.; Kulp, W. D.; Lassen, J.; Leach, K. G.; Leslie, J. R.; Mattoon, C.; Melconian, D.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Rand, E.; Sarazin, F.; Svensson, C. E.; Sumithrarachchi, S.; Schumaker, M. A.; Triambak, S.; Waddington, J. C.; Walker, P. M.; Williams, S. J.; Wood, J. L.; Wong, J.; Zganjar, E. F.

2009-03-01

High-resolution gamma-ray spectroscopy is essential to fully exploit the unique scientific opportunities at the next generation radioactive ion beam facilities such as the TRIUMF Isotope Separator and Accelerator (ISAC). At ISAC the 8π spectrometer and its associated auxiliary detectors is optimize for β-decay studies while TIGRESS an array of segmented clover HPGe detectors has been designed for studies with accelerated beams. This paper gives a brief overview of these facilities and also presents recent examples of the diverse experimental program carried out at the 8π spectrometer.

Multigigahertz beam-current and position monitor

International Nuclear Information System (INIS)

Carlson, R.L.; Stout, L.E.

1985-01-01

A self-integrating magnetic-loop device having a risetime of less than 175 ps has been developed to monitor the temporal behavior of the electron beam current and position within each 3.3-ns micropulse generated by the PHERMEX rf linear accelerator. Beam current is measured with a 2-GHz bandwidth by combining these loops in a four-port hybrid summer. Another application of these loops uses two 180 0 hybrids to give 2-GHz time-resolved beam position to an accuracy of 1 mm. These sensors are nonintrusive to the propagating beam and allow ultrafast beam measurements previously restricted to the technique of recording the Cerenkov-light emission from an intercepting Kapton foil using a streak camera

Low-temperature relative reflectivity measurements of reflective and scintillating foils used in rare event searches

Science.gov (United States)

Langenkämper, A.; Ulrich, A.; Defay, X.; Feilitzsch, F. v.; Lanfranchi, J.-C.; Mondragón, E.; Münster, A.; Oppenheimer, C.; Potzel, W.; Roth, S.; Schönert, S.; Steiger, H.; Trinh Thi, H. H.; Wawoczny, S.; Willers, M.; Zöller, A.

2018-03-01

In this work we investigate the reflectivity of highly reflective multilayer polymer foils used in the CRESST experiment. The CRESST experiment searches directly for dark matter via operating scintillating CaWO4 crystals as targets for elastic dark matter-nucleon scattering. In order to suppress background events, the experiment employs the so-called phonon-light technique which is based on the simultaneous measurement of the heat signal in the main CaWO4 target crystal and of the emitted scintillation light with a separate cryogenic light detector. Both detectors are surrounded by a highly reflective and scintillating multilayer polymer foil to increase the light collection efficiency and to veto surface backgrounds. While this study is motivated by the CRESST experiment, the results are also relevant for other rare event searches using scintillating cryogenic bolometers in the field of the search of dark matter and neutrinoless double beta decay (0 νββ). In this work a dedicated experiment has been set up to determine the relative reflectivity at 300 K and 20 K of three multilayer foils ("VM2000", "VM2002", "Vikuiti") produced by the company 3M. The intensity of a light beam reflected off the foil is measured with a CCD camera. The ratio of the intensities at 300 K and 20 K corresponds to the relative reflectivity change. The measurements performed in this work show no variation of the reflectivity with temperature at a level of ∼1%.

Release studies of a thin foil tantalum target for the production of short-lived radioactive nuclei

CERN Document Server

Bennett, J R J; Drumm, P V; Lettry, Jacques; Nilsson, T; Catherall, R; Jonsson, O C; Ravn, H L; Simon, H

2002-01-01

Measurements have been made at ISOLDE, of the release curves and yields of radioactive beams of lithium, sodium and beryllium from a target constructed from 2 $\\mu$m thick foils. The release curves have been analysed by fitting to a mathematical model to determine the coefficients of diffusion of the particles in the foils and effusion through the target and ionizer at several temperatures. Through a better understanding of the rate of transport of the particles, it is possible to design targets and ionizers with improved yields. This is most important for the rare, short-lived isotopes in which there is considerable interest for physics experiments. This target has demonstrated large increases in the yields of $^{11}$Li and $^{12}$Be, in agreement with the predictions of the model. (11 refs).

Chemical states of localized Fe atoms in ethylene matrices using in-beam Mössbauer spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Y., E-mail: kyoshio@pc.uec.ac.jp [University of Electro-Communications, Graduate School of Engineering Science (Japan); Yamada, Y. [Tokyo University of Science, Department of Chemistry (Japan); Tanigawa, S. [University of Electro-Communications, Graduate School of Engineering Science (Japan); Mihara, M. [Osaka University, Graduate School of Science (Japan); Kubo, M. K. [International Christian University, Division of Arts and Sciences (Japan); Sato, W. [Kanazawa University, Institute of Science and Engineering (Japan); Miyazaki, J. [Tokyo University of Agriculture and Technology, Department of Chemical Engineering (Japan); Nagatomo, T. [RIKEN, Nishina Center for Accelerator-Based Science (Japan); Sato, Y.; Natori, D.; Suzuki, M. [University of Electro-Communications, Graduate School of Engineering Science (Japan); Kobayashi, J. [International Christian University, Division of Arts and Sciences (Japan); Sato, S.; Kitagawa, A. [National Institute of Radiological Science (Japan)

2016-12-15

The reaction products of isolated single iron atoms in a low concentration matrix of ethylene were studied using in-beam Mössbauer spectroscopy with a short-lived {sup 57}Mn (T{sub 1/2}=1.45 m) beam. The in-beam Mössbauer spectrum of {sup 57}Fe arising from {sup 57}Mn in a matrix of ethylene and argon measured at 16 K was analyzed with four components. Density functional theory calculations were carried out to confirm the assignments. It was suggested that the reaction produced monoiron species of Fe(C {sub 2}H{sub 4}) with a spin state of S = 2.

Epithermal beam development at the BMRR [Brookhaven Medical Research Reactor]: Dosimetric evaluation

International Nuclear Information System (INIS)

Saraf, S.K.; Fairchild, R.G.; Kalef-Ezra, J.; Laster, B.H.; Fiarman, S.; Ramsey, E.; Ioannina Univ.; Brookhaven National Lab., Upton, NY; State Univ. of New York, Stony Brook, NY

1989-01-01

The utilization of an epithermal neutron beam for neutron capture therapy (NCT) is desirable because of the increased tissue penetration relative to a thermal neutron beam. Over the past few years, modifications have been and continue to be made at the Brookhaven Medical Research Reactor (BMRR) by changing its filter components to produce an optimal epithermal beam. An optimal epithermal beam should contain a low fast neutron contamination and no thermal neutrons in the incident beam. Recently a new moderator for the epithermal beam has been installed at the epithermal port of the BMRR and has accomplished this task. This new moderator is a combination of alumina (Al 2 O 3 ) bricks and aluminum (Al) plates. A 0.51 mm thick cadmium (Cd) sheet has reduced the thermal neutron intensity drastically. Furthermore, an 11.5 cm thick bismuth (Bi) plate installed at the port surface has reduced the gamma dose component to negligible levels. Foil activation techniques have been employed by using bare gold and cadmium-covered gold foil to determine thermal as well as epithermal neutron fluence. Fast neutron fluence has been determined by indium foil counting. Fast neutron and gamma dose in soft tissue, free in air, is being determined by the paired ionization chamber technique, using tissue equivalent (TE) and graphite chambers. Thermoluminescent dosimeters (TLD-700) have also been used to determine the gamma dose independently. This paper describes the methods involved in the measurements of the above mentioned parameters. Formulations have been developed and the various corrections involved have been detailed. 12 refs

Symposium on atomic spectroscopy (SAS-83): abstracts and program

International Nuclear Information System (INIS)

1983-09-01

Abstracts of papers given at the symposium are presented. Session topics include: Rydbergs, optical radiators, and planetary atoms; highly ionized atoms; ultraviolet radiation; theory, ion traps, and laser cooling; beam foil; and astronomy

X-ray spectroscopy of highly-ionized atoms in an electron beam ion trap (EBIT)

International Nuclear Information System (INIS)

Marrs, R.E.; Bennett, C.; Chen, M.H.

1988-01-01

An Electron Beam Ion Trap at Lawrence Livermore National Laboratory is being used to produce and trap very-highly-charged-ions (q /le/ 70+) for x-ray spectroscopy measurements. Recent measurements of dielectronic recombination, electron impact excitation and transition energies are presented. 15 refs., 12 figs., 1 tab

Ion Acceleration from the Interaction of Ultra-Intense Lasers with Solid Foils

International Nuclear Information System (INIS)

Allen, M

2004-01-01

The discovery that ultra-intense laser pulses (I > 10 18 W/cm 2 ) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 10 18 W/cm 2 ), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by U p = ([1 + Iλ 2 /1.3 x 10 18 ] 1/2 - 1) m o c 2 , where Iλ 2 is the irradiance in W (micro)m 2 /cm 2 and m o c 2 is the electron rest mass. At laser irradiance of Iλ 2 ∼ 10 20 W (micro)m 2 /cm 2 , the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target. In this thesis we present several experiments that study the accelerated ions by affecting the contamination layer from which they originate. Radiative heating was employed as a method of removing contamination from palladium targets doped

Simulating systematic errors in X-ray absorption spectroscopy experiments: Sample and beam effects

Energy Technology Data Exchange (ETDEWEB)

Curis, Emmanuel [Laboratoire de Biomathematiques, Faculte de Pharmacie, Universite Rene, Descartes (Paris V)-4, Avenue de l' Observatoire, 75006 Paris (France)]. E-mail: emmanuel.curis@univ-paris5.fr; Osan, Janos [KFKI Atomic Energy Research Institute (AEKI)-P.O. Box 49, H-1525 Budapest (Hungary); Falkenberg, Gerald [Hamburger Synchrotronstrahlungslabor (HASYLAB), Deutsches Elektronen-Synchrotron (DESY)-Notkestrasse 85, 22607 Hamburg (Germany); Benazeth, Simone [Laboratoire de Biomathematiques, Faculte de Pharmacie, Universite Rene, Descartes (Paris V)-4, Avenue de l' Observatoire, 75006 Paris (France); Laboratoire d' Utilisation du Rayonnement Electromagnetique (LURE)-Ba-hat timent 209D, Campus d' Orsay, 91406 Orsay (France); Toeroek, Szabina [KFKI Atomic Energy Research Institute (AEKI)-P.O. Box 49, H-1525 Budapest (Hungary)

2005-07-15

The article presents an analytical model to simulate experimental imperfections in the realization of an X-ray absorption spectroscopy experiment, performed in transmission or fluorescence mode. Distinction is made between sources of systematic errors on a time-scale basis, to select the more appropriate model for their handling. For short time-scale, statistical models are the most suited. For large time-scale, the model is developed for sample and beam imperfections: mainly sample inhomogeneity, sample self-absorption, beam achromaticity. The ability of this model to reproduce the effects of these imperfections is exemplified, and the model is validated on real samples. Various potential application fields of the model are then presented.

Simulating systematic errors in X-ray absorption spectroscopy experiments: Sample and beam effects

International Nuclear Information System (INIS)

Curis, Emmanuel; Osan, Janos; Falkenberg, Gerald; Benazeth, Simone; Toeroek, Szabina

2005-01-01

The article presents an analytical model to simulate experimental imperfections in the realization of an X-ray absorption spectroscopy experiment, performed in transmission or fluorescence mode. Distinction is made between sources of systematic errors on a time-scale basis, to select the more appropriate model for their handling. For short time-scale, statistical models are the most suited. For large time-scale, the model is developed for sample and beam imperfections: mainly sample inhomogeneity, sample self-absorption, beam achromaticity. The ability of this model to reproduce the effects of these imperfections is exemplified, and the model is validated on real samples. Various potential application fields of the model are then presented

Capillary self-alignment of mesoscopic foil components for sensor-systems-in-foil

International Nuclear Information System (INIS)

Arutinov, Gari; Smits, Edsger C P; Van Heck, Gert; Van den Brand, Jeroen; Schoo, Herman F M; Mastrangeli, Massimo; Dietzel, Andreas

2012-01-01

This paper reports on the effective use of capillary self-alignment for low-cost and time-efficient assembly of heterogeneous foil components into a smart electronic identification label. Particularly, we demonstrate the accurate (better than 50 µm) alignment of cm-sized functional foil dies. We investigated the role played by the assembly liquid, by the size and the weight of assembling dies and by their initial offsets in the self-alignment performance. It was shown that there is a definite range of initial offsets allowing dies to align with high accuracy and within approximately the same time window, irrespective of their initial offset. (paper)

Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth

Energy Technology Data Exchange (ETDEWEB)

Lastras-Martínez, A., E-mail: alm@cactus.iico.uaslp.mx, E-mail: alastras@gmail.com; Ortega-Gallegos, J.; Guevara-Macías, L. E.; Nuñez-Olvera, O.; Balderas-Navarro, R. E.; Lastras-Martínez, L. F. [Instituto de Investigación en Comunicación Optica, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, San Luis Potosí, SLP 78000 (Mexico); Lastras-Montaño, L. A. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Lastras-Montaño, M. A. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California 93106 (United States)

2014-03-01

We report on real time-resolved Reflectance-difference (RD) spectroscopy of GaAs(001) grown by molecular beam epitaxy, with a time-resolution of 500 ms per spectrum within the 2.3–4.0 eV photon energy range. Through the analysis of transient RD spectra we demonstrated that RD line shapes are comprised of two components with different physical origins and determined their evolution during growth. Such components were ascribed to the subsurface strain induced by surface reconstruction and to surface stoichiometry. Results reported in this paper render RD spectroscopy as a powerful tool for the study of fundamental processes during the epitaxial growth of zincblende semiconductors.

Ion desorption induced by charged particle beams: mechanisms and mass spectroscopy

International Nuclear Information System (INIS)

Silveira, E.F. da; Schweikert, E.A.

1988-01-01

Surface analysis, through desorption, induced by fast particles, is presented and discussed. The stopping of projectils is essentially made by collisions with the target electrons. The desorbed particles are generally emmited with kinetic energy from 0.1 to 20 eV. Mass, charge, velocity and emission angle give information about the surface components, its structure as well as beam-solid interaction processes. Time-of-flight mass spectroscopy of desorbed ions, determine the mass of organic macromolecules and biomolecules. (A.C.A.S.) [pt

Cascaded two-photon spectroscopy of Yb atoms with a transportable effusive atomic beam apparatus

Energy Technology Data Exchange (ETDEWEB)

Song, Minsoo; Yoon, Tai Hyun [Department of Physics, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

2013-02-15

We present a transportable effusive atomic beam apparatus for cascaded two-photon spectroscopy of the dipole-forbidden transition (6s{sup 2} {sup 1}S{sub 0}{r_reversible} 6s7s {sup 1}S{sub 0}) of Yb atoms. An ohmic-heating effusive oven is designed to have a reservoir volume of 1.6 cm{sup 3} and a high degree of atomic beam collimation angle of 30 mrad. The new atomic beam apparatus allows us to detect the spontaneously cascaded two-photons from the 6s7s{sup 1}S{sub 0} state via the intercombination 6s6p{sup 3}P{sub 1} state with a high signal-to-noise ratio even at the temperature of 340 Degree-Sign C. This is made possible in our apparatus because of the enhanced atomic beam flux and superior detection solid angle.

Q-switch Nd:YAG laser welding of AISI 304 stainless steel foils

Energy Technology Data Exchange (ETDEWEB)

P' ng, Danny [Laboratory for Lasers, MEMS and Nanotechnology, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011-2161 (United States); Molian, Pal [Laboratory for Lasers, MEMS and Nanotechnology, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011-2161 (United States)], E-mail: molian@iastate.edu

2008-07-15

Conventional fusion welding of stainless steel foils (<100 {mu}m thickness) used in computer disk, precision machinery and medical device applications suffer from excessive distortion, formation of discontinuities (pore, void and hot crack), uncontrolled melting (melt-drop through) and poor aesthetics. In this work, a 15 ns pulsed, 400 mJ Nd:YAG laser beam was utilized to overcome these barriers in seam welding of 60 {mu}m thin foil of AISI 304 stainless steel. Transmission electron microscopy was used to characterize the microstructures while hardness and tensile-shear tests were used to evaluate the strengths. Surface roughness was measured using a DekTak profilometer while porosity content was estimated using the light microscope. Results were compared against the data obtained from resistance seam welding. Laser welding, compared to resistance seam welding, required nearly three times less heat input and produced welds having 50% narrower seam, 15% less porosity, 25% stronger and improved surface aesthetics. In addition, there was no evidence of {delta}-ferrite in laser welds, supporting the absence of hot cracking unlike resistance welding.

The stopping powers and energy straggling of heavy ions in polymer foils

Energy Technology Data Exchange (ETDEWEB)

Mikšová, R., E-mail: miksova@ujf.cas.cz [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Macková, A.; Malinský, P. [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Hnatowicz, V. [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Slepička, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-07-15

The stopping power and energy straggling of {sup 7}Li, {sup 12}C and {sup 16}O ions in thin poly(etheretherketone) (PEEK), polyethylene terephthalate (PET) and polycarbonate (PC) foils were measured in the incident beam energy range of 9.4–11.8 MeV using an indirect transmission method. Ions scattered from a thin gold target at an angle of 150° were registered by a partially depleted PIPS detector, partly shielded with a polymer foil placed in front of the detector. Therefore, the signals from both direct and slowed down ions were visible in the same energy spectrum, which was evaluated by the ITAP code, developed at our laboratory. The ITAP code was employed to perform a Gaussian-fitting procedure to provide a complete analysis of each measured spectrum. The measured stopping powers were compared with the predictions obtained from the SRIM-2008 and MSTAR codes and with previous experimental data. The energy straggling data were compared with those calculated by using Bohr’s, Lindhard–Scharff and Bethe–Livingston theories.

The stopping powers and energy straggling of heavy ions in polymer foils

International Nuclear Information System (INIS)

Mikšová, R.; Macková, A.; Malinský, P.; Hnatowicz, V.; Slepička, P.

2014-01-01

The stopping power and energy straggling of 7 Li, 12 C and 16 O ions in thin poly(etheretherketone) (PEEK), polyethylene terephthalate (PET) and polycarbonate (PC) foils were measured in the incident beam energy range of 9.4–11.8 MeV using an indirect transmission method. Ions scattered from a thin gold target at an angle of 150° were registered by a partially depleted PIPS detector, partly shielded with a polymer foil placed in front of the detector. Therefore, the signals from both direct and slowed down ions were visible in the same energy spectrum, which was evaluated by the ITAP code, developed at our laboratory. The ITAP code was employed to perform a Gaussian-fitting procedure to provide a complete analysis of each measured spectrum. The measured stopping powers were compared with the predictions obtained from the SRIM-2008 and MSTAR codes and with previous experimental data. The energy straggling data were compared with those calculated by using Bohr’s, Lindhard–Scharff and Bethe–Livingston theories

Determination of the secondary energy from the electron beam with a flattening foil by computer. Percentage depth dose curve fitting using the specific higher order polynomial

Energy Technology Data Exchange (ETDEWEB)

Kawakami, H [Kyushu Univ., Beppu, Oita (Japan). Inst. of Balneotherapeutics

1980-09-01

A computer program written in FORTRAN is described for determining the secondary energy of the electron beam which passed through a flattening foil, using a time-sharing computer service. The procedure of this program is first to fit the specific higher order polynomial to the measured percentage depth dose curve. Next, the practical range is evaluated by the point of intersection R of the line tangent to the fitted curve at the inflection point P and the given dose E, as shown in Fig. 2. Finally, the secondary energy corresponded to the determined practical range can be obtained by the experimental equation (2.1) between the practial range R (g/cm/sup 2/) and the electron energy T (MeV). A graph for the fitted polynomial with the inflection points and the practical range can be plotted on a teletype machine by request of user. In order to estimate the shapes of percentage depth dose curves correspond to the electron beams of different energies, we tried to find some specific functional relationships between each coefficient of the fitted seventh-degree equation and the incident electron energies. However, exact relationships could not be obtained for irreguarity among these coefficients.

Beam profile for Malaysian electron accelerator

International Nuclear Information System (INIS)

Abu Bakar Ghazali; Muhamad Zahidee Taat

2007-01-01

This paper comprises of two calculations that require in designing a dose profile for an electron accelerator machine before its fabrication. The first is to calculate the beam deflection due to changes of high voltage (HV) supply as well as the deflection coil currents so that the electron beam will only scan at the window foil of 18 cm length and 6 cm width. Secondly, we also require to calculate the beam profile at 50 mm underneath the window foil. The electron gun that produces a beam of 10 mm diameter has to be oscillated in a sawtooth wave for the prescribed window size at frequencies of 50 Hz and 400 Hz along the length and width directions respectively. For the beam deflection, we apply a basic formula from Lorentz force law to obtain a set of HV supply and the coil current that is suitable for both deflections and this result can assist in designing the coil current against HV changes via an electronic controller. The dose profile was calculated using the RMS current formulation along the length direction. We found that the measured and the calculated RMS currents are in comparable for the case of 1 MeV, 50 mA accelerator facility that is going to be installed at Nuclear Malaysia complex. A similar measurement will be carried out for our locally designed accelerator of 150 KeV, 10 mA after fabrication and installation of the machine are completed. (Author)

SU-E-T-557: Measuring Neutron Activation of Cardiac Devices Irradiated During Proton Therapy Using Indium Foils

Energy Technology Data Exchange (ETDEWEB)

Avery, S; Christodouleas, J; Delaney, K; Diffenderfer, E; Brown, K [University of Pennsylvania, Sicklerville, NJ (United States)

2014-06-01

Purpose: Measuring Neutron Activation of Cardiac devices Irradiated during Proton Therapy using Indium Foils Methods: The foils had dimensions of 25mm x 25mm x 1mm. After being activated, the foils were placed in a Canberra Industries well chamber utilizing a NaI(Tl) scintillation detector. The resulting gamma spectrum was acquired and analyzed using Genie 2000 spectroscopy software. One activation foil was placed over the upper, left chest of RANDO where a pacemaker would be. The rest of the foils were placed over the midline of the patient at different distances, providing a spatial distribution over the phantom. Using lasers and BBs to align the patient, 200 MU square fields were delivered to various treatment sites: the brain, the pancreas, and the prostate. Each field was shot at least a day apart, giving more than enough time for activity of the foil to decay (t1=2 = 54.12 min). Results: The net counts (minus background) of the three aforementioned peaks were used for our measurements. These counts were adjusted to account for detector efficiency, relative photon yields from decay, and the natural abundance of 115-In. The average neutron flux for the closed multi-leaf collimator irradiation was measured to be 1.62 x 106 - 0.18 x 106 cm2 s-1. An order of magnitude estimate of the flux for neutrons up to 1 keV from Diffenderfer et al. gives 3 x 106 cm2 s-1 which does agree on the order of magnitude. Conclusion: Lower energy neutrons have higher interaction cross-sections and are more likely to damage pacemakers. The thermal/slow neutron component may be enough to estimate the overall risk. The true test of the applicability of activation foils is whether or not measurements are capable of predicting cardiac device malfunction. For that, additional studies are needed to provide clinical evidence one way or the other.

Method and apparatus for coating thin foil with a boron coating

Science.gov (United States)

Lacy, Jeffrey L.

2018-01-16

An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

Beam-ripple monitor with secondary electrons

International Nuclear Information System (INIS)

Sato, Shinji; Kanazawa, Mitsutaka; Noda, Koji; Takada, Eiichi; Komiyama, Akihito; Ichinohe, Ken-ichi; Sano, Yoshinobu

1997-01-01

To replace the scintillation-ripple monitor, we have developed a new monitor with a smaller destructive effect on the beam. In this monitor, we use secondary electrons emitted from an aluminum foil with a thickness of 2 μm. The signals of secondary electrons are amplified by an electron multiplier having a maximum gain of 10 6 . By using the new monitor, we could clearly observe the beam ripple with a beam intensity of 3.6x10 8 pps (particle per second). This monitor can also be used as an intensity monitor in the range of 10 4 - 10 9 pps. (author)

Additional security features for optically variable foils

Science.gov (United States)

Marshall, Allan C.; Russo, Frank

1998-04-01

For thousands of years, man has exploited the attraction and radiance of pure gold to adorn articles of great significance. Today, designers decorate packaging with metallic gold foils to maintain the prestige of luxury items such as perfumes, chocolates, wine and whisky, and to add visible appeal and value to wide range of products. However, today's products do not call for the hand beaten gold leaf of the Ancient Egyptians, instead a rapid production technology exists which makes use of accurately coated thin polymer films and vacuum deposited metallic layers. Stamping Foils Technology is highly versatile since several different layers may be combined into one product, each providing a different function. Not only can a foil bring visual appeal to an article, it can provide physical and chemical resistance properties and also protect an article from human forms of interference, such as counterfeiting, copying or tampering. Stamping foils have proved to be a highly effective vehicle for applying optical devices to items requiring this type of protection. Credit cards, bank notes, personal identification documents and more recently high value packaged items such as software and perfumes are protected by optically variable devices applied using stamping foil technology.

Actinide Foil Production for MPACT Research

Energy Technology Data Exchange (ETDEWEB)

Beller, Denis

2012-10-30

or UO2 in extremely thin layers (1 to 2 mg/cm2) on various media such as films, foils, or discs. After many months of investigation and trials in FY10 and 11, UNLV researchers developed a new method to produce pure UO2 deposits on foils using a unique approach, which has never been demonstrated, that involves dissolution of U3O8 directly into room temperature ionic liquid (RTIL) followed by electrodeposition from the RTIL-uDU solution (Th deposition from RTIL had been previously demonstrated). The high-purity dissolution of the U3O8 permits the use of RTIL solutions for deposition of U on metal foils in layers without introducing contamination. In FY10 and early FY11 a natural U surrogate for the uDU was used to investigate this and other techniques. In this research project UNLV will deposit directly from RTIL to produce uDU and Th foils devoid of possible contaminants. After these layers have been deposited, they will be examined for purity and uniformity. UNLV will complete the development and demonstration of the RTIL technology/ methodology to prepare uDU and Th samples for use in constructing fast-neutron detectors. Although this material was purchased for use in research using fast-fission chamber detectors for active inspection techniques for MPACT, it could also contribute to R&D for other applications, such as cross section measurements or neutron spectroscopy for national security

Time resolved optical emission spectroscopy of cross-beam pulsed laser ablation on graphite targets

International Nuclear Information System (INIS)

Sangines, R.; Sanchez Ake, C.; Sobral, H.; Villagran-Muniz, M.

2007-01-01

Cross-beam pulsed laser ablation with two delayed lasers is performed on two perpendicular graphite targets. The time delay between lasers is varied by up to 5 μs, and physical changes on the second plasma, due to the interaction with the first generated one, are determined by time resolved optical emission spectroscopy

Excimer laser assisted re-oxidation of BaTiO3 thin films on Ni metal foils

International Nuclear Information System (INIS)

Bharadwaja, S. S. N.; Ko, S. W.; Qu, W.; Clark, T.; Rajashekhar, A.; Motyka, M.; Podraza, N.; Randall, C. A.; Trolier-McKinstry, S.

2016-01-01

Excimer laser assisted re-oxidation for reduced, crystallized BaTiO 3 thin films on Ni-foils was investigated. It was found that the BaTiO 3 can be re-oxidized at an oxygen partial pressure of ∼50 mTorr and substrate temperature of 350 °C without forming a NiO x interface layer between the film and base metal foil. The dielectric permittivity of re-oxidized films was >1000 with loss tangent values <2% at 100 Hz, 30 mV rms excitation signal. Electron Energy Loss Spectroscopy indicated that BaTiO 3 thin films can be re-oxidized to an oxygen stoichiometry close to ∼3 (e.g., stoichiometric). High resolution cross sectional transmission electron microscopy showed no evidence of NiO x formation between the BaTiO 3 and the Ni foil upon excimer laser re-oxidation. Spectroscopic ellipsometry studies on laser re-oxidized [001] C and [111] C BaTiO 3 single crystals indicate that the re-oxidation of BaTiO 3 single crystals is augmented by photo-excitation of the ozone, as well as laser pulse induced temperature and local stress gradients

Hybrid-type long-lived carbon stripper foils

International Nuclear Information System (INIS)

Sugai, Isao; Kato, Hajime

1989-01-01

A new method for the preparation of hybrid-type long-lived carbon stripper foils was developed. The new procedure is based on a modification of our controlled dc arc-discharge method. The carbon foils are of the multilayer type and the layers are composed of carbon particles emitted from the electrodes in the ac arc-discharge and from the cathode in the dc arc-discharge. With this simple and powerful method long lived carbon stripper foils can be prepared with higher reliability and reproducibility than with the previous procedure. (orig.)

Charge collection in an external proton beam

International Nuclear Information System (INIS)

Wookey, C.W.; Somswasdi, B.; Rouse, J.L.

1982-01-01

Results from the measurement of the stability of charge collected from the target and exit foil, or as alternatives, the γ-ray or backscattered proton counts from the exit foil and the Ar X-ray counts from the air path in an external proton beam are presented. These results show that comparative analysis of material mounted in air is reliable, using either the collected charge or the γ-ray counts as the normalizing factor, if there are no earthed objects in close geometry. The backscattered proton counts can also be used, but not the Ar X-ray counts, unless the current is stabilized. The electrical or thermal conductivity of the target and the target to exit foil separation do not affect the proportionality of the collected charge and the γ-ray counts to the charge incident on the target

M.C. simulation of GEM neutron beam monitor with 10B

International Nuclear Information System (INIS)

Wang Yanfeng; Sun Zhijia; Liu Ben; Zhou Jianrong; Yang Guian; Dong Jing; Xu Hong; Zhou Liang; Huang Guangming; Yang Lei; Li Yi

2010-01-01

The neutron beam monitor based on GEM detector has been carefully studied with the Monte-Carlo method in this article. The simulation framework is including the ANSYS and the Garfield, which was used to compute the electric field of GEM foils and simulate the movement of electrons in gas mixture respectively. The GEM foils' focus and extract coefficients have been obtained. According to the primary results, the performing of the monitor is improved. (authors)

Spatial and temporal beam profile monitor with nanosecond resolution for CERN's Linac4 and Superconducting Proton Linac

CERN Document Server

Hori, M

2008-01-01

The Linac4, now being developed at CERN, will provide 160-MeV H- beams of high intensity . Before this beam can be injected into the CERN Proton Synchrotron Booster or future Superconducting Proton Linac for further acceleration, some sequences of 500-ps-long micro-bunches must be removed from it, using a beam chopper. These bunches, if left in the beam, would fall outside the longitudinal acceptance of the accelerators and make them radioactive. We developed a monitor to measure the time structure and spatial profile of this chopped beam, with respective resolutions and . Its large active area and dynamic range also allows investigations of beam halos. The ion beam first struck a carbon foil, and secondary electrons emerging from the foil were accelerated by a series of parallel grid electrodes. These electrons struck a phosphor screen, and the resulting image of the scintillation light was guided to a thermoelectrically cooled, charge-coupled device camera. The time resolution was attained by applying high-...

Birefringence and dichroism of poly(vinyl-alcohol) foils containing phthalazinium ylids

Science.gov (United States)

Rogojanu, Alina; Dascalu, Carmen Felicia; Zelinschi, Beatrice Carmen; Caprosu, Maria; Dorohoi, Dana Ortansa

2011-10-01

Pure and colored with phthalazinium ylids poly(vinyl-alcohol) (PVA) foils were stretched under gentile heating. The birefringence of the thin foils was determined with a Babinet compensator standardized for yellow radiation of a Sodium lamp. The determined birefringence of the colored PVA foils is higher than that of the pure PVA foils. This fact indicates that the phthalazinium ylids facilitate the increase in the anisotropy of the stretched foils. The visible absorption electronic band of phthalazinium ylids was used to estimate the dichroic ratio and the degree of order of the ylid molecules in the stretched PVA foils. An increase in dichroism and birefringence with the degree of stretching has been evidenced for uncolored and colored PVA foils.

Preparation of location-specific thin foils from Fe-3%Si bi- and tri- crystals for examination in a FEG-STEM

Czech Academy of Sciences Publication Activity Database

Sorbello, F.; Hughes, G.M.; Lejček, Pavel; Heard, P.J.; Flewitt, P.E.J.

2009-01-01

Roč. 109, č. 2 (2009), 147-153 ISSN 0304-3991 R&D Projects: GA AV ČR IAA1010414 Institutional research plan: CEZ:AV0Z10100520 Keywords : FEG-STEM * Fe-3%Si * Thin foils * focused ion beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.067, year: 2009

Three-dimensional modeling of beam emission spectroscopy measurements in fusion plasmas

Energy Technology Data Exchange (ETDEWEB)

Guszejnov, D.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Pusztai, I. [Nuclear Engineering, Applied Physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Refy, D.; Zoletnik, S. [MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Lampert, M. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Gwahangno 113, Daejeon 305-333 (Korea, Republic of)

2012-11-15

One of the main diagnostic tools for measuring electron density profiles and the characteristics of long wavelength turbulent wave structures in fusion plasmas is beam emission spectroscopy (BES). The increasing number of BES systems necessitated an accurate and comprehensive simulation of BES diagnostics, which in turn motivated the development of the Rate Equations for Neutral Alkali-beam TEchnique (RENATE) simulation code that is the topic of this paper. RENATE is a modular, fully three-dimensional code incorporating all key features of BES systems from the atomic physics to the observation, including an advanced modeling of the optics. Thus RENATE can be used both in the interpretation of measured signals and the development of new BES systems. The most important components of the code have been successfully benchmarked against other simulation codes. The primary results have been validated against experimental data from the KSTAR tokamak.

Using Target Ablation for Ion Beam Quality Improvement

International Nuclear Information System (INIS)

Zhao Shuan; Chen Jia-Er; Lin Chen; Ma Wen-Jun; Yan Xue-Qing; Wang Jun-Jie

2016-01-01

During the laser foil interaction, the output ion beam quality including the energy spread and beam divergence can be improved by the target ablation, due to the direct laser acceleration (DLA) electrons generated in the ablation plasma. The acceleration field established at the target rear by these electrons, which is highly directional and triangle-envelope, is helpful for the beam quality. With the help of the target ablation, both the beam divergence and energy spread will be reduced. If the ablation is more sufficient, the impact of DLA-electron-caused field will be strengthened, and the beam quality will be better, confirmed by the particle-in-cell simulation. (paper)

Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth

Directory of Open Access Journals (Sweden)

A. Lastras-Martínez

2014-03-01

Full Text Available We report on real time-resolved Reflectance-difference (RD spectroscopy of GaAs(001 grown by molecular beam epitaxy, with a time-resolution of 500 ms per spectrum within the 2.3–4.0 eV photon energy range. Through the analysis of transient RD spectra we demonstrated that RD line shapes are comprised of two components with different physical origins and determined their evolution during growth. Such components were ascribed to the subsurface strain induced by surface reconstruction and to surface stoichiometry. Results reported in this paper render RD spectroscopy as a powerful tool for the study of fundamental processes during the epitaxial growth of zincblende semiconductors.

Measurements of laser-imprinting sensitivity to relative beam mistiming in planar plastic foils driven by multiple overlapping laser beams

International Nuclear Information System (INIS)

Smalyuk, V.A.; Goncharov, V.N.; Boehly, T.R.; Delettrez, J.A.; Li, D.Y.; Marozas, J.A.; Maximov, A.V.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

2005-01-01

In a direct-drive, inertial confinement fusion implosion, a spherical target is irradiated by a large number of overlapped laser beams. Imprinting of laser modulations depends on the relative arrival time of laser beams and their angles of incidence. This dependence was measured in planar plastic targets using six overlapping beams on the OMEGA laser system [T. R. Boehly, D. L. Brown, R. S. Craxton, R. L. Keck, J. P. Knauer, J. H. Kelly, T. J. Kessler, S. A. Kumpan, S. J. Loucks, S. A. Letzring, F. J. Marshall, R. L. McCrory, S. F. B. Morse, W. Seka, J. M. Soures, and C. P. Verdon, Opt. Commun. 133, 495 (1997)]. One of the beams (the imprint beam) had a special phase plate that produced two-dimensional modulations on the target, easily distinguishable from the features imprinted by the other five drive beams. The timing of the imprint beam was varied with respect to the drive beams to study imprinting sensitivity to beam mistiming. Shifting the imprint beam to arrive before the other beams significantly increased the imprint efficiency. The results are in very good agreement with the model predictions

Formation of Rydberg states in fast ion-atom collisions

International Nuclear Information System (INIS)

Schneider, D.; Kanter, E.P.; Vager, Z.; Gemmell, D.; Koch, P.; Mariani, D.; Van de Water, W.

1983-01-01

Previous results from beam-foil spectroscopy and from experiments using field ionization techniques have shown that a significant fraction of fast ionic projectiles traversing solid targets can be excited to high Rydberg states. We report an experimental investigation of Rydberg states formed in atomic and molecular ion beams (MeV) emerging from thin-carbon foils. Different field arrangements, including μ-wave fields, have been applied to study the effects of field ionization. The yields of electrons produced via field ionization are compared for different projectile atoms and molecules

Development of beam diagnostic devices for characterizing electron guns

International Nuclear Information System (INIS)

Bhattacharjee, D.; Tiwari, R.; Jayaprakash, D.; Mishra, R.L.; Sarukte, H.; Waghmare, A.; Thakur, N.; Dixit, K.P.

2015-01-01

The electron guns for the DC accelerators and RF Linacs are designed and developed at EBC/APPD/BARC, Kharghar. These electron guns need to be characterized for its design and performance. Two test benches were developed for characterizing the electron guns. Various beam diagnostic devices for measuring beam currents and beam sizes were developed. Conical faraday cup, segmented faraday cup, slit scanning bellows movement arrangement, multi-plate beam size measurement setup, multi- wire beam size measurement setup, Aluminum foil puncture assembly etc. were developed and used. The paper presents the in-house development of various beam diagnostics for characterizing electron guns and their use. (author)

Experimental control of the beam properties of laser-accelerated protons and carbon ions

Energy Technology Data Exchange (ETDEWEB)

Amin, Munib

2008-12-15

The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

Experimental control of the beam properties of laser-accelerated protons and carbon ions

International Nuclear Information System (INIS)

Amin, Munib

2008-12-01

The laser generation of energetic high quality beams of protons and heavier ions has opened up the door to a plethora of applications. These beams are usually generated by the interaction of a short pulse high power laser with a thin metal foil target. They could already be applied to probe transient phenomena in plasmas and to produce warm dense matter by isochoric heating. Other applications such as the production of radioisotopes and tumour radiotherapy need further research to be put into practice. To meet the requirements of each application, the properties of the laser-accelerated particle beams have to be controlled precisely. In this thesis, experimental means to control the beam properties of laser-accelerated protons and carbon ions are investigated. The production and control of proton and carbon ion beams is studied using advanced ion source designs: Experiments concerning mass-limited (i.e. small and isolated) targets are conducted. These targets have the potential to increase both the number and the energy of laser-accelerated protons. Therefore, the influence of the size of a plane foil target on proton beam properties is measured. Furthermore, carbon ion sources are investigated. Carbon ions are of particular interest in the production of warm dense matter and in cancer radiotherapy. The possibility to focus carbon ion beams is investigated and a simple method for the production of quasi-monoenergetic carbon ion beams is presented. This thesis also provides an insight into the physical processes connected to the production and the control of laser-accelerated ions. For this purpose, laser-accelerated protons are employed to probe plasma phenomena on laser-irradiated targets. Electric fields evolving on the surface of laser-irradiated metal foils and hollow metal foil cylinders are investigated. Since these fields can be used to displace, collimate or focus proton beams, understanding their temporal and spatial evolution is crucial for the design of

BANGERTER FOILS IN THE POSTOPERATIVE MANAGEMENT OF ESOTROPIA.

Directory of Open Access Journals (Sweden)

Galina G. Dimitrova

2014-12-01

Full Text Available Purpose: To evaluate the application of Bangerter foils in the postoperative management of esotropia Methods: A retrospective study of 200 patients who underwent bimedial recessions for various forms of alternating/alternated esotropia in the period of 2000-2013. In the cases of residual postoperative angle, tendency of recurrence of strabismus and preferred fixation, Bangerter foil was fixed on the corrective glass of the dominant eye- either on the next day of surgery, or on the 10-th postoperative day and was in use for at least 6 months. Results: Bangerter foils were applied in 67(35,1% under corrected patients with a mean residual angle for near 7,01±3,51Δ. Mean residual angle in patients without foils was 3,47±4,06Δ (p<0,001. Statistically significant factors in patients with filters were amblyopia treatment before surgery (p<0,001, anisometropia (p=0,003 and type of esotropia (accommodative vs. non accommodative (p<0,001. Within the group without filters there was a significant increase of the residual angle for near on the third (p<0,001 and sixth month (p=0,036, while within the group with foils angle was not significantly changed (p=0,325; p=0,058 with time. In the group with foils no cases with relapse of strabismus and amblyopia were recorded and even a decrease of the postoperative angle was clinically observed in some patients. Conclusion: To our experience Bangerter foils are a reliable tool in the postoperative management of undercorrected esotropia.

Analysis of Mechanical Properties for GEM Foil

CERN Document Server

Chin, Yuk Ming

2016-01-01

In view of new assembly technique of the GEM detector; in which three foils stack is stretched to get the uniform gaps among the foils. We studied the mechanical properties of the foil material. We conditioned the samples in different environments to make them extra dry and wet. As holes are the major source of the charge amplification their deformation can effect the detector performance. Therefore in our studies we also studied at which level of the stress the holes deformation is seen. These tensile and holes deformation studies can help to optimize the stress during detector assembly.

A new non intercepting beam size diagnostics using diffraction radiation from a Slit

International Nuclear Information System (INIS)

Castellano, M.

1996-09-01

A new non interpreting beam size diagnostic for high charge electron beams is presented. This diagnostics is based on the analysis of the angular distribution of the 'diffracted' transition radiation emitted by the beam when crossing a slit cut in metallic foil. It allows a resolution better then the radiation transverse formation zone. Numerical results based on the parameters of the TTF FEL beam are given as example

Hydrogen permeation through metallic foils

International Nuclear Information System (INIS)

Bernardi, M.I.B.; Rodrigues, J.A.

1987-01-01

The process of electrolytic permeation of hydrogen through metallic foils is studied. A double electrolytic cell, in glass, in which the two compartments of reaction are separated by a metallic foil to be studied, was built. As direct result, the hydrogen diffusion coefficient in the metal is obtained. The hydrogen diffusion coefficients in the palladium and, in austenitic stainless steels 304 and 304 L, used in the Angra-1 reactor, were obtained. Samples of stainless steels with and without welding, were used. (Author) [pt

Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

International Nuclear Information System (INIS)

Liu, Chuan S.; Shao Xi; Liu, T. C.; Dudnikova, Galina; Sagdeev, Roald Z.; Eliasson, Bengt

2011-01-01

We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

P-type diamond stripper foils for tandem ion accelerators

International Nuclear Information System (INIS)

Phelps, A.W.; Koba, R.

1989-01-01

The authors are developing a stripper foil composed of a p-type diamond membrane. This diamond stripper foil should have a significantly longer lifetime than any conventional stripper foil material. To be useful for stripper foils, the boron-doped blue diamond films must be thinner than 0.8 μm and pore-free. Two methods are compared for their ability to achieve a high nucleation areal density on a W substrate. Some W substrates were first coated with think layer of boron (≤20 nm) in order to enhance nucleation. Other W substrates were scratched with submicron diamond particles. A schematic diagram of the stripper foil is shown. Stripper foils were created by etching away the central area of W substrates. The diamond membrane was then supported by an annulus of W. Tungsten was selected as a ring-support material because of its high electrical and thermal conductivity, relatively low thermal expansion, and proven suitability as a substrate for diamond CVD. Warping or fracture of the diamond film after substrate etch-back was investigated

Automatic spark counting of alpha-tracks in plastic foils

International Nuclear Information System (INIS)

Somogyi, G.; Medveczky, L.; Hunyadi, I.; Nyako, B.

1976-01-01

The possibility of alpha-track counting by jumping spark counter in cellulose acetate and polycarbonate nuclear track detectors was studied. A theoretical treatment is presented which predicts the optimum residual thickness of the etched foils in which completely through-etched tracks (i.e. holes) can be obtained for alpha-particles of various energies and angles of incidence. In agreement with the theoretical prediction it is shown that a successful spark counting of alpha-tracks can be performed even in polycarbonate foils. Some counting characteristics, such as counting efficiency vs particle energy at various etched foil thicknesses, surface spark density produced by electric breakdowns in unexposed foils vs foil thickness, etc. have been determined. Special attention was given to the spark counting of alpha-tracks entering thin detectors at right angle. The applicability of the spark counting technique is demonstrated in angular distribution measurements of the 27 Al(p,α 0 ) 24 Mg nuclear reaction at Ep = 1899 keV resonance energy. For this study 15 μm thick Makrofol-G foils and a jumping spark counter of improved construction were used. (orig.) [de

Beam profile measurements using nonimaging gamma optics

International Nuclear Information System (INIS)

Norem, J.; Dawson, J.; Haberichter, W.; Lam, R.; Reed, L.; Yang, X.F.; Spencer, J.

1995-01-01

High energy photons produced from bremsstrahlung foils, Compton scattering or beamstrahlung from high energy e + e - collisions can be used to measure beam profiles using nonimaging optics. We describe the method and its limitations (resolution, backgrounds etc.), as well as the apparatus required to implement it. Data from a low energy test run is described as well as other possible applications, such as a 250+250 GeV linear collider and possible experiments with existing beams. (orig.)

In-beam γ-ray spectroscopy of 38,40,42Si

Directory of Open Access Journals (Sweden)

Matsushita M.

2014-03-01

Full Text Available Excited states in the nuclei 38,40,42 Si have been studied using in-beam Γ-ray spectroscopy following multi-nucleon removal reactions to investigate the systematics of excitation energies along the Z=14 isotopic chain. The most probable candidates for the transition from the yrast 4+ state were tentatively assigned among several γ lines newly observed in the present study. The energy ratios between the 21+ and 41+ states were obtained to be 2.09(5, 2.56(5 and 2.93(5 for 38,40,42Si, respectively, indicating a rapid development of deformation in Si isotopes from N=24 to, at least, N=28.

Generation of linearly polarized resonant transition radiation X-ray beam

International Nuclear Information System (INIS)

Yajima, Kazuaki; Awata, Takaaki; Ikeda, Mitsuharu; Ikeda, Kenichi; Yogo, Akifumi; Itoh, Akio; Imanishi, Nobutsugu

2000-01-01

We have proposed a method to generate almost linearly polarized resonant transition radiation X rays by using a rectangular slit placed on an electron beam axis. Our calculation predicted that the linearity is 93.5% for the resonant transition radiation X-ray beam extracted through a slit of 0.5 mrad long and 0.2 mrad wide in case of 1-GeV electron beam irradiating a 7.5-μm thick Kapton foil stack. (author)

Generation of linearly polarized resonant transition radiation X-ray beam

Energy Technology Data Exchange (ETDEWEB)

Yajima, Kazuaki; Awata, Takaaki; Ikeda, Mitsuharu; Ikeda, Kenichi; Yogo, Akifumi; Itoh, Akio; Imanishi, Nobutsugu [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

2000-03-01

We have proposed a method to generate almost linearly polarized resonant transition radiation X rays by using a rectangular slit placed on an electron beam axis. Our calculation predicted that the linearity is 93.5% for the resonant transition radiation X-ray beam extracted through a slit of 0.5 mrad long and 0.2 mrad wide in case of 1-GeV electron beam irradiating a 7.5-{mu}m thick Kapton foil stack. (author)

New membranes obtained by grafted irradiated PVDF foils

International Nuclear Information System (INIS)

Mazzei, R.; García Bermúdez, G.; Camporotondi, D.E.; Arbeitman, C.

2012-01-01

The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar + beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid–glycidyl methacrylate (AAc–GMA); acrylic acid–styrene (AAc–S), acrylic acid-N-isopropyl acrylamide (AAc–NIPAAm) and acrylic acid-N-isopropyl acrylamide–glycidyl methacrylate (AAc-NIPAAm–GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

Method of fabricating a uranium-bearing foil

Science.gov (United States)

Gooch, Jackie G [Seymour, TN; DeMint, Amy L [Kingston, TN

2012-04-24

Methods of fabricating a uranium-bearing foil are described. The foil may be substantially pure uranium, or may be a uranium alloy such as a uranium-molybdenum alloy. The method typically includes a series of hot rolling operations on a cast plate material to form a thin sheet. These hot rolling operations are typically performed using a process where each pass reduces the thickness of the plate by a substantially constant percentage. The sheet is typically then annealed and then cooled. The process typically concludes with a series of cold rolling passes where each pass reduces the thickness of the plate by a substantially constant thickness amount to form the foil.

Light Barrier for Non-Foil Packaging

Science.gov (United States)

2010-12-16

foil and all-plastic materials were retorted and a second set of all-plastic packaged entrees were Microwave Sterilized on the Washington State...Copolymers for Retort Applications; SPE Polyolefins and Flexible Packaging Conference: Society of Plastics Engineers. Newtown. CT, 43pp. Thellen C...Final Scientific Report Light Barrier for Non-Foil Packaging Contract No. W911QY-08-C-0132 Final Scientific Report Contract No. W911QY-08-C-0132

Method of stabilizing Nb3Sn superconducting foils

International Nuclear Information System (INIS)

Kruzliak, J.; Lences, P.; Allarova, H.

1982-01-01

The stabilization of niobium-tin Nb 3 Sn superconducting foils with copper is carried out by deposition or by diffusion in pure copper or in a tin bath containing different copper levels, with the surface etched or unetched. The foils are covered with a copper film at a temperature of 300 to 5O0 degC using a tin solder, spread on a copper, silver or nickel layer deposited on the foil surface from solutions for electroless plating. The bond between the surface of the superconducting foil and the electroless plated metal layer is annealed in a controlled atmosphere or in a vacuum at a temperature of 200 to 500 degC for over 20 to 60 minutes. The copper stabilization layer can also be produced electrolytically. (J.B.)

Auger electron spectroscopy, ionization loss spectroscopy, appearance potential spectroscopy

International Nuclear Information System (INIS)

Riwan, R.

1973-01-01

The spectroscopy of surfaces using an incident electron beam is studied. The fundamental mechanisms are discussed together with the parameters involved in Auger emission: excitation of the atom, de-excitation by electron emission, and the migration of electrons towards the surface and their ejection. Some examples of applications are given (surface structures, metallurgy, chemical information). Two new techniques for analyzing surfaces are studied: ionization spectroscopy, and appearance potential spectroscopy [fr

$\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

CERN Multimedia

We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

Yrast spectroscopy in {sup 49-51}Ti via fusion-evaporation reaction induced by a radioactive beam

Energy Technology Data Exchange (ETDEWEB)

Niikura, M.; Ideguchi, E.; Michimasa, S.; Ota, S.; Shimoura, S.; Wakabayashi, Y. [University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Aoi, N.; Baba, H.; Fukuchi, T.; Ichikawa, Y.; Kubo, T.; Kurokawa, M.; Ohnishi, T.; Suzuki, H.; Yoshida, K. [RIKEN Nishina Center, Wako, Saitama (Japan); Iwasaki, H.; Onishi, T.K.; Suzuki, D. [University of Tokyo, Department of Physics, Tokyo (Japan); Liu, M.; Zheng, Y. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

2009-12-15

In-beam {gamma} -ray spectroscopy of high-spin states in {sup 49-51}Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and {gamma} - {gamma} coincidence analysis, yrast high-spin levels up to I=(21/2{sup -}),(11{sup +}),(17/2{sup -}) in {sup 49-51}Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N=28 shell gap at yrast states in {sup 49-51}Ti. (orig.)

Gas electron multiplier (GEM) foil test, repair and effective gain calculation

Science.gov (United States)

Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

2018-06-01

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

Multiple track Doppler-shift spectroscopy system for TFTR neutral beam injectors

International Nuclear Information System (INIS)

Kamperschroer, J.H.; Kugel, H.W.; Reale, M.A.

1986-09-01

A Doppler-shift spectroscopy system has been installed on the TFTR neutral beam injection system to measure species composition during both conditioning and injection pulses. Two intensified vidicon detectors and two spectrometers are utilized in a system capable of resolving data from up to twelve ion sources simultaneously. By imaging the light from six ion sources onto one detector, a cost-effective system has been achieved. Fiber optics are used to locate the diagnostic in an area remote from the hazards of the tokamak test cell allowing continuous access, and eliminating the need for radiation shielding of electronic components. Automatic hardware arming and interactive data analysis allow beam composition to be computed between tokamak shots for use in analyzing plasma heating experiments. Measurements have been made using lines of sight into both the neutralizer and the drift duct. Analysis of the data from the drift duct is both simpler and more accurate since only neutral particles are present in the beam at this location. Comparison of the data taken at these two locations reveals the presence of partially accelerated particles possessing an estimated 1/e half-angle divergence of 15 0 and accounting for up to 30% of the extracted power

Secondary electrons detectors for beam tracking: micromegas and wire chamber

International Nuclear Information System (INIS)

Pancin, J; Chaminade, T; Drouart, A; Kebbiri, M; Riallot, M; Fernandez, B; Naqvi, F

2009-01-01

SPIRAL2 or FAIR will be able to deliver beams of radioactive isotopes of low energy (less than 10 MeV/n). The emittance of these new beams will impose the use of beam tracking detectors to reconstruct the exact impact position of the nuclei on the experimental target. However, due to their thickness, the classical detectors will generate a lot of energy and angular straggling. A possible alternative is the SED principle (Secondary Electron Detector). It consists of an emissive foil placed in beam and a detector for the secondary electrons ejected by the passing of the nuclei through the foil. An R and D program has been initiated at CEA Saclay to study the possibility to use low pressure gaseous detectors as SED for beam tracking. Some SED have been already used on the VAMOS spectrometer at GANIL since 2004. We have constructed new detectors on this model to measure their performances in time and spatial resolution, and counting rate. Other detector types are also under study. For the first time, a test with different micromegas detectors at 4 Torr has been realized. A comparison on the time resolution has been performed between wire chamber and micromegas at very low pressure. The use of micromegas could be promising to improve the counting rate capability and the robustness of beam tracking detectors.

Small-sized monitor of beam current and profile for the proton pulse electrostatic accelerator

International Nuclear Information System (INIS)

Getmanov, V.N.

1985-01-01

Design and principle of operation of current monitor and beam profile of range-coordinate type are described. Monitor operation peculiarities are discussed using diagnostics of a beam of 330-420 keV electrostatic pulse proton accelerator with a beam current of up to 20 mA, at a current density of up to 23 mA x cm -2 and wth pulse duraton of about 20 μs. The monitor consists of a vacuum-dense foil of 3.0+-0.1 μm in thickness (or 0.81+-0.0x- mg x cm -2 ) two grid electrodes, each containing 12 wires, and as solid copper bottom. Foil serves for chopping off background particles with a path lesser 3.0 μm and stands thermal pulse load up to 0.5 J/cm -2 . Grid electrode wires are oriented perpendicularly to lach other and form a two-coordinate secondary-emisson roughness indicator. The bothhom is used for measuring an absolute value of beam current

Chemical vapour deposition at atmospheric pressure of graphene on molybdenum foil: Effect of annealing time on characteristics and corrosion stability of graphene coatings

International Nuclear Information System (INIS)

Naghdi, Samira; Jevremović, Ivana; Mišković-Stanković, Vesna; Rhee, Kyong Yop

2016-01-01

Highlights: • Atmospheric pressure chemical vapor deposition of graphene on molybdenum foils. • Quality and domain size of graphene layers increased with longer annealing times. • The number of graphene layers decreased with longer annealing times. • Graphene coatings on molybdenum foils exhibited corrosion inhibitive properties. - Abstract: In this work, the effect of pre-annealing of Mo substrate on the quality of graphene layers grown by chemical vapour deposition was investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. Moreover, different electrochemical techniques were employed to investigate the corrosion stability of the graphene coated Mo in 0.1 M NaCl. Longer annealing time resulted in less defective graphene coatings with fewer layers. Graphene coating on the annealed Mo provided better protection against corrosion during the initial exposure times, while after prolonged exposure times, both graphene coatings on annealed and non-annealed Mo exhibited nearly the same corrosion inhibitive properties.

Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research

Energy Technology Data Exchange (ETDEWEB)

Lampert, M. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); BME NTI, Budapest (Hungary); Anda, G.; Réfy, D.; Zoletnik, S. [Wigner RCP, Euratom Association-HAS, Budapest (Hungary); Czopf, A.; Erdei, G. [Department of Atomic Physics, BME IOP, Budapest (Hungary); Guszejnov, D.; Kovácsik, Á.; Pokol, G. I. [BME NTI, Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Daejeon (Korea, Republic of)

2015-07-15

A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera’s measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties.

The Development of a Hibachi Window for Electron Beam Transmission in a KrF Laser

International Nuclear Information System (INIS)

Gentile, C.A.; Parsells, R.; Butler, J.E.; Sethian, J.D.; Ciebiera, L.; Hegeler, F.; Jun, C.; Langish, S.; Myers, M.

2003-01-01

In support of Inertial Fusion Energy (IFE), a 150 (micro)m thick silicon (Si) wafer coated on one side with a 1.2 (micro)m nanocrystalline diamond foil is being fabricated as an electron beam transmission (hibachi) window for use in KrF lasers. The hibachi window separates the lasing medium from the electron beam source while allowing the electron beam to pass through. The hibachi window must be capable of withstanding the challenging environment presented in the lasing chamber, which include: fluorine gas, delta pressure >2 atm at 5 Hz, and a high heat flux due to the transmission of electrons passing through the foil. Tests at NRL/Electra and at PPPL have shown that a device employing these novel components in the stated configuration provide for a robust hibachi window with structural integrity

Liquid-film stripper for high-intensity heavy-ion beams

International Nuclear Information System (INIS)

Leemann, B.T.; Merrill, P.; Syversrud, H.K.; Wada, R.; Yourd, R.B.

1981-03-01

Electron strippers are widely used in heavy ion accelerators such as tandem Van de Graaff generators and heavy ion linacs. The SuperHILAC at Lawrence Berkeley Laboratory, employs a fluorocarbon oil vapor stripper at 113 keV/A for its high intensity injector ABEL, while after acceleration to 1.199 MeV/A a 35 μg/cm 2 carbon foil stripper is used. At present, the lifetime of these foils is about 1 hour for an 40 Ar beam of approx. 1 μA average particle current. With higher intensity high mass (100 less than or equal to A less than or equal to 238) beams available from ABEL injector the lifetime is expected to drop drastically and might be as low as one minute. A different approach to solve the stripper foil lifetime problem uses a thin free standing oil film spun from the edge of a sharp-edged rotating disc touching the surface of an oil reservoir. Areas of about 10 cm 2 with areal densities down to 20 μg/cm 2 have been reported. The work described here is based on the same concept, and produces a constantly regenerated, stable, free standing oil film of appropriate thickness for use at the SuperHILAC

Design of foil implosion system for Pioneer I experiments

International Nuclear Information System (INIS)

Erickson, D.J.; Caird, R.S.; Fowler, C.M.

1985-01-01

A foil implosion system is described that integrates an explosive flux-compression generator, a flat plate feed section with power conditioning switches, and a vacuum electrode region containing a cylindrical foil/plasma load. Power conditioning, obtained with an explosive-driven plasma compression opening switch and explosive-actuated closing switches, provides a submicrosecond multimegampere pulse for the implosion of an aluminum plasma. The flat plate section is configured for bidirectional feed to the coaxial vacuum electrodes. Important considerations in the design of the vacuum power flow region include gap failure, feed symmetry, and radial diagnostic access. The system presently accommodates a foil radius of 3 cm. Innovative foil insertion and clamping techniques are also described

Effects of film/foil interactions on X-ray image quality - experimental studies

International Nuclear Information System (INIS)

Maurer, H.J.; Goos, F.

1985-01-01

When assessing the quality of X-ray images, the interaction between film and foil should never be left out of account. Except for the case of green-emitting foils which require green-emitting films, films and foils are normally regarded separately, so that many variations are possible. The authors review the interaction between film and foil under practical aspects. Studies published so far have concentrated either on the amplification factor of foils or an the object imaging characteristics of certain films. Systematic studies on the interaction between film and foil have never been carried out. (orig.) [de

Three-Dimensional Simulations of Flat-Foil Laser-Imprint Experiments at the National Ignition Facility

Science.gov (United States)

Shvydky, A.; Radha, P. B.; Rosenberg, M. J.; Anderson, K. S.; Goncharov, V. N.; Marozas, J. A.; Marshall, F. J.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Hohenberger, M.; di Nicola, J. M.; Koning, J. M.; Marinak, M. M.; Masse, L.; Karasik, M.

2017-10-01

Control of shell nonuniformities imprinted by the laser and amplified by hydrodynamic instabilities in the imploding target is critical for the success of direct-drive ignition at the National Ignition Facility (NIF). To measure a level of imprint and its reduction by the NIF smoothing by spectral dispersion (SSD), we performed experiments that employed flat CH foils driven with a single NIF beam with either no SSD or the NIF indirect-drive SSD applied to the laser pulse. Face-on x-ray radiography was used to measure optical depth variations, from which the amplitudes of the foil areal-density modulations were obtained. Results of 3-D, radiation-hydrodynamic code HYDRA simulations of the growth of the imprint-seeded perturbations are presented and compared with the experimental data. This work was supported by the U.S. Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract Number DE-AC52-07NA27344.

Scaling laws for radial foil bearings

Science.gov (United States)

Honavara Prasad, Srikanth

The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

Depth profiles of production yields of natPb(p, xn206,205,204,203,202 Bi reactions using 100-MeV proton beam

Directory of Open Access Journals (Sweden)

Oranj Leila Mokhtari

2017-01-01

Full Text Available In this study, results of the experimental study on the depth profiles of production yields of 206,205,204,203,202Bi radio-nuclei in the natural Pb target irradiated by a 100-MeV proton beam are presented. Irradiation was performed at proton linac facility (KOMAC in Korea. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of natural Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3p1n24Na, 197Au(p, p1n196Au, and 197Au(p, p3n194Au monitor reactions and also using dosimetry method by a Gafchromic film. The production yields of produced Bi radio-nuclei in the natural Pb foils and monitor reactions were measured by gamma-ray spectroscopy. Monte Carlo simulations were performed by FLUKA, PHITS, and MCNPX codes and compared with the measurements in order to verify validity of physical models and nuclear data libraries in the Monte Carlo codes. A fairly good agreement was observed between the present experimental data and the simulations by FLUKA, PHITS, and MCNPX. However, physical models and the nuclear data relevant to the end of range of protons in the codes need to be improved.

Health status of cows fed maize silage covered with oxo-biodegradable foil

OpenAIRE

Piotr SZTERK; Piotr DORSZEWSKI; Małgorzata GRABOWICZ; Lucyna PODKÓWKA

2017-01-01

In agricultural practice, silage production uses pure, low density polyethylene foil. This foil, after use, becomes farm waste, having a negative impact on the environment. Instead of conventional foil, an environmentally safe biodegradable foil can be used, made from naturally occurring polymers or from synthetic multiparticulates, easily degradable by microorganisms. Silage covered with this type of foil should be safe for animal health. The purpose of the study was to determine whether oxo...

IBEX - annular beam propagation experiment

International Nuclear Information System (INIS)

Mazarakis, M.G.; Miller, R.B.; Shope, S.L.; Poukey, J.W.; Ramirez, J.J.; Ekdahl, C.A.; Adler, R.J.

1983-01-01

IBEX is a 4-MV, 100-kA, 20-ns cylindrical isolated Blumlein accelerator. In the experiments reported here, the accelerator is fitted with a specially designed foilless diode which is completely immersed in a uniform magnetic field. Several diode geometries have been studied as a function of magnetic field strength. The beam propagates a distance of 50 cm (approx. 10 cyclotron wavelengths) in vacuum before either striking a beam stop or being extracted through a thin foil. The extracted beam was successfully transported 60 cm downstream into a drift pipe filled either with 80 or 640 torr air. The main objectives of this experiment were to establish the proper parameters for the most quiescent 4 MV, 20 to 40 kA annular beam, and to compare the results with available theory and numerical code simulations

New membranes obtained by grafted irradiated PVDF foils

Energy Technology Data Exchange (ETDEWEB)

Mazzei, R. [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Universidad Tecnologica Nacional Facultad Regional, Buenos Aires (Argentina); Garcia Bermudez, G. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Camporotondi, D.E., E-mail: camporotondi@cae.cnea.gov.ar [Unidad de Actividades Tecnologicas y Agropecuarias, Laboratorio de Polimeros, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Arbeitman, C. [Gerencia de Investigacion y Aplicaciones, Laboratorio Tandar, Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); and others

2012-09-15

The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar{sup +} beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S), acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide-glycidyl methacrylate (AAc-NIPAAm-GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

Measurements of direct drive laser imprint in thin foils by radiography using an x-ray laser backlighter

International Nuclear Information System (INIS)

Kalantar, D.H.; Key, M.H.; Da Silva, L.B.; Glendinning, S.G.; Remington, B.A.; Rothenberg, J.E.; Weber, F.; Weber, S.V.; Wolfrum, E.; Kim, N.S.; Neely, D.; Zhang, J.; Wark, J.S.; Demir, A.; Lin, J.; Smith, R.; Tallents, G.J.; Lewis, C.L.; MacPhee, A.; Warwick, J.; Knauer, J.P.

1997-01-01

In direct drive inertial confinement fusion, the residual speckle pattern remaining after beam smoothing plays an important role in the seeding of instabilities at the ablation front. An x-ray laser is used as an extreme ultraviolet backlighter to characterize the imprinted modulation in thin foils for smoothing by random phase plate and by spectral dispersion for both 0.35 and 0.53 μm irradiation, and by induced spatial incoherence for 0.53 μm irradiation. Measurements of the imprinted modulation due to a single optical mode generated by two beam interference, and modification of the imprint with a superposed smooth irradiation to study time dependence of the imprinting process are demonstrated. copyright 1997 American Institute of Physics

Ion-beam bombardment induced texture in nickel substrates for coated high-Tc superconductors

International Nuclear Information System (INIS)

Wang, S S; Wu, K; Zhou, Y; Godfrey, A; Meng, J; Liu, M L; Liu, Q; Liu, W; Han, Z

2003-01-01

Biaxially textured metal substrates are often used for making YBa 2 Cu 3 O 7-x coated conductors with high critical current density. Generally, specific rolling and high-temperature annealing procedures are required to obtain the biaxial texture for metal substrates. Here, we report on a new method for developing strongly biaxially textured grain structure in rolled nickel tape by argon ion-beam bombardment. X-ray diffraction (XRD) θ-2θ scans have shown that a (200) diffraction peak intensity of the Ni foil processed by ion-beam structure modification (ISM) is two orders of magnitude greater than that of cold-rolled foil, while the (111) and (220) intensities are very weak. In the ISM processed Ni foils, from the rocking curve, the full width at half maximum (FWHM) value of the (200) peak has been found to be less than 5.9 deg., whilst the in-plane FWHM obtained from a pole figure analysis is just 8 deg. We discuss the possible mechanisms leading to the texture changes during ISM. (rapid communication)

A suspended boron foil multi-wire proportional counter neutron detector

Energy Technology Data Exchange (ETDEWEB)

Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

2014-12-11

Three natural boron foils, approximately 1.0 cm in diameter and 1.0 µm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the {sup 10}B(n,α){sup 7}Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal–neutron detection efficiency for enriched {sup 10}B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

A suspended boron foil multi-wire proportional counter neutron detector

Science.gov (United States)

Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

2014-12-01

Three natural boron foils, approximately 1.0 cm in diameter and 1.0 μm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the 10B(n,α)7Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal-neutron detection efficiency for enriched 10B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

Laser-accelerated proton beams as a new particle source

Energy Technology Data Exchange (ETDEWEB)

Nuernberg, Frank

2010-11-15

The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. In this work, an experimental method to fully reconstruct laser-accelerated proton beam parameters, called radiochromic film imaging spectroscopy (RIS), was developed. Since the proton beam expansion is a plasma expansion with accompanying electrons, a low-energy electron spectrometer was developed, built and tested to study the electron distribution matching to the proton beam energy distribution. Two experiments were carried out at the VULCAN Petawatt laser with the aim of showing dynamic control and enhancement of proton acceleration using multiple or defocused laser pulses. Irradiating the target with a long pulse, low-intensity laser (10{sup 12} W/cm{sup 2}) prior to the main pulse ({proportional_to}ns), an optimum pre-plasma density scale length of 60 {mu}m is generated leading to an enhancement of the maximum proton energy ({proportional_to}25%), the proton flux (factor of 3) and the beam uniformity. Proton beams were generated more efficiently than previously by driving thinner target foils at a lower intensity over a large area. The optimum condition was a 2 {mu}m foil irradiated with an intensity of 10{sup 19} W/cm{sup 2} onto a 60 {mu}m spot. Laser to proton beam efficiencies of 7.8% have been achieved (2.2% before) - one of the highest conversion efficiencies ever achieved. In the frame of this work, two separate experiments at the TRIDENT laser system have shown that these laser-accelerated proton beams, with their high number of particles in a short pulse duration, are well-suited for creating isochorically heated matter in extreme conditions. Besides the manipulation of the proton beam parameters directly during the generation, the primary aim of this thesis was the capture, control and transport of laser-accelerated proton beams by a solenoidal magnetic field lense for further purpose. In a joint project proposal, the laser and

Laser-accelerated proton beams as a new particle source

International Nuclear Information System (INIS)

Nuernberg, Frank

2010-01-01

The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. In this work, an experimental method to fully reconstruct laser-accelerated proton beam parameters, called radiochromic film imaging spectroscopy (RIS), was developed. Since the proton beam expansion is a plasma expansion with accompanying electrons, a low-energy electron spectrometer was developed, built and tested to study the electron distribution matching to the proton beam energy distribution. Two experiments were carried out at the VULCAN Petawatt laser with the aim of showing dynamic control and enhancement of proton acceleration using multiple or defocused laser pulses. Irradiating the target with a long pulse, low-intensity laser (10 12 W/cm 2 ) prior to the main pulse (∝ns), an optimum pre-plasma density scale length of 60 μm is generated leading to an enhancement of the maximum proton energy (∝25%), the proton flux (factor of 3) and the beam uniformity. Proton beams were generated more efficiently than previously by driving thinner target foils at a lower intensity over a large area. The optimum condition was a 2 μm foil irradiated with an intensity of 10 19 W/cm 2 onto a 60 μm spot. Laser to proton beam efficiencies of 7.8% have been achieved (2.2% before) - one of the highest conversion efficiencies ever achieved. In the frame of this work, two separate experiments at the TRIDENT laser system have shown that these laser-accelerated proton beams, with their high number of particles in a short pulse duration, are well-suited for creating isochorically heated matter in extreme conditions. Besides the manipulation of the proton beam parameters directly during the generation, the primary aim of this thesis was the capture, control and transport of laser-accelerated proton beams by a solenoidal magnetic field lense for further purpose. In a joint project proposal, the laser and plasma physics group of the Technische Universitat

Dosimetric response of united, commercially available CTA foils for 60Co gamma rays

International Nuclear Information System (INIS)

Peimel-Stuglik, Z.

2001-01-01

The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for 60 Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for 60 Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life. (author)

Development of an external beam nuclear microprobe on the Aglae facility of the Louvre museum

Energy Technology Data Exchange (ETDEWEB)

Calligaro, T.; Dran, J.-C. E-mail: dran@culture.fr; Ioannidou, E.; Moignard, B.; Pichon, L.; Salomon, J

2000-03-01

The external beam line of our facility has been recently equipped with the focusing system previously mounted on a classical nuclear microprobe. When using a 0.1 {mu}m thick Si{sub 3}N{sub 4} foil for the exit window and flowing helium on the sample under analysis, a beam spot as small as 10 {mu}m is attainable at a distance of 3 mm from the window. Elemental micromapping is performed by mechanical scanning. An electronic device has been designed which allows XY scanning by moving the sample under the beam by steps down to 0.1 {mu}m. Beam monitoring is carried out by means of the weak X-ray signal emitted by the exit foil and detected by a specially designed Si(Li) detector cooled by Peltier effect. The characteristics of external beams of protons and alpha particles are evaluated by means of resonance scanning and elemental mapping of a grid. An example of application is presented, dealing with elemental micro-mapping of inclusions in gemstones.

In-beam γ-ray spectroscopy of the neutron rich 39Si

International Nuclear Information System (INIS)

Sohler, D.; Dombradi, Zs.; Achouri, N.L.; Angelique, J.C.; Bastin, B.; Azaiez, F.; Baiborodin, D.; Borcea, R.

2009-01-01

Complete text of publication follows. In order to clarify the role of proton excitations across the Z = 14 subshell closure in neutron-rich Si isotopes, we investigated the structure of the 14 39 Si 25 isotope, having three neutron-hole configurations with respect to an N = 28 core. The excited states of 39 Si were studied by in-beam γ-ray spectroscopy trough fragmentation of radioactive beams. The experiment was performed at the GANIL facility in France. The radioactive beams were produced by the fragmentation of the stable 48 Ca beam of 60 MeV/u energy and 4μA intensity on a 12 C target in the SISSI device. The cocktail beam produced was impinged onto a 9 Be target. The nuclei produced in the secondary fragmentation reaction were selected and unambiguously identified by the SPEG spectrometer. In the performed experiment the 39 Si nuclei were obtained via 1p, 1p1n, 2p1n and 2p2n knockout reactions from the 40,41 P and 42,43 S secondary beams. To measure the γ rays emitted from the excited states, the secondary target was surrounded by the 4π 'Chateau de Crystal' array consisting of 74 BaF 2 scintillators. The γ-ray spectra were generated by gating event-by-event on the incoming secondary beam particles and the ejectiles after the secondary target. For the γ rays emitted by the fast moving fragments accurate Doppler correction was performed. From the obtained γ spectra of 39 Si displayed in Figure 1, two strong γ transitions at 163 and 397 keV as well as weaker ones at 303, 657, 906, 1143 and 1551 keV have been identified. γγ coincidences were obtained in 39 Si after having added all data from the various reaction channels giving rise to 39 Si. Analysing these data the 163 keV transition was found to be in coincidence with the 657, 1143 and 1551 keV ones, but not with the 397 keV transition. The two lines of the 303+397 keV doublet are in mutual coincidence, and one or both of them are found in coincidence with the 906 keV transition.

Quantitative assessment of the ion-beam irradiation induced direct damage of nucleic acid bases through FTIR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Huang, Qing, E-mail: huangq@ipp.ac.cn [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China); University of Science and Technology of China, Hefei 230029, Anhui (China); Su, Xi; Yao, Guohua; Lu, Yilin; Ke, Zhigang; Liu, Jinghua; Wu, Yuejin; Yu, Zengliang [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China)

2014-07-01

Energetic particles exist ubiquitously in nature, and when they hit DNA molecules in organisms, they may induce critical biological effects such as mutation. It is however still a challenge to measure directly and quantitatively the damage imposed by the energetic ions on target DNA molecules. In this work we attempted to employ Fourier transformation infrared (FTIR) spectroscopy to assess the ion-induced direct damage of four nucleic acid bases, namely, thymine (T), cytosine (C), guanine (G), and adenine (A), which are the building blocks of DNA molecules. The samples were prepared as thin films, irradiated by argon ion-beams at raised ion fluences, and in the meantime measured by FTIR spectroscopy for the damage in a quasi-in-situ manner. It was found that the low-energy ion-beam induced radiosensitivity of the four bases shows the sequence G > T > C > A, wherein the possible mechanism was also discussed.

Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging

International Nuclear Information System (INIS)

Bohlin, Alexis; Kliewer, Christopher J.

2014-01-01

We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N 2 , H 2 , CO 2 , O 2 , and CH 4 . Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location

Development, characterization and qualification of first GEM foils produced in India

Science.gov (United States)

Shah, Aashaq; Ahmed, Asar; Gola, Mohit; Sharma, Ram Krishna; Malhotra, Shivali; Kumar, Ashok; Naimuddin, Md.; Menon, Pradeep; Srinivasan, K.

2018-06-01

The increasing demand for Gas Electron Multiplier (GEM) foils has been driven by their application in many current and proposed high-energy physics experiments. Micropack, a Bengaluru-based company, has established and commercialized GEM foils for the first time in India. Micropack used the double-mask etching technique to successfully produce 10 cm × 10 cm GEM foil. In this paper, we report on the development as well as the geometrical and electrical properties of these foils, including the size uniformity of the holes and leakage current measurements. Our characterization studies show that the foils are of good quality and satisfy all the necessary quality control criteria.

Optimization of laser accelerated proton beams for possible applications

Energy Technology Data Exchange (ETDEWEB)

Al-Omari, Husam [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Collaboration: LIGHT-Collaboration

2013-07-01

Optimization of transported proton beams through a pulsed solenoid in the laser proton experiment LIGHT at GSI has been studied numerically. TraceWin, SRIM and ATIMA codes were employed for this study with an initial distribution generated by MATLAB program fitted to Phelix measured data. Two individual tools have been used to produce protons beam as a later beam source: an aperture located at the solenoid focal spot as energy selection tool; and a scattering foil at a suitable position in the beam path that smoothens the simulated radial energy imprint on the beam profile. The simulation results show that the proton energy spectrum is filtered by the aperture and the radial energy correlation is smoothened.

Depth profiling of residual activity of ^{237}U fragments as a range verification technique for ^{238}U primary ion beam

Directory of Open Access Journals (Sweden)

I. Strašík

2012-07-01

Full Text Available Experimental and simulation data concerning fragmentation of ^{238}U ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950  MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the ^{237}U isotope that has a range very close to the range of the primary ^{238}U ions. Therefore, the depth profiling of the ^{237}U isotope can be utilized for experimental verification of the ^{238}U primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

Apparatus and process for ultrasonic seam welding stainless steel foils

Science.gov (United States)

Leigh, Richard W.

1992-01-01

An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

Thermohydrodynamic analysis of airfoil bearing based on bump foil structure

Directory of Open Access Journals (Sweden)

S.Y. Maraiy

2016-09-01

Full Text Available The load carrying capacity of the gas foil bearing depends on the material properties and the configuration of the underlying bump strip’s structure. This paper presents three different cases for selecting the dimensions of the foil bearing to guarantee the highest possible load carrying capacity. It focuses on three main parameters that affect the compliance number; these parameters are the length of bump in θ direction, the pitch of bump foil, and the thickness of bump foil. It also studies the effect of changing these parameters on load carrying capacity according to both isothermal and thermohydrodynamic approaches.

LENA Conversion Foils Using Single-Layer Graphene, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Our key innovation will be the use of single-layer graphene as LENA conversion foils, with appropriate microgrids and nanogrids to support the foils. Phase I...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

High-quality graphene grown on polycrystalline PtRh{sub 20} alloy foils by low pressure chemical vapor deposition and its electrical transport properties

Energy Technology Data Exchange (ETDEWEB)

Yang, He; Shen, Chengmin, E-mail: cmshen@iphy.ac.cn; Tian, Yuan; Bao, Lihong; Chen, Peng; Yang, Rong; Yang, Tianzhong; Li, Junjie; Gu, Changzhi; Gao, Hong-Jun [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2016-02-08

High-quality continuous uniform monolayer graphene was grown on polycrystalline PtRh{sub 20} alloy foils by low pressure chemical vapor deposition. The morphology of graphene was investigated by Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. Analysis results confirm that high quality single-layer graphene was fabricated on PtRh{sub 20} foil at 1050 °C using a lower flux of methane under low pressure. Graphene films were transferred onto the SiO{sub 2}/Si substrate by the bubbling transfer method. The mobility of a test field effect transistor made of the graphene grown on PtRh{sub 20} was measured and reckoned at room temperature, showing that the carrier mobility was about 4000 cm{sup 2} V{sup −1} s{sup −1}. The results indicate that desired quality of single-layer graphene grown on PtRh{sub 20} foils can be obtained by tuning reaction conditions.

Transient oxidation of Al-deposited Fe-Cr-Al alloy foil

International Nuclear Information System (INIS)

Andoh, A.

1997-01-01

The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (θ-Al 2 O 3 , γ-Al 2 O 3 ). Scales consisting of θ-Al 2 O 3 and a small amount of α-Al 2 O 3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of θ-Al 2 O 3 and α-Al 2 O 3 grow rapidly on the Al-deposited foil. The transformation from θ-Al 2 O 3 to α-Al 2 O 3 is very fast, and the scales result in only α-Al 2 O 3 . In contrast, α-Al 2 O 3 scales containing a minor amount of FeAl 2 O 4 develop on the alloy foil. The growth rate of α-Al 2 O 3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

Compact Source of Electron Beam with Energy of 200 kEv and Average Power of 2 kW

CERN Document Server

Kazarezov, Ivan; Balakin, Vladimir E; Bryazgin, Alex; Bulatov, Alexandre; Glazkov, Ivan; Kokin, Evgeny; Krainov, Gennady; Kuznetsov, Gennady I; Molokoedov, Andrey; Tuvik, Alfred

2005-01-01

The paper describes a compact electron beam source with average electron energy of 200 keV. The source operates with pulse power up to 2 MW under average power not higher than 2 kW, pulsed beam current up to 10 A, pulse duration up to 2 mks, and repetition rate up to 5 kHz. The electron beam is extracted through aluminium-beryllium alloy foil. The pulse duration and repetition rate can be changed from control desk. High-voltage generator for the source with output voltage up to 220 kV is realized using the voltage-doubling circuit which consists of 30 sections. The insulation type - gas, SF6 under pressure of 8 atm. The cooling of the foil supporting tubes is provided by a water-alcohol mixture from an independent source. The beam output window dimensions are 180?75 mm, the energy spread in the beam +10/-30%, the source weight is 80 kg.

Chemistry, spectroscopy and isotope separation of zirconium and its compounds as revealed by laser diagnostics of laser produced metal beams

International Nuclear Information System (INIS)

Hackett, P.A.; Humphries, M.; Rayner, D.M.; Bourne, O.L.; Mitchell, A.

1986-01-01

Recent work from the author's laboratory on zirconium beams is reviewed. Zirconium metal beams have been produced by laser vaporization of solid zirconium targets coupled with supersonic expansion of helium gas. The resultant supersonic metal beam is shown to present an ideal environment for various spectroscopic techniques. The state distribution of zirconium atoms in the beam is obtained from low resolution laser induced fluorescence (LIF) studies. High resolution LIF studies give information on the hyperfine splitting in the ground state of the zirconium-91 isotope. Information on the hyperfine splitting in the excited state is obtained from quantum beat spectroscopy. Low resolution 2 color multiphoton ionization spectroscopy using a XeCl laser allows isotope separation of all isotopes of zirconium. These metal beams are highly reactive and can be used to produce novel chemical species. The results of two studies in which a reactant is added to the expansion gas are reported here. Zirconium oxide (ZrO), a molecule observed in the emission spectra of cool stars and in laboratory studies at high temperatures, is produced in a low temperature, collision free environment by adding small quantities of oxygen to the expansion gas. Zirconium fluoride (ZrF), a molecule previously unobserved, is produced by the addition of small quantities of CF/sub 4/

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

International Nuclear Information System (INIS)

Pacheco, Robin Montoya; Alexander, David John; Mccabe, Rodney James; Clarke, Kester Diederik; Scott, Jeffrey E.; Montalvo, Joel Dwayne; Papin, Pallas; Ansell, George S.

2017-01-01

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Al cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

Energy Technology Data Exchange (ETDEWEB)

Pacheco, Robin Montoya [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mccabe, Rodney James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester Diederik [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel Dwayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Papin, Pallas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ansell, George S. [Colorado School of Mines, Golden, CO (United States)

2017-01-20

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Al cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.

Recent progress in the development of a polarized proton target for reactions with radioactive ion beams

International Nuclear Information System (INIS)

Urrego-Blanco, J.P.; Bingham, C.R.; Brandt, B. van den; Galindo-Uribarri, A.; Gomez del Campo, J.; Hautle, P.; Konter, J.A.; Padilla-Rodal, E.; Schmelzbach, P.A.

2007-01-01

Polarization observables in nuclear reactions with stable beams have provided important information concerning structural properties of nuclei and reaction mechanisms and hold great promise in the context of exotic nuclei. We report on the development of a polarized target based on plastic foils of 20-200 μm thickness to be used with radioactive ion beams. The operation of such a target requires a moderately high magnetic field and very low temperatures. The plastic foil is placed inside a chamber attached to the mixing chamber of a 3 He- 4 He dilution refrigerator. Cooling of the foil is achieved via a superfluid film of 4 He that can be supplied through two capillaries. The chamber has two thin, highly uniform silicon nitride windows. An NMR coil is attached to the target to monitor the polarization. Results of a first test to characterize the target system, using the elastic scattering of 38 MeV 12 C by protons in inverse kinematics are presented

Process for producing molybdenum foil and collapsible tubing

Science.gov (United States)

Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

1971-01-01

Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

The feed-out process: Rayleigh-Taylor and Richtmyer-Meshkov instabilities in thin, laser-driven foils

Energy Technology Data Exchange (ETDEWEB)

Smitherman, D.P.

1998-04-01

Eight beams carrying a shaped pulse from the NOVA laser were focused into a hohlraum with a total energy of about 25 kJ. A planar foil was placed on the side of the hohlraum with perturbations facing away from the hohlraum. All perturbations were 4 {micro}m in amplitude and 50 {micro}m in wavelength. Three foils of pure aluminum were shot with thicknesses and pulse lengths respectively of 86 {micro}m and 2. 2 ns, 50 {micro}m and 4.5 ns, and 35 {micro}m with both 2.2 ns and 4. 5 ns pulses. Two composite foils constructed respectively of 32 and 84 {micro}m aluminum on the ablative side and 10 {micro}m beryllium on the cold surface were also shot using the 2.2 ns pulse. X-ray framing cameras recorded perturbation growth using both face- and side-on radiography. The LASNEX code was used to model the experiments. A shock wave interacted with the perturbation on the cold surface generating growth from a Richtmyer-Meshkov instability and a strong acoustic mode. The cold surface perturbation fed-out to the Rayleigh-Taylor unstable ablation surface, both by differential acceleration and interface coupling, where it grew. A density jump did not appear to have a large effect on feed-out from interface coupling. The Rayleigh-Taylor instability`s vortex pairs overtook and reversed the direction of flow of the Richtmyer-Meshkov vortices, resulting in the foil moving from a sinuous to a bubble and spike configuration. The Rayleigh-Taylor instability may have acted as an ablative instability on the hot surface, and as a classical instability on the cold surface, on which grew second and third order harmonics.

Status of electron temperature and density measurement with beam emission spectroscopy on thermal helium at TEXTOR

NARCIS (Netherlands)

Schmitz, O.; Beigman, I. L.; Vainshtein, L. A.; Schweer, B.; Kantor, M.; Pospieszczyk, A.; Xu, Y.; Krychowiak, M.; Lehnen, M.; Samm, U.; Unterberg, B.

2008-01-01

Beam emission spectroscopy on thermal helium is used at the TEXTOR tokamak as a reliable method to obtain radial profiles of electron temperature T-e(r, t) and electron density ne(r, t). In this paper the experimental realization of this method at TEXTOR and the status of the atomic physics employed

Facile preparation of dendritic Ag-Pd bimetallic nanostructures on the surface of Cu foil for application as a SERS-substrate

Energy Technology Data Exchange (ETDEWEB)

Yi Zao [College of Physics and Electronics, Central South University, Changsha 410083 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Tan Xiulan; Niu Gao [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Xu Xibin [College of Physics and Electronics, Central South University, Changsha 410083 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Li Xibo; Ye Xin; Luo Jiangshan; Luo Binchi; Wu Weidong; Tang Yongjian [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yi Yougen, E-mail: yougenyi@mail.csu.edu.cn [College of Physics and Electronics, Central South University, Changsha 410083 (China)

2012-05-01

Dendritic Ag-Pd bimetallic nanostructures have been synthesized on the surface of Cu foil via a multi-stage galvanic replacement reaction (MGRR) of Ag dendrites in a Na{sub 2}PdCl{sub 4} solution. After five stages of replacement reaction, one obtained structures with protruding Ag-Pd flakes; these will mature into many porous structures with a few Ag atoms that are left over dendrites. The dendritic Ag-Pd bimetallic nanostructures were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS). The morphology of the products strongly depended on the stage of galvanic replacement reaction and reaction temperature. The morphology and composition-dependent surface-enhanced Raman scattering (SERS) of the as-synthesized Ag-Pd bimetallic nanostructures were investigated. The effectiveness of these dendritic Ag-Pd bimetallic nanostructures on the surface of Cu foil as substrates toward SERS detection was evaluated by using rhodamine 6G (R6G) as a probe molecule. The results indicate that as-synthesized dendritic Ag-Pd bimetallic nanostructures are good candidates for SERS spectroscopy.

Preliminary research results for the generation and diagnostics of high power ion beams on FLASH II accelerator

International Nuclear Information System (INIS)

Yang Hailiang; Qiu Aici; Sun Jianfeng; He Xiaoping; Tang Junping; Wang Haiyang; Li Jingya; Ren Shuqing; Ouyang Xiaoping; Zhang Guoguang; Li Hongyu

2004-01-01

The preliminary experimental results of the generation and diagnostics of high-power ion beams on FLASH II accelerator are reported. The high-power ion beams presently are being produced in a pinched diode. The method for enhancing the ratio of ion to electron current is to increase the electron residing time by pinching the electron flow. Furthermore, electron beam pinching can be combined with electron reflexing to achieve ion beams with even higher efficiency and intensity. The anode plasma is generated by anode foil bombarded with electron and anode foil surface flashover. In recent experiments on FLASH II accelerator, ion beams have been produced with a current of 160 kA and an energy of 500 keV corresponding to an ion beam peak power of about 80 GW. The ion number and current of high power ion beams were determined by monitoring delayed radioactivity from nuclear reactions induced in a 12 C target by the proton beams. The prompt γ-rays and diode Bremsstrahlung X-rays were measured with a PIN semi-conductor detector and a plastic scintillator detector. The current density distribution of ion beam was measured with a biased ion collector array. The ion beams were also recorded with a CR-39 detector. (authors)

Simultaneous laser cutting and welding of metal foil to edge of a plate

Science.gov (United States)

Pernicka, J.C.; Benson, D.K.; Tracy, C.E.

1996-03-19

A method is described for welding an ultra-thin foil to the edge of a thicker sheet to form a vacuum insulation panel comprising the steps of providing an ultra-thin foil having a thickness less than 0.002, providing a top plate having an edge and a bottom plate having an edge, clamping the foil to the edge of the plate wherein the clamps act as heat sinks to distribute heat through the foil, providing a laser, moving the laser relative to the foil and the plate edges to form overlapping weld beads to weld the foil to the plate edges while simultaneously cutting the foil along the weld line formed by the overlapping beads. 7 figs.

Comparison between measurements of hyperfine structures of Pr II - lines investigated by collinear laser ion beam spectroscopy (CLIBS) ans saturation spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Akhtar, Nadeem; Anjum, Naveed [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria); Optics Labs, Nilore, Islamabad (Pakistan); Huehnermann, Harry [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria); Fachbereich Physik, Univ. Marburg/Lahn (Germany); Windholz, Laurentius [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria)

2011-07-01

Investigation of narrow hyperfine structures needs a reduction of the Doppler broadening of the investigated lines. Here we have used two methods: collinear laser spectroscopy (CLIBS) and laser saturation spectroscopy. In the first method, the Doppler width is reduced by accelerating Pr ions to a high velocity and excitation with a collinear laser beam, while in the second method ions with velocity group zero are selected by nonlinear saturation. In this work the hyperfine spectra of several Pr II lines were investigated using CLIBS. A line width of ca. 60 MHz was measured. The same lines were then investigated in a hollow cathode discharge lamp using intermodulated laser-induced fluorescence spectroscopy. Using this technique a spectral line width of about 200 MHz was achieved. In both methods, the excitation source is a ring dye laser operated with R6G. Using a fit program, magnetic dipole interaction constants A and the electric-quadrupole interaction constants B of the involved levels have been determined in both cases. We discuss advantages and disadvantages of both methods.

Decontamination with pasty pickling agents forming a strippable foil

International Nuclear Information System (INIS)

Weichselgartner, H.

1991-01-01

This paper describes the development of an in-situ decontamination procedure by applying onto the contaminated surface (in an one-step or multi-step process) pasty, chemically aggressive agents causing dilution and adsorption of the contaminant and then hardening to form a strippable foil. The use of such a foil will result in following advantages, with respect to usual techniques: - sensibly shorter operation duration resulting in lower personnel doses; - reduction of the arising secondary waste volume because there is no need for washing; the volume of the spent strippable foil is much smaller than currently used water volumes; - optimal conditioning of the radioactive waste due to its fixation in a solid (foil); - an accidental contamination in a controlled area can easily be fixed and covered avoiding its propagation

Measurements of laser generated soft X-ray emission from irradiated gold foils

Energy Technology Data Exchange (ETDEWEB)

Davis, J. S.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D. [University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109 (United States); Frank, Y.; Raicher, E.; Fraenkel, M. [Soreq Nuclear Research Center, Yavne (Israel)

2016-11-15

Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

Self-corrected sensors based on atomic absorption spectroscopy for atom flux measurements in molecular beam epitaxy

International Nuclear Information System (INIS)

Du, Y.; Liyu, A. V.; Droubay, T. C.; Chambers, S. A.; Li, G.

2014-01-01

A high sensitivity atom flux sensor based on atomic absorption spectroscopy has been designed and implemented to control electron beam evaporators and effusion cells in a molecular beam epitaxy system. Using a high-resolution spectrometer and a two-dimensional charge coupled device detector in a double-beam configuration, we employ either a non-resonant line or a resonant line with low cross section from the same hollow cathode lamp as the reference for nearly perfect background correction and baseline drift removal. This setup also significantly shortens the warm-up time needed compared to other sensor technologies and drastically reduces the noise coming from the surrounding environment. In addition, the high-resolution spectrometer allows the most sensitive resonant line to be isolated and used to provide excellent signal-to-noise ratio

Preliminary studies on a variable energy positron annihilation lifetime spectroscopy system

International Nuclear Information System (INIS)

Kwan, P.Y.; Cheung, C.K.; Beling, C.D.; Fung, S.

2006-01-01

There are many advantages in being able to perform positron annihilation lifetime spectroscopy (PALS) using a variable energy positron beam, the most obvious being the easy identification of different defect types at different depths. The difficulty in conducting variable energy (VE) PALS studies lies in the fact that a 'start' signal is required to signal the entry of the positron into the target. Two methods have been used to overcome this problem, namely the bunching technique, which employs radio frequency (RF) cavities and choppers, and secondly the use of secondary electrons emitted from the target. The latter technique is in terms of experimental complexity much simpler, but has in the past suffered from poor time resolution (typically ∼500 ps). In this work, we present a series of computer simulations of a design based on the secondary electron emission from thin C-foils in transmission mode which shows that significant improvements in time resolution can be made with resolutions ∼200 ps being in principle possible

Investigation of electrically exploded large area foil for current switching

International Nuclear Information System (INIS)

Chernyshev, V.K.; Boyko, A.M.; Kostyukov, V.N.; Kuzyaev, A.I.; Kulagin, A.A.; Mamyshev, V.I.; Mezhevov, A.B.; Nechaev, A.I.; Petrukhin, A.A.; Protasov, M.S.; Shevtsov, V.I.; Yakubov, V.B.

1990-01-01

The possibility of microsecond ∼40 MA current switching from EMG into a quasiconstant inductive load by an electrically exploded foil is investigated. The copper foil of large area, S ∼ 10 4 cm 2 , was placed between thin-walled insulators into a coaxial transmission line (TL). This paper shows a conceptual device scheme. To feed a foil opening switch (FOS), a disc explosive magnetic generator (DEMG) with 20 μs current rise time was employed. An inductive coaxial load was connected to a FOS at a moment, that was close to the foil vaporization start by means of an axisymmetric explosive current commutator (ECC)

A new method for making long-lived carbon stripper foils

International Nuclear Information System (INIS)

Sugai, Isao; Ishii, Sabro; Hattori, Toshiyuki; Muto, Hideshi; Takahashi, Yohsuke; Kato, Hajime; Yamazaki, Kuniaki.

1989-01-01

We have developed a new method for preparation of long-lived carbon stripper foils, based on the modification of our 'controlled DC arc-discharge method'. The carbon foils consist of multi-layers, and carbon particles in each layer are emitted from the electrode in AC arc-discharge or from the cathode electrode in DC arc-discharge. The lifetimes of the carbon foils made by the new method are equal to or longer than those prepared by the controlled DC arc-discharge method. The new method is simple and powerful to make long-lived carbon stripper foils with higher reliability and reproducibility than the previous method. (author)

Examination of the picture properties of luminescence memory foils

International Nuclear Information System (INIS)

Ewert, U.; Heine, S.; Nockemann, C.; Stade, J.; Tillack, G.R.; Wessel, H.; Zscherpel, U.; Mattis, A.

1995-01-01

Luminescence memory foils are a new medium for radiography without films. They are known by the name of image plates or digital memory foils. The suitability of such systems for industrial radiography is examined. (orig.) [de

A state enumeration of the foil knot

OpenAIRE

Ramaharo, Franck; Rakotondrajao, Fanja

2017-01-01

We split the crossings of the foil knot and enumerate the resulting states with a generating polynomial. Unexpectedly, the number of such states which consist of two components are given by the lazy caterer's sequence. This sequence describes the maximum number of planar regions that is obtained with a given number of straight lines. We then establish a bijection between this partition of the plane and the concerned foil splits sequence.

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming.

Science.gov (United States)

Wang, Xiao; Li, Cong; Ma, Youjuan; Shen, Zongbao; Sun, Xianqing; Sha, Chaofei; Gao, Shuai; Li, Liyin; Liu, Huixia

2016-07-13

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Electron beam exposure mechanisms in hydrogen silsesquioxane investigated by vibrational spectroscopy and in-situ electron beam induced desorption

Energy Technology Data Exchange (ETDEWEB)

Olynick, D.L.; Cord, B.; Schipotinin, A.; Ogletree, D.F.; Schuck, P.J.

2009-11-13

Hydrogen Silsesquioxane (HSQ) is used as a high-resolution resist with resolution down below 10nm half-pitch. This material or materials with related functionalities could have widespread impact in nanolithography and nanoscience applications if the exposure mechanism was understood and instabilities controlled. Here we have directly investigated the exposure mechanism using vibrational spectroscopy (both Raman and Fourier transform Infrared) and electron beam desorption spectrocscopy (EBDS). In the non-networked HSQ system, silicon atoms sit at the corners of a cubic structure. Each silicon is bonded to a hydrogen atom and bridges 3 oxygen atoms (formula: HSiO3/2). For the first time, we have shown, via changes in the Si-H2 peak at ~;;2200 cm -1 in the Raman spectra and the release of SiHx products in EBID, that electron-bam exposed materials crosslinks via a redistribution reaction. In addition, we observe the release of significantly more H2 than SiH2 during EBID, which is indicative of additional reaction mechanisms. Additionally, we compare the behavior of HSQ in response to both thermal and electron-beam induced reactions.

Selecting foils for identification lineups: matching suspects or descriptions?

Science.gov (United States)

Tunnicliff, J L; Clark, S E

2000-04-01

Two experiments directly compare two methods of selecting foils for identification lineups. The suspect-matched method selects foils based on their match to the suspect, whereas the description-matched method selects foils based on their match to the witness's description of the perpetrator. Theoretical analyses and previous results predict an advantage for description-matched lineups both in terms of correctly identifying the perpetrator and minimizing false identification of innocent suspects. The advantage for description-matched lineups should be particularly pronounced if the foils selected in suspect-matched lineups are too similar to the suspect. In Experiment 1, the lineups were created by trained police officers, and in Experiment 2, the lineups were constructed by undergraduate college students. The results of both experiments showed higher suspect-to-foil similarity for suspect-matched lineups than for description-matched lineups. However, neither experiment showed a difference in correct or false identification rates. Both experiments did, however, show that there may be an advantage for suspect-matched lineups in terms of no-pick and rejection responses. From these results, the endorsement of one method over the other seems premature.

Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging

Energy Technology Data Exchange (ETDEWEB)

Bohlin, Alexis; Kliewer, Christopher J., E-mail: cjkliew@sandia.gov [Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550 (United States)

2014-01-20

We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N{sub 2}, H{sub 2}, CO{sub 2}, O{sub 2}, and CH{sub 4}. Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location.

UV Ink-Jet printability and durability of stone and foil

Directory of Open Access Journals (Sweden)

Tadeja Muck

2014-07-01

Full Text Available he use of ultraviolet (UV printing technology has impacted printing industry in last years due to its applicability on many different »absorptive« as well as »non-absorptive« printing materials. The printability of building materials and recycled foils is relatively unknown. For primary building materials like stones, functionality can be explored with the use of UV printing technology; increased visual, informative effect or even “creative printing” of buildings. Also several aspects of recycled foils reusability as a printing material could be find (printed packaging material or also like secondary building materials. In the present study, printability of the stone and recycled foil and durability of UV prints was explored by means of macroscopically and microscopically characterization. Results indicate that higher print quality can be achieved on polished stone and on coated foil, which surfaces have higher smoothness. Durability of UV prints at freezing is higher at unpolished stone and coated foil that is at materials with the higher surface energy.

Composite Design for a Foiling Optimist Dinghy

Directory of Open Access Journals (Sweden)

Carolyn Oddy

2018-02-01

Full Text Available In April 2017, a foiling Optimist dingy designed entirely by students, was successfully tested under standard sailing conditions in the waters outside Gothenburg. In order to achieve take of wind speeds as low as 6 m/s, a stiff and lightweight design of the dinghy and its foiling components was necessary. There have been few successful attempts to make an Optimist foil in a stable manner, as such there were no standards or recommendations available for the design. Therefore, a simulation driven structural design methodology for hydrofoils, centreboards, centreboard-to-hull connections, and necessary hull reinforcements using sandwich structures was adopted. The proposed design was then manufactured, allowing for a significantly stiffer hull and a 20% decrease in weight over a conventional Optimist. Excluding the rig and sail, the final weight came to 27 kg.

Innovative energy efficient low-voltage electron beam emitters

International Nuclear Information System (INIS)

Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

2002-01-01

Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates

Innovative energy efficient low-voltage electron beam emitters

Science.gov (United States)

Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

2002-03-01

Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates.

Dynamic environmental control mechanisms for pneumatic foil constructions

Science.gov (United States)

Flor, Jan-Frederik; Wu, Yupeng; Beccarelli, Paolo; Chilton, John

2017-11-01

Membrane and foil structures have become over the last decades an attractive alternative to conventional materials and building systems with increasing implementation in different typologies and scale. The development of transparent, light, flexible and resistant materials like Ethylene Tetrafluoroethylene (ETFE) has triggered a rethinking of the building envelope in the building industry towards lightweight systems. ETFE foil cushions have proven to fulfil the design requirements in terms of structural efficiency and aesthetic values. But the strategies to satisfy increasing demands of energy efficiency and comfort conditions are still under development. The prediction and manipulation of the thermo-optical behaviour of ETFE foil cushion structures currently remain as one of the main challenges for designers and manufacturers. This paper reviews ongoing research regarding the control of the thermo-optical performance of ETFE cushion structures and highlights challenges and possible improvements. An overview of different dynamic and responsive environmental control mechanisms for multilayer foil constructions is provided and the state of the art in building application outlined by the discussion of case studies.

Material Properties of Laser-Welded Thin Silicon Foils

Directory of Open Access Journals (Sweden)

M. T. Hessmann

2013-01-01

Full Text Available An extended monocrystalline silicon base foil offers a great opportunity to combine low-cost production with high efficiency silicon solar cells on a large scale. By overcoming the area restriction of ingot-based monocrystalline silicon wafer production, costs could be decreased to thin film solar cell range. The extended monocrystalline silicon base foil consists of several individual thin silicon wafers which are welded together. A comparison of three different approaches to weld 50 μm thin silicon foils is investigated here: (1 laser spot welding with low constant feed speed, (2 laser line welding, and (3 keyhole welding. Cross-sections are prepared and analyzed by electron backscatter diffraction (EBSD to reveal changes in the crystal structure at the welding side after laser irradiation. The treatment leads to the appearance of new grains and boundaries. The induced internal stress, using the three different laser welding processes, was investigated by micro-Raman analysis. We conclude that the keyhole welding process is the most favorable to produce thin silicon foils.

An Experimental Study on Micro Clinching of Metal Foils with Cutting by Laser Shock Forming

Directory of Open Access Journals (Sweden)

Xiao Wang

2016-07-01

Full Text Available This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Thin-foil phase transformations of tetragonal ZrO/sub 2/ in a ZrO/sub 2/-8 wt% Y/sub 2/O/sub 3/ alloy

International Nuclear Information System (INIS)

Bestgen, H.; Chaim, R.; Heuer, A.H.

1988-01-01

Tetragonal zirconia (t-ZrO/sub 2/) grains in an annealed ZrO/sub 2/-8 wt% Y/sub 2/O/sub 3/ alloy transformed to orthorhombic (o) or mono-clinic (m) symmetry by stresses induced by localized electron beam heating in the transmission electron microscope. Different transformation mechanisms were observed, depending on foil thickness and orientation of individual grains. In thicker grains (≥150 nm), the transformation proceeded by a burst-like growth of m laths, and this is believed to approximate bulk behavior. In thinner grains near the edge of the foil, usually those with a [100]/sub t/ orientation perpendicular to the thin-foil surface, continuous growth of an o or m phase with an antiphase-boundary-containing microstructure was observed. The o phase is believed to be a high-pressure polymorph of ZrO/sub 2/, which forms (paradoxically) as a thin-foil artifact because it is less dense than t-ZrO/sub 2/, but more dense than m-ZrO/sub 2/. In some very thin grains, the t → m transformation was thermoelastic. Furthermore, a mottled structure often occurred just before the t → m or t → o transformation, which is attributed to surface transformation. Aside from the lath formation, the observed transformation modes are a result of the reduced constraints in thin foils

Electron microscopy and auger spectroscopy study of the wetting of the grain boundaries in the systems Mo-Pb, Mo-Sn, Mo-Ni and Ni-Pb; Etude par microscopie electronique et spectroscopie auger du mouillage des joints de grains dans les systemes Mo-Pb, Mo-Sn, Mo-Ni et Ni-Pb

Energy Technology Data Exchange (ETDEWEB)

Charai, A. [Faculte des Sciences et Techniques de Saint Jerome, Lab. TECSEN, UMR 6122 du CNRS, 13 - Marseille (France); Kutcherinenko, I.; Priester, L. [Paris-11 Univ., ISMA, 91 - Orsay (France); Penisson, J.M. [CEA Grenoble, Dept. de Recherche Fondamentale sur la Matiere Condensee, DRFMC-SP2M, 38 (France); Pontikis, V. [Centre National de la Recherche Scientifique (CNRS), Centre d' Etudes de Chimie Metallurgique, 94 - Vitry-sur-Seine (France); Wolski, K. [Ecole NationaleSuperieure des Mines de Saint Etienne, Centre SMS/MPI, URA 1884 du CNRS, 42 - Saint Etienne (France); Vystavel, T. [Academy of Sciences of Czech Republic, Institute of Physics, Praha (Czech Republic)

2002-09-01

Understanding the mechanism of the intergranular penetration of a liquid phase into a metallic solid is an important problem. The structural and chemical characterization of nano-metric films at grain boundaries is now possible by using high resolution electron microscopy associated with X-ray micro-analysis, electron energy loss spectroscopy and Auger spectroscopy. In order to study this problem, two different classes of model materials were selected according to their crystallographic structure: a bcc metal (molybdenum) and an fcc one (nickel). The wetting element was either lead or tin or nickel. In a first approach, the metallic matrix was polycrystalline. The conditions in which the liquid phase penetrates into the grain boundaries were studied by using special preparation and observation techniques. In particular, the use of a Focused Ion Beam microscope (FIB) allowed the preparation of thin foils located very precisely inside the matrix as well as multi-scale observations. These specimens were further observed in electron microscopy with a very high resolution. (authors)

PENGEMBANGAN FOIL NACA SERI 2412 SEBAGAI SISTEM PENYELAMAN MODEL KAPAL SELAM

Directory of Open Access Journals (Sweden)

Ali Munazid

2015-06-01

Full Text Available Bentuk  foil menghasilkan gaya angkat (lift force ketika foil dilewati oleh aliran fluida  karena adanya pengaruh interaksi antara aliran fluida dengan permukaan foil yang mengakibatkan tekanan permukaan atas lebih kecil dari permukaan bawah. Bagaimana mengaplikasikan teori foil pada hydroplane kapal selam sebagai  system penyelaman, dengan membalik foil maka lift force tersebut menjadi gaya ke bawah, dengan demikian memungkinkan kapal selam dapat menyelam, melayang dan bermanouver di bawah air, seperti halnya gerak pesawat terbang yang terbang dan melayang dengan menggunakan sayap. Dilakukan penelitian dan pengamatan terhadap kemampuan penyelaman (diving plan dari foil NACA seri 2412 pada model kapal selam, dengan mencari nilai Cl (coefisien lift di Laboratorium, serta mendesain bentuk badan kapal selam dan analisa gaya-gaya yang bekerja pada model kapal selam, jumlah gaya-gaya yang bekerja keatas lebih rendah dari gaya-gaya ke bawah maka kapal selam mampu menyelam. Penerapan Hydroplane sebagai diving plane dapat diterapkan, kemampuan penyelaman dipengaruhi oleh sudut flip  Hydroplane dan kecepatan model, semakin besar kecepatan dan sudut flip maka semakin besar kedalaman penyelaman yang dapat dilakukan.

Gold removal rate by ion sputtering as a function of ion-beam voltage and raster size using Auger electron spectroscopy. Final report

International Nuclear Information System (INIS)

Boehning, C.W.

1983-01-01

Gold removal rate was measured as a function of ion beam voltage and raster size using Auger electron spectroscopy (AES). Three different gold thicknesses were developed as standards. Two sputter rate calibration curves were generated by which gold sputter rate could be determined for variations in ion beam voltage or raster size

Recent progress in particle acceleration from the interaction between thin-foil targets and J-KAREN laser pulses

Science.gov (United States)

Nishiuchi, Mamiko; Pirozhkov, Alexander S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, Timur Zh; Tanimoto, Tsuyoshi; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; Kanasaki, Masato; Kiriyama, Hiromitsu; Shimomura, Takuya; Tanoue, Manabu; Nakai, Yoshiki; Sasao, Hajime; Sasao, Fumitaka; Kanazawa, Shuhei; Kondo, Shuji; Matsumoto, Yoshihiro; Sakai, Seiji; Brenner, Ceri; Neely, David; Bulanov, Sergei V.; Kondo, Kiminori

2012-07-01

From the interaction between the high-contrast (˜more than 1010) 130 TW Ti:sapphire laser pulse and Stainless Steel-2.5 um-thick tape target, proton beam with energies up to 23 MeV with the conversion efficiency of ˜1% is obtained. After plasma mirror installation for contrast improvement, from the interaction between the 30 TW laser pulse and thin-foil target installed on the target holder with the hole whose shape is associated with the design of the well-known Wehnelt electrode of electron-gun, a 7 MeV intense proton beam is controlled dynamically and energy selected by the self-induced quasi-static electric field on the target holder. From the highly divergent beam having continuous spectrum, which are the typical features of the laser-driven proton beams from the interactions between the short-pulse laser and solid target, the spatial distribution of 7 MeV proton bunch is well manipulated to be focused to an small spots with an angular distribution of ˜10 mrad. The number of protons included in the bunch is >106.

Positron Beam Characteristics at NEPOMUC Upgrade

Science.gov (United States)

Hugenschmidt, C.; Ceeh, H.; Gigl, T.; Lippert, F.; Piochacz, C.; Reiner, M.; Schreckenbach, K.; Vohburger, S.; Weber, J.; Zimnik, S.

2014-04-01

In 2012, the new neutron induced positron source NEPOMUC upgrade was put into operation at FRMII. Major changes have been made to the source which consists of a neutron-γ-converter out of Cd and a Pt foil structure for electron positron pair production and positron moderation. The new design leads to an improvement of both intensity and brightness of the mono-energetic positron beam. In addition, the application of highly enriched 113Cd as neutron-γ-converter extends the lifetime of the positron source to 25 years. A new switching and remoderation device has been installed in order to allow toggling from the high-intensity primary beam to a brightness enhanced remoderated positron beam. At present, an intensity of more than 109 moderated positrons per second is achieved at NEPOMUC upgrade. The main characteristics are presented which comprise positron yield and beam profile of both the primary and the remoderated positron beam.

Simple emittance measurement of H- beams from a large plasma source

International Nuclear Information System (INIS)

Guharay, S.K.; Tsumori, K.; Hamabe, M.; Takeiri, Y.; Kaneko, O.; Kuroda, T.

1996-03-01

An emittance meter is developed using pepper-pot method. Kapton foils are used to detect intensity distributions of small beamlets at the 'image' plane of the pepper-pot. Emittance of H - beams from a large plasma source for the neutral beam injector of the Large Helical Device (LHD) has been measured. The normalized emittance (95%) of a 6 mA H - beam with emission current density of about 10 mA/cm 2 is ∼0.59 mm mrad. The present system is very simple, and it eliminates many complexities of the existing schemes. (author)

Numerical study of neutron beam divergence in a beam-fusion scenario employing laser driven ions

Science.gov (United States)

Alejo, A.; Green, A.; Ahmed, H.; Robinson, A. P. L.; Cerchez, M.; Clarke, R.; Doria, D.; Dorkings, S.; Fernandez, J.; McKenna, P.; Mirfayzi, S. R.; Naughton, K.; Neely, D.; Norreys, P.; Peth, C.; Powell, H.; Ruiz, J. A.; Swain, J.; Willi, O.; Borghesi, M.; Kar, S.

2016-09-01

The most established route to create a laser-based neutron source is by employing laser accelerated, low atomic-number ions in fusion reactions. In addition to the high reaction cross-sections at moderate energies of the projectile ions, the anisotropy in neutron emission is another important feature of beam-fusion reactions. Using a simple numerical model based on neutron generation in a pitcher-catcher scenario, anisotropy in neutron emission was studied for the deuterium-deuterium fusion reaction. Simulation results are consistent with the narrow-divergence (∼ 70 ° full width at half maximum) neutron beam recently served in an experiment employing multi-MeV deuteron beams of narrow divergence (up to 30° FWHM, depending on the ion energy) accelerated by a sub-petawatt laser pulse from thin deuterated plastic foils via the Target Normal Sheath Acceleration mechanism. By varying the input ion beam parameters, simulations show that a further improvement in the neutron beam directionality (i.e. reduction in the beam divergence) can be obtained by increasing the projectile ion beam temperature and cut-off energy, as expected from interactions employing higher power lasers at upcoming facilities.

Isomer 103Rh excitation in the electron beam

International Nuclear Information System (INIS)

Alpatov, V.G.; Berezkin, V.V.; Vysotskij, S.A.

1993-01-01

Rhodium foil targets were irradiated by a beam of electrons from a linear accelerator containing a minor impurity of bremsstrahlung. X-ray and γ-quanta from decay of 103m Rh isomer states were detected. The ratio of isomer cross section activation by bremsstrahlung, formed in the target, and electrons, equals 89. 7 refs.; 3 figs.; 2 tabs

Formation of virtual cathodes and microwave generation in relativistic electron beams

International Nuclear Information System (INIS)

Kwan, T.J.T.; Thode, L.E.

1984-01-01

Simulation of the generation of a relativistic electron beam in a foil diode configuration and the subsequent intense microwave generation resulting from the formation of the virtual cathode is presented. The oscillating virtual cathode and the trapped beam electrons between the real and the virtual cathodes were found to generate microwaves at two distinct frequencies. Generation of high-power microwaves with about 10% efficiency might reasonably be expected from such a virtual-cathode configuration

Design of large size segmented GEM foils and Drift PCB for CBM MUCH

International Nuclear Information System (INIS)

Saini, J.; Dubey, A.K.; Chattopadhyay, S.

2016-01-01

Triple GEM (Gas Electron Multiplier), sector shaped detectors will be used for Muon tracking in the Compressed Baryonic Matter (CBM) experiment at Anti-proton Ion Research (FAIR) facility at Darmstadt, Germany. The sizes of the detectors modules in the Muon Chambers (MUCH) are of the order of 1 meter with active area of about 75cms. Progressive pad geometry is chosen for the readout from these detectors. In construction of these chambers, three GEM foils are stacked on top of each other in a 3/2/2/2 gap configuration. The GEM foils are double layered copper clad 50μm thin Kapton foil. Each GEM foil has millions of holes on it. Foils of large surface area are prone to damages due to discharges owing to the high capacitance of the foil. Hence, these foils have their top surfaces divided into segments of about 100 sq.cm. Further segmentation may be necessary when there are high rate requirements, as in the case of CBM. For the GEM foils of CBM MUCH, a 24 segment layout has been adopted. Short-circuit in any of the GEM-holes will make entire foil un-usable. To reduce such occurrences, segment to segment isolation using opto-coupler in series with the GEM-foil segments has been introduced. Hence, a novel design for GEM chamber drift-PCB and foils has been made. In this scheme, each segment is powered and controlled individually. At the same time, the design takes into account, the space constraints, not only in x-y plane, but also in the z, due to compact assembly of MUCH detector layers

Effects of stern-foil submerged elevation on the lift and drag of a hydrofoil craft

Science.gov (United States)

Suastika, K.; Apriansyah

2018-03-01

Effects of the stern-foil submerged elevation on the lift and drag of a hydrofoil craft are studied by using computational fluid dynamics (CFD) and by considering three alternative stern-foil submerged elevations. The submerged elevation of the front foil is kept constant in all the alternatives. From among the alternatives, the deepest stern-foil placement results in the highest stern-foil lift with the highest foil’s lift-to-drag ratio. However, considering the lift-to-drag ratio of the whole foil-strut-hull system, the shallowest stern-foil placement results in the highest lift-to-drag ratio. The struts and the foil’s submerged elevation significantly affects the drag of the whole foil-strut-hull system.

Scattering of 14. 0 MeV electrons. Fundamental study of the scattering foil. [Angular distribution, 14. 0 MeV, gaussian distribution

Energy Technology Data Exchange (ETDEWEB)

Takei, C [Kyushu Univ., Fukuoka (Japan). School of Health Sciences; Yoshimoto, S

1977-07-01

The angular distribution of 14.0 MeV electrons scattered by thin Al and Pb foils has been measured, since the beam flatness is important on the high energy electron therapy. These distributions measured were almost completely Gaussian. The root mean square scattering angles were obtained and were compared with the theories of Williams and Rossi. In our experiments the root mean square scattering angles obtained have the experimental errors of about 4% and 1% for 5/sup 0/ and 10/sup 0/, respectively. For Al foils of 0.5 mm to 3.0 mm the experimental values of the root mean square scattering angles are 5.49/sup 0/ and 12.43/sup 0/ and are 30% to 10% higher than those predicted by Williams. Although, these values are 4% to 9% lower than those calculated from the theory of Rossi. The root mean square scattering angles obtained with Pb foils of 0.1 mm to 0.3 mm are 9.62/sup 0/ to 18.05/sup 0/ and are 14% to 18% higher than Williams, and are 14% to 7% lower than those theoretically calculated by Rossi.

Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

International Nuclear Information System (INIS)

Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

1985-01-01

These measurements were undertaken as a consequence of our failure early this year to accelerate Au +46 ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV 197 Au +17 from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV 197 Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs

Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

Energy Technology Data Exchange (ETDEWEB)

Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

1985-01-01

These measurements were undertaken as a consequence of our failure early this year to accelerate Au/sup +46/ ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV /sup 197/Au/sup +17/ from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV /sup 197/Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs.

Dynamics of laser mass-limited foil interaction at ultra-high laser intensities

Energy Technology Data Exchange (ETDEWEB)

Yu, T. P., E-mail: tongpu@nudt.edu.cn [College of Science, National University of Defense Technology, Changsha 410073 (China); State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073 (China); Sheng, Z. M. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, Y.; Zhuo, H. B.; Ma, Y. Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Pukhov, A. [Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf (Germany)

2014-05-15

By using three-dimensional particle-in-cell simulations with synchrotron radiation damping incorporated, dynamics of ultra-intense laser driven mass-limited foils is presented. When a circularly polarized laser pulse with a peak intensity of ∼10{sup 22} W/cm{sup 2} irradiates a mass-limited nanofoil, electrons are pushed forward collectively and a strong charge separation field forms which acts as a “light sail” and accelerates the protons. When the laser wing parts overtake the foil from the foil boundaries, electrons do a betatron-like oscillation around the center proton bunch. Under some conditions, betatron-like resonance takes place, resulting in energetic circulating electrons. Finally, bright femto-second x rays are emitted in a small cone. It is also shown that the radiation damping does not alter the foil dynamics radically at considered laser intensities. The effects of the transverse foil size and laser polarization on x-ray emission and foil dynamics are also discussed.

Control of Oscillating Foil for Propulsion of Biorobotic Autonomous Underwater Vehicle (AUV

Directory of Open Access Journals (Sweden)

S. N. Singh

2005-01-01

Full Text Available The paper treats the question of control of a laterally and rotationally oscillating hydrofoil for the propulsion of biologically inspired robotic (biorobotic autonomous underwater vehicles (BAUVs. Sinusoidal oscillations of foils produce maneuvering and propulsive forces. The design is based on the internal model principle. Two springs are used to transmit forces from the actuators to the foil. Oscillating fins produce periodic forces, which can be used for fish-like propulsion and control of autonomous underwater vehicles (AUVs. The equations of motion of the foil include hydrodynamic lift and moment based on linear, unsteady, aerodynamic theory. A control law is derived for the lateral and rotational sinusoidal oscillation of the foil. In the closed-loop system, the lateral displacement and the rotational angle of the foil asymptotically follow sinusoidal trajectories of distinct frequencies and amplitudes independently. Simulation results are presented to show the trajectory tracking performance of the foil for different freestream velocities and sinusoidal command trajectories.

Monolithic exploding foil initiator

Science.gov (United States)

Welle, Eric J; Vianco, Paul T; Headley, Paul S; Jarrell, Jason A; Garrity, J. Emmett; Shelton, Keegan P; Marley, Stephen K

2012-10-23

A monolithic exploding foil initiator (EFI) or slapper detonator and the method for making the monolithic EFI wherein the exploding bridge and the dielectric from which the flyer will be generated are integrated directly onto the header. In some embodiments, the barrel is directly integrated directly onto the header.

Generation of electrical defects in ion beam assisted deposition of Cu(In,Ga)Se2 thin film solar cells

International Nuclear Information System (INIS)

Zachmann, H.; Puttnins, S.; Daume, F.; Rahm, A.; Otte, K.

2011-01-01

Thin films of Cu(In,Ga)Se 2 (CIGS) absorber layers for thin film solar cells have been manufactured on polyimide foil in a low temperature, ion beam assisted co-evaporation process. In the present work a set of CIGS thin films was produced with varying selenium ion energy. Solar cell devices have been manufactured from the films and characterized via admittance spectroscopy and capacitance-voltage profiling to determine the influence of the selenium ion energy on the electric parameters of the solar cells. It is shown that the impact of energetic selenium ions in the CIGS deposition process leads to a change in the activation energy and defect density and also in the spatial distribution of electrically active defects. For the interpretation of the results two defect models are taken into account.

Precessed electron beam electron energy loss spectroscopy of graphene: Beyond channelling effects

Energy Technology Data Exchange (ETDEWEB)

Yedra, Ll.; Estradé, S., E-mail: sestrade@ub.edu [LENS, MIND-IN2UB, Departament d' Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); TEM-MAT, CCiT, Universitat de Barcelona, Solé i Sabarís 1, 08028 Barcelona (Spain); Torruella, P.; Eljarrat, A.; Peiró, F. [LENS, MIND-IN2UB, Departament d' Electrònica, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Darbal, A. D. [AppFive LLC, 1095 W Rio Salado Pkway, Suite 110, Tempe, Arizona 85281 (United States); Weiss, J. K. [AppFive LLC, 1095 W Rio Salado Pkway, Suite 110, Tempe, Arizona 85281 (United States); NanoMEGAS SPRL, Blvd. Edmond Machtens 79, B-1080 Brussels (Belgium)

2014-08-04

The effects of beam precession on the Electron Energy Loss Spectroscopy (EELS) signal of the carbon K edge in a 2 monolayer graphene sheet are studied. In a previous work, we demonstrated the use of precession to compensate for the channeling-induced reduction of EELS signal when in zone axis. In the case of graphene, no enhancement of EELS signal is found in the usual experimental conditions, as graphene is not thick enough to present channeling effects. Interestingly, though it is found that precession makes it possible to increase the collection angle, and, thus, the overall signal, without a loss of signal-to-background ratio.

Preparation of self-supporting metallic foils of nickel isotopes

International Nuclear Information System (INIS)

Sugai, Isao.

1975-01-01

This is the fourth report on the practical methods of target preparation for use in low energy nuclear experiments following the previous one (INS-J-150). An electroplating method has been developed as a dependable and reproducible technique for making self-supporting metallic foils of nickel in the thickness range of 0.5 to 10 mg/cm 2 . The procedures minimized the necessary amount of material so that nickel isotopes could be processed economically. Impurity contamination of the nickel foils during the electroplating process was less than 500 ppm, and the thickness variation in each foil was less than 3% of the central thickness. (auth.)