WorldWideScience

Sample records for measured heterogeneous ion

  1. Scanning ion micro-beam techniques for measuring diffusion in heterogeneous materials

    International Nuclear Information System (INIS)

    Jenneson, P.M.; Clough, A.S.

    1998-01-01

    A raster scanning MeV micro-beam of 1 H + or 3 He + ions was used to study the diffusion of small molecules in heterogeneous materials. The location of elemental contaminants (heavier than Lithium) in polymer insulated cables was studied with 1 H micro-Particle Induced X-ray Emission (μPIXE). Concentration profiles of a deuterated molecule in a hair fibre were determined with 3 He micro-Nuclear Reaction Analysis (μNRA). Chlorine and heavy water (D 2 0) diffusion into cement pastes were profiled using a combination of 3 He μPIXE and μNRA. (authors)

  2. Ion Microprobe Measurements of Comet Dust and Implications for Models of Oxygen Isotope Heterogeneity in the Solar System

    Science.gov (United States)

    Snead, C. J.; McKeegan, K. D.; Keller, L. P.; Messenger, S.

    2017-01-01

    ]. These studies have been largely focused on the coarse-grained terminal particles extracted from aerogel collectors; hypervelocity capture into aerogel resulted in fine-grained material that was melted and intimately mixed with the SiO2 capture medium. Hypervelocity impacts into Al foils surrounding the aerogel tiles produced impact craters that captured material from the impactor without significant oxygen contamination, allowing for analysis of both the coarse and fine-grained components of the Wild 2 dust. To date, no particles with definitive hydrated mineralogy have been observed in Stardust samples, though this may be a result of alteration due to hypervelocity capture. High-carbon hydrated CS-IDPs have been suggested as resulting from the aqueous alteration of CP-IDPs [7], and may retain evidence for interaction with O-17, O-18-enriched "cometary" water predicted by CO self-shielding. Here we present results of oxygen isotope measurements of twelve Stardust foil craters and four C-rich hydrated IDPs [8, 9], and discuss implications for models of oxygen isotope heterogeneity in the early solar system.

  3. How to measure genetic heterogeneity

    International Nuclear Information System (INIS)

    Yamada, Ryo

    2009-01-01

    Genetic information of organisms is coded as a string of four letters, A, T, G and C, a sequence in macromolecules called deoxyribonucleic acid (DNA). DNA sequence offers blueprint of organisms and its heterogeneity determines identity and variation of species. The quantitation of this genetic heterogeneity is fundamental to understand biology. We compared previously-reported three measures, covariance matrix expression of list of loci (pair-wise r 2 ), the most popular index in genetics, and its multi-dimensional form, Ψ, and entropy-based index, ε. Thereafter we proposed two methods so that we could handle the diplotypic heterogeneity and quantitate the conditions where the number of DNA sequence samples is much smaller than the number of possible variants.

  4. Ion beam analysis of diffusion in heterogeneous materials

    International Nuclear Information System (INIS)

    Clough, A.S.; Jenneson, P.M.

    1998-01-01

    Ion-beam analysis has been applied to a variety of problems involving diffusion in heterogeneous materials. An energy loss technique has been used to study both the diffusion of water and the surface segregation of fluoropolymers in polymeric matrices. A scanning micro-beam technique has been developed to allow water concentrations in hydrophilic polymers and cements to be measured together with associated solute elements. It has also been applied to the diffusion of shampoo into hair. (orig.)

  5. Ion beam analysis of diffusion in heterogeneous materials

    Energy Technology Data Exchange (ETDEWEB)

    Clough, A.S.; Jenneson, P.M. [Surrey Univ., Guildford (United Kingdom). Dept. of Physics

    1998-04-01

    Ion-beam analysis has been applied to a variety of problems involving diffusion in heterogeneous materials. An energy loss technique has been used to study both the diffusion of water and the surface segregation of fluoropolymers in polymeric matrices. A scanning micro-beam technique has been developed to allow water concentrations in hydrophilic polymers and cements to be measured together with associated solute elements. It has also been applied to the diffusion of shampoo into hair. (orig.) 13 refs.

  6. Neutron ion temperature measurement

    International Nuclear Information System (INIS)

    Strachan, J.D.; Hendel, H.W.; Lovberg, J.; Nieschmidt, E.B.

    1986-11-01

    One important use of fusion product diagnostics is in the determination of the deuterium ion temperature from the magnitude of the 2.5 MeV d(d,n) 3 He neutron emission. The detectors, calibration methods, and limitations of this technique are reviewed here with emphasis on procedures used at PPPL. In most tokamaks, the ion temperature deduced from neutrons is in reasonable agreement with the ion temperature deduced by other techniques

  7. Brachytherapy dose measurements in heterogeneous tissues

    International Nuclear Information System (INIS)

    Paiva F, G.; Luvizotto, J.; Salles C, T.; Guimaraes A, P. C.; Dalledone S, P. de T.; Yoriyaz, H.; Rubo, R.

    2014-08-01

    Recently, Beau lieu et al. published an article providing guidance for Model-Based Dose Calculation Algorithms (MBDCAs), where tissue heterogeneity considerations are addressed. It is well-known that T G-43 formalism which considers only water medium is limited and significant dose differences have been found comparing both methodologies. The aim of the present work is to experimentally quantify dose values in heterogeneous medium using different dose measurement methods and techniques and compare them with those obtained with Monte Carlo simulations. Experiments have been performed using a Nucletron micro Selectron-Hdr Ir-192 brachytherapy source and a heterogeneous phantom composed by PMMA and different tissue equivalent cylinders like bone, lungs and muscle. Several dose measurements were obtained using tissue equivalent materials with height 1.8 cm and 4.3 cm positioned between the radiation source and the detectors. Radiochromic films, TLDs and MOSFET S have been used for the dose measurements. Film dosimetry has been performed using two methodologies: a) linearization for dose-response curve based on calibration curves to create a functional form that linearize s the dose response and b) 177 multichannel analysis dosimetry where the multiple color channels are analyzed allowing to address not only disturbances in the measurements caused by thickness variation in the film layer, but also, separate other external influences in the film response. All experiments have been simulated using the MCNP5 Monte Carlo radiation transport code. Comparison of experimental results are in good agreement with calculated dose values with differences less than 6% for almost all cases. (Author)

  8. Brachytherapy dose measurements in heterogeneous tissues

    Energy Technology Data Exchange (ETDEWEB)

    Paiva F, G.; Luvizotto, J.; Salles C, T.; Guimaraes A, P. C.; Dalledone S, P. de T.; Yoriyaz, H. [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Rubo, R., E-mail: gabrielpaivafonseca@gmail.com [Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, 05403-900 Sao Paulo (Brazil)

    2014-08-15

    Recently, Beau lieu et al. published an article providing guidance for Model-Based Dose Calculation Algorithms (MBDCAs), where tissue heterogeneity considerations are addressed. It is well-known that T G-43 formalism which considers only water medium is limited and significant dose differences have been found comparing both methodologies. The aim of the present work is to experimentally quantify dose values in heterogeneous medium using different dose measurement methods and techniques and compare them with those obtained with Monte Carlo simulations. Experiments have been performed using a Nucletron micro Selectron-Hdr Ir-192 brachytherapy source and a heterogeneous phantom composed by PMMA and different tissue equivalent cylinders like bone, lungs and muscle. Several dose measurements were obtained using tissue equivalent materials with height 1.8 cm and 4.3 cm positioned between the radiation source and the detectors. Radiochromic films, TLDs and MOSFET S have been used for the dose measurements. Film dosimetry has been performed using two methodologies: a) linearization for dose-response curve based on calibration curves to create a functional form that linearize s the dose response and b) 177 multichannel analysis dosimetry where the multiple color channels are analyzed allowing to address not only disturbances in the measurements caused by thickness variation in the film layer, but also, separate other external influences in the film response. All experiments have been simulated using the MCNP5 Monte Carlo radiation transport code. Comparison of experimental results are in good agreement with calculated dose values with differences less than 6% for almost all cases. (Author)

  9. Effects of ionization chamber construction on dose measurements in a heterogeneity

    International Nuclear Information System (INIS)

    Mauceri, T.; Kase, K.

    1987-01-01

    Traditionally, measurements have been made in heterogeneous phantoms to determine the factors which should be applied to dose calculations, when calculating a dose to a heterogeneous medium. Almost all measurements have relied on relatively thin-walled ion chambers, with no attempt to match ion chamber wall material to the measuring medium. The recent AAPM dosimetry protocol has established that a mismatch between ion chamber wall and phantom material can have an effect on dose measurement. To investigate the affect of this mismatch of ion chamber wall material to phantom material, two parallel-plate ion chambers were constructed. One ion chamber from solid water, for measurements in a solid water phantom and the other from plastic lung material, for measurements in a plastic lung material phantom. Correction factors measured by matching ion chamber to media were compared to correction factors measured by using a thin-walled cavity ion chamber with no regard for matching wall and media for cobalt-60, 6-, 10- and 20-MV photon beams. The results demonstrated that the matching of ion chamber to measuring media can be ignored, provided that a small, approximately tissue-equivalent, thin-walled ion chamber is used for measuring the correction factors

  10. Heterogeneity Measurement Based on Distance Measure for Polarimetric SAR Data

    Science.gov (United States)

    Xing, Xiaoli; Chen, Qihao; Liu, Xiuguo

    2018-04-01

    To effectively test the scene heterogeneity for polarimetric synthetic aperture radar (PolSAR) data, in this paper, the distance measure is introduced by utilizing the similarity between the sample and pixels. Moreover, given the influence of the distribution and modeling texture, the K distance measure is deduced according to the Wishart distance measure. Specifically, the average of the pixels in the local window replaces the class center coherency or covariance matrix. The Wishart and K distance measure are calculated between the average matrix and the pixels. Then, the ratio of the standard deviation to the mean is established for the Wishart and K distance measure, and the two features are defined and applied to reflect the complexity of the scene. The proposed heterogeneity measure is proceeded by integrating the two features using the Pauli basis. The experiments conducted on the single-look and multilook PolSAR data demonstrate the effectiveness of the proposed method for the detection of the scene heterogeneity.

  11. The effect of organic ion-exchange resin on properties of heterogeneous ion-exchange membranes

    Czech Academy of Sciences Publication Activity Database

    Křivčík, J.; Vladařová, J.; Hadrava, J.; Černín, A.; Brožová, Libuše

    2010-01-01

    Roč. 14, - (2010), s. 179-184 ISSN 1944-3994. [Membrane Science and Technology Conference of Visegrad Countries /4./ PERMEA 2009, 07.07.2009-11.07.2009] R&D Projects: GA MPO FT-TA4/116 Institutional research plan: CEZ:AV0Z40500505 Keywords : heterogeneous ion-exchange membrane * membrane modification * particle size of distribution Subject RIV: CG - Electrochemistry Impact factor: 0.752, year: 2010

  12. Heterogeneous structure and its effect on properties and electrochemical behavior of ion-exchange membrane

    Science.gov (United States)

    Ariono, D.; Khoiruddin; Subagjo; Wenten, I. G.

    2017-02-01

    Generally, commercially available ion-exchange membrane (IEM) can be classified into homogeneous and heterogeneous membranes. The classification is based on degree of heterogeneity in membrane structure. It is well known that the heterogeneity greatly affects the properties of IEM, such as conductivity, permselectivity, chemical and mechanical stability. The heterogeneity also influences ionic and electrical current transfer behavior of IEM-based processes during their operation. Therefore, understanding the role of heterogeneity in IEM properties is important to provide preliminary information on their operability and applicability. In this paper, the heterogeneity and its effect on IEM properties are reviewed. Some models for describing the heterogeneity of IEM and methods for characterizing the degree of heterogeneity are discussed. In addition, the influence of heterogeneity on the performance of IEM-based processes and their electrochemical behavior are described.

  13. Ion detectors for isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, A.

    1978-12-15

    Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

  14. Accounting for heterogeneity in the measurement of hospital performance

    OpenAIRE

    Philippe K. Widmer; Peter Zweifel; Mehdi Farsi

    2011-01-01

    With prospective payment of hospitals becoming more common, measuring their performance is gaining in importance. However, the standard cost frontier model yields biased efficiency scores because it ignores technological heterogeneity between hospitals. In this paper, efficiency scores are derived from a random intercept and an extended random parameter frontier model, designed to overcome the problem of unobserved heterogeneity in stochastic frontier analysis. Using a sample of 100 Swiss ...

  15. Increasing selectivity of a heterogeneous ion-exchange membrane

    Czech Academy of Sciences Publication Activity Database

    Křivčík, J.; Neděla, D.; Hadrava, J.; Brožová, Libuše

    2015-01-01

    Roč. 56, č. 12 (2015), s. 3160-3166 ISSN 1944-3994. [International Conference on Membrane and Electromembrane Processes - MELPRO 2014. Prague, 18.05.2014-21.05.2014] Institutional support: RVO:61389013 Keywords : ion-exchange membrane * selectivity * permselectivity Subject RIV: JP - Industrial Processing Impact factor: 1.272, year: 2015

  16. Rapid heating evaporation of Pb(NO3)2. Evidence for heterogeneous ion-molecule reactions

    International Nuclear Information System (INIS)

    Radus, T.P.; Udseth, H.R.; Friedman, L.

    1979-01-01

    A mass spectrometric investigation of the lead nitrate system is reported in which the lead nitrate was evaporated from a probe filament that was heated as rapidly as 5000 0 C/s. Both electron impact (EI) and chemical ionization (CI) source techniques were used in this study. Fragment ions and decomposition products were observed under EI conditions. Under CI conditions solvated fragment ions and protonated solvated molecular ions were detected. Temperature measurements of rates of evaporation were made by monitoring the resistance of the probe filament as it was heated. Activation energies calculated by using these temperature coefficients of evaporation rates indicate that evaporations under CI conditions are assisted by heterogeneous ion-molecule reactions

  17. Investigation of interaction between the Pt(II) ions and aminosilane-modified silica surface in heterogeneous system

    Science.gov (United States)

    Nowicki, Waldemar; Gąsowska, Anna; Kirszensztejn, Piotr

    2016-05-01

    UV-vis spectroscopy measurements confirmed the reaction in heterogeneous system between Pt(II) ions and ethylenediamine type ligand, n-(2-aminoethyl)-3-aminopropyl-trimethoxysilane, immobilized at the silica surface. The formation of complexes is a consequence of interaction between the amine groups from the ligand grafted onto SiO2 and ions of platinum. A potentiometric titration technique was to determine the stability constants of complexes of Pt(II) with immobilized insoluble ligand (SG-L), on the silica gel. The results show the formation of three surface complexes of the same type (PtHSG-L, Pt(HSG-L)2, PtSG-L) with SG-L ligand, in a wide range of pH for different Debye length. The concentration distribution of the complexes in a heterogeneous system is evaluated.

  18. Dynamic electrochemical measurement of chloride ions

    NARCIS (Netherlands)

    Abbas, Yawar; de Graaf, Derk B.; Olthuis, Wouter; van den Berg, Albert

    2016-01-01

    This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement,

  19. The influence of activation of heterogeneous ion-exchange membranes on their electrochemical properties

    Czech Academy of Sciences Publication Activity Database

    Brožová, Libuše; Křivčík, J.; Neděla, D.; Kysela, V.; Žitka, Jan

    2015-01-01

    Roč. 56, č. 12 (2015), s. 3228-3232 ISSN 1944-3994. [International Conference on Membrane and Electromembrane Processes - MELPRO 2014. Prague, 18.05.2014-21.05.2014] Institutional support: RVO:61389013 Keywords : heterogeneous ion-exchange membranes * electrochemical properties * activation Subject RIV: JP - Industrial Processing Impact factor: 1.272, year: 2015

  20. Ion Distribution Measurement In Plasma Focus

    International Nuclear Information System (INIS)

    Suryadi; Sunardi; Usada, Widdi; Purwadi, Agus; Zaenuri, Akhmad

    1996-01-01

    Measurement of the Argon ion distribution in plasma focus by using Faraday cup has been done. The intensity of ion beam followed the I Rn rule, n=1,02. In the operation condition of 0,8 mbar and 12,5 kV the current sheath spen 2.2 to 2.4 μsecond in the rundown phase. Cu ion was also been observed in the Faraday cup

  1. Measurements of low energy auroral ions

    International Nuclear Information System (INIS)

    Urban, A.

    1981-01-01

    This paper summarizes ion measurements in the energy range 0.1 to 30 keV observed during the campaigns 'Substorm Phenomena' and 'Porcupine'. For a clear survey of the physical processes during extraordinary events, sometimes ion measurements of higher energies are also taken into account. Generally, the pitch angle distributions were isotropic during all flights except some remarkable events. In general the ion and electron flux intensities correlated, but sometimes revealed a spectral anti-correlation. Acceleration of the ions by an electrostatic field aligned parallel to the magnetic field could be identified accompanied by intense electron precipitation. On the other hand deceleration of the ions was observed in other field-aligned current sheets which are indicated by the electron and magnetic field measurements. Temporal successive monoenergetic ion variations pointed to energy dispersion and to the location of the source region at 9 Rsub(E). Furthermore, ion fluxes higher than those of the electrons were measured at pitch angles parallel to the magnetic field. The integral down-going number and energy flux of the ions contributed to the total particle or energy influx between 65% and less than 7% and did not clearly characterize the geophysical launch conditions or auroral activities. (author)

  2. Upper Bounds on Performance Measures of Heterogeneous // Queues

    Directory of Open Access Journals (Sweden)

    F. S. Q. Alves

    2011-01-01

    Full Text Available In many real-life queueing systems, the servers are often heterogeneous, namely they work at different rates. This paper provides a simple method to compute tight upper bounds on two important performance measures of single-class heterogeneous multi-server Markovian queueing systems, namely the average number in queue and the average waiting time in queue. This method is based on an expansion of the state space that is followed by an approximate reduction of the state space, only considering the most probable states. In most cases tested, we were able to approximate the actual behavior of the system with smaller errors than those obtained from traditional homogeneous multiserver Markovian queues, as shown by GPSS simulations. In addition, we have correlated the quality of the approximation with the degree of heterogeneity of the system, which was evaluated using its Gini index. Finally, we have shown that the bounds are robust and still useful, even considering quite different allocation strategies. A large number of simulation results show the accuracy of the proposed method that is better than that of classical homogeneous multiserver Markovian formulae in many situations.

  3. Beam emittance measurements on multicusp ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Sarstedt, M.; Lee, Y.; Leung, K.N. [and others

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 {mu}m patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma.

  4. Beam emittance measurements on multicusp ion sources

    International Nuclear Information System (INIS)

    Sarstedt, M.; Lee, Y.; Leung, K.N.

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 μm patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma

  5. Estimation of noise-free variance to measure heterogeneity.

    Directory of Open Access Journals (Sweden)

    Tilo Winkler

    Full Text Available Variance is a statistical parameter used to characterize heterogeneity or variability in data sets. However, measurements commonly include noise, as random errors superimposed to the actual value, which may substantially increase the variance compared to a noise-free data set. Our aim was to develop and validate a method to estimate noise-free spatial heterogeneity of pulmonary perfusion using dynamic positron emission tomography (PET scans. On theoretical grounds, we demonstrate a linear relationship between the total variance of a data set derived from averages of n multiple measurements, and the reciprocal of n. Using multiple measurements with varying n yields estimates of the linear relationship including the noise-free variance as the constant parameter. In PET images, n is proportional to the number of registered decay events, and the variance of the image is typically normalized by the square of its mean value yielding a coefficient of variation squared (CV(2. The method was evaluated with a Jaszczak phantom as reference spatial heterogeneity (CV(r(2 for comparison with our estimate of noise-free or 'true' heterogeneity (CV(t(2. We found that CV(t(2 was only 5.4% higher than CV(r2. Additional evaluations were conducted on 38 PET scans of pulmonary perfusion using (13NN-saline injection. The mean CV(t(2 was 0.10 (range: 0.03-0.30, while the mean CV(2 including noise was 0.24 (range: 0.10-0.59. CV(t(2 was in average 41.5% of the CV(2 measured including noise (range: 17.8-71.2%. The reproducibility of CV(t(2 was evaluated using three repeated PET scans from five subjects. Individual CV(t(2 were within 16% of each subject's mean and paired t-tests revealed no difference among the results from the three consecutive PET scans. In conclusion, our method provides reliable noise-free estimates of CV(t(2 in PET scans, and may be useful for similar statistical problems in experimental data.

  6. Ion temperature measurements in the Maryland Spheromak

    International Nuclear Information System (INIS)

    Gauvreau, J.L.

    1992-01-01

    Initial spectroscopic data from MS showed evidence of ion heating as deduced from the line widths of different ion species. Detailed measurements of OIV spectral emission line profiles in space and time revealed that heating takes place at early time, before spheromak formation and is occurring within the current discharge. The measured ion temperature is several times the electron temperature and cannot be explained by classical (Spitzer) resistivity. Classically, ions are expected to have lower temperatures than the electrons and therefore, lower temperatures than observed. High ion temperatures have been observed in different RFP's and Spheromaks but are usually associated with relaxation to the Taylor state and occur in the sustainment phase. During formation, the current delivered to start the discharge is not axisymmetric and as a consequence, X-points appear in the magnetic flux. A two dimensional analysis predicts that magnetic reconnection occurring at an X-point can give rise to high ion heating rates. A simple 0-dimensional calculation showed that within the first 20 μs, a conversion of mass flow kinetic energy into ion temperature could take place due to viscosity

  7. Arrester Resistive Current Measuring System Based on Heterogeneous Network

    Science.gov (United States)

    Zhang, Yun Hua; Li, Zai Lin; Yuan, Feng; Hou Pan, Feng; Guo, Zhan Nan; Han, Yue

    2018-03-01

    Metal Oxide Arrester (MOA) suffers from aging and poor insulation due to long-term impulse voltage and environmental impact, and the value and variation tendency of resistive current can reflect the health conditions of MOA. The common wired MOA detection need to use long cables, which is complicated to operate, and that wireless measurement methods are facing the problems of poor data synchronization and instability. Therefore a novel synchronous measurement system of arrester current resistive based on heterogeneous network is proposed, which simplifies the calculation process and improves synchronization, accuracy and stability and of the measuring system. This system combines LoRa wireless network, high speed wireless personal area network and the process layer communication, and realizes the detection of arrester working condition. Field test data shows that the system has the characteristics of high accuracy, strong anti-interference ability and good synchronization, which plays an important role in ensuring the stable operation of the power grid.

  8. Fluorescence lifetime measurement of radical ions

    International Nuclear Information System (INIS)

    Ichinose, Nobuyuki; Kinugasa, Jun-ichiro; Hagiri, Masahide; Nakayama, Toshihiro; Murakami, Hiroshi; Kishimoto, Maki; Daido, Hiroyuki

    2004-01-01

    One-photonic excitation of a charge transfer complex of hexamethoxybenzene (HMB) and nitrosonium tetrafluoroborate (NO + BF 4 - ) in acetonitrile afforded fluorescences emission from excited radical cation of HMB (HMB + *). Lifetime of the excited radical ion species was measured to be 7 ps by the pump-probe transient absorption technique. The lifetime was much shorter than that of free radical ion (63 ps), indicating the presence of an interaction between HMB + * and NO in the excited complex. (author)

  9. Interpretation of active neutron measurements by the heterogeneous theory

    International Nuclear Information System (INIS)

    Birkhoff, G.; Depraz, J.; Descieux, J.P.

    1979-01-01

    In this paper are presented results from a study on the application of the heterogeneous method for the interpretation of active neutron measurements. The considered apparatus consists out of a cylindrical lead pile, which is provided with two axial channels: a central channel incorporates an antimony beryllium photoneutron source and an excentric channel serves for the insertion of the sample to be assayed for fissionable materials contents. The mathematical model of this apparatus is the heterogeneous group diffusion theory. Sample and source channel are described by multigroup monopolar and dipolar sources and sinks. Monopolar sources take account of neutron production within energy group and in-scatter from upper groups. Monopolar sinks represent neutron removal by absorption within energy group and outscatter to lower groups. Dipol sources describe radial streaming of neutrons across the sample channel. Multigroup diffusion theory is applied throughout the lead pile. The strengths of the monopolar and dipolar sources and sinks are determined by linear extrapolation distances of azimuthal mean and first harmonic flux values at the channels' surface. In an experiment we may measure the neutrons leaking out of the lead pile and linear extrapolation distances at the channels' surface. Such informations are utilized for interpretation in terms of fission neutron source strengh and mean neutron flux values in the sample. In this paper we summarized the theoretical work in course

  10. Fusing metabolomics data sets with heterogeneous measurement errors

    Science.gov (United States)

    Waaijenborg, Sandra; Korobko, Oksana; Willems van Dijk, Ko; Lips, Mirjam; Hankemeier, Thomas; Wilderjans, Tom F.; Smilde, Age K.

    2018-01-01

    Combining different metabolomics platforms can contribute significantly to the discovery of complementary processes expressed under different conditions. However, analysing the fused data might be hampered by the difference in their quality. In metabolomics data, one often observes that measurement errors increase with increasing measurement level and that different platforms have different measurement error variance. In this paper we compare three different approaches to correct for the measurement error heterogeneity, by transformation of the raw data, by weighted filtering before modelling and by a modelling approach using a weighted sum of residuals. For an illustration of these different approaches we analyse data from healthy obese and diabetic obese individuals, obtained from two metabolomics platforms. Concluding, the filtering and modelling approaches that both estimate a model of the measurement error did not outperform the data transformation approaches for this application. This is probably due to the limited difference in measurement error and the fact that estimation of measurement error models is unstable due to the small number of repeats available. A transformation of the data improves the classification of the two groups. PMID:29698490

  11. A complementary measure of heterogeneity on mathematical skills

    Science.gov (United States)

    Fedriani, Eugenio M.; Moyano, Rafael

    2012-06-01

    Finding educational truths is an inherently multivariate problem. There are many factors affecting each student and their performances. Because of this, both measuring of skills and assessing students are always complex processes. This is a well-known problem, and a number of solutions have been proposed by specialists. One of its ramifications is that the variety of progress levels of students in the Mathematics classroom makes teaching more difficult. We think that a measure of the heterogeneity of the different student groups could be interesting in order to prepare some strategies to deal with these kinds of difficulties. The major aim of this study is to develop new tools, complementary to the statistical ones that are commonly used for these purposes, to study situations related to education (mainly to the detection of levels of mathematical education) in which several variables are involved. These tools are thought to simplify these educational analyses and, through a better comprehension of the topic, to improve our teaching. Several authors in our research group have developed some mathematical, theoretical tools, to deal with multidimensional phenomena, and have applied them to measure poverty and also to other business models. These tools are based on multidigraphs. In this article, we implement these tools using symbolic computational software and apply them to study a specific situation related to mathematical education.

  12. HBT measurements in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Zajc, W.A.

    1990-01-01

    The correlations in relative momentum between identical bosons are determined, in part, by the geometrical properties of the boson source. This fact was first exploited in hadron physics by Goldhaber, Goldhaber, Lee and Pais (GGLP) in 1960. In the intervening three decades, this approach has been applied to lepton-lepton, lepton-hadron, hadron-hadron, and heavy-ion collisions. A word about nomenclature: The correlations in relative momentum between identical mesons arise from Bose statistics. Even previous to GGLP, this fact was applied by Hanbury-Brown and Twiss to measure stellar radii via two-photon interferometry. Thus an alternative name for the GGLP effect is the HBT effect. An informal introduction to Hanbury-Brown-Twiss measurements in heavy ion collisions is presented. The systematic effects in interpreting such data are emphasized, rather than the implications of any single experiment

  13. Heavy ion measurement by chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1979-02-01

    In testing the applicability of the threshold system polyvinyl alcohol/methyl orange/chloral hydrate/sodium tetraborate to the quantitative detection of single particles, the chemical detector was irradiated with 4 He, 12 C, 18 O, 22 He ions of different LET. Detectors with 4 different borax concentrations (chloral hydrate concentration kept constant) have been irradiated. The dose causing the colour change increased linearly with the borax concentration. For equal borax concentrations this dose increases with increasing LET due to the decreasing G value of the HCl. The fluence ranges measurable with the various detector compositions are given. 4 He and 18 O ion ranges have been determined. The measured depth dose curves have been corrected because the dose is LET-dependent. The experimentally determined ranges are in good agreement with values calculated for the detector material

  14. Measuring the effects of heterogeneity on distributed systems

    Science.gov (United States)

    El-Toweissy, Mohamed; Zeineldine, Osman; Mukkamala, Ravi

    1991-01-01

    Distributed computer systems in daily use are becoming more and more heterogeneous. Currently, much of the design and analysis studies of such systems assume homogeneity. This assumption of homogeneity has been mainly driven by the resulting simplicity in modeling and analysis. A simulation study is presented which investigated the effects of heterogeneity on scheduling algorithms for hard real time distributed systems. In contrast to previous results which indicate that random scheduling may be as good as a more complex scheduler, this algorithm is shown to be consistently better than a random scheduler. This conclusion is more prevalent at high workloads as well as at high levels of heterogeneity.

  15. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  16. Implementation schemes for unsharp measurements with trapped ions

    CSIR Research Space (South Africa)

    Choudhary, SK

    2013-01-01

    Full Text Available trapped ion. The schemes rely on introducing weak entanglement between the state of a target ion and that of an auxiliary ion, using standard ion-trap quantum logic operations, and then realizing an unsharp measurement through projective measurement...

  17. Synthesis of biodiesel from pongamia oil using heterogeneous ion-exchange resin catalyst.

    Science.gov (United States)

    Jaya, N; Selvan, B Karpanai; Vennison, S John

    2015-11-01

    Biodiesel is a clean-burning renewable substitute fuel for petroleum. Biodiesel could be effectively produced by transesterification reaction of triglycerides of vegetable oils with short-chain alcohols in the presence of homogeneous or heterogeneous catalysts. Conventionally, biodiesel manufacturing processes employ strong acids or bases as catalysts. But, separation of the catalyst and the by-product glycerol from the product ester is too expensive to justify the product use as an automobile fuel. Hence heterogeneous catalysts are preferred. In this study, transesterification of pongamia oil with ethanol was performed using a solid ion-exchange resin catalyst. It is a macro porous strongly basic anion exchange resin. The process parameters affecting the ethyl ester yield were investigated. The reaction conditions were optimized for the maximum yield of fatty acid ethyl ester (FAEE) of pongamia oil. The properties of FAEE were compared with accepted standards of biodiesel. Engine performance was also studied with pongamia oil diesel blend and engine emission characteristics were observed. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Nanoscale Heterogeneity of Multilayered Si Anodes with Embedded Nanoparticle Scaffolds for Li-Ion Batteries.

    Science.gov (United States)

    Haro, Marta; Singh, Vidyadhar; Steinhauer, Stephan; Toulkeridou, Evropi; Grammatikopoulos, Panagiotis; Sowwan, Mukhles

    2017-10-01

    A new approach on the synthesis of Si anodes for Li-ion batteries is reported, combining advantages of both nanoparticulated and continuous Si films. A multilayered configuration prototype is proposed, comprising amorphous Si arranged in nanostructured, mechanically heterogeneous films, interspersed with Ta nanoparticle scaffolds. Particular structural features such as increased surface roughness, nanogranularity, and porosity are dictated by the nanoparticle scaffolds, boosting the lithiation process due to fast Li diffusion and low electrode polarization. Consequently, a remarkable charge/discharge speed is reached with the proposed anode, in the order of minutes (1200 mAh g -1 at 10 C). Moreover, nanomechanical heterogeneity self-limits the capacity at intermediate charge/discharge rates; as a consequence, exceptional cycleability is observed at 0.5 C, with 100% retention over 200 cycles with 700 mAh g -1 . Higher capacity can be obtained when the first cycles are performed at 0.2 C, due to the formation of microislands, which facilitate the swelling of the active Si. This study indicates a method to tune the mechanical, morphological, and electrochemical properties of Si electrodes via engineering nanoparticle scaffolds, paving the way for a novel design of nanostructured Si electrodes for high-performance energy storage devices.

  19. Measurement of stopping power of light ions

    International Nuclear Information System (INIS)

    Sakamoto, Naoki

    1981-01-01

    The stopping power of light ions penetrating various materials has been measured. The data of proton stopping power and the mean ionization potentials are presented. The experiments were made by using the 6.75 MeV protons from a cyclotron and the protons in the energy range from 3 to 9 MeV from a tandem Van de Graaff. The windows with and without sample-foils were rotated in front of a semiconductor detector, and the measured energy loss and the thickness of the sample foils were used to estimate the energy loss at the mean energy of protons in the samples. The analyses were made by considering the inner shell correction, Z 1 3 correction and the Bloch correction. The mean ionization potentials were derived from the data. (Kato, T.)

  20. MEV Energy Electrostatic Accelerator Ion Beam Emittance Measurement

    OpenAIRE

    I.G. Ignat’ev; M.I. Zakharets; S.V. Kolinko; D.P. Shulha

    2014-01-01

    The testing equipment was designed, manufactured and tried out permitting measurements of total current, current profile and emittance of an ion beam extracted from the ion beam. MeV energy electrostatic accelerator ion H + beam emittance measurement results are presented.

  1. Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2015-12-15

    In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

  2. Ion measurements in premixed methane-oxygen flames

    KAUST Repository

    Alquaity, Awad; Hourani, Nadim; Chahine, May; Selim, Hatem; Sarathy, Mani; Farooq, Aamir

    2014-01-01

    Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry

  3. Optimum measuring net for correcting mineralizing heterogeneity effect in XRF sampling

    International Nuclear Information System (INIS)

    Zhou Sichun; Zhao Youqing; Zhang Yuhuan

    2000-01-01

    The mineralizing heterogeneity effect in XRF sampling was investigated with theory of mathematical statistics. A method called 'Optimum measuring Net' has been developed. The theoretical estimation and experimental results show that the mineralizing heterogeneity effect can be cut down to the minimum with the method

  4. Applications of air ion measurement in environmental diagnostics

    International Nuclear Information System (INIS)

    Tammet, H.

    1996-01-01

    The present paper is dealing with the methods employing the measuring of naturally created air ions. The amount and mobility distribution of these ions offer hidden information about air pollution. On the other hand, the natural air ions are active in some environmental processes and they should be considered as an immediate environmental factor

  5. Measurement of few-electron uranium ions on a high-energy electron beam ion trap

    International Nuclear Information System (INIS)

    Beiersdorfer, P.

    1994-01-01

    The high-energy electron beam ion trap, dubbed Super-EBIT, was used to produce, trap, and excite uranium ions as highly charged as fully stripped U 92+ . The production of such highly charged ions was indicated by the x-ray emission observed with high-purity Ge detectors. Moreover, high-resolution Bragg crystal spectromters were used to analyze the x-ray emission, including a detailed measurement of both the 2s 1/2 -2p 3/2 electric dipole and 2p 1/2 -2p 3/2 magnetic dipole transitions. Unlike in ion accelerators, where the uranium ions move at relativistic speeds, the ions in this trap are stationary. Thus very precise measurements of the transition energies could be made, and the QED contribution to the transition energies could be measured within less than 1 %. Details of the production of these highly charged ions and their measurement is given

  6. Experiments of Accuracy Air Ion Field Measurement

    Czech Academy of Sciences Publication Activity Database

    Bartušek, Karel; Fiala, P.; Jirků, T.; Kadlecová, E.

    2007-01-01

    Roč. 3, č. 8 (2007), s. 1330-1333 ISSN 1931-7360 Institutional research plan: CEZ:AV0Z20650511 Keywords : air ion field * gerdien condenser * picoampermeter Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  7. Aspirated capacitor measurements of air conductivity and ion mobility spectra

    International Nuclear Information System (INIS)

    Aplin, K.L.

    2005-01-01

    Measurements of ions in atmospheric air are used to investigate atmospheric electricity and particulate pollution. Commonly studied ion parameters are (1) air conductivity, related to the total ion number concentration, and (2) the ion mobility spectrum, which varies with atmospheric composition. The physical principles of air ion instrumentation are long established. A recent development is the computerized aspirated capacitor, which measures ions from (a) the current of charged particles at a sensing electrode, and (b) the rate of charge exchange with an electrode at a known initial potential, relaxing to a lower potential. As the voltage decays, only ions of higher and higher mobility are collected by the central electrode and contribute to the further decay of the voltage. This enables extension of the classical theory to calculate ion mobility spectra by inverting voltage decay time series. In indoor air, ion mobility spectra determined from both the voltage decay inversion, and an established voltage switching technique, were compared and shown to be of similar shape. Air conductivities calculated by integration were: 5.3±2.5 and 2.7±1.1 fSm -1 , respectively, with conductivity determined to be 3 fSm -1 by direct measurement at a constant voltage. Applications of the relaxation potential inversion method include air ion mobility spectrum retrieval from historical data, and computation of ion mobility spectra in planetary atmospheres

  8. Organic and inorganic ion exchangers as catalysts for the heterogeneous alkylation of aromatics

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J; Widdecke, H [Technische Univ. Braunschweig (Germany, F.R.). Inst. fuer Chemische Technologie

    1979-06-01

    Ion exchangers have advantages over low molecular for use in industrial alkylation reactions. The reactivity and selectivity behaviour of the polymeric catalysts was found to be markedly influenced by the structure of the polymeric matrix as well as the type and number of the functional groups. In this connection many similarities between inorganic ion exchangers (zeolites) and organic ion exchange resins were detected.

  9. Atomic physics measurements in an electron Beam Ion Trap

    International Nuclear Information System (INIS)

    Marrs, R.E.; Beiersdorfer, P.; Bennett, C.

    1989-01-01

    An electron Beam Ion Trap at Lawrence Livermore National Laboratory is being used to produce and trap very-highly-charged ions (q ≤ 70/+/) for x-ray spectroscopy measurements. Recent measurements of transition energies and electron excitation cross sections for x-ray line emission are summarized. 13 refs., 10 figs

  10. Measurements of Beam Ion Loss from the Compact Helical System

    International Nuclear Information System (INIS)

    Darrow, D.S.; Isobe, M.; Kondo, Takashi; Sasao, M.

    2010-01-01

    Beam ion loss from the Compact Helical System (CHS) has been measured with a scintillator-type probe. The total loss to the probe, and the pitch angle and gyroradius distributions of that loss, have been measured as various plasma parameters were scanned. Three classes of beam ion loss were observed at the probe position: passing ions with pitch angles within 10o of those of transition orbits, ions on transition orbits, and ions on trapped orbits, typically 15o or more from transition orbits. Some orbit calculations in this geometry have been performed in order to understand the characteristics of the loss. Simulation of the detector signal based upon the following of orbits from realistic beam deposition profiles is not able to reproduce the pitch angle distribution of the losses measured. Consequently it is inferred that internal plasma processes, whether magnetohydrodynamic modes, radial electric fields, or plasma turbulence, move previously confined beam ions to transition orbits, resulting in their loss.

  11. Experimental measurements of negative hydrogen ion production from surfaces

    International Nuclear Information System (INIS)

    Graham, W.G.

    1977-09-01

    Experimental measurements of the production of H - from surfaces bombarded with hydrogen are reviewed. Some measurements of H + and H 0 production from surfaces are also discussed with particular emphasis on work which might be relevant to ion source applications

  12. Gene coexpression measures in large heterogeneous samples using count statistics.

    Science.gov (United States)

    Wang, Y X Rachel; Waterman, Michael S; Huang, Haiyan

    2014-11-18

    With the advent of high-throughput technologies making large-scale gene expression data readily available, developing appropriate computational tools to process these data and distill insights into systems biology has been an important part of the "big data" challenge. Gene coexpression is one of the earliest techniques developed that is still widely in use for functional annotation, pathway analysis, and, most importantly, the reconstruction of gene regulatory networks, based on gene expression data. However, most coexpression measures do not specifically account for local features in expression profiles. For example, it is very likely that the patterns of gene association may change or only exist in a subset of the samples, especially when the samples are pooled from a range of experiments. We propose two new gene coexpression statistics based on counting local patterns of gene expression ranks to take into account the potentially diverse nature of gene interactions. In particular, one of our statistics is designed for time-course data with local dependence structures, such as time series coupled over a subregion of the time domain. We provide asymptotic analysis of their distributions and power, and evaluate their performance against a wide range of existing coexpression measures on simulated and real data. Our new statistics are fast to compute, robust against outliers, and show comparable and often better general performance.

  13. Ion binding by humic and fulvic acids: A computational procedure based on functional site heterogeneity and the physical chemistry of polyelectrolyte solutions

    International Nuclear Information System (INIS)

    Marinsky, J.A.; Reddy, M.M.; Ephraim, J.; Mathuthu, A.

    1988-04-01

    Ion binding equilibria for humic and fulvic acids are examined from the point of view of functional site heterogeneity and the physical chemistry of polyelectrolyte solutions. A detailed explanation of the potentiometric properties of synthetic polyelectrolytes and ion-exchange gels is presented first to provide the basis for a parallel consideration of the potentiometric properties exhibited by humic and fulvic acids. The treatment is then extended to account for functional site heterogeneity. Sample results are presented for analysis of the ion-binding reactions of a standard soil fulvic acid (Armadale Horizons Bh) with this approach to test its capability for anticipation of metal ion removal from solution. The ultimate refined model is shown to be adaptable, after appropriate consideration of the heterogeneity and polyelectrolyte factors, to programming already available for the consideration of ion binding by inorganics in natural waters. (orig.)

  14. Heavy ion measurements at ATLAS and CMS

    CERN Document Server

    Chapon, Emilien

    2018-01-01

    We present an overview of recent results from the ATLAS and CMS collaborations on heavy ion physics. Using data from proton-proton, proton-lead and lead-lead collisions at the LHC, these results help to shed light on the properties of nuclear matter.

  15. Algorithmic Foundation of Spectral Rarefaction for Measuring Satellite Imagery Heterogeneity at Multiple Spatial Scales

    Science.gov (United States)

    Rocchini, Duccio

    2009-01-01

    Measuring heterogeneity in satellite imagery is an important task to deal with. Most measures of spectral diversity have been based on Shannon Information theory. However, this approach does not inherently address different scales, ranging from local (hereafter referred to alpha diversity) to global scales (gamma diversity). The aim of this paper is to propose a method for measuring spectral heterogeneity at multiple scales based on rarefaction curves. An algorithmic solution of rarefaction applied to image pixel values (Digital Numbers, DNs) is provided and discussed. PMID:22389600

  16. Electrical shielding box measurement of the negative hydrogen beam from Penning ion gauge ion source.

    Science.gov (United States)

    Wang, T; Yang, Z; Dong, P; long, J D; He, X Z; Wang, X; Zhang, K Z; Zhang, L W

    2012-06-01

    The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H(-)) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H(-) beam extraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H(-) beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.

  17. LAI and chlorophyll estimation for a heterogeneous grassland using hyperspectral measurements

    NARCIS (Netherlands)

    Darvishzadeh, R.; Skidmore, A.K.; Schlerf, M.; Atzberger, C.; Corsi, F.; Cho, M.A.

    2008-01-01

    The study shows that leaf area index (LAI), leaf chlorophyll content (LCC) and canopy chlorophyll content (CCC) can be mapped in a heterogeneous Mediterranean grassland from canopy spectral reflectance measurements. Canopy spectral measurements were made in the field using a GER 3700

  18. Measurement of ion energy by a calorimetric method

    Energy Technology Data Exchange (ETDEWEB)

    Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Bunak, Suwat

    1996-12-01

    In calorimetric method, ion energy is determined based on the temperature changes during radiation of an absorbing material, radiation current and heat capacity of the calorimeter. This method is convenient and its measuring procedures are simple as well as the measuring apparatus. Here, the temperature changes of the calorimeter during {sup 14}N ion beam radiation were determined. The temperature increased linearly when irradiated with {sup 14}N{sup 3+}, 8.3 MeV or {sup 14}N{sup 2+}, 6 MeV, but not linearly for {sup 14}N{sup 1+}, 3.6 MeV, resulting in a comparatively large error. Thus, the measurement of ion energy by calorimetric method was found available as a convenient method for an accelerator having an energy stability less than 10{sup -3}. Especially this method seems to be useful for low-energy ion accelerator or ion injecting apparatus. (M.N.)

  19. Measurement of stopping power of heavy ions

    International Nuclear Information System (INIS)

    Kitahara, Tetsuo

    1981-01-01

    The stopping power of heavy ions is discussed. In the low energy region, heavy ions keep some of their orbital electrons, and have equilibrium electron charge. The stopping power of penetrating particles depends on this effective charge. At present, it is hard to estimate this effective charge theoretically, accordingly, the estimation is made experimentally. Another difficulty in this estimation is that the Born approximation is not effective for heavy ions. In the low energy region, electronic stopping and nuclear stopping contribute to the stopping power. For the electronic stopping, a formula for the stopping power was given by Lindhard et al. The experimental values were obtained at GSI, and are inconsistent with the estimation by the Lindhard's formula. In the high energy region, where the Born approximation can be used, the Bethe's formula is applied, but the experimental data are scarce. Oscillations are seen in the Z dependence graph of the experimental stopping cross sections. Experimental works on the stopping power have been done. The differential and the integral methods were carried out. (Kato, T.)

  20. Measurements of ion concentration in gasoline and diesel engine exhaust

    Science.gov (United States)

    Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

    The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

  1. Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay

    Directory of Open Access Journals (Sweden)

    Seidel Clemens

    2012-04-01

    Full Text Available Abstract Background To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. Methods Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III and twice (IV irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V and mean variance (Mvar, mutual comparisons were done by one-way analysis of variance (ANOVA. Results Heterogeneity of initial DNA-damage (I, 0 min repair increased without histones (II. Absence of histones was balanced by addition of antioxidants (III. Repair reduced heterogeneity of all samples (with and without irradiation. However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88. Conclusions Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity.

  2. Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay

    International Nuclear Information System (INIS)

    Seidel, Clemens; Lautenschläger, Christine; Dunst, Jürgen; Müller, Arndt-Christian

    2012-01-01

    To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III) and twice (IV) irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V) and mean variance (Mvar), mutual comparisons were done by one-way analysis of variance (ANOVA). Heterogeneity of initial DNA-damage (I, 0 min repair) increased without histones (II). Absence of histones was balanced by addition of antioxidants (III). Repair reduced heterogeneity of all samples (with and without irradiation). However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88). Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity

  3. Spectroscopic measurements of anode plasma with cryogenic pulsed ion sources

    International Nuclear Information System (INIS)

    Yoneda, H.; Urata, T.; Ohbayashi, K.; Kim, Y.; Horioka, K.; Kasuya, K.

    1987-01-01

    In ion beam diodes, electromagnetic wave is coupled to ion beam. Ion is extracted from anode plasma, which is produced early in the power pulse. However, exact mechanism of anode plasma production, expansion and ion extraction process is unknown. In particularly, anode plasma expansion is seemed to be one of the reasons of rapid impedance collapse of the diode, which is serious problem in high power experiments. Some experimental results showed that anode plasma expansion velocity was about 5 times larger than that inferred from simple thermal velocity. Several explanations for these results were proposed; for example, electron collisionarity in anode plasma, fast neutral gas particle, diamagnetism. To solve this question, it is necessary to measure the characteristic of anode plasma with space and time resolution. The authors made spectroscopic measurements to investigate variety of electron temperature, electron density, expansion velocity of anode plasma with various ion sources

  4. Measurement of acetates in air using differential ion mobility spectrometer

    Science.gov (United States)

    Szczurek, Andrzej; Maciejewska, Monika; Zajiczek, Żaneta; Maziejuk, Mirosław

    2017-11-01

    Volatile organic compounds are one of the most important group of air pollutants. Potential health and environmental problems resulting from their emission prompted the requirement for monitoring these species. It motivates development of new measurement techniques which are fast, cost effective, reliable and field deployable. One of novel approaches is ion mobility spectrometry. It dwells on ion separation in electric field, based on differences in ion mobility. Many variants of this method are developed. In this wok, differential ion mobility spectrometry (DMS) was considered in respect of acetate measurements in air. It was demonstrated that DMS offers linear response to methyl, ethyl, propyl and butyl acetate in concentration range from 0.3 ppm to 7 ppm. Positive ions spectrum has to be utilised for this purpose. We showed that fragments of DMS spectrum which secure linearity are compound-specific. The obtained results are promising from the application point of view.

  5. Simulation study on heterogeneous variance adjustment for observations with different measurement error variance

    DEFF Research Database (Denmark)

    Pitkänen, Timo; Mäntysaari, Esa A; Nielsen, Ulrik Sander

    2013-01-01

    of variance correction is developed for the same observations. As automated milking systems are becoming more popular the current evaluation model needs to be enhanced to account for the different measurement error variances of observations from automated milking systems. In this simulation study different...... models and different approaches to account for heterogeneous variance when observations have different measurement error variances were investigated. Based on the results we propose to upgrade the currently applied models and to calibrate the heterogeneous variance adjustment method to yield same genetic......The Nordic Holstein yield evaluation model describes all available milk, protein and fat test-day yields from Denmark, Finland and Sweden. In its current form all variance components are estimated from observations recorded under conventional milking systems. Also the model for heterogeneity...

  6. Measuring the sensitivity of a boron-lined ion chamber

    International Nuclear Information System (INIS)

    Barton, D.M.

    1992-03-01

    Boron-lined ion chambers are used to monitor external neutron flux from fissionable materials assembled at the Los Alamos Critical Assembly Experiment Facility. The sensitivity of these chambers must be measured periodically in order to detect changes in filling gas and to evaluate other factors that may affect chamber performance. We delineate a procedure to measure ion chamber response using a particular neutron source ( 239 PuBe) in a particular moderating geometry of polyethylene. We also discuss use of the amplifier, high-voltage power supply, recorders, and scram circuits that comprise the complete ion chamber monitoring system

  7. Flexible probe for measuring local conductivity variations in Li-ion electrode films

    Science.gov (United States)

    Hardy, Emilee; Clement, Derek; Vogel, John; Wheeler, Dean; Mazzeo, Brian

    2018-04-01

    Li-ion battery performance is governed by electronic and ionic properties of the battery. A key metric that characterizes Li-ion battery cell performance is the electronic conductivity of the electrodes, which are metal foils with thin coatings of electrochemically active materials. To accurately measure the spatial variation of electronic conductivity of these electrodes, a micro-four-line probe (μ4LP) was designed and used to non-destructively measure the properties of commercial-quality Li-ion battery films. This previous research established that the electronic conductivity of film electrodes is not homogeneous throughout the entirety of the deposited film area. In this work, a micro-N-line probe (μNLP) and a flexible micro-flex-line probe (μFLP) were developed to improve the non-destructive micro-scale conductivity measurements that we can take. These devices were validated by comparing test results to that of the predecessor, the micro-four-line probe (μ4LP), on various commercial-quality Li-ion battery electrodes. Results show that there is significant variation in conductivity on a millimeter and even micrometer length scale through the electrode film. Compared to the μ4LP, the μNLP and μFLP also introduce additional measurement configuration possibilities, while providing a more robust design. Researchers and manufacturers can use these probes to identify heterogeneity in their electrodes during the fabrication process, which will lead to the development of better batteries.

  8. Spatially-Resolved Ion Trajectory Measurements During Cl2 Reactive Ion Beam Etching and Ar Ion Beam Etching

    International Nuclear Information System (INIS)

    Vawter, G. Allen; Woodworth, Joseph R.; Zubrzycki, Walter J.

    1999-01-01

    The angle of ion incidence at the etched wafer location during RIBE and IBE using Cl 2 , Ar and O 2 ion beams has been characterized using an ion energy and angle analyzer. Effects of beam current and accelerator grid bias on beam divergence and the spatial uniformity of the spread of incident angles are measured. It is observed that increased total beam current can lead to reduced current density at the sample stage due to enhanced beam divergence at high currents. Results are related to preferred etch system design for uniform high-aspect-ratio etching across semiconductor wafers

  9. Ion measurements in premixed methane-oxygen flames

    KAUST Repository

    Alquaity, Awad

    2014-07-25

    Ions are formed as a result of chemi-ionization processes in combustion systems. Recently, there has been an increasing interest in understanding flame ion chemistry due to the possible application of external electric fields to reduce emissions and improve combustion efficiency by active control of combustion process. In order to predict the effect of external electric fields on combustion plasma, it is critical to gain a good understanding of the flame ion chemistry. In this work, a Molecular Beam Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry on equivalence ratio of premixed flames. The relative ion concentration profiles are compared qualitatively with previous methane-oxygen studies and show good agreement. The relative ion concentration data obtained in the present study can be used to validate and improve ion chemistry models for methane-oxygen flames.

  10. GEOS-2 measurements of cold ions in the magnetosheath

    International Nuclear Information System (INIS)

    Rodgers, D.J.; Johnstone, A.D.; Sojka, J.J.

    1985-01-01

    The Suprathermal Plasma Analysers on GEOS-2 are able to make differential energy measurements of plasma particles down to sub-eV energies because the entire sensor package can be biased relative to the spacecraft. When the package is biased negatively with respect to space potential, low energy positive ions are sucked in and are more easily detected against the background. Large fluxes of ions with temperatures of the order of 1 eV or less were consistently detected at space potential when the spacecraft was in the magnetosheath though not when it was in the nearby magnetosphere. This apparent geophysical correlation, suggesting that the ions were part of the magnetosheath ion population, was contradicted by the fact that the ions showed no signs of the large drift velocity associated with the electric field in the magnetosheath. It is concluded, after further investigation, that the observed ions were probably sputtered as neutrals from the spacecraft surface by the impact of solar wind ions and subsequently ionized by sunlight or electron impact. The effect of sputtering by solar wind ions has not been previously observed, although it could have consequences for the long-term stability of spacecraft surfaces. (author)

  11. Measurement of electron emission due to energetic ion bombardment in plasma source ion implantation

    Science.gov (United States)

    Shamim, M. M.; Scheuer, J. T.; Fetherston, R. P.; Conrad, J. R.

    1991-11-01

    An experimental procedure has been developed to measure electron emission due to energetic ion bombardment during plasma source ion implantation. Spherical targets of copper, stainless steel, graphite, titanium alloy, and aluminum alloy were biased negatively to 20, 30, and 40 kV in argon and nitrogen plasmas. A Langmuir probe was used to detect the propagating sheath edge and a Rogowski transformer was used to measure the current to the target. The measurements of electron emission coefficients compare well with those measured under similar conditions.

  12. Fast-ionmeasurements of the fast-ion distribution (invited)

    International Nuclear Information System (INIS)

    Heidbrink, W. W.

    2010-01-01

    The fast-ion Dα (FIDA) diagnostic is an application of charge-exchange recombination spectroscopy. Fast ions that neutralize in an injected neutral beam emit Balmer-α light with a large Doppler shift. The spectral shift is exploited to distinguish the FIDA emission from other bright sources of Dα light. Background subtraction is the main technical challenge. A spectroscopic diagnostic typically achieves temporal, energy, and transverse spatial resolution of ∼1 ms, ∼10 keV, and ∼2 cm, respectively. Installations that use narrow-band filters achieve high spatial and temporal resolution at the expense of spectral information. For high temporal resolution, the bandpass-filtered light goes directly to a photomultiplier, allowing detection of ∼50 kHz oscillations in FIDA signal. For two-dimensional spatial profiles, the bandpass-filtered light goes to a charge-coupled device camera; detailed images of fast-ion redistribution at instabilities are obtained. Qualitative and quantitative models relate the measured FIDA signals to the fast-ion distribution function. The first quantitative comparisons between theory and experiment found excellent agreement in beam-heated magnetohydrodynamics (MHD)-quiescent plasmas. FIDA diagnostics are now in operation at magnetic-fusion facilities worldwide. They are used to study fast-ion acceleration by ion cyclotron heating, to detect fast-ion transport by MHD modes and microturbulence, and to study fast-ion driven instabilities.

  13. Direct measurement of the plasma response to electrostatic ion waves

    International Nuclear Information System (INIS)

    Sarfaty, M.; DeSouza-Machado, S.; Skiff, F.

    1995-01-01

    Plasma wave-wave and wave-particle interactions are studied in a linear magnetized plasma. The relatively quiet plasma is produced by an argon gas-discharge. The plasma density is n e ≅ 10 9 cm -3 and the electron/ion temperatures are T e ≅ 5eV and T i = 0.05eV. A grid and a four ring antenna, both mounted on a scanning carriage, are used to launch electrostatic ion waves in the plasma. Laser Induced Fluorescence measurements of both the linear and the nonlinear plasma response to the wave fields are presented. The Vlasov-Poisson equations are used to explain the measured zero, first and second order terms of the ion distribution function in the presence of wave fields. In addition to the broadening (heating) of the ion distribution as the authors increase the wave amplitudes, induced plasma flows are observed both along and across the magnetic field

  14. Heterogeneous ion-exchange membranes based on sulfonated poly(1,4-phenylene sulfide)

    Czech Academy of Sciences Publication Activity Database

    Schauer, Jan; Kůdela, Vlastimil; Richau, K.; Mohr, R.

    2006-01-01

    Roč. 198, 1-3 (2006), s. 256-264 ISSN 0011-9164 R&D Projects: GA ČR GA203/05/0080 Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(1,4-phenylene sulfide) sulfonated * ion-exchange membrane Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

  15. A method to measure depth distributions of implanted ions

    International Nuclear Information System (INIS)

    Arnesen, A.; Noreland, T.

    1977-04-01

    A new variant of the radiotracer method for depth distribution determinations has been tested. Depth distributions of radioactive implanted ions are determined by dissolving thin, uniform layers of evaporated material from the surface of a backing and by measuring the activity before and after the layer removal. The method has been used to determine depth distributions for 25 keV and 50 keV 57 Co ions in aluminium and gold. (Auth.)

  16. High mass-resolution electron-ion-ion coincidence measurements on core-excited organic molecules

    CERN Document Server

    Tokushima, T; Senba, Y; Yoshida, H; Hiraya, A

    2001-01-01

    Total electron-ion-ion coincidence measurements on core excited organic molecules have been carried out with high mass resolution by using multimode (reflectron/linear) time-of-flight mass analyzer. From the ion correlation spectra of core excited CH sub 3 OH and CD sub 3 OH, the reaction pathway to form H sub 3 sup + (D sub 3 sup +) is identified as the elimination of three H (D) atoms from the methyl group, not as the inter-group (-CH sub 3 and -OH) interactions. In a PEPIPICO spectrum of acetylacetone (CH sub 3 COCH sub 2 COCH sub 3) measured by using a reflectron TOF, correlations between ions up to mass number 70 with one-mass resolution was recorded.

  17. Evaluation of Hydraulic Parameters Obtained by Different Measurement Methods for Heterogeneous Gravel Soil

    Directory of Open Access Journals (Sweden)

    Chen Zeng

    2012-01-01

    Full Text Available Knowledge of soil hydraulic parameters for the van Genuchten function is important to characterize soil water movement for watershed management. Accurate and rapid prediction of soil water flow in heterogeneous gravel soil has become a hot topic in recent years. However, it is difficult to precisely estimate hydraulic parameters in a heterogeneous soil with rock fragments. In this study, the HYDRUS-2D numerical model was used to evaluate hydraulic parameters for heterogeneous gravel soil that was irregularly embedded with rock fragments in a grape production base. The centrifugal method (CM, tensiometer method (TM and inverse solution method (ISM were compared for various parameters in the van Genuchten function. The soil core method (SCM, disc infiltration method (DIM and inverse solution method (ISM were also investigated for measuring saturated hydraulic conductivity. Simulation with the DIM approach revealed a problem of overestimating soil water infiltration whereas simulation with the SCM approach revealed a problem of underestimating water movement as compared to actual field observation. The ISM approach produced the best simulation result even though this approach slightly overestimated soil moisture by ignoring the impact of rock fragments. This study provides useful information on the overall evaluation of soil hydraulic parameters attained with different measurement methods for simulating soil water movement and distribution in heterogeneous gravel soil.

  18. Measurement of ion profiles in TFTR neutral beamlines

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-02-01

    A technique is described whereby the ion dumps inside the TFTR Neutral Beam Test Stand were used to measure thermal profiles of the full-, half-, and third-energy ions. 136 thermocouples were installed on the full-energy ion dump, allowing full beam contours. Additional linear arrays across the widths of the half- and third-energy ion dumps provided a measure of the shape, in the direction parallel to the grid rails, of the half- and third-energy ions, and, hence, of the molecular ions extracted from the source. As a result of these measurements it was found that the magnet was more weakly focusing, by a factor of two, than expected, explaining past overheating of the full-energy ion dump. Hollow profiles on the half- and third-energy ion dumps were observed, suggesting that extraction of D 2 + and D 3 + are primarily from the edge of the ion source. If extraction of half-energy ions is from the edge of the accelerator, a divergence parallel to the grid rails of 0.6 degrees ±0.1 degrees results. It is postulated that a nonuniform gas profile near the accelerator is the cause of the hollow partial-energy ion profiles; the pressure being depressed over the accelerator by particles passing through this highly transparent structure. Primary electrons reaching the accelerator produce nonuniform densities of D 2 + through the ionization of this across the full-energy dump was examined as a means of reducing the power density. By unbalancing the current in the two coils of the magnet, on a shot by shot basis, by up to 2:1 ratio, it was possible to move the centerline of the full-energy ion beam sideways by ∼12.5 cm. The adoption of such a technique, with a ramp of the coil imbalance from 2:1 to 1:2 over a beam pulse, could reduce the power density by a factor of ≥1.5

  19. Measuring Radiation Damage from Heavy Energetic Ions in Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kostin, M., PI-MSU; Ronningen, R., PI-MSU; Ahle, L., PI-LLNL; Gabriel, T., Scientific Investigation and Development; Mansur, L., PI-ORNL; Leonard, K., ORNL; Mokhov, N., FNAL; Niita, K., RIST, Japan

    2009-02-21

    An intense beam of 122 MeV/u (9.3 GeV) 76Ge ions was stopped in aluminum samples at the Coupled Cyclotron Facility at NSCL, MSU. Attempts were made at ORNL to measure changes in material properties by measuring changes in electrical resistivity and microhardness, and by transmission electron microscopy characterization, for defect density caused by radiation damage, as a function of depth and integrated ion flux. These measurements are relevant for estimating damage to components at a rare isotope beam facility.

  20. Development of a simple, low cost, indirect ion beam fluence measurement system for ion implanters, accelerators

    Science.gov (United States)

    Suresh, K.; Balaji, S.; Saravanan, K.; Navas, J.; David, C.; Panigrahi, B. K.

    2018-02-01

    We developed a simple, low cost user-friendly automated indirect ion beam fluence measurement system for ion irradiation and analysis experiments requiring indirect beam fluence measurements unperturbed by sample conditions like low temperature, high temperature, sample biasing as well as in regular ion implantation experiments in the ion implanters and electrostatic accelerators with continuous beam. The system, which uses simple, low cost, off-the-shelf components/systems and two distinct layers of in-house built softwarenot only eliminates the need for costly data acquisition systems but also overcomes difficulties in using properietry software. The hardware of the system is centered around a personal computer, a PIC16F887 based embedded system, a Faraday cup drive cum monitor circuit, a pair of Faraday Cups and a beam current integrator and the in-house developed software include C based microcontroller firmware and LABVIEW based virtual instrument automation software. The automatic fluence measurement involves two important phases, a current sampling phase lasting over 20-30 seconds during which the ion beam current is continuously measured by intercepting the ion beam and the averaged beam current value is computed. A subsequent charge computation phase lasting 700-900 seconds is executed making the ion beam to irradiate the samples and the incremental fluence received by the sampleis estimated usingthe latest averaged beam current value from the ion beam current sampling phase. The cycle of current sampling-charge computation is repeated till the required fluence is reached. Besides simplicity and cost-effectiveness, other important advantages of the developed system include easy reconfiguration of the system to suit customisation of experiments, scalability, easy debug and maintenance of the hardware/software, ability to work as a standalone system. The system was tested with different set of samples and ion fluences and the results were verified using

  1. Experimental ion mobility measurements in Xe-CH4

    Science.gov (United States)

    Perdigoto, J. M. C.; Cortez, A. F. V.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

    2017-09-01

    Data on ion mobility is important to improve the performance of large volume gaseous detectors. In the present work, the method, experimental setup and results for the ion mobility measurements in Xe-CH4 mixtures are presented. The results for this mixture show the presence of two distinct groups of ions. The nature of the ions depend on the mixture ratio since they are originated by both Xe and CH4. The results here presented were obtained for low reduced electric fields, E/N, 10-25 Td (2.4-6.1 kV ṡ cm-1 ṡ bar-1), at low pressure (8 Torr) (10.6 mbar), and at room temperature.

  2. Mass and Charge Measurements on Heavy Ions

    Science.gov (United States)

    Sugai, Toshiki

    2017-01-01

    The relationship between mass and charge has been a crucial topic in mass spectrometry (MS) because the mass itself is typically evaluated based on the m/z ratio. Despite the fact that this measurement is indirect, a precise mass can be obtained from the m/z value with a high m/z resolution up to 105 for samples in the low mass and low charge region under 10,000 Da and 20 e, respectively. However, the target of MS has recently been expanded to the very heavy region of Mega or Giga Da, which includes large particles and biocomplexes, with very large and widely distributed charge from kilo to Mega range. In this region, it is necessary to evaluate charge and mass simultaneously. Recent studies for simultaneous mass and charge observation and related phenomena are discussed in this review. PMID:29302406

  3. Measurement of heterogeneous distribution on technegas SPECT images by three-dimensional fractal analysis

    International Nuclear Information System (INIS)

    Nagao, Michinobu; Murase, Kenya

    2002-01-01

    This review article describes a method for quantifying heterogeneous distribution on Technegas ( 99m Tc-carbon particle radioaerosol) SPECT images by three-dimensional fractal analysis (3D-FA). Technegas SPECT was performed to quantify the severity of pulmonary emphysema. We delineated the SPECT images by using five cut-offs (15, 20, 25, 30 and 35% of the maximal voxel radioactivity), and measured the total number of voxels in the areas surrounded by the contours obtained with each cut-off level. We calculated fractal dimensions from the relationship between the total number of voxels and the cut-off levels transformed into natural logarithms. The fractal dimension derived from 3D-FA is the relative and objective measurement, which can assess the heterogeneous distribution on Technegas SPECT images. The fractal dimension strongly correlate pulmonary function in patients with emphysema and well documented the overall and regional severity of emphysema. (author)

  4. The influence of idealized surface heterogeneity on virtual turbulent flux measurements

    Science.gov (United States)

    De Roo, Frederik; Mauder, Matthias

    2018-04-01

    The imbalance of the surface energy budget in eddy-covariance measurements is still an unsolved problem. A possible cause is the presence of land surface heterogeneity, which affects the boundary-layer turbulence. To investigate the impact of surface variables on the partitioning of the energy budget of flux measurements in the surface layer under convective conditions, we set up a systematic parameter study by means of large-eddy simulation. For the study we use a virtual control volume approach, which allows the determination of advection by the mean flow, flux-divergence and storage terms of the energy budget at the virtual measurement site, in addition to the standard turbulent flux. We focus on the heterogeneity of the surface fluxes and keep the topography flat. The surface fluxes vary locally in intensity and these patches have different length scales. Intensity and length scales can vary for the two horizontal dimensions but follow an idealized chessboard pattern. Our main focus lies on surface heterogeneity of the kilometer scale, and one order of magnitude smaller. For these two length scales, we investigate the average response of the fluxes at a number of virtual towers, when varying the heterogeneity length within the length scale and when varying the contrast between the different patches. For each simulation, virtual measurement towers were positioned at functionally different positions (e.g., downdraft region, updraft region, at border between domains, etc.). As the storage term is always small, the non-closure is given by the sum of the advection by the mean flow and the flux-divergence. Remarkably, the missing flux can be described by either the advection by the mean flow or the flux-divergence separately, because the latter two have a high correlation with each other. For kilometer scale heterogeneity, we notice a clear dependence of the updrafts and downdrafts on the surface heterogeneity and likewise we also see a dependence of the energy

  5. Measurements of gamma-ray energy deposition in a heterogeneous reactor experimental configuration and their analysis

    International Nuclear Information System (INIS)

    Calamand, D.; Wouters, R. de; Knipe, A.D.; Menil, R.

    1984-10-01

    An important contribution to the power output of a fast reactor is provided by the energy deposition from gamma-rays, and is particularly significant in the inner fertile zones of heterogeneous breeder reactor designs. To establish the validity of calculational methods and data for such systems an extensive series of measurements was performed in the zero power reactor Masurca, as part of the RACINE programme. The experimental study involved four European laboratories and the measurement techniques covered a range of thermoluminescent dosemeters and an ionization chamber. The present paper describes and compares the gamma-ray energy deposition measurements and analysis

  6. Measuring the electron-ion ring parameters by bremsstrahlung

    International Nuclear Information System (INIS)

    Inkin, V.D.; Mozelev, A.A.; Sarantsev, V.P.

    1982-01-01

    A system is described for measuring the number of electrons and ions in the electron-ion rings of a collective heavy ion accelerator. The system operation is based on detecting gamma quanta of bremsstrahlung following the ring electron interaction with the nuclei of neutral atoms and ions at different stages of filling the ring with ions. The radiation detector is a scintillation block - a photomultiplier operating for counting with NaI(Tl) crystal sized 30x30 mm and ensuring the detection efficiency close to unity. The system apparatus is made in the CAMAC standard and rems on-line with the TRA/i miniature computer. The block-diagrams of the system and algorithm of data processing are presented. A conclusion is drawn that the results of measuring the ring parameters with the use of the diagnostics system described are in good agreement within the range of measuring errors with those obtained by means of the diagnostics system employing synchrotron radiation and induction sensors

  7. Recent ion measurements within the modified DPF-1000U facility

    Directory of Open Access Journals (Sweden)

    Kwiatkowski Roch

    2015-06-01

    Full Text Available In this note we describe measurements of ion beams emitted along the z-axis of the DPF-1000U facility operated at 23 kV, 334 kJ, and with the initial deuterium pressure of 1.6–2 hPa. The DPF-1000U device was recently renewed and equipped with a dynamic gas-puff valve placed inside the inner electrode. The investigated ions were recorded by means of ion pinhole cameras equipped with solid state nuclear track detectors of the PM-355® (PADC type. The energy spectra of ions were determined using a Thomson spectrometer placed on the symmetry axis at a distance of 160 cm from the electrodes outlets. The ion images recorded during discharges performed under different experimental conditions show that the ion beams have a complex structure, usually in the form of a central bunch and an annular stream composed of many micro-beams. Energies of the registered deuterons have been in the range of 30–700 keV, while the fast protons (which originated from the hydrogen remnants had energies in the range of 300–850 keV.

  8. Energetic ion diagnostics using neutron flux measurements during pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W.W.

    1986-01-01

    Neutron measurements during injection of deuterium pellets into deuterium plasmas on the Tokamak Fusion Test Reactor (TFTR) indicate that the fractional increase in neutron emission about 0.5 msec after pellet injection is proportional to the fraction of beam-plasma reactions to total fusion reactions in the unperturbed plasma. These observations suggest three diagnostic applications of neutron measurements during pellet injection: (1) measurement of the beam-plasma reaction rate in deuterium plasmas for use in determining the fusion Q in an equivalent deuterium-tritium plasma, (2) measurement of the radial profile of energetic beam ions by varying the pellet size and velocity, and (3) measurement of the ''temperature'' of ions accelerated during wave heating. 18 refs., 3 figs.

  9. Energetic ion diagnostics using neutron flux measurements during pellet injection

    International Nuclear Information System (INIS)

    Heidbrink, W.W.

    1986-01-01

    Neutron measurements during injection of deuterium pellets into deuterium plasmas on the Tokamak Fusion Test Reactor (TFTR) indicate that the fractional increase in neutron emission about 0.5 msec after pellet injection is proportional to the fraction of beam-plasma reactions to total fusion reactions in the unperturbed plasma. These observations suggest three diagnostic applications of neutron measurements during pellet injection: (1) measurement of the beam-plasma reaction rate in deuterium plasmas for use in determining the fusion Q in an equivalent deuterium-tritium plasma, (2) measurement of the radial profile of energetic beam ions by varying the pellet size and velocity, and (3) measurement of the ''temperature'' of ions accelerated during wave heating. 18 refs., 3 figs

  10. Helicon plasma ion temperature measurements and observed ion cyclotron heating in proto-MPEX

    Science.gov (United States)

    Beers, C. J.; Goulding, R. H.; Isler, R. C.; Martin, E. H.; Biewer, T. M.; Caneses, J. F.; Caughman, J. B. O.; Kafle, N.; Rapp, J.

    2018-01-01

    The Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) linear plasma device is a test bed for exploring and developing plasma source concepts to be employed in the future steady-state linear device Material Plasma Exposure eXperiment (MPEX) that will study plasma-material interactions for the nuclear fusion program. The concept foresees using a helicon plasma source supplemented with electron and ion heating systems to reach necessary plasma conditions. In this paper, we discuss ion temperature measurements obtained from Doppler broadening of spectral lines from argon ion test particles. Plasmas produced with helicon heating alone have average ion temperatures downstream of the Helicon antenna in the range of 3 ± 1 eV; ion temperature increases to 10 ± 3 eV are observed with the addition of ion cyclotron heating (ICH). The temperatures are higher at the edge than the center of the plasma either with or without ICH. This type of profile is observed with electrons as well. A one-dimensional RF antenna model is used to show where heating of the plasma is expected.

  11. Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC

    International Nuclear Information System (INIS)

    Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S.; Bolte, N.; Marsili, P.; Roche, T.; Wessel, F.

    2010-01-01

    One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

  12. Review of intense-ion-beam propagation with a view toward measuring ion energy

    International Nuclear Information System (INIS)

    Garcia, M.

    1982-01-01

    The subject of this review is intense ion beam propagation and the possibilities of measuring time dependent ion energy in the beam. Propagation effects discussed include charge separation, charge and current autoneutralization, electron thermalization and current neutralization decay. The interaction of a plasma beam with material obstacles, like collimators, and with transverse magnetic fields is also described. Depending on beam energy, density and pulse length, these interactions can include material ablation with plasmadynamic flow and undeflected propagation across transverse magnetic fields by a polarization drift. On the basis of this review I conclude that three diagnostics: a single floating potential probe, net current probes (Faraday cups) and a Rutherford scattering spectrometer appear capable of giving prompt, time dependent ion energy measurements

  13. Electrophysiological heterogeneity of pacemaker cells in the rabbit intercaval region, including the SA node: insights from recording multiple ion currents in each cell.

    Science.gov (United States)

    Monfredi, Oliver; Tsutsui, Kenta; Ziman, Bruce; Stern, Michael D; Lakatta, Edward G; Maltsev, Victor A

    2018-03-01

    Cardiac pacemaker cells, including cells of the sinoatrial node, are heterogeneous in size, morphology, and electrophysiological characteristics. The exact extent to which these cells differ electrophysiologically is unclear yet is critical to understanding their functioning. We examined major ionic currents in individual intercaval pacemaker cells (IPCs) sampled from the paracristal, intercaval region (including the sinoatrial node) that were spontaneously beating after enzymatic isolation from rabbit hearts. The beating rate was measured at baseline and after inhibition of the Ca 2+ pump with cyclopiazonic acid. Thereafter, in each cell, we consecutively measured the density of funny current ( I f ), delayed rectifier K + current ( I K ) (a surrogate of repolarization capacity), and L-type Ca 2+ current ( I Ca,L ) using whole cell patch clamp . The ionic current densities varied to a greater extent than previously appreciated, with some IPCs demonstrating very small or zero I f . The density of none of the currents was correlated with cell size, while I Ca,L and I f densities were related to baseline beating rates. I f density was correlated with I K density but not with that of I Ca,L . Inhibition of Ca 2+ cycling had a greater beating rate slowing effect in IPCs with lower I f densities. Our numerical model simulation indicated that 1) IPCs with small (or zero) I f or small I Ca,L can operate via a major contribution of Ca 2+ clock, 2) I f -Ca 2+ -clock interplay could be important for robust pacemaking function, and 3) coupled I f - I K function could regulate maximum diastolic potential. Thus, we have demonstrated marked electrophysiological heterogeneity of IPCs. This heterogeneity is manifested in basal beating rate and response to interference of Ca 2+ cycling, which is linked to I f . NEW & NOTEWORTHY In the present study, a hitherto unrecognized range of heterogeneity of ion currents in pacemaker cells from the intercaval region is demonstrated

  14. Measurements of isomers at the FRS ion catcher

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, Christine [Justus-Liebig Universitaet Giessen (Germany); Collaboration: FRS Ion Catcher-Collaboration

    2016-07-01

    Projectile fragmentation and fission reactions at in-flight facilities are important production mechanisms to access short-lived exotic nuclei. It is a challenge to describe the angular momentum distribution after the collision of relativistic nuclei. This can be experimentally accessed by measuring the population of isomeric states. Isomeric ratios and excitation energies of isomers of short-lived exotic nuclei can be determined at the FRS Ion Catcher at GSI. At the FRS, projectile and fission fragments are produced at relativistic energies, separated in-flight and range-focused. They are slowed down and thermalized in a cryogenic stopping cell. In a multi-purpose RFQ beamline alpha spectroscopy can be performed. Alternatively the ions can be transported to a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS), where masses of the ground and isomeric states can be measured simultaneously with high resolving power. The MR-TOF-MS can also be used to spatially separate the ions in order to provide isomerically clean ion beams. During a recent experiment isomer-to-ground state ratios and excitation energies of uranium projectile and fission fragments produced at 1 GeV/u were measured. The ratios, measured with the MR-TOF-MS, were verified by alpha spectroscopy. Furthermore the ratios were compared to calculations based on an abrasion-ablation model of fragmentation.

  15. The GOES-16 Energetic Heavy Ion Sensor (EHIS) Ion Composition and Flux Measurements

    Science.gov (United States)

    Connell, J. J.; Lopate, C.

    2017-12-01

    The Energetic Heavy Ion Sensor (EHIS) was built by the University of New Hampshire, subcontracted to Assurance Technology Corporation, as part of the Space Environmental In-Situ Suite (SEISS) on the new GOES-16 satellite (formerly GOES-R) in Geostationary orbit. EHIS measures energetic ions over the range 10-200 MeV for protons, and energy ranges for heavy ions corresponding to the same stopping range (e.g., 19-207 MeV/u for carbon and 38-488 MeV/u for iron). EHIS uses the Angle Detecting Inclined Sensors (ADIS) technique to provide single-element charge resolution. Though on an operational mission for Space Weather monitoring, EHIS can thus provide a new source of high quality Solar Particle Event (SPE) data for science studies. With a high rate of on-board processing ( 2000 events/s), EHIS will provide exceptional statistics for ion composition measurements in large SPEs. For the GOES Level 1-B and Level 2 data products, heavy ions are distinguished in EHIS using pulse-height analysis with on-board processing producing charge histograms for five energy bands. Fits to these data are normalized to priority rate data on the ground. The instrumental cadence for histograms is 1 minute and the primary Level 1-B heavy ion data products are 1-minute and 5-minute averages. We discuss the preliminary EHIS heavy ion data results which show elemental peaks from H to Fe, with peaks for the isotopes D and 3He. (GOES-16 was launched in 19 November, 2016 and data has, though July 2017, been dominated by Galactic Cosmic Rays.) The EHIS instrument development project was funded by NASA under contract NNG06HX01C.

  16. Helicon plasma potential measurements using a heavy ion beam probe

    International Nuclear Information System (INIS)

    P. Schoch; K. Connor; J. Si

    2005-01-01

    A Heavy Ion Beam Probe, HIBP, has been installed on a helicon plasma device. The objective was to measure plasma fluctuations at the 13.55MHz RF frequency. This offers a unique challenge for the HIBP, because the transit time of the probing ion is long compared to the fluctuations of interest. For previous HIBPs, the transit time has been short compared to the period of the fluctuations which permits one to assume that the magnetic and electric fields are static. Modeling has shown that the diagnostic will still accurately measure the average potential. The fluctuating potential was to be detected but the absolute magnitude is difficult to determine with signal from a single point. However, modeling indicates multipoint measurements will allow one to resolve the absolute fluctuation magnitude. Work supported by DOE Grant No. DE-FG02-99ER5452985 During the funding of this grant, a helicon plasma discharge device was built and operated. A Heavy Ion Beam Probe primary system was installed and operated. A primary beam detector was installed and primary beam was detected both with and without plasma. Attempts were made to detect secondary ions using the primary beam detector, without success. Given the lack of a detectable signal, the energy analyzer of the HIBP system was never installed. It is available for installation if there is a reason to do so in the future. Analysis of the system indicated that the plasma electron temperature, estimated to be a few eV, was the likely reason for the lack of detectable secondary ions. A change of ion species to either Boron or Magnesium would greatly increase the signal, but neither of these ions have been used in a HIBP system. The ion source used in this system is made by using a charge exchange process to create a zeolite loaded with the desired ion. Attempts were made to use charge exchange to load Magnesium into a zeolite, and were not successful. It is felt that Magnesium and/or Boron zeolite sources could be created, but

  17. Target-ion source unit ionization efficiency measurement by method of stable ion beam implantation

    CERN Document Server

    Panteleev, V.N; Fedorov, D.V; Moroz, F.V; Orlov, S.Yu; Volkov, Yu.M

    The ionization efficiency is one of the most important parameters of an on-line used target-ion source system exploited for production of exotic radioactive beams. The ionization efficiency value determination as a characteristic of a target-ion source unit in the stage of its normalizing before on-line use is a very important step in the course of the preparation for an on-line experiment. At the IRIS facility (Petersburg Nuclear Physics Institute, Gatchina) a reliable and rather precise method of the target-ion source unit ionization efficiency measurement by the method of stable beam implantation has been developed. The method worked out exploits an off-line mass-separator for the implantation of the ion beams of selected stable isotopes of different elements into a tantalum foil placed inside the Faraday cup in the focal plane of the mass-separator. The amount of implanted ions has been measured with a high accuracy by the current integrator connected to the Faraday cup. After the implantation of needed a...

  18. A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions

    International Nuclear Information System (INIS)

    Engelage, J.; Crawford, H.J.; Greiner, L.; Kuo, C.

    1996-06-01

    The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed

  19. Bremsstrahlung and Ion Beam Current Measurements with SuSI ECR Ion Source

    International Nuclear Information System (INIS)

    Ropponen, T.

    2012-01-01

    This series of slides presents: the Superconducting Source for Ions (SuSI), the X-ray measurement setup, the different collimation schemes, the flat B operation versus B(min) operation, and the impact of tuning ∇B while keeping fixed field profile

  20. Experimental ion mobility measurements in Ne-N2

    International Nuclear Information System (INIS)

    Cortez, A.F.V.; Encarnação, P.M.C.C.; Santos, F.P.; Borges, F.I.G.M.; Conde, C.A.N.; Veenhof, R.; Neves, P.N.B.

    2016-01-01

    Data on ion mobility is important to improve the performance of large volume gaseous detectors, such as the ALICE TPC or in the NEXT experiment. In the present work the method, experimental setup and results for the ion mobility measurements in Ne-N 2 mixtures are presented. The results for this mixture show the presence of two peaks for different gas ratios of Ne-N 2 , low reduced electric fields, E / N , 10–20 Td (2.4–4.8 kV·cm −1 ·bar −1 ), low pressures 6–8 Torr (8–10.6 mbar) and at room temperature.

  1. Radioactive ion implantation as a tool for wear measurements

    International Nuclear Information System (INIS)

    Bagger, C.; Soerensen, G.

    1979-01-01

    The present paper deals with ion implantation of radioactive krypton ions in surfaces with aim of measuring wear of different magnetic materials in sound-heads. The technique is especially suited for a relatively fast comparison of wear-characteristics of materials of varying composition in small inaccessible areas. In the present case utilisation of a 60 KeV accelerator allows determination of a total wear as small as 0.05 μm with an accuracy of 10%. Further the technique yields information of the time dependence of the wear process with an accuracy less than 0.001 μm. (author)

  2. Experimental ion mobility measurements in Xe-CO2

    Science.gov (United States)

    Cortez, A. F. V.; Santos, M. A. G.; Veenhof, R.; Patra, R. N.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

    2017-06-01

    Data on ion mobility is important to improve the performance of large volume gaseous detectors. In the present work the method, experimental setup and results for the ion mobility measurements in Xe-CO2 mixtures are presented. The results for this mixture show the presence of only one peak for all gas ratios of Xe-CO2, low reduced electric fields, E/N, 10-25 Td (2.4-6.1 kV·cm-1·bar-1), low pressures 6-8 Torr (8-10.6 mbar), at room temperature.

  3. Dose measurement of ion implanted silicon by RBS technique

    International Nuclear Information System (INIS)

    Kamawanna, Teerasak; Intarasiri, Saweat; Prapunsri, Chowunchun; Thongleurm, Chome; Maleepatra, Saenee; Singkarat, Somsorn

    2003-10-01

    Surface modification can be achieved by ion implantation. This study used a 1 mm thick silicon wafer as a target which was implanted with Ar+ at 80 keV. The degree of the modification depends on both the ion energy and the implanted dose. The distribution of argon in the silicon substrate and the absolute implanted dose can be measured by using Rutherford Backscattering Spectrometry (RBS). These investigations utilized a 1.7 MV Tandetron accelerator system at Chiang Mai University. The dose determination by a direct calculation is in agreement with the simulation by the SIMNRA code

  4. A method for measuring light ion reaction cross sections

    International Nuclear Information System (INIS)

    Carlson, R.F.; Ingemarsson, A.; Lantz, M.

    2005-03-01

    An experimental procedure for measuring reaction cross sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross sections for five different sizes of the solid angles in steps from 99.1 to 99.8% of the total solid angle. The final reaction cross section values are obtained by extrapolation to the full solid angle

  5. Study of ion cyclotron fluctuations. Application to the measurement of the ion temperature

    International Nuclear Information System (INIS)

    Lehner, T.

    1982-02-01

    A diagnostic technique for measuring the ion temperature of tokamak-type plasmas was developed. A theoretical study was made of the form factor associated with the ion cyclotron waves; the influence of Te/Ti on the frequency of the extrema of the dispersion relations was demonstrated. The different effects able to modify the spectral density (in particular the drift velocity and the impurities) were investigated. The mechanisms of suprathermal excitation of cylotron waves in tokamaks were reviewed together with the various effects stabilizing the spectrum: collisions, shear of the magnetic field lines. The experimental realization of the diagnostic technique is based on Thomson scattering by the electron density fluctuations [fr

  6. Focal depth measurement of scanning helium ion microscope

    International Nuclear Information System (INIS)

    Guo, Hongxuan; Itoh, Hiroshi; Wang, Chunmei; Zhang, Han; Fujita, Daisuke

    2014-01-01

    When facing the challenges of critical dimension measurement of complicated nanostructures, such as of the three dimension integrated circuit, characterization of the focal depth of microscopes is important. In this Letter, we developed a method for characterizing the focal depth of a scanning helium ion microscope (HIM) by using an atomic force microscope tip characterizer (ATC). The ATC was tilted in a sample chamber at an angle to the scanning plan. Secondary electron images (SEIs) were obtained at different positions of the ATC. The edge resolution of the SEIs shows the nominal diameters of the helium ion beam at different focal levels. With this method, the nominal shapes of the helium ion beams were obtained with different apertures. Our results show that a small aperture is necessary to get a high spatial resolution and high depth of field images with HIM. This work provides a method for characterizing and improving the performance of HIM.

  7. Zero-inflated count models for longitudinal measurements with heterogeneous random effects.

    Science.gov (United States)

    Zhu, Huirong; Luo, Sheng; DeSantis, Stacia M

    2017-08-01

    Longitudinal zero-inflated count data arise frequently in substance use research when assessing the effects of behavioral and pharmacological interventions. Zero-inflated count models (e.g. zero-inflated Poisson or zero-inflated negative binomial) with random effects have been developed to analyze this type of data. In random effects zero-inflated count models, the random effects covariance matrix is typically assumed to be homogeneous (constant across subjects). However, in many situations this matrix may be heterogeneous (differ by measured covariates). In this paper, we extend zero-inflated count models to account for random effects heterogeneity by modeling their variance as a function of covariates. We show via simulation that ignoring intervention and covariate-specific heterogeneity can produce biased estimates of covariate and random effect estimates. Moreover, those biased estimates can be rectified by correctly modeling the random effects covariance structure. The methodological development is motivated by and applied to the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study, the largest clinical trial of alcohol dependence performed in United States with 1383 individuals.

  8. Advances in Surface Plasmon Resonance Imaging enable quantitative measurement of laterally heterogeneous coatings of nanoscale thickness

    Science.gov (United States)

    Raegen, Adam; Reiter, Kyle; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John

    2013-03-01

    The Surface Plasmon Resonance (SPR) phenomenon is routinely exploited to qualitatively probe changes to the optical properties of nanoscale coatings on thin metallic surfaces, for use in probes and sensors. Unfortunately, extracting truly quantitative information is usually limited to a select few cases - uniform absorption/desorption of small biomolecules and films, in which a continuous ``slab'' model is a good approximation. We present advancements in the SPR technique that expand the number of cases for which the technique can provide meaningful results. Use of a custom, angle-scanning SPR imaging system, together with a refined data analysis method, allow for quantitative kinetic measurements of laterally heterogeneous systems. We first demonstrate the directionally heterogeneous nature of the SPR phenomenon using a directionally ordered sample, then show how this allows for the calculation of the average coverage of a heterogeneous sample. Finally, the degradation of cellulose microfibrils and bundles of microfibrils due to the action of cellulolytic enzymes will be presented as an excellent example of the capabilities of the SPR imaging system.

  9. Simulation studies on measures to mitigate ion clouds

    Energy Technology Data Exchange (ETDEWEB)

    Babu Ganta, Prasanth; Masood, Ahmed; Rienen, Ursula van [Universitaet Rostock, Institut fuer Allgemeine Elektrotechnik (Germany); Sauerland, Dennis; Hillert, Wolfgang [Physikalisches Institut der Universitaet Bonn, ELSA (Germany); Meseck, Atoosa [HZB, Institut Beschleunigerphysik, Berlin (Germany)

    2016-07-01

    For future Energy Recovery Linacs (ERL), parasitic ions, which are generated by collisions of the beam and the rest gas in the vacuum chamber, present a limiting factor for the high current-low emittance electron beams. Clearing gaps, clearing electrodes and appropriate filling patterns are a remedy to keep the ion density in the accelerator at a level that allows for a minimum stability of the beam parameters. The MOEVE PIC Tracking code, which employs a 2D wake matrix, enables tracking simulations of the ion distribution over a relatively long period of up to thousands of interactions with the passing bunches. It enables to develop a deeper understanding of the ion-cloud behavior in order to design appropriate measures for their mitigation. For certain cases, it is sufficient to study the problem in 2D. Therefore, an additional 2D solver shall be implemented into MOEVE PIC Tracking in order to reduce the computation times. Numerical studies of ion cloud dynamics in beam guiding magnets and drift sections of electron machines will be shown and compared with experimental results obtained at the ELSA facility.

  10. EISCAT measurements of ion temperatures which indicate non-isotropic ion velocity distributions

    International Nuclear Information System (INIS)

    Perraut, S.; Brekke, A.; Hubert, D.

    1984-01-01

    Substantial increases of the ion temperature can be observed at high latitudes as a consequence of strong convection electric fields. We have measured, with EISCAT, three independent components of the ion velocity vector and temperature in the same scattering volume, at about 300 km. During periods of strong variations in ion velocity (consequently of the E-field), the ion temperatures derived at the 3 sites are different. This difference, which appears to be systematic for the two experiments studied, can be interpreted in terms of different ion temperature perpendicular and parallel to the magnetic field, i.e. Tsub(i perpendicular) greater than Tsub(i parallel). Assuming that a bi-Maxwellian distribution is present for convection electric field strengths as large as 50 mV m -1 , one obtains an anisotropy factor of approximately 1.5. It also appears that resonant charge exchange is the dominant collision process. During the evening sector events studied, the electron density was decreasing, whereas the electron temperature was generally increasing. Such events are strongly related to variations in the magnetic H component detected on the ground. (author)

  11. Positron emission medical measurements with accelerated radioactive ion beams

    International Nuclear Information System (INIS)

    Llacer, J.

    1988-01-01

    This paper reviews in some detail the process by which a heavy ion accelerator can be used to inject positron emitting radioactive particles into a human body for a range of possible medical measurements. The process of radioactive beam generation and injection is described, followed by a study of the relationship between activity that can be injected versus dose to the patient as a function of which of the positron emitting ions is used. It is found that 6 C 10 and 10 Ne 19 are the two isotopes that appear more promising for injection into humans. The design considerations for a non-tomographic instrument to obtain images from beam injections are outlined and the results of 10 Ne 19 preliminary measurements with human phantoms and actual patients for the determination of end-of-range of cancer therapy ion beams is reported. Accuracies in the order of ±1 mm in the measurements of stopping point of a therapy beam with safe doses to the patient are reported. The paper concludes with a simple analysis of requirements to extend the technique to on-line verification of cancer treatment and to nuclear medicine research and diagnostics measurements. 17 refs.; 16 figs.; 3 tabs

  12. MURI: An Integrated Multi-Scale Approach for Understanding Ion Transport in Complex Heterogeneous Organic Materials

    Science.gov (United States)

    2018-01-12

    small membrane samples. Mechanical properties were tested at 30 and 60°C under dry or water saturated gas conditions. Water in the membrane has a...hydroxide conductivity (Figure 3) of the films was measured under a CO2 free environment, using UHP nitrogen gas . We noticed PCMS-PCOE-PCMS-TTMPP gave a...movement of anions is not confined, thus showing a higher degree of freedom for diffusion. This kind of behaviour can tell us about lack of defined

  13. Application of ion chemistry to tropospheric VOC measurements

    International Nuclear Information System (INIS)

    Hansel, A.; Wisthaler, A.; Graus, M.; Grabmer, W.

    2002-01-01

    The main interest in tropospheric volatile organic compounds (VOCs) originating from biogenic sources such as forests and anthropogenic sources such as cities is because these reactive trace gases can have a significant impact on levels of oxidants such as ozone (O 3 ) and the hydroxyl radical (OH). The proton-transfer-reaction mass-spectrometry (PTR-MS) technique developed by Werner Lindingers Laboratory, utilizes positive ion chemistry to measure trace neutral concentrations in air. It has been applied in food research, medicine and environmental studies to gain gas phase information about VOCs at parts per trillion (pptv) levels.The real-time method relies on proton transfer reactions between H 3 O + primary ions and VOCs which have a higher proton affinity than water molecules. Organic trace gases such as hydrocarbons, carbonyls, alcohols, acetonitrile, and others can be monitored on-line.Results on tropospheric VOCs measurements in tropical regions and in cities are discussed. (nevyjel)

  14. Measurements of sputtering yields for low-energy plasma ions

    International Nuclear Information System (INIS)

    Nishi, M.; Yamada, M.; Suckewer, S.; Rosengaus, E.

    1979-04-01

    Sputtering yields of various wall/limiter materials of fusion devices have been extensively measured in the relevant plasma environment for low-energy light ions (E 14 cm -3 and electron temperature up to 10eV. Target materials used were C (graphite), Ti, Mo, Ta, W, and Fe (stainless steel). In order to study the dependence of the sputtering yields on the incident energy of ions, the target samples were held at negative bias voltage up to 300V. The sputtering yields were determined by a weight-loss method and by spectral line intensity measurements. The data obtained in the present experiment agree well with those previously obtained at the higher energies (E greater than or equal to 200eV) by other authors using different schemes; the present data also extend to substantially lower energies (E approx. > 30eV) than hitherto

  15. Active ion temperature measurement with heating neutral beam

    International Nuclear Information System (INIS)

    Miura, Yukitoshi; Matsuda, Toshiaki; Yamamoto, Shin

    1987-03-01

    When the heating neutral-beam (hydrogen beam) is injected into a deuterium plasma, the density of neutral particles is increased locally. By using this increased neutral particles, the local ion temperature is measured by the active charge-exchange method. The analyzer is the E//B type mass-separated neutral particle energy analyzer and the measured position is about one third outside of the plasma radius. The deuterium energy spectrum is Maxwellian, and the temperature is increased from 350 eV to 900 eV during heating. Since the local hydrogen to deuterium density concentration and the density of the heating neutral-beam as well as the ion temperature can be obtained good S/N ratio, the usefulness of this method during neutral-beam heating is confirmed by this experiment. (author)

  16. Airborne-Measured Spatially-Averaged Temperature and Moisture Turbulent Structure Parameters Over a Heterogeneous Surface

    Science.gov (United States)

    Platis, Andreas; Martinez, Daniel; Bange, Jens

    2014-05-01

    Turbulent structure parameters of temperature and humidity can be derived from scintillometer measurements along horizontal paths of several 100 m to several 10 km. These parameters can be very useful to estimate the vertical turbulent heat fluxes at the surface (applying MOST). However, there are many assumptions required by this method which can be checked using in situ data, e.g. 1) Were CT2 and CQ2 correctly derived from the initial CN2 scintillometer data (structure parameter of density fluctuations or refraction index, respectively)? 2) What is the influence of the surround hetereogeneous surface regarding its footprint and the weighted averaging effect of the scintillometer method 3) Does MOST provide the correct turbulent fluxes from scintillometer data. To check these issues, in situ data from low-level flight measurements are well suited, since research aircraft cover horizontal distances in very short time (Taylor's hypothesis of a frozen turbulence structure can be applyed very likely). From airborne-measured time series the spatial series are calculated and then their structure functions that finally provide the structure parameters. The influence of the heterogeneous surface can be controlled by the definition of certain moving-average window sizes. A very useful instrument for this task are UAVs since they can fly very low and maintain altitude very precisely. However, the data base of such unmanned operations is still quite thin. So in this contribution we want to present turbulence data obtained with the Helipod, a turbulence probe hanging below a manned helicopter. The structure parameters of temperature and moisture, CT2 and CQ2, in the lower convective boundary layer were derived from data measured using the Helipod in 2003. The measurements were carried out during the LITFASS03 campaign over a heterogeneous land surface around the boundary-layer field site of the Lindenberg Meteorological Observatory-Richard-Aßmann-Observatory (MOL) of the

  17. Measurement of the ion temperature in a diffuse theta pinch

    International Nuclear Information System (INIS)

    Kudo, Koichi; Watanabe, Yukio; Ogi, Sukeomi; Sumikawa, Toshio; Akazaki, Masanori

    1979-01-01

    The Doppler broadening of helium ion spectra was observed, and the ion temperature of theta pinch plasma was obtained. The apparatus for the measurement consists of a spectroscope, a photomultiplier and an oscilloscope. The time variation of initial plasma density was obtained. The doppler broadening of the spectra was observed in case of the plasma density of 2 x 10 13 /cm 3 and 3 x 10 12 /cm 3 . The analyses of the spectra gave the ion temperature. The double temperature distribution was seen. The temperature of the low temperature part was 5 to 9 electron-volt, and that of the high temperature part several hundred electron-volt. The high temperature is caused by the thermalization of particles accelerated by the magnetic piston. The decay of high temperature ions is due to the charge exchange with the neutral particles. The time of the highest temperature corresponds to the time at which the luminescent layer reaches to the central axis. (Kato, T.)

  18. Raman microprobe measurements of stress in ion implanted materials

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, K W; Prawer, S; Weiser, P S; Dooley, S P [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1994-12-31

    Raman microprobe measurements of ion implanted diamond and silicon have shown significant shifts in the Raman line due to stresses in the materials. The Raman line shifts to higher energy if the stress is compressive and to lower energy for tensile stress{sup 1}. The silicon sample was implanted in a 60 {mu}m square with 2.56 x 10{sup 17} ions per square centimeter of 2 MeV Helium. This led to the formation of raised squares with the top 370mm above the original surface. In Raman studies of silicon using visible light, the depth of penetration of the laser beam into the sample is much less than one micron. It was found that the Raman line is due to the silicon overlying the damage region. The diamond sample was implanted with 2 x 10{sup 15} ions per square centimeter of 2.8 MeV carbon. It was concluded that the Raman spectrum could provide information concerning both the magnitude and the direction of stress in an ion implanted sample. It was possible in some cases to determine whether the stress direction is parallel or perpendicular to the sample surface. 1 refs., 2 figs.

  19. Raman microprobe measurements of stress in ion implanted materials

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, K.W.; Prawer, S.; Weiser, P.S.; Dooley, S.P. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Raman microprobe measurements of ion implanted diamond and silicon have shown significant shifts in the Raman line due to stresses in the materials. The Raman line shifts to higher energy if the stress is compressive and to lower energy for tensile stress{sup 1}. The silicon sample was implanted in a 60 {mu}m square with 2.56 x 10{sup 17} ions per square centimeter of 2 MeV Helium. This led to the formation of raised squares with the top 370mm above the original surface. In Raman studies of silicon using visible light, the depth of penetration of the laser beam into the sample is much less than one micron. It was found that the Raman line is due to the silicon overlying the damage region. The diamond sample was implanted with 2 x 10{sup 15} ions per square centimeter of 2.8 MeV carbon. It was concluded that the Raman spectrum could provide information concerning both the magnitude and the direction of stress in an ion implanted sample. It was possible in some cases to determine whether the stress direction is parallel or perpendicular to the sample surface. 1 refs., 2 figs.

  20. Measurements of scattering processes in negative ion-atom collisions

    International Nuclear Information System (INIS)

    Kvale, T.J.

    1992-01-01

    This Technical Progress Report describes the progress made on the research objectives during the past twelve months. This research project is designed to provide measurements of various scattering processes which occur in H - collisions with atomic (specifically, noble gas and atomic hydrogen) targets at intermediate energies. These processes include: elastic scattering,single- and double-electron detachment, and target excitation/ionization. For the elastic and target inelastic processes where H - is scattered intact, the experimental technique of Ion Energy-Loss Spectroscopy (IELS) will be employed to identify the final target state(s). In most of the above processes, cross sections are unknown both experimentally and theoretically. The measurements in progress will provide either experimentally-determined cross sections or set upper limits to those cross sections. In either case, these measurements will be stringent tests of our understanding in energetic negative ion-atom collisions. This series of experiments required the construction of a new facility and the initial ion beam was accelerated through the apparatus in April 1991

  1. Modeling the heterogeneity of human dynamics based on the measurements of influential users in Sina Microblog

    Science.gov (United States)

    Wang, Chenxu; Guan, Xiaohong; Qin, Tao; Yang, Tao

    2015-06-01

    Online social network has become an indispensable communication tool in the information age. The development of microblog also provides us a great opportunity to study human dynamics that play a crucial role in the design of efficient communication systems. In this paper we study the characteristics of the tweeting behavior based on the data collected from Sina Microblog. The user activity level is measured to characterize how often a user posts a tweet. We find that the user activity level follows a bimodal distribution. That is, the microblog users tend to be either active or inactive. The inter-tweeting time distribution is then measured at both the aggregate and individual levels. We find that the inter-tweeting time follows a piecewise power law distribution of two tails. Furthermore, the exponents of the two tails have different correlations with the user activity level. These findings demonstrate that the dynamics of the tweeting behavior are heterogeneous in different time scales. We then develop a dynamic model co-driven by the memory and the interest mechanism to characterize the heterogeneity. The numerical simulations validate the model and verify that the short time interval tweeting behavior is driven by the memory mechanism while the long time interval behavior by the interest mechanism.

  2. Measurement of energy deposition near heavy ion tracks

    International Nuclear Information System (INIS)

    Metting, N.F.; Brady, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Wong, M.; Schimmerling, W.; Rapkin, M.

    1985-01-01

    In November of 1982 work was begun in collaboration with Columbia University and Lawrence Berkeley Laboratory to use microdosimetric methods to measure energy deposition of heavy ions produced at LBL's Bevalac Biomedical Facility. Last year the authors reported preliminary results indicating that secondary charged particle equilibrium was probably obtained using this experimental setup, but that there seemed to be poor spatial resolution in the solid state position-sensitive detector. Further analysis of the measurements taken in August 1983 shows that because of this electronic noise in the position-sensitive detector, only the 56 Fe data yielded useful microdosimetric spectra

  3. Development of negative heavy ion sources for plasma potential measurement

    International Nuclear Information System (INIS)

    Sasao, M.; Okabe, Y.; Fujisawa, A.; Iguchi, H.; Fujita, J.; Yamaoka, H.; Wada, M.

    1991-10-01

    A plasma sputter negative ion source was studied for its applicability to the potential measurement of a fusion plasma. Both the beam current density and the beam energy spread are key issues. Energy spectra of a self extracted Au - beam from the source were measured under the condition of a constant work function of the production surface. The full width of half maximum (FWHM) increases from 3 eV to 9 eV monotonically as the target voltage increases from 50 V to 300 V, independently from the target surface work function of 2.2 - 3 eV. (author)

  4. A method for measuring light ion reaction cross-sections

    International Nuclear Information System (INIS)

    Carlson, R.F.; Ingemarsson, A.; Lantz, M.; Arendse, G.J.; Auce, A.; Cox, A.J.; Foertsch, S.V.; Jacobs, N.M.; Johansson, R.; Nyberg, J.; Peavy, J.; Renberg, P.-U.; Sundberg, O.; Stander, J.A.; Steyn, G.F.; Tibell, G.; Zorro, R.

    2005-01-01

    An experimental procedure for measuring reaction cross-sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross-sections for five different sizes of the solid angle in steps from 99.1% to 99.8% of the total solid angle. The final reaction cross-section values are obtained by extrapolation to the full solid angle

  5. Measurements of the sensitivity of radiochromic film using ion beams

    Science.gov (United States)

    Steidle, J. A.; Shortino, J. P.; Ellison, D. M.; Freeman, C. G.; Sangster, T. C.

    2013-10-01

    Radiochromic film (RCF) is used in several diagnostics as a dosimeter that chromatically responds to incident particles. This response depends on the fluence, energy, and species of the incident particles. A 1.7 MV tandem Pelletron accelerator is used to create a monoenergetic ion beam which is scattered off a thin gold target onto a strip of RCF. A surface barrier detector is positioned behind a small hole in the film to measure the ion fluence on the nearby film. Once the film develops, it is scanned to examine its optical density. A response curve is acquired by fitting a three parameter formula to optical density and dose. These calibration curves can be used to help determine incident doses in a variety of situations.

  6. Heavy ion measurements by use of chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1980-01-01

    In order to test whether the threshold system polyvinyl alcohol/methyl organe/chloral hydrate/sodium tetraborate permits quantitative detection of individual particles, the chemical detector was irradiated at the JINR U-200 cyclotron with 4 He, 12 C, 18 O, 22 Ne ions having different LET. Irradiations were performed with detectors of four different borax concentrations (the chloral hydrate concentration being constant). The colour change dose Dsub(u) increases linearly with increasing borax concentration and at constant borax concentration with increasing LET. Hence it follows that the G value of dehydrochlorination decreases with increasing LET. Fluence ranges measurable with detectors of different composition are given for the heavy ions studied. (author)

  7. Experimental ion mobility measurements in Xe-CF4 mixtures

    Science.gov (United States)

    Cortez, A. F. V.; Kaja, M. A.; Escada, J.; Santos, M. A. G.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

    2018-04-01

    In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon with carbon tetrafluoride (Xe-CF4) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 to 25 Td range (2.4-6.1 kVṡcm‑1ṡbar‑1), at room temperature. The time-of-arrival spectra revealed one or two peaks depending on the gas relative abundances, which were attributed to CF3+ and to Xe2+ ions. However, for Xe concentrations above 60%, only one peak remains (Xe2+). The reduced mobilities obtained from the peak centroid of the time-of-arrival spectra are presented for Xe concentrations in the 5%-95% range.

  8. Network measurements at the heavy ion synchrotron SIS at GSI

    International Nuclear Information System (INIS)

    Vossbeck, P.; Pschorn, I.; Gebhard, Moritz

    1999-01-01

    The Heavy Ion Synchrotron SIS forms together with the Linear Accelerator UNILAC and the Storage Ring ESR the accelerator complex of the Gesellschaft fuer Schwerionenforschung in Darmstadt. It accelerates heavy ions up to Uranium to 1 GeV/amu. The accelerators and beamlines have been surveyed and aligned using the TASA method. For SIS a network was established in order to survey the synchrotron with the TASA method. Goal of a diploma thesis was to establish an alternative network for a Laser Tracker instrument and to reach error ellipsoids below 30 μm. In this paper a comparison of the two methods is given. Since the Tracker measurements are done automatically only one person is needed. That reduces the man power. Time consumption for both methods is about the same, although much more network points were used with the Laser Tracker method. As a consequence of the larger number of network points the homogeneity of the results is better. (authors)

  9. Magnetized retarding field energy analyzer measuring the particle flux and ion energy distribution of both positive and negative ions

    International Nuclear Information System (INIS)

    Rafalskyi, Dmytro; Aanesland, Ane; Dudin, Stanislav

    2015-01-01

    This paper presents the development of a magnetized retarding field energy analyzer (MRFEA) used for positive and negative ion analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic ion energy barrier allowing both positive and negative ions to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for ion-ion beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced. The optimal design consists of a uniform magnetic field barrier created in a rectangular channel and an electrostatic barrier consisting of a single grid and a collector placed behind the magnetic field. The magnetic barrier alone provides an electron suppression ratio inside the analyzer of up to 6000, while keeping the ion energy resolution below 5 eV. The effective ion transparency combining the magnetic and electrostatic sections of the MRFEA is measured as a function of the ion energy. It is found that the ion transparency of the magnetic barrier increases almost linearly with increasing ion energy in the low-energy range (below 200 eV) and saturates at high ion energies. The ion transparency of the electrostatic section is almost constant and close to the optical transparency of the entrance grid. We show here that the MRFEA can provide both accurate ion flux and ion energy distribution measurements in various experimental setups with ion beams or plasmas run at low pressure and with ion energies above 10 eV

  10. Reactor for in situ measurements of spatially resolved kinetic data in heterogeneous catalysis

    Science.gov (United States)

    Horn, R.; Korup, O.; Geske, M.; Zavyalova, U.; Oprea, I.; Schlögl, R.

    2010-06-01

    The present work describes a reactor that allows in situ measurements of spatially resolved kinetic data in heterogeneous catalysis. The reactor design allows measurements up to temperatures of 1300 °C and 45 bar pressure, i.e., conditions of industrial relevance. The reactor involves reactants flowing through a solid catalyst bed containing a sampling capillary with a side sampling orifice through which a small fraction of the reacting fluid (gas or liquid) is transferred into an analytical device (e.g., mass spectrometer, gas chromatograph, high pressure liquid chromatograph) for quantitative analysis. The sampling capillary can be moved with μm resolution in or against flow direction to measure species profiles through the catalyst bed. Rotation of the sampling capillary allows averaging over several scan lines. The position of the sampling orifice is such that the capillary channel through the catalyst bed remains always occupied by the capillary preventing flow disturbance and fluid bypassing. The second function of the sampling capillary is to provide a well which can accommodate temperature probes such as a thermocouple or a pyrometer fiber. If a thermocouple is inserted in the sampling capillary and aligned with the sampling orifice fluid temperature profiles can be measured. A pyrometer fiber can be used to measure the temperature profile of the solid catalyst bed. Spatial profile measurements are demonstrated for methane oxidation on Pt and methane oxidative coupling on Li/MgO, both catalysts supported on reticulated α -Al2O3 foam supports.

  11. Physical measurements for ion range verification in charged particle therapy

    International Nuclear Information System (INIS)

    Testa, M.

    2010-10-01

    This PhD thesis reports on the experimental investigation of the prompt photons created during the fragmentation of the carbon beam used in particle therapy. Two series of experiments have been performed at the GANIL and GSI facilities with 95 MeV/u and 305 MeV/u 12 C 6+ ion beams stopped in PMMA and water phantoms. In both experiments a clear correlation was obtained between the C-ion range and the prompt photon profile. A major issue of these measurements is the discrimination between the prompt photon signal (which is correlated with the ion path) and a vast neutron background uncorrelated with the Bragg-Peak position. Two techniques are employed to allow for this photon-neutron discrimination: the time-of-flight (TOF) and the pulse-shape-discrimination (PSD). The TOF technique allowed demonstrating the correlation of the prompt photon production and the primary ion path while the PSD technique brought great insights to better understand the photon and neutron contribution in TOF spectra. In this work we demonstrated that a collimated set-up detecting prompt photons by means of TOF measurements, could allow real-time control of the longitudinal position of the Bragg-peak under clinical conditions. In the second part of the PhD thesis a simulation study was performed with Geant4 Monte Carlo code to assess the influence of the main design parameters on the efficiency and spatial resolution achievable with a multidetector and multi-collimated Prompt Gamma Camera. Several geometrical configurations for both collimators and stack of detectors have been systematically studied and the considerations on the main design constraints are reported. (author)

  12. Heterogeneity in white blood cells has potential to confound DNA methylation measurements.

    Directory of Open Access Journals (Sweden)

    Bjorn T Adalsteinsson

    Full Text Available Epigenetic studies are commonly conducted on DNA from tissue samples. However, tissues are ensembles of cells that may each have their own epigenetic profile, and therefore inter-individual cellular heterogeneity may compromise these studies. Here, we explore the potential for such confounding on DNA methylation measurement outcomes when using DNA from whole blood. DNA methylation was measured using pyrosequencing-based methodology in whole blood (n = 50-179 and in two white blood cell fractions (n = 20, isolated using density gradient centrifugation, in four CGIs (CpG Islands located in genes HHEX (10 CpG sites assayed, KCNJ11 (8 CpGs, KCNQ1 (4 CpGs and PM20D1 (7 CpGs. Cellular heterogeneity (variation in proportional white blood cell counts of neutrophils, lymphocytes, monocytes, eosinophils and basophils, counted by an automated cell counter explained up to 40% (p<0.0001 of the inter-individual variation in whole blood DNA methylation levels in the HHEX CGI, but not a significant proportion of the variation in the other three CGIs tested. DNA methylation levels in the two cell fractions, polymorphonuclear and mononuclear cells, differed significantly in the HHEX CGI; specifically the average absolute difference ranged between 3.4-15.7 percentage points per CpG site. In the other three CGIs tested, methylation levels in the two fractions did not differ significantly, and/or the difference was more moderate. In the examined CGIs, methylation levels were highly correlated between cell fractions. In summary, our analysis detects region-specific differential DNA methylation between white blood cell subtypes, which can confound the outcome of whole blood DNA methylation measurements. Finally, by demonstrating the high correlation between methylation levels in cell fractions, our results suggest a possibility to use a proportional number of a single white blood cell type to correct for this confounding effect in analyses.

  13. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging

    Directory of Open Access Journals (Sweden)

    Zuzana eBurdikova

    2015-03-01

    Full Text Available Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g. pH, redox potential due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM. In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.

  14. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging.

    Science.gov (United States)

    Burdikova, Zuzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G; Panek, Jiri; Auty, Mark A E; Periasamy, Ammasi; Sheehan, Jeremiah J

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.

  15. Spectroscopic techniques for measuring ion diode space-charge distributions and ion source properties

    Energy Technology Data Exchange (ETDEWEB)

    Filuk, A B; Bailey, J E; Adams, R G [Sandia Labs., Albuquerque, NM (United States); and others

    1997-12-31

    The authors are using time- and space-resolved visible spectroscopy to measure applied-B ion diode dynamics on the 20 TW Particle Beam Fusion Accelerator II. Doppler broadening of fast Li atoms, as viewed parallel to the anode, is used in a charge-exchange model to obtain the Li{sup +} ion divergence within 100 {mu}m of the anode surface. The characteristic Stark/Zeeman shifts in spectra of alkali neutrals or singly-ionized alkaline-earths are used to measure the strong electric (10{sup 9} V/m) an magnetic ({approx} 6 T) fields in the diode gap. Large Stark shifts within 0.5 mm of the anode indicate the LiF emits with a finite field threshold rather than with Child-Langmuir-type emission, and the small slope in the electric field indicates an unexpected build-up of electrons near the anode. In the diode gap, the authors aim to unfold fields to quantify the time-dependent ion and electron space-charge distributions that determine the ion beam properties. Observed electric field non-uniformities give local beam deflections that can be comparable to the total beam microdivergence. The authors are implementing active laser absorption and laser-induced fluorescence spectroscopy on low-density Na atoms injected into the diode gap prior to the power pulse. The small Doppler broadening in the Na spectra should allow simultaneous electric and magnetic field mapping with improved spatial resolution. (author). 4 figs., 13 refs.

  16. Application of spatial time domain reflectometry measurements in heterogeneous, rocky substrates

    Science.gov (United States)

    Gonzales, C.; Scheuermann, A.; Arnold, S.; Baumgartl, T.

    2016-10-01

    Measurement of soil moisture across depths using sensors is currently limited to point measurements or remote sensing technologies. Point measurements have limitations on spatial resolution, while the latter, although covering large areas may not represent real-time hydrologic processes, especially near the surface. The objective of the study was to determine the efficacy of elongated soil moisture probes—spatial time domain reflectometry (STDR)—and to describe transient soil moisture dynamics of unconsolidated mine waste rock materials. The probes were calibrated under controlled conditions in the glasshouse. Transient soil moisture content was measured using the gravimetric method and STDR. Volumetric soil moisture content derived from weighing was compared with values generated from a numerical model simulating the drying process. A calibration function was generated and applied to STDR field data sets. The use of elongated probes effectively assists in the real-time determination of the spatial distribution of soil moisture. It also allows hydrologic processes to be uncovered in the unsaturated zone, especially for water balance calculations that are commonly based on point measurements. The elongated soil moisture probes can potentially describe transient substrate processes and delineate heterogeneity in terms of the pore size distribution in a seasonally wet but otherwise arid environment.

  17. Measurements of the fast ion distribution during neutral beam injection and ion cyclotron heating in ATF [Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Wade, M.R.; Kwon, M.; Thomas, C.E.; Colchin, R.J.; England, A.C.; Gossett, J.M.; Horton, L.D.; Isler, R.C.; Lyon, J.F.; Rasmussen, D.A.; Rayburn, T.M.; Shepard, T.D.; Bell, G.L.; Fowler, R.H.; Morris, R.N.

    1990-01-01

    A neutral particle analyzer (NPA) with horizontal and vertical scanning capability has been used to make initial measurements of the fast ion distribution during neutral beam injection (NBI) and ion cyclotron heating (ICH) on the Advanced Toroidal Facility (ATF). These measurements are presented and compared with the results of modeling codes that predict the analyzer signals during these heating processes. 6 refs., 5 figs

  18. Lifetime measurements in an electrostatic ion beam trap using image charge monitoring

    International Nuclear Information System (INIS)

    Rahinov, Igor; Toker, Yoni; Heber, Oded; Rappaport, Michael; Zajfman, Daniel; Strasser, Daniel; Schwalm, Dirk

    2012-01-01

    A technique for mass-selective lifetime measurements of keV ions in a linear electrostatic ion beam trap is presented. The technique is based on bunching the ions using a weak RF potential and non-destructive ion detection by a pick-up electrode. This method has no mass-limitation, possesses the advantage of inherent mass-selectivity, and offers a possibility of measuring simultaneously the lifetimes of different ion species with no need for prior mass-selection.

  19. Towards polarization measurements of laser-accelerated helium-3 ions

    Energy Technology Data Exchange (ETDEWEB)

    Engin, Ilhan

    2015-08-28

    In the framework of this thesis, preparatory investigations for the spin-polarization measurement of {sup 3}He ions from laser-induced plasmas have been performed. Therefore, experiments aiming at an efficient laser-induced ion acceleration out of a {sup 4}He gas target were carried out at two high-intensity laser facilities: the Arcturus laser at Heinrich-Heine-Universitaet Duesseldorf as well as PHELIX at GSI Darmstadt. The scientific goal of both experiments was to investigate the ion-acceleration process in underdense plasmas by measuring the ion energy spectra and the angular distribution of the ion signal around the gas-jet target. Laser-accelerated MeV-He-ions could successfully be detected. The main acceleration direction at large angles with regard to the laser propagation direction was determined. In a second step, unpolarized {sup 3}He gas was attached in order to cross-check the experimental results with those of {sup 4}He. With the help of the achieved ion yield data, the expected rates of the fusion reaction D({sup 3}He,p){sup 4}He in the polarized case have been estimated: the information regarding the fusion proton yield from this nuclear reaction allows an experimentally based estimation for future experiments with pre-polarized {sup 3}He gas as plasma target. The experimental data is in line with supporting Particle-in-Cell (PIC) simulations performed on the Juelich supercomputers. For this purpose, the simulated target was defined as a neutral gas. The use of pre-polarized {sup 3}He gas demands a special preparation of a polarized {sup 3}He target for laser-acceleration experiments. This layout includes an (external) homogeneous magnetic holding field (field strength of ∝1.4 mT) for storing the pre-polarized gas for long time durations inside the PHELIX target chamber. For this purpose, a precise Halbach array consisting of horizontally arranged rings with built-in permanent magnets had to be designed, optimized, and constructed to deliver high

  20. Heterogeneity of Glucose Metabolism in Esophageal Cancer Measured by Fractal Analysis of Fluorodeoxyglucose Positron Emission Tomography Image: Correlation between Metabolic Heterogeneity and Survival.

    Science.gov (United States)

    Tochigi, Toru; Shuto, Kiyohiko; Kono, Tsuguaki; Ohira, Gaku; Tohma, Takayuki; Gunji, Hisashi; Hayano, Koichi; Narushima, Kazuo; Fujishiro, Takeshi; Hanaoka, Toshiharu; Akutsu, Yasunori; Okazumi, Shinichi; Matsubara, Hisahiro

    2017-01-01

    Intratumoral heterogeneity is a well-recognized characteristic feature of cancer. The purpose of this study is to assess the heterogeneity of the intratumoral glucose metabolism using fractal analysis, and evaluate its prognostic value in patients with esophageal squamous cell carcinoma (ESCC). 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) studies of 79 patients who received curative surgery were evaluated. FDG-PET images were analyzed using fractal analysis software, where differential box-counting method was employed to calculate the fractal dimension (FD) of the tumor lesion. Maximum standardized uptake value (SUVmax) and FD were compared with overall survival (OS). The median SUVmax and FD of ESCCs in this cohort were 13.8 and 1.95, respectively. In univariate analysis performed using Cox's proportional hazard model, T stage and FD showed significant associations with OS (p = 0.04, p heterogeneity measured by fractal analysis can be a novel imaging biomarker for survival in patients with ESCC. © 2016 S. Karger AG, Basel.

  1. Energy-loss measurements with heavy ions at relativistic energies

    International Nuclear Information System (INIS)

    Blank, B.; Gaimard, J.J.; Geissel, H.; Muenzenberg, G.; Schmidt, K.H.; Stelzer, H.; Suemmerer; Clerc, H.G.; Hanelt, E.; Steiner, M.; Voss, B.

    1990-03-01

    Using the magnetic spectrometer SPES I at SATURNE, energy-loss measurements have been performed for projectiles of 40 Ar (401 MeV/u), 36 P (362 MeV/u), 15 N (149 MeV/u), 11 Li (131 MeV/u) and 8 Li, 9 Li (130 MeV/u) in carbon, aluminum and lead targets. The experimental results are compared to calculations based on a modified relativistic Bethe formula and to a semi-empirical formula using a Z 2 scaling law for the stopping power and an effective charge parametrization for the heavy ions. (orig.)

  2. Measurement of extent of intense ion beam charge neutralization

    Energy Technology Data Exchange (ETDEWEB)

    Engelko, V [Efremov Institute of Electrophysical Apparatus, St. Petersburg (Russian Federation); Giese, H; Schalk, S [Forschungszentrum Karlsruhe (Germany). INR

    1997-12-31

    Various diagnostic tools were employed to study and optimize the extent of space charge neutralization in the pulsed intense proton beam facility PROFA, comprising Langmuir probes, capacitive probes, and a novel type of the three electrode collector. The latter does not only allow us to measure ion and electron beam current densities in a high magnetic field environment, but also to deduce the density spectrum of the beam electrons. Appropriate operating conditions were identified to attain a complete space charge neutralisation. (author). 5 figs., 4 refs.

  3. STM and transport measurements of highly charged ion modified materials

    International Nuclear Information System (INIS)

    Pomeroy, J.M.; Grube, H.; Perrella, A.C.; Gillaspy, J.D.

    2007-01-01

    Careful measurements of highly charged ions (HCIs) colliding with gases and surfaces have provided glimpses of intense electronic interactions, but a comprehensive model for the interaction mechanisms, time scales, and resultant nano-features that bridges materials systems is yet to be realized. At the National Institute of Standards and Technology (NIST) electron beam ion trap (EBIT) facility, new apparatus is now connected to the HCI beamline to allow preparation of clean, atomically flat surfaces of single crystals, e.g. gold, tungsten and silicon, and deposition and patterning of thin films, e.g. high resistivity oxides, ferromagnetic metals, normal metals and superconductors. Experiments reported here focus on the electronic and morphological structure of HCI induced nano-features. Current activities are focused on using in situ scanning tunneling microscope (STM) on Au(1 1 1) and (separately) ex situ transport measurements to study electronic properties within HCI modified magnetic multilayer systems. Specifically, we are fabricating magnetic multilayers similar to magnetic tunnel junctions (MTJs) (important in advanced magnetic field sensors and superconducting Josephson junction devices) and using HCIs to adjust critical electronic properties. The electrical response of the tunnel junction to HCIs provides a novel approach to performing HCI-induced nanostructure ensemble measurements

  4. Junction Potentials Bias Measurements of Ion Exchange Membrane Permselectivity.

    Science.gov (United States)

    Kingsbury, Ryan S; Flotron, Sophie; Zhu, Shan; Call, Douglas F; Coronell, Orlando

    2018-04-17

    Ion exchange membranes (IEMs) are versatile materials relevant to a variety of water and waste treatment, energy production, and industrial separation processes. The defining characteristic of IEMs is their ability to selectively allow positive or negative ions to permeate, which is referred to as permselectivity. Measured values of permselectivity that equal unity (corresponding to a perfectly selective membrane) or exceed unity (theoretically impossible) have been reported for cation exchange membranes (CEMs). Such nonphysical results call into question our ability to correctly measure this crucial membrane property. Because weighing errors, temperature, and measurement uncertainty have been shown to not explain these anomalous permselectivity results, we hypothesized that a possible explanation are junction potentials that occur at the tips of reference electrodes. In this work, we tested this hypothesis by comparing permselectivity values obtained from bare Ag/AgCl wire electrodes (which have no junction) to values obtained from single-junction reference electrodes containing two different electrolytes. We show that permselectivity values obtained using reference electrodes with junctions were greater than unity for CEMs. In contrast, electrodes without junctions always produced permselectivities lower than unity. Electrodes with junctions also resulted in artificially low permselectivity values for AEMs compared to electrodes without junctions. Thus, we conclude that junctions in reference electrodes introduce two biases into results in the IEM literature: (i) permselectivity values larger than unity for CEMs and (ii) lower permselectivity values for AEMs compared to those for CEMs. These biases can be avoided by using electrodes without a junction.

  5. Measurements of scattering processes in negative ion-atom collisions

    International Nuclear Information System (INIS)

    Kvale, T.J.

    1991-01-01

    This research project is designed to provide measurements of various scattering processes which occur in H - collisions with atomic targets at intermediate energies. The immediate goal is to study elastic scattering, single electron detachment, and target excitation/ionization in H - scattering from noble gas targets. For the target inelastic processes, these cross sections are unknown both experimentally and theoretically. The present measurements will provide either experimentally-determined cross sections or set upper limits to those cross sections. In either case, these measurements will be stringent tests of our understanding in energetic negative ion collisions. This series of experiments required the construction of a new facility, and significant progress toward its operation has been realized during this period. The proposed research is described in this report. The progress on and the status of the apparatus is also detailed in this report

  6. Linac4 low energy beam measurements with negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Scrivens, R., E-mail: richard.scrivens@cern.ch; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T. [CERN, 1211 Geneva 23 (Switzerland)

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  7. Preclinical evaluation of acoustic radiation force impulse measurements in regions of heterogeneous elasticity

    Energy Technology Data Exchange (ETDEWEB)

    Hollerieth, Katharina; Moog, Philipp; Vo-Cong, Minh-Truc; Heemann, Uwe [Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich (Germany); Gassmann, Bernhard [Meso International GmbH, Berlin (Germany); Wagenpfeil, Stefan [Institute for Medical Biometry, Epidemiology and Medical Informatics, Saarland University, Campus Homburg (Saar), Homburg (Germany)

    2016-08-15

    The purpose of this study was to compare the reliability of ultrasound-based shear wave elastography in regions of homogeneous versus heterogeneous elasticity by using two different probes. Using acoustic radiation force impulse (ARFI) elastography, we measured the shear wave velocity (SWV) in different lesions of an elastography phantom with the convex {sub 4}C{sub 1} probe and the linear {sub 9}L{sub 4} probe. The region of interest (ROI) was positioned in such a way that it was partly filled by one of the lesions (0%, 25%, 50%, 75%, and 100%) and partly by the background of the phantom (100%, 75%, 50%, 25%, and 0%, respectively). The success rate was 98.5%. The measured value and the reference value of SWV correlated significantly (r=0.89, P<0.001). Further, a comparison of the two probes revealed that there was no statistical difference in either the mean or the variance values. However, the deviation of SWV from the reference was higher in the case of the {sub 9}L{sub 4} probe than in the case of the {sub 4}C{sub 1} probe, both overall and in measurements in which the ROI contained structures of different elasticity (P=0.021 and P=0.002). Taking into account all data, for both probes, we found that there was a greater spread and deviation of the SWV from the reference value when the ROI was positioned in structures having different elastic properties (standard deviation, 0.02±0.01 m/sec vs. 0.04±0.04 m/sec; P=0.010; deviation from the reference value, 0.21±0.12 m/sec vs. 0.38±0.27 m/sec; P=0.050). Quantitative ARFI elastography was achievable in structures of different elasticity; however, the validity and the reliability of the SWV measurements decreased in comparison to those of the measurements performed in structures of homogeneous elasticity. Therefore, a convex probe is preferred for examining heterogeneous structures.

  8. Comparison of NDA and DA measurement techniques for excess plutonium powders at the Hanford Site: Statistical design and heterogeneity testing

    International Nuclear Information System (INIS)

    Welsh, T.L.; McRae, L.P.; Delegard, C.H.; Liebetrau, A.M.; Johnson, W.C.; Theis, W.; Lemaire, R.J.; Xiao, J.

    1995-06-01

    Quantitative physical measurements are a n component of the International Atomic Energy Agency (IAEA) nuclear material m ampersand guards verification regime. In December 1994, LA.FA safeguards were initiated on an inventory of excess plutonium powder items at the Plutonium Finishing Plant, Vault 3, on the US Department of Energy's Hanford Site. The material originl from the US nuclear weapons complex. The diversity of the chemical form and the heterogenous physical form of this inventory were anticipated to challenge the precision and accuracy of quantitative destructive analytical techniques. A sampling design was used to estimate the degree of heterogeneity of the plutonium content of a variety of inventory items. Plutonium concentration, the item net weight, and the 240 Pu content were among the variables considered in the design. Samples were obtained from randomly selected location within each item. Each sample was divided into aliquots and analyzed chemically. Operator measurements by calorimetry and IAEA measurements by coincident neutron nondestructive analysis also were performed for the initial physical inventory verification materials and similar items not yet under IAEA safeguards. The heterogeneity testing has confirmed that part of the material is indeed significantly heterogeneous; this means that precautionary measures must be taken to obtain representative samples for destructive analysis. In addition, the sampling variability due to material heterogeneity was found to be comparable with, or greater than, the variability of the operator's calorimetric measurements

  9. Note on measuring electronic stopping of slow ions

    Science.gov (United States)

    Sigmund, P.; Schinner, A.

    2017-11-01

    Extracting stopping cross sections from energy-loss measurements requires careful consideration of the experimental geometry. Standard procedures for separating nuclear from electronic stopping treat electronic energy loss as a friction force, ignoring its dependence on impact parameter. In the present study we find that incorporating this dependence has a major effect on measured stopping cross sections, in particular for light ions at low beam energies. Calculations have been made for transmission geometry, nuclear interactions being quantified by Bohr-Williams theory of multiple scattering on the basis of a Thomas-Fermi-Molière potential, whereas electronic interactions are characterized by Firsov theory or PASS code. Differences between the full and the restricted stopping cross section depend on target thickness and opening angle of the detector and need to be taken into account in comparisons with theory as well as in applications of stopping data. It follows that the reciprocity principle can be violated when checked on restricted instead of full electronic stopping cross sections. Finally, we assert that a seeming gas-solid difference in stopping of low-energy ions is actually a metal-insulator difference. In comparisons with experimental results we mostly consider proton data, where nuclear stopping is only a minor perturbation.

  10. Fitting phase shifts to electron-ion elastic scattering measurements

    International Nuclear Information System (INIS)

    Per, M.C.; Dickinson, A.S.

    2000-01-01

    We have derived non-Coulomb phase shifts from measured differential cross sections for electron scattering by the ions Na + , Cs + , N 3+ , Ar 8+ and Xe 6+ at energies below the inelastic threshold. Values of the scaled squared deviation between the observed and fitted differential cross sections, χ 2 , for the best-fit phase shifts were typically in the range 3-6 per degree of freedom. Generally good agreement with experiment is obtained, except for wide-angle scattering by Ar 8+ and Xe 6+ . Current measurements do not define phase shifts to better than approx. 0.1 rad even in the most favourable circumstances and uncertainties can be much larger. (author)

  11. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  12. Mini biased collimated faraday cups for measurement of intense pulsed ion beams

    International Nuclear Information System (INIS)

    He Xiaoping; Shi Lei; Zhang Jiasheng; Qiu Aici

    2000-01-01

    An analysis of principle of a biased Faraday cup for measuring ion beams density and the main reasons related to the measuring accuracy were presented. An array of mini biased collimated Faraday cups was manufactured for the measurement of ion beam density of a compact 200 keV high power ion beam source. In the experiments the maximum density of ion beam was in the center of the beam, and it was about 170 A/cm 2

  13. Effect of ion clouds micromotion on measured signal in Fourier transform ion cyclotron resonance: Computer simulation.

    Science.gov (United States)

    Vladimirov, Gleb; Kostyukevich, Yury; Kharybin, Oleg; Nikolaev, Eugene

    2017-08-01

    Particle-in-cell-based realistic simulation of Fourier transform ion cyclotron resonance experiments could be used to generate ion trajectories and a signal induced on the detection electrodes. It has been shown recently that there is a modulation of "reduced" cyclotron frequencies in ion cyclotron resonance signal caused by Coulomb interaction of ion clouds. In this work it was proposed to use this modulation in order to determine frequency difference between an ion of known m/z and all other ions generating signal in ion cyclotron resonance cell. It is shown that with an increase of number of ions in ion cyclotron resonance trap, the modulation index increases, which lead to a decrease in the accuracy of determination of peak intensities by super Fourier transform resolution methods such as filter diagonalization method.

  14. Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

    International Nuclear Information System (INIS)

    Lin Xiaodong

    2000-01-01

    Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

  15. Progress on precision measurements of inner shell transitions in highly charged ions at an ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Csilla I.; Indelicato, Paul; LeBigot, Eric-Olivier; Vallette, Alexandre; Amaro, Pedro; Guerra, Mauro; Gumberidze, Alex [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France); Centro de Fisica Atomica, CFA, Departamento de Fisica (Portugal); Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France)

    2012-05-25

    Inner shell transitions of highly charged ions produced in the plasma of an Electron Cyclotron Resonance Ion Source (ECRIS) were observed the first time by a Double Crystal Spectrometer (DCS). The DCS is a well-used tool in precision x-ray spectroscopy due to its ability of precision wavelength measurement traced back to a relative angle measurement. Because of its requirement for a bright x-ray source the DCS has not been used before in direct measurements of highly charged ions (HCI). Our new precision measurement of inner shell transitions in HCI is not just going to provide new x-ray standards for quantum metrology but can also give information about the plasma in which the ions reside. Ionic temperatures and with that the electron density can be determined by thorough examination of line widths measured with great accuracy.

  16. Electron density measurements during ion beam transport on Gamble II

    International Nuclear Information System (INIS)

    Weber, B.V.; Hinshelwood, D.D.; Neri, J.M.; Ottinger, P.F.; Rose, D.V.; Stephanakis, S.J.; Young, F.C.

    1999-01-01

    High-sensitivity laser interferometry was used to measure the electron density created when an intense proton beam (100 kA, 1 MeV, 50 ns) from the Gamble II generator was transported through low-pressure gas as part of a project investigating Self-Pinched Transport (SPT) of intense ion beams. This measurement is non-perturbing and sufficiently quantitative to allow benchmarking of codes (particularly IPROP) used to model beam-gas interaction and ion-beam transport. Very high phase sensitivity is required for this measurement. For example, a 100-kA, 1-MeV, 10-cm-radius proton beam with uniform current density has a line-integrated proton density equal to n b L = 3 x 10 13 cm -2 . An equal electron line-density, n e L = n b L, (expected for transport in vacuum) will be detected as a phase shift of the 1.064 microm laser beam of only 0.05degree, or an optical path change of 1.4 x 10 -4 waves (about the size of a hydrogen atom). The time-history of the line-integrated electron density, measured across a diameter of the transport chamber at 43 cm from the input aperture, starts with the proton arrival time and decays differently depending on the gas pressure. The gas conditions included vacuum (10 -4 Torr air), 30 to 220 mTorr He, and 1 Torr air. The measured densities vary by three orders of magnitude, from 10 13 to 10 16 cm -2 for the range of gas pressures investigated. In vacuum, the measured electron densities indicate only co-moving electrons (n e L approximately n b L). In He, when the gas pressure is sufficient for ionization by beam particles and SPT is observed, n e L increases to about 10 n b L. At even higher pressures where electrons contribute to ionization, even higher electron densities are observed with an ionization fraction of about 2%. The diagnostic technique as used on the SPT experiment will be described and a summary of the results will be given. The measurements are in reasonable agreement with theoretical predictions from the IPROP code

  17. Dynamics of fast ions during sawtooth oscillations in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Salewski, Mirko; Bindslev, Henrik

    2011-01-01

    Experimental investigations of sawteeth interaction with fast ions measured by collective Thomson scattering on TEXTOR are presented. Time-resolved measurements of localized 1D fast-ion distribution functions allow us to study fast-ion dynamics during several sawtooth cycles. Sawtooth oscillation...

  18. Dielectronic recombination measurements using the Electron Beam Ion Trap

    International Nuclear Information System (INIS)

    Knapp, D.A.

    1991-01-01

    We have used the Electron Beam Ion Trap at LLNL to study dielectronic recombination in highly charged ions. Our technique is unique because we observe the x-rays from dielectronic recombination at the same time we see x-rays from all other electron-ion interactions. We have recently taken high-resolution, state-selective data that resolves individual resonances

  19. Heavy ion beam measurement of the hydration of cementitious materials

    International Nuclear Information System (INIS)

    Livingston, R.A.; Schweitzer, J.S.; Spillane, T.; Zickefoose, J.; Rolfs, C.; Becker, H.-W.; Kubsky, S.; Castellote, M.; Viedma, P.G. de; Cheung, J.

    2008-01-01

    Full text: The setting and development of strength of Portland cement concrete depends upon the reaction of water with various phases in the Portland cement including dicalcium silicate (C 2 S), tricalcium silicate (C 3 S) and tricalcium aluminate (C 3 A). The early age hydration reaction and setting time are determined by surface layers on the cement grains that form a region that is only a few 100 nm thick. This has been difficult to observe with conventional methods. Ion beam techniques have been used to investigate these layers in detail at the Tandem Accelerator facility of the University of the Ruhr in Bochum, Germany. The primary method has been Nuclear Resonance Reaction Analysis (NRRA) involving the 1 H( 15 N,αγ) 12 C reaction to measure the hydrogen depth profile. This technique has an H detection sensitivity of about 10 ppm and an H-depth resolution of a few nm at the surface.. Freshly cleaved mica is used as a calibration standard for conversion of gamma-ray counts to H concentration. The beam energy to depth conversion factor is obtained by numerical simulation using the Monte Carlo code TRIM. NRRA with the 1 H( 19 F, αγ) 16 O reaction has also been used to measure the hydrogen depth profile. Some samples were implanted with a 131 Xe layer in order to measure the depth profile of other significant elements such as calcium with Rutherford Backscattering (RBS), and also to measure the erosion of the surface layers

  20. Apparatus for the measurement of ion activety caused by radiation

    International Nuclear Information System (INIS)

    Stroem, S.

    1989-01-01

    The invention relates to a linear amplifier for the monitoring of very small currents from a high pressure ionization chamber. In the traditional design of an ionization chamber current amplifier, selected semiconductors and resistors are chosen to measure the very small currents in question. As the leakage currents in these semiconductors are larger than the smallest currents to be measured, very sophisticated electronics must be employed to succeed with the design. In order to overcome this disadvantage, the invention is based on the following basic features: A capacitor is charged by the chamber ion current during a fixed time period, without loading the amplifier input. The use of a peak detector makes bouncing of the time-lag relay contacts unimportant, and allows an anlog-to-digital converter to store the voltage build-up in the capacitor as a digital value. The measuring range of the amplifier, 0.001 pA to 1000 pA, makes it suitable for measuring gamma radiation in the air, both under normal and abnormal conditions. 1 fig

  1. Measurement of line overlap for resonant photopumping of transitions in neonlike ions by nickel-like ions

    International Nuclear Information System (INIS)

    Elliott, S.; Beiersdorfer, P.; Nilsen, J.

    1993-01-01

    A measurement is made of the 3d-4f transition energies in the Ni-like ions Re 47+ , Ir 49+ , Pt 50+ , Au 51+ , and Bi 55+ and the 2p-4d transition energies in the Ne-like ions Br 25+ , Kr 26+ , Rb 27+ , and Y 29+ using the Livermore electron-beam ion trap. The ions studied are candidates for an x-ray laser scheme based on resonant photopumping which predicts lasing among the 3p-3s transitions in a Ne-like ion. The results of the measurements are compared to multiconfiguration Dirac-Fock calculations and systematic differences are found. The best resonance is found for the Pt-Rb pair at 2512 eV, whose energies differ by 0.4±0.1 eV, that is, by only 160 ppm

  2. Complete strangeness measurements in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Tomasik, Boris [Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia); Czech Technical University in Prague, FNSPE, Prague 1 (Czech Republic); Kolomeitsev, Evgeni E. [Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia)

    2016-08-15

    We discuss strangeness production in heavy-ion collisions within and around the energy range of the planned NICA facility. We describe a minimal statistical model, in which the total strangeness yield is fixed by the observed or calculated K{sup +} multiplicity. We show how the exact strangeness conservation can be taken into account on event-by-event basis in such a model. We argue that from strange particle yields one can reveal information about the collision dynamics and about possible modifications of particle properties in medium. This can be best achieved if the complete strangeness measurement is performed, i.e. kaons, antikaons, hyperons and multistrange hyperons are registered in the same experimental setup. In particular, production of hadrons containing two and more strange quarks, like Ξ and Ω baryons could be of interest. (orig.)

  3. Self-diffusion measurements in heterogeneous systems using NMR pulsed field gradient technique

    International Nuclear Information System (INIS)

    Heink, W.; Kaerger, J.; Walter, A.

    1978-01-01

    The experimental pecularities of the NMR pulsed field gradient technique are critical surveyed in its application to zeolite adsorbate adsorbent systems. After a presentation of the different transport parameters accessible by this technique, the consequences of the existence of inner field gradients being inherent to heterogeneous systems are analyzed. Experimental conditions and consequences of an application of pulsed field gradients of high intensity which are necessary for the measurement of small intracrystalline self-diffusion coefficients, are discussed. Gradient pulses of 0.15 Tcm -1 with pulse widths of 2 ms maximum and relative deviations of less than 0.01 per mille can be realized. Since for a number of adsorbate adsorbent systems a distinct dependence of the intracrystalline self-diffusion coeffcients on adsorbate concentration is observed, determination of zeolite pore fiiling factor is of considerable importance for the interpretation of the diffusivities obtained. It is demonstrated that also this information can be obtained by NMR technique in a straightforward way with a mean error of less than 5 to 10 %. Applying this new method and using an optimum experimental device as described, pore filling factor dependences of the self-diffusion coefficients of alkanes in NaX zeolites can be followed over more than two orders of magnitude. (author)

  4. Cryogenic current comparators for precise ion beam current measurements

    International Nuclear Information System (INIS)

    Kurian, Febin

    2015-01-01

    The planned Facility for Antiproton and Ion Research (FAIR) at GSI has to cope with a wide range of beam intensities in its high-energy beam transport systems and in the storage rings. To meet the requirements of a non-intercepting intensity measurement down to nA range, it is planned to install a number of Cryogenic Current Comparator (CCC) units at different locations in the FAIR beamlines. In this work, the first CCC system for intensity measurement of heavy ion beams, which was developed at GSI, was re-commissioned and upgraded to be used as a 'GSI - CCC prototype' for extensive optimization and development of an improved CCC for FAIR. After installation of a new SQUID sensor and related electronics, as well as implementation of improved data acquisition components, successful beam current measurements were performed at a SIS18 extraction line. The measured intensity values were compared with those of a Secondary Electron Monitor (SEM). Furthermore, the spill-structure of a slowly extracted beam was measured and analyzed, investigating its improvement due to bunching during the slow-extraction process. Due to the extreme sensitivity of the superconducting sensor, the determined intensity values as well as the adjustment of the system for optimal performance are strongly influenced by the numerous noise sources of the accelerators environment. For this reason, detailed studies of different effects caused by noise have been carried out, which are presented together with proposals to reduce them. Similarly, studies were performed to increase the dynamic range and overcome slew rate limitations, the results of which are illustrated and discussed as well. By combining the various optimizations and characterizations of the GSI CCC prototype with the experiences made during beam operation, criteria for a more efficient CCC System could be worked out, which are presented in this work. The details of this new design are worked out with respect to the

  5. Measurements of visible forbidden lines and ion distributions of tungsten highly charged ions at the LHD

    International Nuclear Information System (INIS)

    Kato, D.; Sakaue, H.A.; Murakami, I.; Goto, M.; Morita, S.; Nakamura, N.; Koike, F.; Sasaki, Akira; Ding, X.-B.; Dong, C.-Z.

    2013-01-01

    Visible lines, which are presumably associated with forbidden lines from tungsten highly charged ions, were clearly observed in a spectrum of 370 - 410 nm recorded shortly after a tungsten pellet injection at the LHD. One of the measured lines has been assigned to a magnetic-dipole (M1) line of the ground-term fine-structure transition of W 26+ . Photon emission was observed at 44 lines of sight divided along the vertical direction of a horizontally elongated poloidal cross section of the LHD plasma. The line-integrated intensity of the lines along each line of sight indicates peaked profiles near the plasma center, while visible line emissions of neutral hydrogen and helium recoded in the same sampling time have a maximum located in the peripheral region of the poloidal cross section. (author)

  6. Sub-cellular Electrical Heterogeneity Revealed by Loose Patch Recording Reflects Differential Localization of Sarcolemmal Ion Channels in Intact Rat Hearts

    Directory of Open Access Journals (Sweden)

    Igor V. Kubasov

    2018-02-01

    Full Text Available The cardiac action potential (AP is commonly recoded as an integral signal from isolated myocytes or ensembles of myocytes (with intracellular microelectrodes and extracellular macroelectrodes, respectively. These signals, however, do not provide a direct measure of activity of ion channels and transporters located in two major compartments of a cardiac myocyte: surface sarcolemma and the T-tubule system, which differentially contribute to impulse propagation and excitation-contraction (EC coupling. In the present study we investigated electrical properties of myocytes within perfused intact rat heart employing loose patch recording with narrow-tip (2 μm diameter extracellular electrodes. Using this approach, we demonstrated two distinct types of electric signals with distinct waveforms (single peak and multi-peak AP; AP1 and AP2, respectively during intrinsic pacemaker activity. These two types of waveforms depend on the position of the electrode tip on the myocyte surface. Such heterogeneity of electrical signals was lost when electrodes of larger pipette diameter were used (5 or 10 μm, which indicates that the electric signal was assessed from a region of <5 μm. Importantly, both pharmacological and mathematical simulation based on transverse (T-tubular distribution suggested that while the AP1 and the initial peak of AP2 are predominantly attributable to the fast, inward Na+ current in myocyte's surface sarcolemma, the late components of AP2 are likely representative of currents associated with L-type Ca2+ channel and Na+/Ca2+ exchanger (NCX currents which are predominantly located in T-tubules. Thus, loose patch recording with narrow-tip pipette provides a valuable tool for studying cardiac electric activity on the subcellular level in the intact heart.

  7. Laser-induced fluorescence measurements of argon and xenon ion velocities near the sheath boundary in 3 ion species plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Chi-Shung; Hershkowitz, Noah [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Severn, Greg [Department of Physics, University of San Diego, San Diego, California 92110 (United States); Baalrud, Scott D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2016-05-15

    The Bohm sheath criterion is studied with laser-induced fluorescence in three ion species plasmas using two tunable diode lasers. Krypton is added to a low pressure unmagnetized DC hot filament discharge in a mixture of argon and xenon gas confined by surface multi-dipole magnetic fields. The argon and xenon ion velocity distribution functions are measured at the sheath-presheath boundary near a negatively biased boundary plate. The potential structures of the plasma sheath and presheath are measured by an emissive probe. Results are compared with previous experiments with Ar–Xe plasmas, where the two ion species were observed to reach the sheath edge at nearly the same speed. This speed was the ion sound speed of the system, which is consistent with the generalized Bohm criterion. In such two ion species plasmas, instability enhanced collisional friction was demonstrated [Hershkowitz et al., Phys. Plasmas 18(5), 057102 (2011).] to exist which accounted for the observed results. When three ion species are present, it is demonstrated under most circumstances the ions do not fall out of the plasma at their individual Bohm velocities. It is also shown that under most circumstances the ions do not fall out of the plasma at the system sound speed. These observations are also consistent with the presence of the instabilities.

  8. Measurement of negative ion mobility in O2 at high pressures using a point plate gap as an ion detector

    International Nuclear Information System (INIS)

    Okuyama, Y; Kimura, T; Suzuki, S; Itoh, H

    2012-01-01

    This paper describes the experimental results for negative ion mobility in O 2 at 0.5-2.0 atm. The ion mobility is observed using a high-pressure ion drift tube with a positive corona gap (Geiger counter), which is constructed from a point plate gap and acts as a negative ion detector. The variation of waveforms in the burst pulse is observed by varying the voltage applied to the ion detector to find the optimum voltage that must be applied across the ion detector in O 2 . This is investigated carefully to ensure the precise determination of mobility. The distortion of the electric field near the mesh electrode, which operates as the cathode of the ion detector and as the anode of the ion drift gap, is then examined to determine the optimum applied voltage to suppress its effect on the measurement of mobility. The mobility is subsequently measured at a reduced electric field intensity of 2.83 × 10 -3 to 2.83. The observed mobility of 2.31 ± 0.03 cm 2 V -1 s -1 in O 2 is concluded to be that of O 2 - . This value is also obtained in experiments over a wide range of gas pressures (0.5-2.0 atm) and drift lengths (1.00-9.00 cm). The mobilities of O 3 - and O - are also obtained experimentally. (paper)

  9. Evaluation of the ion-density measurements by the Indian satellite SROSS-C2

    Science.gov (United States)

    Subrahmanyam, P.; Jain, A. R.; Maini, H. K.; Bahl, M.; Das, Rupesh M.; Garg, S. C.; Niranjan, K.

    2010-12-01

    The ion and electron F region plasma measurements made by the ion and electron Retarding Potential Analyzers (RPAs) onboard the Indian satellite SROSS-C2, have yielded excellent data set over the Indian region for more than half a solar cycle, after the SROSS-C2 launch in May 1994. The absolute ion density, ion temperature, and ion composition parameters are derived from these in situ measurements and used by many workers. In this paper the absolute values of ion density derived from the ion RPA measurements are compared and evaluated with the measurements made by ground-based ionosondes located in the Indian region and close to the SROSS-C2 orbital path. It is shown that a slight adjustment in efficiency factor of the ion RPA sensor brings the in situ measurements much closer to those obtained from the ground-based ionosonde measurements taking into account the model calculations. It may be mentioned that this is a correction to the ion density measurement by SROSS-C2 by a fixed proportion (14-11.4%). The effect of change in efficiency factor on the ion current, which is used to deduce the ion number density, is demonstrated and discussed.

  10. Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

    Directory of Open Access Journals (Sweden)

    G. Kremser

    1995-06-01

    Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/e\\leqE/Q\\leq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H+ and He++ ions were encountered in all of these regions. He+ ions were present only in the ring current. The number of O+ and O++ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H+ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H+ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H+ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies \\leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the magnetic field configuration and dynamic processes inside and close to the cusp.

  11. Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

    Directory of Open Access Journals (Sweden)

    G. Kremser

    Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/eleqE/Qleq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H+ and He++ ions were encountered in all of these regions. He+ ions were present only in the ring current. The number of O+ and O++ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H+ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H+ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H+ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the

  12. Spatial profile measurements of ion-confining potentials using novel position-sensitive ion-energy spectrometer arrays

    International Nuclear Information System (INIS)

    Yoshida, M.; Cho, T.; Hirata, M.; Ito, H.; Kohagura, J.; Yatsu, K.; Miyoshi, S.

    2003-01-01

    The first experimental demonstration of simultaneous measurements of temporally and spatially resolved ion-confining potentials phi c and end-loss-ion fluxes I ELA has been carried out during a single plasma discharge alone by the use of newly designed ion-energy-spectrometer arrays installed in both end regions of the GAMMA 10 tandem mirror. This position-sensitive ion-detector structure is proposed to obtain precise ion-energy spectra without any perturbations from simultaneously incident energetic electrons into the arrays. The relation between phi c and I ELA is physically interpreted in terms of Pastukhov's potential confinement theory. In particular, the importance of axisymmetric phi c formation is found for the plasma confinement

  13. Novel Faraday cup for the simultaneous observation and measurement of ion-beam currents

    International Nuclear Information System (INIS)

    Wei, C.; Seidman, D.N.

    1977-01-01

    A novel Faraday cup is described which allows the simultaneous observation and measurement of ion-beam currents. The Faraday cup is constructed around a Galileo channel electron multiplier array (CEMA), which serves as the basis of an internal image intensification system (a gain of >10 4 ) for the observation of the ion beam; the CEMA also acts as a collector for the ion current which is measured by a Keithley 602 electrometer. The ion current is integrated by a simple and inexpensive dosimeter; the electronic circuit for the dosimeter is described. The application of the Faraday cup to the observation and measurement of a 30-keV Ar + ion beam is presented as an illustrative example. We have also employed this Faraday cup to observe and measure 30-keV Cr + , Mo + , or W + , and 18-keV Au + ion beams employed for the in situ irradiation of field-ion microscope specimens

  14. A system for tumor heterogeneity evaluation and diagnosis based on tumor markers measured routinely in the laboratory.

    Science.gov (United States)

    Hui, Liu; Rixv, Liu; Xiuying, Zhou

    2015-12-01

    To develop an efficient and reliable approach to estimate tumor heterogeneity and improve tumor diagnosis using multiple tumor markers measured routinely in the clinical laboratory. A total of 161 patients with different cancers were recruited as the cancer group, and 91 patients with non-oncological conditions were required as the non-oncological disease group. The control group comprised 90 randomly selected healthy subjects. AFP, CEA, CYFRA, CA125, CA153, CA199, CA724, and NSE levels were measured in all these subjects with a chemiluminescent microparticle immunoassay. The tumor marker with the maximum S/CO value (sample test value:cutoff value for discriminating individuals with and without tumors) was considered as a specific tumor marker (STM) for an individual. Tumor heterogeneity index (THI)=N/P (N: number of STMs; P: percentage of individuals with STMs in a certain tumor population) was used to quantify tumor heterogeneity: high THI indicated high tumor heterogeneity. The tumor marker index (TMI), TMI = STM×(number of positive tumor markers+1), was used for diagnosis. The THIs of lung, gastric, and liver cancers were 8.33, 9.63, and 5.2, respectively, while the ROC-areas under the curve for TMI were 0.862, 0.809, and 0.966. In this study, we developed a novel index for tumor heterogeneity based on the expression of various routinely evaluated serum tumor markers. Development of an evaluation system for tumor heterogeneity on the basis of this index could provide an effective diagnostic tool for some cancers. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Ra+ ion trapping : toward an atomic parity violation measurement and an optical clock

    NARCIS (Netherlands)

    Portela, M. Nunez; Dijck, E. A.; Mohanty, A.; Bekker, H.; van den Berg, Joost E.; Giri, G. S.; Hoekstra, S.; Onderwater, C. J. G.; Schlesser, S.; Timmermans, R.G.E.; Versolato, O. O.; Willmann, L.; Wilschut, H. W.; Jungmann, K.

    2014-01-01

    A single Ra+ ion stored in a Paul radio frequency ion trap has excellent potential for a precision measurement of the electroweak mixing angle at low momentum transfer and as the most stable optical clock. The effective transport and cooling of singly charged ions of the isotopes Ra-209 to Ra-214 in

  16. Fusion product measurements of the local ion thermal diffusivity in the PLT tokamak

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Lovberg, J.; Strachan, J.D.; Bell, R.E.

    1986-03-01

    Measurement of the gradient of the d-d fusion rate profile in an ohmic PLT plasma is used to deduce the gradient of the ion temperature and, thus, the local ion thermal diffusivity through an energy balance analysis. The inferred ion diffusivity is consistent with neoclassical theory

  17. Variations in hydraulic conductivity with scale of measurement during aquifer tests in heterogeneous, porous carbonate rocks

    Science.gov (United States)

    Schulze-Makuch, Dirk; Cherkauer, Douglas S.

    Previous studies have shown that hydraulic conductivity of an aquifer seems to increase as the portion of the aquifer tested increases. To date, such studies have all relied on different methods to determine hydraulic conductivity at each scale of interest, which raises the possibility that the observed increase in hydraulic conductivity is due to the measurement method, not to the scale. This study analyzes hydraulic conductivity with respect to scale during individual aquifer tests in porous, heterogeneous carbonate rocks in southeastern Wisconsin, USA. Results from this study indicate that hydraulic conductivity generally increases during an individual test as the volume of aquifer impacted increases, and the rate of this increase is the same as the rate of increase determined by using different measurement methods. Thus, scale dependence of hydraulic conductivity during single tests does not depend on the method of measurement. This conclusion is supported by 22 of 26 aquifer tests conducted in porous-flow-dominated carbonate units within the aquifer. Instead, scale dependency is probably caused by heterogeneities within the aquifer, a conclusion supported by digital simulation. All of the observed types of hydraulic-conductivity variations with scale during individual aquifer tests can be explained by a conceptual model of a simple heterogeneous aquifer composed of high-conductivity zones within a low-conductivity matrix. Résumé Certaines études ont montré que la conductivité hydraulique d'un aquifère semble augmenter en même temps que la partie testée de l'aquifère s'étend. Jusqu'à présent, ces études ont toutes reposé sur des méthodes de détermination de la conductivité hydraulique différentes pour chaque niveau d'échelle, ce qui a conduit à penser que l'augmentation observée de la conductivité hydraulique pouvait être due aux méthodes de mesure et non à l'effet d'échelle. Cette étude analyse la conductivité hydraulique par

  18. Investigation on thermodynamics of ion-slicing of GaN and heterogeneously integrating high-quality GaN films on CMOS compatible Si(100) substrates.

    Science.gov (United States)

    Huang, Kai; Jia, Qi; You, Tiangui; Zhang, Runchun; Lin, Jiajie; Zhang, Shibin; Zhou, Min; Zhang, Bo; Yu, Wenjie; Ou, Xin; Wang, Xi

    2017-11-08

    Die-to-wafer heterogeneous integration of single-crystalline GaN film with CMOS compatible Si(100) substrate using the ion-cutting technique has been demonstrated. The thermodynamics of GaN surface blistering is in-situ investigated via a thermal-stage optical microscopy, which indicates that the large activation energy (2.5 eV) and low H ions utilization ratio (~6%) might result in the extremely high H fluence required for the ion-slicing of GaN. The crystalline quality, surface topography and the microstructure of the GaN films are characterized in detail. The full width at half maximum (FWHM) for GaN (002) X-ray rocking curves is as low as 163 arcsec, corresponding to a density of threading dislocation of 5 × 10 7  cm -2 . Different evolution of the implantation-induced damage was observed and a relationship between the damage evolution and implantation-induced damage is demonstrated. This work would be beneficial to understand the mechanism of ion-slicing of GaN and to provide a platform for the hybrid integration of GaN devices with standard Si CMOS process.

  19. The prospect for fuel ion ratio measurements in ITER by collective Thomson scattering

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Korsholm, Søren Bang; Nielsen, Stefan Kragh

    2012-01-01

    We show that collective Thomson scattering (CTS) holds the potential to become a new diagnostic principle for measurements of the fuel ion ratio, nT/nD, in ITER. Fuel ion ratio measurements will be important for plasma control and machine protection in ITER. Measurements of ion cyclotron structures...... in CTS spectra have been suggested as the basis for a new fuel ion ratio diagnostic which would be well suited for reactor environments and capable of providing spatially resolved measurements in the plasma core. Such measurements were demonstrated in recent experiments in the TEXTOR tokamak. Here we...... conduct a sensitivity study to investigate the potential measurement accuracy of a CTS fuel ion ratio diagnostic on ITER. The study identifies regions of parameter space in which CTS can be expected to provide useful information on plasma composition, and we find that a CTS fuel ion ratio diagnostic could...

  20. Accounting for response behavior heterogeneity in the measurement of attitudes: an application to demand for electric vehicles

    OpenAIRE

    Glerum, Aurélie; Bierlaire, Michel

    2012-01-01

    Hybrid choice models have proved to be a powerful framework that integrates attitudinal and perceptional data into discrete choice models. However the measurement component of such a framework often fails to exploit individual-specific information that might affect the way subjects answer to indicators of opinion. In this paper we propose an HCM with a measurement model that takes into account heterogeneity in the response behavior. Precisely, we capture effects of exaggeration in answers to ...

  1. Measurements of Prompt and MHD-Induced Fast Ion Loss from National Spherical Torus Experiment Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    D.S. Darrow; S.S. Medley; A.L. Roquemore; W.W. Heidbrink; A. Alekseyev; F.E. Cecil; J. Egedal; V.Ya. Goloborod' ko; N.N. Gorelenkov; M. Isobe; S. Kaye; M. Miah; F. Paoletti; M.H. Redi; S.N. Reznik; A. Rosenberg; R. White; D. Wyatt; V.A. Yavorskij

    2002-10-15

    A range of effects may make fast ion confinement in spherical tokamaks worse than in conventional aspect ratio tokamaks. Data from neutron detectors, a neutral particle analyzer, and a fast ion loss diagnostic on the National Spherical Torus Experiment (NSTX) indicate that neutral beam ion confinement is consistent with classical expectations in quiescent plasmas, within the {approx}25% errors of measurement. However, fast ion confinement in NSTX is frequently affected by magnetohydrodynamic (MHD) activity, and the effect of MHD can be quite strong.

  2. A measurement of the local ion temperature gradient in the PLT tokamak

    International Nuclear Information System (INIS)

    Lovberg, J.A.; Strachan, J.D.; Princeton Univ., NJ

    1989-12-01

    Local ion temperature gradients were measured at two radial positions in the PLT tokamak by counting escaping d(d,p)t protons on orbits at closely spaced intervals. A single surface barrier detector was used to make each gradient measurement, eliminating relative calibration uncertainties. The ion thermal diffusivities inferred through ion energy balance with the measured temperature gradients are within a factor of two of Chang-Hinton neoclassical values for the 3 He-minority ICRH plasmas. 12 refs., 8 figs

  3. Ion current prediction model considering columnar recombination in alpha radioactivity measurement using ionized air transportation

    International Nuclear Information System (INIS)

    Naito, Susumu; Hirata, Yosuke; Izumi, Mikio; Sano, Akira; Miyamoto, Yasuaki; Aoyama, Yoshio; Yamaguchi, Hiromi

    2007-01-01

    We present a reinforced ion current prediction model in alpha radioactivity measurement using ionized air transportation. Although our previous model explained the qualitative trend of the measured ion current values, the absolute values of the theoretical curves were about two times as large as the measured values. In order to accurately predict the measured values, we reinforced our model by considering columnar recombination and turbulent diffusion, which affects columnar recombination. Our new model explained the considerable ion loss in the early stage of ion diffusion and narrowed the gap between the theoretical and measured values. The model also predicted suppression of ion loss due to columnar recombination by spraying a high-speed air flow near a contaminated surface. This suppression was experimentally investigated and confirmed. In conclusion, we quantitatively clarified the theoretical relation between alpha radioactivity and ion current in laminar flow and turbulent pipe flow. (author)

  4. Constituent Ion Temperatures Measured in the Topside Ionosphere

    Science.gov (United States)

    Hsu, C. T.; Heelis, R. A.

    2017-12-01

    Plasma temperatures in the ionosphere are associated with both the dynamics and structure of the neutral and charge particles. The temperatures are determined by solar energy inputs and energy exchange between charged particles and neutrals. Previous observations show that during daytime the O+ temperature is generally higher when the fractional contribution of H+ to the plasma is high. Further simulations confirm that the daytime heat balance between the H+ and O+ always keeps the H+ at a temperature higher than the O+. In addition the plasma transport parallel and perpendicular to the magnetic field influences the plasma temperature through adiabatic heating and cooling effects. These processes are also important during the nighttime, when the source of photoionization is absent. In this work we examine a more sophisticated analysis procedure to extract individual mass dependent ion temperature and apply it on the DMSP F15 RPA measurements. The result shows that the daytime TH+ is a few hundred degrees higher than the TO+ and the nighttime temperature difference between TH+ and TO+ is indicative of mass dependent adiabatic heating and cooling processes across the equatorial region.

  5. Heterogeneous reactivity of sea spray particles during the CalNex field campaign: Insight from single particle measurements and correlations with gas phase measurements

    Science.gov (United States)

    Gaston, C. J.; Riedel, T. P.; Thornton, J. A.; Wagner, N.; Brown, S. S.; Quinn, P.; Bates, T. S.; Prather, K. A.

    2011-12-01

    Sea spray particles are ubiquitous in marine environments. Heterogeneous reactions between sea spray particles and gas phase pollutants, such as HNO3(g), and N2O5(g), alter particle composition by displacing particulate phase halogens in sea spray and releasing these halogen species into the gas phase; these halogen-containing gas phase species play a significant role in tropospheric ozone production. Measurements of both gas phase and particle phase species on board the R/V Atlantis during the CalNEX 2010 field campaign provided an opportunity to examine the impact of heterogeneous reactivity of marine aerosols along the California coast. During the cruise, coastal measurements were made near the Santa Monica and Port of Los Angeles regions to monitor the chemical processing of marine aerosols. Sea spray particles were analyzed since these particles were the major chloride-containing particles detected. Real-time single particle measurements made using an aerosol time-of-flight mass spectrometer (ATOFMS) revealed the nocturnal processing of sea spray particles through the loss of particulate chloride and a simultaneous gain in particulate nitrate. Gas phase measurements are consistent with the particle phase observations: As N2O5(g) levels rose overnight, the production of ClNO2(g) coincided with the decrease in particulate chloride. These observations provide unique insight into heterogeneous reactivity from both a gas and particle phase perspective. Results from these measurements can be used to better constrain the rate of heterogeneous reactions on sea spray particles.

  6. Measuring energy performance with sectoral heterogeneity: A non-parametric frontier approach

    International Nuclear Information System (INIS)

    Wang, H.; Ang, B.W.; Wang, Q.W.; Zhou, P.

    2017-01-01

    Evaluating economy-wide energy performance is an integral part of assessing the effectiveness of a country's energy efficiency policy. Non-parametric frontier approach has been widely used by researchers for such a purpose. This paper proposes an extended non-parametric frontier approach to studying economy-wide energy efficiency and productivity performances by accounting for sectoral heterogeneity. Relevant techniques in index number theory are incorporated to quantify the driving forces behind changes in the economy-wide energy productivity index. The proposed approach facilitates flexible modelling of different sectors' production processes, and helps to examine sectors' impact on the aggregate energy performance. A case study of China's economy-wide energy efficiency and productivity performances in its 11th five-year plan period (2006–2010) is presented. It is found that sectoral heterogeneities in terms of energy performance are significant in China. Meanwhile, China's economy-wide energy productivity increased slightly during the study period, mainly driven by the technical efficiency improvement. A number of other findings have also been reported. - Highlights: • We model economy-wide energy performance by considering sectoral heterogeneity. • The proposed approach can identify sectors' impact on the aggregate energy performance. • Obvious sectoral heterogeneities are identified in evaluating China's energy performance.

  7. A quenched-flow system for measuring heterogeneous enzyme kinetics with sub-second time resolution

    DEFF Research Database (Denmark)

    Olsen, Johan Pelck; Kari, Jeppe; Borch, Kim

    2017-01-01

    of insoluble substrate. Perhaps for this reason, transient kinetics has rarely been reported for heterogeneous enzyme reactions. Here, we describe a quenched-flow system using peristaltic pumps and stirred substrate suspensions with a dead time below 100 ms. The general performance was verified by alkali...

  8. Measuring biogeochemical heterogeneity at the micro scale in soils and sediments

    DEFF Research Database (Denmark)

    Pedersen, Lasse L.; Smets, Barth F.; Dechesne, Arnaud

    2015-01-01

    Steep physiochemical gradients and diffusive limitation associated with microscale features such as cracks and pores make soil and sediments remarkably heterogeneous environments, which is reflected on many environmentally important processes. If we are to understand and attempt to control the ec...

  9. A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix.

    Science.gov (United States)

    Saito, Akira; Numata, Yasushi; Hamada, Takuya; Horisawa, Tomoyoshi; Cosatto, Eric; Graf, Hans-Peter; Kuroda, Masahiko; Yamamoto, Yoichiro

    2016-01-01

    Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity. In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features. CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image

  10. Principles of fuel ion ratio measurements in fusion plasmas by collective Thomson scattering

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Nielsen, Stefan Kragh; Bindslev, Henrik

    2011-01-01

    ratio. Measurements of the fuel ion ratio will be important for plasma control and machine protection in future experiments with burning fusion plasmas. Here we examine the theoretical basis for fuel ion ratio measurements by CTS. We show that the sensitivity to plasma composition is enhanced......For certain scattering geometries collective Thomson scattering (CTS) measurements are sensitive to the composition of magnetically confined fusion plasmas. CTS therefore holds the potential to become a new diagnostic for measurements of the fuel ion ratio—i.e. the tritium to deuterium density...... by the signatures of ion cyclotron motion and ion Bernstein waves which appear for scattering geometries with resolved wave vectors near perpendicular to the magnetic field. We investigate the origin and properties of these features in CTS spectra and give estimates of their relative importance for fuel ion ratio...

  11. First multispacecraft ion measurements in and near the Earth’s magnetosphere with the identical Cluster ion spectrometry (CIS experiment

    Directory of Open Access Journals (Sweden)

    H. Rème

    2001-09-01

    Full Text Available On board the four Cluster spacecraft, the Cluster Ion Spectrometry (CIS experiment measures the full, three-dimensional ion distribution of the major magnetospheric ions (H+, He+, He++, and O+ from the thermal energies to about 40 keV/e. The experiment consists of two different instruments: a COmposition and DIstribution Function analyser (CIS1/CODIF, giving the mass per charge composition with medium (22.5° angular resolution, and a Hot Ion Analyser (CIS2/HIA, which does not offer mass resolution but has a better angular resolution (5.6° that is adequate for ion beam and solar wind measurements. Each analyser has two different sensitivities in order to increase the dynamic range. First tests of the instruments (commissioning activities were achieved from early September 2000 to mid January 2001, and the operation phase began on 1 February 2001. In this paper, first results of the CIS instruments are presented showing the high level performances and capabilities of the instruments. Good examples of data were obtained in the central plasma sheet, magnetopause crossings, magnetosheath, solar wind and cusp measurements. Observations in the auroral regions could also be obtained with the Cluster spacecraft at radial distances of 4–6 Earth radii. These results show the tremendous interest of multispacecraft measurements with identical instruments and open a new area in magnetospheric and solar wind-magnetosphere interaction physics.Key words. Magnetospheric physics (magnetopause, cusp and boundary layers; magnetopheric configuration and dynamics; solar wind - magnetosphere interactions

  12. Spectral measurements of few-electron uranium ions produced and trapped in a high-energy electron beam ion trap

    International Nuclear Information System (INIS)

    Beiersdorfer, P.

    1994-01-01

    Measurements of 2s l/2 -2p 3/2 electric dipole and 2p 1/2 -2p 3/2 magnetic dipole and electric quadrupole transitions in U 82+ through U 89+ have been made with a high-resolution crystal spectrometer that recorded the line radiation from stationary ions produced and trapped in a high-energy electron beam ion trap. From the measurements we infer -39.21 ± 0.23 eV for the QED contribution to the 2s 1/2 -2p 3/2 transition energy of lithiumlike U 89+ . A comparison between our measurements and various computations illustrates the need for continued improvements in theoretical approaches for calculating the atomic structure of ions with two or more electrons in the L shell

  13. Volumetric segmentation of ADC maps and utility of standard deviation as measure of tumor heterogeneity in soft tissue tumors.

    Science.gov (United States)

    Singer, Adam D; Pattany, Pradip M; Fayad, Laura M; Tresley, Jonathan; Subhawong, Ty K

    2016-01-01

    Determine interobserver concordance of semiautomated three-dimensional volumetric and two-dimensional manual measurements of apparent diffusion coefficient (ADC) values in soft tissue masses (STMs) and explore standard deviation (SD) as a measure of tumor ADC heterogeneity. Concordance correlation coefficients for mean ADC increased with more extensive sampling. Agreement on the SD of tumor ADC values was better for large regions of interest and multislice methods. Correlation between mean and SD ADC was low, suggesting that these parameters are relatively independent. Mean ADC of STMs can be determined by volumetric quantification with high interobserver agreement. STM heterogeneity merits further investigation as a potential imaging biomarker that complements other functional magnetic resonance imaging parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Measurements of diameters of selectively etchable tracks produced in polymer by heavy ions

    International Nuclear Information System (INIS)

    Apel', P.Yu.

    1981-01-01

    The process of pore formation in polyethyleneterephtalate films irradiated by the 136 Xe, 84 Kr, 40 Ar ions was investigated by measuring the conductivity of the samples during etching. The diameters of the damaged tracks within which the local etching rate was larger than etching rate for non-destroyed polymer were determined. In the case of the 136 Xe ions measurements have been carried out at different ion energies [ru

  15. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources

    International Nuclear Information System (INIS)

    Christ-Koch, Sina

    2007-01-01

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields (∝ 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H - )=1.10 17 1/m 3 , which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  16. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Bindslev, H.; Nielsen, S.K.; Porte, L.

    2006-01-01

    Here we present the first measurements by collective Thomson scattering of the evolution of fast-ion populations in a magnetically confined fusion plasma. 150 kW and 110 Ghz radiation from a gyrotron were scattered in the TEXTOR tokamak plasma with energetic ions generated by neutral beam injection...... and ion cyclotron resonance heating. The temporal behavior of the spatially resolved fast-ion velocity distribution is inferred from the received scattered radiation. The fast-ion dynamics at sawteeth and the slowdown after switch off of auxiliary heating is resolved in time. The latter is shown...

  17. Electric field measurement in microwave discharge ion thruster with electro-optic probe.

    Science.gov (United States)

    Ise, Toshiyuki; Tsukizaki, Ryudo; Togo, Hiroyoshi; Koizumi, Hiroyuki; Kuninaka, Hitoshi

    2012-12-01

    In order to understand the internal phenomena in a microwave discharge ion thruster, it is important to measure the distribution of the microwave electric field inside the discharge chamber, which is directly related to the plasma production. In this study, we proposed a novel method of measuring a microwave electric field with an electro-optic (EO) probe based on the Pockels effect. The probe, including a cooling system, contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. This method enables measurement of the electric field profile under ion beam acceleration. We first verified the measurement with the EO probe by a comparison with a finite-difference time domain numerical simulation of the microwave electric field in atmosphere. Second, we showed that the deviations of the reflected microwave power and the beam current were less than 8% due to inserting the EO probe into the ion thruster under ion beam acceleration. Finally, we successfully demonstrated the measurement of the electric-field profile in the ion thruster under ion beam acceleration. These measurements show that the electric field distribution in the thruster dramatically changes in the ion thruster under ion beam acceleration as the propellant mass flow rate increases. These results indicate that this new method using an EO probe can provide a useful guide for improving the propulsion of microwave discharge ion thrusters.

  18. Electron beam based transversal profile measurements of intense ion beams

    International Nuclear Information System (INIS)

    El Moussati, Said

    2014-01-01

    A non-invasive diagnostic method for the experimental determination of the transverse profile of an intense ion beam has been developed and investigated theoretically as well as experimentally within the framework of the present work. The method is based on the deflection of electrons when passing the electromagnetic field of an ion beam. To achieve this an electron beam is employed with a specifically prepared transversal profile. This distinguish this method from similar ones which use thin electron beams for scanning the electromagnetic field [Roy et al. 2005; Blockland10]. The diagnostic method presented in this work will be subsequently called ''Electron-Beam-Imaging'' (EBI). First of all the influence of the electromagnetic field of the ion beam on the electrons has been theoretically analyzed. It was found that the magnetic field causes only a shift of the electrons along the ion beam axis, while the electric field only causes a shift in a plane transverse to the ion beam. Moreover, in the non-relativistic case the magnetic force is significantly smaller than the Coulomb one and the electrons suffer due to the magnetic field just a shift and continue to move parallel to their initial trajectory. Under the influence of the electric field, the electrons move away from the ion beam axis, their resulting trajectory shows a specific angle compared to the original direction. This deflection angle practically depends just on the electric field of the ion beam. Thus the magnetic field has been neglected when analysing the experimental data. The theoretical model provides a relationship between the deflection angle of the electrons and the charge distribution in the cross section of the ion beam. The model however only can be applied for small deflection angles. This implies a relationship between the line-charge density of the ion beam and the initial kinetic energy of the electrons. Numerical investigations have been carried out to clarify the

  19. Measurement and modeling of flow through unsaturated heterogeneous rock in the context of geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Sagar, B.; Bagtzoglou, A.C.; Green, R.T.; Stothoff, S.A.

    1995-01-01

    Deep geologic disposal of high-level and transuranic waste is currently being pursued vigorously. Assessing long-term performance of such repositories involves laboratory and field measurements, and numerical modeling. There exist two primary characteristics, associated with assessing repository performance, that define problems of modeling and measurement of non-isothermal flow through geologic media exposed to variable boundary conditions (e.g., climatic changes). These are: (1) the large time scale (tens of thousands of years) and highly variable space scale (from one meter to 10 5 meters); and (2) the hierarchy of heterogeneities and discontinuities characterizing the medium. This paper provides an overview of recent work, conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA), related to laboratory experiments, consideration of similitude, and numerical modeling of flow through heterogeneous media under non-homogeneous boundary conditions. As discussed, there exist neither good methods of measuring flows at these scales nor are there adequate similitude analyses that would allow reasonable scaling up of laboratory-scale experiments. Reliable assessment of long-term geologic repositories will require sophisticated geostatistical models capable of addressing variables scales of heterogeneities conditioned with observed results from adequately sized field-scale experiments conducted for sufficiently long durations

  20. Software network analyzer for computer network performance measurement planning over heterogeneous services in higher educational institutes

    OpenAIRE

    Ismail, Mohd Nazri

    2009-01-01

    In 21st century, convergences of technologies and services in heterogeneous environment have contributed multi-traffic. This scenario will affect computer network on learning system in higher educational Institutes. Implementation of various services can produce different types of content and quality. Higher educational institutes should have a good computer network infrastructure to support usage of various services. The ability of computer network should consist of i) higher bandwidth; ii) ...

  1. Measurement of the density profile of pure and seeded molecular beams by femtosecond ion imaging

    NARCIS (Netherlands)

    Meng, C.; Janssen, M.H.M.

    2015-01-01

    Here, we report on femtosecond ion imaging experiments to measure the density profile of a pulsed supersonic molecular beam. Ion images are measured for both a molecular beam and bulk gas under identical experimental conditions via femtosecond multiphoton ionization of Xe atoms. We report the

  2. Storing keV negative ions for hours: Lifetime measurements in new time domains

    International Nuclear Information System (INIS)

    Kaminska, M; Bäckström, E; Hole, O M; Nascimento, R F; Blom, M; Björkhage, M; Källberg, A; Löfgren, P; Reinhed, P; Rosèn, S; Thomas, R D; Mannervik, S; Schmidt, H T; Cederquist, H; Hanstorpt, D

    2015-01-01

    We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2 P° 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion. (paper)

  3. Measuring main-ion temperatures in ASDEX upgrade using scattering of ECRH radiation

    DEFF Research Database (Denmark)

    Pedersen, Morten Stejner; Nielsen, Stefan Kragh; Jacobsen, Asger Schou

    2016-01-01

    We demonstrate that collective Thomson scattering of millimeter wave electron cyclotron resonance heating radiation can be used for measurements of the main-ion temperature in the ASDEX Upgrade tokamak.......We demonstrate that collective Thomson scattering of millimeter wave electron cyclotron resonance heating radiation can be used for measurements of the main-ion temperature in the ASDEX Upgrade tokamak....

  4. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    International Nuclear Information System (INIS)

    Bindslev, H; Nielsen, S K; Porte, L; Hoekzema, J A; Korsholm, S B; Meo, F; Michelsen, P K; Michelsen, S; Oosterbeek, J W; Tsakadze, E L; Westerhof, E; Woskov, P

    2007-01-01

    The dynamics of fast ion populations in the TEXTOR tokamak are measured by collective Thomson scattering of millimetre wave radiation generated by a gyrotron operated at 110 GHz and 100-150 kW. Temporal evolution of the energetic ion velocity distribution at switch on of neutral beam injection (NBI) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also measured

  5. Coincidence measurements of slow recoil ions with projectile ions in 42-MeV Arq+-Ar collisions

    International Nuclear Information System (INIS)

    Tonuma, T.; Kumagai, H.; Matsuo, T.; Tawara, H.

    1989-01-01

    Slow Ar recoil-ion production cross sections by projectiles of 1.05-MeV/amu Ar q+ (q=4,6,8,10,12,14) were measured using a projectile-ion--recoil-ion coincidence technique. The present results indicate that the average recoil ion charges left-angle i right-angle increase with increasing the incident projectile charge q and the number of the lost and captured electrons from and/or into projectiles, whereas the projectile charge-changing cross sections for loss ionization decrease steeply with increasing q for low-charge-state projectiles, and those for transfer ionization increase rapidly with increasing q for high-charge-state projectiles. For Ar projectiles with q=10, which corresponds to the equilibrium charge state of Ar projectiles at the present collision energy, the average recoil-ion charges are nearly the same in both loss and transfer ionization, and a pure ionization process plays a much more important role in producing highly charged recoil ions, in contrast to projectile electron loss or transfer processes, which play a role in other projectile charge states

  6. On-line measurement of microwave power in ECR ion source

    International Nuclear Information System (INIS)

    Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang; Li Xiaoyun

    2005-01-01

    It is a new technology to apply an ECR ion source to the neutron generator. Because of the structure limitation, working state of the ECR ion source could not be judged by the color of gas discharging in discharge chamber. Therefore, it was hard to estimate if the ECR ion source was working properly in the neutron generator. The method to resolve the problem was described in this paper. The microwave power was measured on-line by a directional coupler and a small microwave power meter. The ion beam current could be educed from the measured incidence microwave power, and discharge state in discharge chamber could be determined. (authors)

  7. Measuring energy efficiency under heterogeneous technologies using a latent class stochastic frontier approach: An application to Chinese energy economy

    International Nuclear Information System (INIS)

    Lin, Boqiang; Du, Kerui

    2014-01-01

    The importance of technology heterogeneity in estimating economy-wide energy efficiency has been emphasized by recent literature. Some studies use the metafrontier analysis approach to estimate energy efficiency. However, for such studies, some reliable priori information is needed to divide the sample observations properly, which causes a difficulty in unbiased estimation of energy efficiency. Moreover, separately estimating group-specific frontiers might lose some common information across different groups. In order to overcome these weaknesses, this paper introduces a latent class stochastic frontier approach to measure energy efficiency under heterogeneous technologies. An application of the proposed model to Chinese energy economy is presented. Results show that the overall energy efficiency of China's provinces is not high, with an average score of 0.632 during the period from 1997 to 2010. - Highlights: • We introduce a latent class stochastic frontier approach to measure energy efficiency. • Ignoring technological heterogeneity would cause biased estimates of energy efficiency. • An application of the proposed model to Chinese energy economy is presented. • There is still a long way for China to develop an energy efficient regime

  8. Heterogeneous ion-exchange polyethylene-based membranes with sulfonated poly(1,4-phenylene sulfide) particles

    Czech Academy of Sciences Publication Activity Database

    Schauer, Jan; Brožová, Libuše; Pientka, Zbyněk; Bouzek, K.

    2006-01-01

    Roč. 200, 1-3 (2006), s. 632-633 ISSN 0011-9164. [Conference Euromembrane. Giardini Naxos - Taormina, 24.09.2006-28.09.2006] R&D Projects: GA ČR GA203/05/0080 Institutional research plan: CEZ:AV0Z40500505 Keywords : ion-exchange membrane * poly(phenylene sulfide) * fuel cell Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

  9. The Application of the EIS in Li-ion Batteries Measurement

    Science.gov (United States)

    Zhai, N. S.; Li, M. W.; Wang, W. L.; Zhang, D. L.; Xu, D. G.

    2006-10-01

    The measurement and determination of the lithium ion battery's electrochemical impedance spectroscopy (EIS) and the application of EIS to battery classification are researched in this paper. The lithium ion battery gets extensive applications due to its inherent advantages over other batteries. For proper and sustainable performance, it is very necessary to check the uniformity of the lithium ion batteries. In this paper, the equivalent circuit of the lithium ion battery is analyzed; the design of hardware circuit based on DSP and software that calculates the EIS of the lithium ion battery is critically done and evaluated. The parameters of the lithium ion equivalent circuit are determined, the parameter values of li-ion equivalent circuit are achieved by least square method, and the application of Principal Component Analysis (CPA) to the battery classification is analyzed.

  10. The Application of the EIS in Li-ion Batteries Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, N S [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen (China); Li, M W [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen (China); Wang, W L [Shenzhen BPL instrument Ltd., Shenzhen (China); Zhang, D L [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen (China); Xu, D G [Electrical Engineering and Automation School, Harbin Institute of Technology, Harbin (China)

    2006-10-15

    The measurement and determination of the lithium ion battery's electrochemical impedance spectroscopy (EIS) and the application of EIS to battery classification are researched in this paper. The lithium ion battery gets extensive applications due to its inherent advantages over other batteries. For proper and sustainable performance, it is very necessary to check the uniformity of the lithium ion batteries. In this paper, the equivalent circuit of the lithium ion battery is analyzed; the design of hardware circuit based on DSP and software that calculates the EIS of the lithium ion battery is critically done and evaluated. The parameters of the lithium ion equivalent circuit are determined, the parameter values of li-ion equivalent circuit are achieved by least square method, and the application of Principal Component Analysis (CPA) to the battery classification is analyzed.

  11. The Application of the EIS in Li-ion Batteries Measurement

    International Nuclear Information System (INIS)

    Zhai, N S; Li, M W; Wang, W L; Zhang, D L; Xu, D G

    2006-01-01

    The measurement and determination of the lithium ion battery's electrochemical impedance spectroscopy (EIS) and the application of EIS to battery classification are researched in this paper. The lithium ion battery gets extensive applications due to its inherent advantages over other batteries. For proper and sustainable performance, it is very necessary to check the uniformity of the lithium ion batteries. In this paper, the equivalent circuit of the lithium ion battery is analyzed; the design of hardware circuit based on DSP and software that calculates the EIS of the lithium ion battery is critically done and evaluated. The parameters of the lithium ion equivalent circuit are determined, the parameter values of li-ion equivalent circuit are achieved by least square method, and the application of Principal Component Analysis (CPA) to the battery classification is analyzed

  12. Measurement of negative ion mobilities in O2 and O3 mixtures at atmospheric pressure

    International Nuclear Information System (INIS)

    Itoh, H.; Norimoto, K.; Hayashi, T.

    1998-01-01

    Mobility measurements of negative molecular oxygen ions in pure oxygen and in an oxygen-ozone mixture are reported. A cascaded gap consisting of an ion drift gap and an ion detection gap was used in the experiment. The ion detection gap was formed by a positive point and a grounded plane electrode was operated at atmospheric pressure. The zero field mobility of negative molecular oxygen ions was determined to be 2.07+-0.02 cm 2 /V.s. A somewhat higher value of oxygen mobility was found at higher electric field/pressure ratios; this is presumed to be due to negative ozone ions. When changing the electric field/pressure ratio the mobility of negative oxygen ions in oxygen-ozone mixtures becomes smaller than that in pure oxygen; this is probably due to the cumulative effect of other particles produced by silent discharges. (J.U.)

  13. Single-cell quantitative HER2 measurement identifies heterogeneity and distinct subgroups within traditionally defined HER2-positive patients.

    Science.gov (United States)

    Onsum, Matthew D; Geretti, Elena; Paragas, Violette; Kudla, Arthur J; Moulis, Sharon P; Luus, Lia; Wickham, Thomas J; McDonagh, Charlotte F; MacBeath, Gavin; Hendriks, Bart S

    2013-11-01

    Human epidermal growth factor receptor 2 (HER2) is an important biomarker for breast and gastric cancer prognosis and patient treatment decisions. HER2 positivity, as defined by IHC or fluorescent in situ hybridization testing, remains an imprecise predictor of patient response to HER2-targeted therapies. Challenges to correct HER2 assessment and patient stratification include intratumoral heterogeneity, lack of quantitative and/or objective assays, and differences between measuring HER2 amplification at the protein versus gene level. We developed a novel immunofluorescence method for quantitation of HER2 protein expression at the single-cell level on FFPE patient samples. Our assay uses automated image analysis to identify and classify tumor versus non-tumor cells, as well as quantitate the HER2 staining for each tumor cell. The HER2 staining level is converted to HER2 protein expression using a standard cell pellet array stained in parallel with the tissue sample. This approach allows assessment of HER2 expression and heterogeneity within a tissue section at the single-cell level. By using this assay, we identified distinct subgroups of HER2 heterogeneity within traditional definitions of HER2 positivity in both breast and gastric cancers. Quantitative assessment of intratumoral HER2 heterogeneity may offer an opportunity to improve the identification of patients likely to respond to HER2-targeted therapies. The broad applicability of the assay was demonstrated by measuring HER2 expression profiles on multiple tumor types, and on normal and diseased heart tissues. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  14. Ion association at discretely-charged dielectric interfaces: Giant charge inversion [Dielectric response controlled ion association at physically heterogeneous surfaces: Giant charge reversal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi -Yong [Chongqing Univ. of Technology, Chongqing (China); Univ. of California, Riverside, CA (United States); Wu, Jianzhong [Univ. of California, Riverside, CA (United States)

    2017-07-11

    Giant charge reversal has been identified for the first time by Monte Carlo simulation for a discretely charged surface in contact with a trivalent electrolyte solution. It takes place regardless of the surface charge density under study and the monovalent salt. In stark contrast to earlier predictions based on the 2-dimensional Wigner crystal model to describe strong correlation of counterions at the macroion surface, we find that giant charge reversal reflects an intricate interplay of ionic volume effects, electrostatic correlations, surface charge heterogeneity, and the dielectric response of the confined fluids. While the novel phenomenon is yet to be confirmed with experiment, the simulation results appear in excellent agreement with a wide range of existing observations in the subregime of charge inversion. Lastly, our findings may have far-reaching implications to understanding complex electrochemical phenomena entailing ionic fluids under dielectric confinements.

  15. Ion diode optics: measurement of divergence and aiming of beams for transport to light-ion ICF targets

    International Nuclear Information System (INIS)

    Krastelev, E.G.; Kniazev, B.A.; Lindholm, F.; Hammer, D.A.; Kusse, B.R.; Greenly, J.B.

    1996-01-01

    Diagnostic development for measurements of anode plasma structure and ion beam local aiming and micro-divergence are being developed on the COBRA accelerator at Cornell University. Results of streaked-scintillator and tracer target beam diagnostics, and streaked anode light imaging are described. (author). 5 figs., 1 ref

  16. Ion diode optics: measurement of divergence and aiming of beams for transport to light-ion ICF targets

    Energy Technology Data Exchange (ETDEWEB)

    Krastelev, E G; Kniazev, B A; Lindholm, F; Hammer, D A; Kusse, B R; Greenly, J B [Cornell Univ., Ithaca, NY (United States). Lab. of Plasma Studies

    1997-12-31

    Diagnostic development for measurements of anode plasma structure and ion beam local aiming and micro-divergence are being developed on the COBRA accelerator at Cornell University. Results of streaked-scintillator and tracer target beam diagnostics, and streaked anode light imaging are described. (author). 5 figs., 1 ref.

  17. Novel Faraday cup for the simultaneous observation and measurement of ion-beam currents

    International Nuclear Information System (INIS)

    Wei, C.Y.; Seidman, D.N.

    1977-07-01

    The Faraday cup is constructed around a Galileo channel electron multiplier array (CEMA) which serves as the basis of an internal image intensification system (a gain of greater than 10 4 ) for the observation of the ion beam; the CEMA also acts as a collector for the ion cured by a Keithley 602 electrometer. The ion current is integrated by a simple and inexpensive dosimeter; the electronic circuit for the dosimeter is described. The application of the Faraday cup to the observation and measurement of a 30 keV Ar + ion beam is presented as an illustrative example. This Faraday cup was also employed to observe and measure 30 keV Cr + , Mo + or W + and 18 keV Au + ion beams employed for the in-situ irradiation of field-ion microscope specimens

  18. Scintillator-based diagnostic for fast ion loss measurements on DIII-D

    International Nuclear Information System (INIS)

    Fisher, R. K.; Van Zeeland, M. A.; Pace, D. C.; Heidbrink, W. W.; Muscatello, C. M.; Zhu, Y. B.; Garcia-Munoz, M.

    2010-01-01

    A new scintillator-based fast ion loss detector has been installed on DIII-D with the time response (>100 kHz) needed to study energetic ion losses induced by Alfven eigenmodes and other MHD instabilities. Based on the design used on ASDEX Upgrade, the diagnostic measures the pitch angle and gyroradius of ion losses based on the position of the ions striking the two-dimensional scintillator. For fast time response measurements, a beam splitter and fiberoptics couple a portion of the scintillator light to a photomultiplier. Reverse orbit following techniques trace the lost ions to their possible origin within the plasma. Initial DIII-D results showing prompt losses and energetic ion loss due to MHD instabilities are discussed.

  19. Insights on Measuring and Reporting Heterogeneous Photocatalysis: Efficiency Definitions and Setup Examples

    KAUST Repository

    Qureshi, Muhammad

    2016-08-29

    Heterogeneous photocatalysis is a potentially competitive solution for the direct production of solar fuels. This research field has seen tremendous growth over the last five decades, and with such an exciting research topic, it has seen—and will continue to see—an increasing number of papers being published in a variety of journals. However, it is becoming increasingly difficult to compare the efficiencies of heterogeneous photocatalyst powders, because different researchers report their results in different ways. Efforts have been made to create standards for reporting data in this field, but there continues to be a discrepancy in published works. This article intends to clarify efficiency definitions, and clarify misconceptions as to why researchers should avoid reporting rates of evolution per gram, per surface area of catalyst, or as turnover frequencies (TOFs) alone, to be able to compare photocatalytic efficiency among different materials. By providing an example of a photoreactor for water splitting in the authors’ laboratory, the paper also intends to guide new researchers in the field. This article does not discuss how to improve photocatalysis but rather how to improve the reporting of photocatalysis to ensure reproducibility and effective benchmarking. Researchers should not only ensure that they have all the appropriate characterization and statistical data to support their claims but should also recognize that improperly reported data may lead to faulty benchmarking that prevents their results from being compared with those of other photocatalysts, inhibiting the progress of photocatalytic research.

  20. Employing Measures of Heterogeneity and an Object-Based Approach to Extrapolate Tree Species Distribution Data

    Directory of Open Access Journals (Sweden)

    Trevor G. Jones

    2014-07-01

    Full Text Available Information derived from high spatial resolution remotely sensed data is critical for the effective management of forested ecosystems. However, high spatial resolution data-sets are typically costly to acquire and process and usually provide limited geographic coverage. In contrast, moderate spatial resolution remotely sensed data, while not able to provide the spectral or spatial detail required for certain types of products and applications, offer inexpensive, comprehensive landscape-level coverage. This study assessed using an object-based approach to extrapolate detailed tree species heterogeneity beyond the extent of hyperspectral/LiDAR flightlines to the broader area covered by a Landsat scene. Using image segments, regression trees established ecologically decipherable relationships between tree species heterogeneity and the spectral properties of Landsat segments. The spectral properties of Landsat bands 4 (i.e., NIR: 0.76–0.90 µm, 5 (i.e., SWIR: 1.55–1.75 µm and 7 (SWIR: 2.08–2.35 µm were consistently selected as predictor variables, explaining approximately 50% of variance in richness and diversity. Results have important ramifications for ongoing management initiatives in the study area and are applicable to wide range of applications.

  1. Insights on Measuring and Reporting Heterogeneous Photocatalysis: Efficiency Definitions and Setup Examples

    KAUST Repository

    Qureshi, Muhammad; Takanabe, Kazuhiro

    2016-01-01

    Heterogeneous photocatalysis is a potentially competitive solution for the direct production of solar fuels. This research field has seen tremendous growth over the last five decades, and with such an exciting research topic, it has seen—and will continue to see—an increasing number of papers being published in a variety of journals. However, it is becoming increasingly difficult to compare the efficiencies of heterogeneous photocatalyst powders, because different researchers report their results in different ways. Efforts have been made to create standards for reporting data in this field, but there continues to be a discrepancy in published works. This article intends to clarify efficiency definitions, and clarify misconceptions as to why researchers should avoid reporting rates of evolution per gram, per surface area of catalyst, or as turnover frequencies (TOFs) alone, to be able to compare photocatalytic efficiency among different materials. By providing an example of a photoreactor for water splitting in the authors’ laboratory, the paper also intends to guide new researchers in the field. This article does not discuss how to improve photocatalysis but rather how to improve the reporting of photocatalysis to ensure reproducibility and effective benchmarking. Researchers should not only ensure that they have all the appropriate characterization and statistical data to support their claims but should also recognize that improperly reported data may lead to faulty benchmarking that prevents their results from being compared with those of other photocatalysts, inhibiting the progress of photocatalytic research.

  2. Depth profile of In and As in Si measured by RBS with He and C ions

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Q; Fang, Z [Newcastle Univ., NSW (Australia). Dept. of Physics; Ophel, T R [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1994-12-31

    The depth profile of As and In implanted into Si have been measured by RBS (Rutherford Backscattering Spectrometry) with 2 MeV He ions and 6 MeV C ions. Advantages of enhanced depth and mass resolution with C ions have been demonstrated over the conventional He RBS. More reliable information for the depth profile of In and As in Si has been obtained. 12 refs., 3 figs.

  3. Predicted precision of ion temperature and impurity fractional density measurements using the JET collective scattering diagnostic

    International Nuclear Information System (INIS)

    Orsitto, F.

    1992-11-01

    In a previous investigation the possibility of measuring the bulk ion temperature was considered in detail, in the context of the proposed Thomson scattering diagnostic for fast ions and alpha particles in the Joint European Torus project. In this report we give an affirmative answer to the question of whether good precision can be obtained in the simultaneous determination of the temperatures and densities of plasma ions from a collective scattering experiment provided some conditions are satisfied. (Author)

  4. Depth profile of In and As in Si measured by RBS with He and C ions

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Q.; Fang, Z. [Newcastle Univ., NSW (Australia). Dept. of Physics; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1993-12-31

    The depth profile of As and In implanted into Si have been measured by RBS (Rutherford Backscattering Spectrometry) with 2 MeV He ions and 6 MeV C ions. Advantages of enhanced depth and mass resolution with C ions have been demonstrated over the conventional He RBS. More reliable information for the depth profile of In and As in Si has been obtained. 12 refs., 3 figs.

  5. The uncertainties calculation of acoustic method for measurement of dissipative properties of heterogeneous non-metallic materials

    Directory of Open Access Journals (Sweden)

    Мaryna O. Golofeyeva

    2015-12-01

    Full Text Available The effective use of heterogeneous non-metallic materials and structures needs measurement of reliable values of dissipation characteristics, as well as common factors of their change during the loading process. Aim: The aim of this study is to prepare the budget for measurement uncertainty of dissipative properties of composite materials. Materials and Methods: The method used to study the vibrational energy dissipation characteristics based on coupling of vibrations damping decrement and acoustic velocity in a non-metallic heterogeneous material is reviewed. The proposed method allows finding the dependence of damping on vibrations amplitude and frequency of strain-stress state of material. Results: Research of the accuracy of measurement method during the definition of decrement attenuation of fluctuations in synthegran was performed. The international approach for evaluation of measurements quality is used. It includes the common practice international rules for uncertainty expression and their summation. These rules are used as internationally acknowledged confidence measure to the measurement results, which includes testing. The uncertainties budgeting of acoustic method for measurement of dissipative properties of materials were compiled. Conclusions: It was defined that there are two groups of reasons resulting in errors during measurement of materials dissipative properties. The first group of errors contains of parameters changing of calibrated bump in tolerance limits, displacement of sensor in repeated placement to measurement point, layer thickness variation of contact agent because of irregular hold-down of resolvers to control surface, inaccuracy in reading and etc. The second group of errors is linked with density and Poisson’s ratio measurement errors, distance between sensors, time difference between signals of vibroacoustic sensors.

  6. Analysis of heterogeneous hydrological properties of a mountainous hillslope using intensive water flow measurements

    Science.gov (United States)

    Masaoka, Naoya; Kosugi, Ken'ichirou; Yamakawa, Yosuke; Mizuyama, Takahisa; Tsutsumi, Daizo

    2013-04-01

    Heterogeneous hydrological properties in a foot slope area of mountainous hillslopes should be assessed to understand hydrological phenomena and their effects on discharge and sediment transport. In this study, we analyzed the high-resolution and three-dimensional water movement data to clarify the hydrological process, including heterogeneous phenomena, in detail. We continuously monitored the soil matric pressure head, psi, using 111 tensiometers installed at grid intervals of approximately 1 meter within the soil mantle at the study hillslope. Under a no-rainfall condition, the existence of perennial groundwater seepage flow was detected by exfiltration flux and temporal psi waveforms, which showed delayed responses, only to heavy storm events, and gradual recession limbs. The seepage water spread in the downslope direction and supplied water constantly to the lower section of the slope. At some points in the center of the slope, a perched saturated area was detected in the middle of soil layer, while psi exhibited negative values above the bedrock surface. These phenomena could be inferred partly from the bedrock topography and the distribution of soil hydraulic conductivity assumed from the result of penetration test. At the peak of a rainfall event, on the other hand, continuous high pressure zones (i.e., psi > 50 cmH2O) were generated in the right and left sections of the slope. Both of these high pressure zones converged at the lower region, showing a sharp psi spike up to 100 cmH2O. Along the high pressure zones, flux vectors showed large values and water exfiltration, indicating the occurrence of preferential flow. Moreover, the preferential flow occurred within the area beneath the perched water, indicating the existence of a weathered bedrock layer. This layer had low permeability, which prevented the vertical infiltration of water in the upper part of the layer, but had high permeability as a result of the fractures distributed heterogeneously inside

  7. COMPLIS: COllinear spectroscopy Measurements using a Pulsed Laser Ion Source

    CERN Multimedia

    2002-01-01

    A Pulsed Laser spectroscopy experiment has been installed for the study of hyperfine structure and isotope shift of refractory and daughter elements from ISOLDE beams. It includes decelerated ion-implantation, element-selective laser ionization, magnetic and time-of-flight mass separation. The laser spectroscopy has been performed on the desorbed atoms in a set-up at ISOLDE-3 but later on high resolution laser collinear spectroscopy with the secondary pulsed ion beam is planned for the Booster ISOLDE set-up. During the first operation time of ISOLDE-3 we restricted our experiments to Doppler-limited resonant ionization laser and $\\gamma$-$\\gamma$ nuclear spectroscopy on neutron deficient platinum isotopes of even mass number down to A~=~186 and A~=~179 respectively. These isotopes have been produced by implantation of radioactive Hg and their subsequent $\\beta$-decay.

  8. Analysis of O-glycan heterogeneity in IgA1 myeloma proteins by Fourier transform ion cyclotron resonance mass spectrometry: implications for IgA nephropathy

    DEFF Research Database (Denmark)

    Renfrow, MB; Mackay, CL; Chalmers, MJ

    2007-01-01

    deficiency in IgA1 proteins occurs randomly or preferentially at specific sites. We have previously demonstrated the first direct localization of multiple O-glycosylation sites on a single IgA1 myeloma protein by use of activated ion-electron capture dissociation (AI-ECD) Fourier transform ion cyclotron...... resonance (FT-ICR) tandem mass spectrometry. Here, we report the analysis of IgA1 O-glycan heterogeneity by use of FT-ICR MS and liquid chromatography FT-ICR MS to obtain unbiased accurate mass profiles of IgA1 HR glycopeptides from three different IgA1 myeloma proteins. Additionally, we report the first AI......-ECD fragmentation on an individual IgA1 O-glycopeptide from an IgA1 HR preparation that is reproducible for each IgA1 myeloma protein. These results suggest that future analysis of IgA1 HR from IgAN patients and normal healthy controls should be feasible....

  9. Acetylene Black Induced Heterogeneous Growth of Macroporous CoV2O6 Nanosheet for High-Rate Pseudocapacitive Lithium-Ion Battery Anode.

    Science.gov (United States)

    Zhang, Lei; Zhao, Kangning; Luo, Yanzhu; Dong, Yifan; Xu, Wangwang; Yan, Mengyu; Ren, Wenhao; Zhou, Liang; Qu, Longbing; Mai, Liqiang

    2016-03-23

    Metal vanadates suffer from fast capacity fading in lithium-ion batteries especially at a high rate. Pseudocapacitance, which is associated with surface or near-surface redox reactions, can provide fast charge/discharge capacity free from diffusion-controlled intercalation processes and is able to address the above issue. In this work, we report the synthesis of macroporous CoV2O6 nanosheets through a facile one-pot method via acetylene black induced heterogeneous growth. When applied as lithium-ion battery anode, the macroporous CoV2O6 nanosheets show typical features of pseudocapacitive behavior: (1) currents that are mostly linearly dependent on sweep rate and (2) redox peaks whose potentials do not shift significantly with sweep rate. The macroporous CoV2O6 nanosheets display a high reversible capacity of 702 mAh g(-1) at 200 mA g(-1), excellent cyclability with a capacity retention of 89% (against the second cycle) after 500 cycles at 500 mA g(-1), and high rate capability of 453 mAh g(-1) at 5000 mA g(-1). We believe that the introduction of pseudocapacitive properties in lithium battery is a promising direction for developing electrode materials with high-rate capability.

  10. Measuring Light Air Ions in a Speleotherapeutic Cave

    Czech Academy of Sciences Publication Activity Database

    Roubal, Z.; Bartušek, Karel; Szabó, Z.; Drexler, P.; Überhuberová, J.

    2017-01-01

    Roč. 17, č. 1 (2017), s. 27-36 ISSN 1335-8871 R&D Projects: GA MŠk(CZ) LO1212; GA ČR GA13-09086S Institutional support: RVO:68081731 Keywords : speleotherapy * air ions * Gerdien tube * climatology Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Meteorology and atmospheric sciences Impact factor: 1.344, year: 2016

  11. The localization of focal heart activity via body surface potential measurements: tests in a heterogeneous torso phantom

    International Nuclear Information System (INIS)

    Wetterling, F; Liehr, M; Haueisen, J; Schimpf, P; Liu, H

    2009-01-01

    The non-invasive localization of focal heart activity via body surface potential measurements (BSPM) could greatly benefit the understanding and treatment of arrhythmic heart diseases. However, the in vivo validation of source localization algorithms is rather difficult with currently available measurement techniques. In this study, we used a physical torso phantom composed of different conductive compartments and seven dipoles, which were placed in the anatomical position of the human heart in order to assess the performance of the Recursively Applied and Projected Multiple Signal Classification (RAP-MUSIC) algorithm. Electric potentials were measured on the torso surface for single dipoles with and without further uncorrelated or correlated dipole activity. The localization error averaged 11 ± 5 mm over 22 dipoles, which shows the ability of RAP-MUSIC to distinguish an uncorrelated dipole from surrounding sources activity. For the first time, real computational modelling errors could be included within the validation procedure due to the physically modelled heterogeneities. In conclusion, the introduced heterogeneous torso phantom can be used to validate state-of-the-art algorithms under nearly realistic measurement conditions.

  12. The localization of focal heart activity via body surface potential measurements: tests in a heterogeneous torso phantom

    Science.gov (United States)

    Wetterling, F.; Liehr, M.; Schimpf, P.; Liu, H.; Haueisen, J.

    2009-09-01

    The non-invasive localization of focal heart activity via body surface potential measurements (BSPM) could greatly benefit the understanding and treatment of arrhythmic heart diseases. However, the in vivo validation of source localization algorithms is rather difficult with currently available measurement techniques. In this study, we used a physical torso phantom composed of different conductive compartments and seven dipoles, which were placed in the anatomical position of the human heart in order to assess the performance of the Recursively Applied and Projected Multiple Signal Classification (RAP-MUSIC) algorithm. Electric potentials were measured on the torso surface for single dipoles with and without further uncorrelated or correlated dipole activity. The localization error averaged 11 ± 5 mm over 22 dipoles, which shows the ability of RAP-MUSIC to distinguish an uncorrelated dipole from surrounding sources activity. For the first time, real computational modelling errors could be included within the validation procedure due to the physically modelled heterogeneities. In conclusion, the introduced heterogeneous torso phantom can be used to validate state-of-the-art algorithms under nearly realistic measurement conditions.

  13. A calorimeter-Faraday cup to measure energy content of ion beams

    International Nuclear Information System (INIS)

    Luzzi, G.

    1984-01-01

    A calorimeter-Faraday cup to measure energy content of ion beams is described. It uses an HP quartz thermometer having a 10 -40 C sensitivity; contact potential problems, arising when working with thermocouples, are so avoided. Calibration has been performed with a resistive filament and with an electron beam. The apparatus is profitable if the measured ion beams are constant in time. The measured sensitivity was 10 -40 C/10 -5 W. (author)

  14. Some new hydraulic and tracer measurement techniques for heterogeneous aquifer formations

    International Nuclear Information System (INIS)

    Ptak, T.; Teutsch, G.

    1990-01-01

    Groundwater contamination assessment and remediation activities demand reliable techniques for the determination of the governing aquifer parameters and their spatial distribution. In order to define guidelines and recommendations, some existing underground investigation techniques were tested and new methods have been developed as a part of the research program at the Horkheimer Insel experimental field site. In this paper, some new developed field and laboratory techniques are introduced and the results compared for two example monitoring wells located in the northern part of the field site. It is shown that highly conductive and highly heterogeneous aquifers demand high resolution investigation techniques. For transport predictions, new methods are needed that are able to detect preferential flow paths. Results from multilevel tracer tests show that simple analytical interpretations are not valid for this type of aquifer. (Author) (8 refs., 12 figs., tab.)

  15. New device to measure dynamic intrusion/extrusion cycles of lyophobic heterogeneous systems.

    Science.gov (United States)

    Guillemot, Ludivine; Galarneau, Anne; Vigier, Gérard; Abensur, Thierry; Charlaix, Élisabeth

    2012-10-01

    Lyophobic heterogeneous systems (LHS) are made of mesoporous materials immersed in a non-wetting liquid. One application of LHS is the nonlinear damping of high frequency vibrations. The behaviour of LHS is characterized by P - ΔV cycles, where P is the pressure applied to the system, and ΔV its volume change due to the intrusion of the liquid into the pores of the material, or its extrusion out of the pores. Very few dynamic studies of LHS have been performed until now. We describe here a new apparatus that allows us to carry out dynamic intrusion/extrusion cycles with various liquid/porous material systems, controlling the temperature from ambient to 120 °C and the frequency from 0.01 to 20 Hz. We show that for two LHS: water/MTS and Galinstan/CPG, the energy dissipated during one cycle depends very weakly on the cycle frequency, in strong contrast to conventional dampers.

  16. Measurements of secondary neutrons producted from thick targets bombarded by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Nakao, N.; Shibata, T.; Uwamino, Y.; Nakanishi, N.; Fukumura, A.; Kumamoto, Y.

    1997-03-01

    We measured neutron angular and energy distributions from high energy heavy ions stopping in targets of carbon, aluminum, copper and lead at HIMAC. These spectra are much harder for the lighter target nucleus like carbon. This means that the momentum transfer in the forward direction from heavy ion beam to lighter nuclei is much higher than that to heavier nuclei. (author)

  17. Some experimental considerations regarding ion beam simulation of neutron irradiation for mechanical property measurements

    International Nuclear Information System (INIS)

    Styris, D.L.; Jones, R.H.; Harling, O.K.; Kulcinski, G.L.; Marshall, R.P.

    1975-01-01

    A preliminary assessment of the requirements for mechanical property data related to CTR materials is given. The status of ion simulation for mechanical property measurements is described. A damage analysis and calculations for light ions are presented along with sample size, heating and cooling, and surface considerations

  18. Measurements of the Properties of Highly-charged high-Z ions

    International Nuclear Information System (INIS)

    Augustine J. Smith, Ph.D.

    2007-01-01

    We had proposed carrying out a systematic experimental investigation of the atomic physics of highly charged, high-Z ions, produced in the Lawrence Livermore National Laboratory LLNL electron beam ion trap (EBIT-I) in its high energy mode, superEBIT. In particular we were going to accurately measure line positions for Δn=0 transitions in few electron high-Z ions; this was meant to enable us to investigate relativistic and quantum electrodynamics QED contributions to the energy levels as well as the nuclear properties of heavy ions. We were also going to measure cross sections for various electron-ion interactions, the degree of polarization of emitted x-rays, and radiation cooling rates of various ionization stages of highly charged, high-Z ions. This would enable us to study fundamental atomic physics of high-Z ions at relativistic electron impact energies and in the intense nuclear fields of highly ionized, high-Z ions. This would extend previous measurements we have carried out to a regime where there is a paucity of good data. These measurements were expected to generate increased theoretical interest and activity in this area. The project will extend a very successful collaboration between Morehouse College (MC) and a national laboratory LLNL, Minority student training and development are major components of the proposal

  19. Measurements of bremsstrahlung spectra of Lanzhou ECR Ion Source No. 3 (LECR3)

    International Nuclear Information System (INIS)

    Zhao, H.Y.; Zhao, H.W.; Ma, X.W.; Zhang, S.F.; Feng, W.T.; Zhu, X.L.; Zhang, Z.M.; He, W.; Sun, L.T.; Feng, Y.C.; Cao, Y.; Li, J.Y.; Li, X.X.; Wang, H.; Ma, B.H.

    2006-01-01

    In order to diagnose the electron cyclotron resonance (ECR) plasma, electron bremsstrahlung spectra were measured by a HPGe detector on Lanzhou ECR Ion Source No. 3 at IMP. The ion source was operated with argon under various working conditions, including different microwave power, mixing gas, extraction high voltage (HV), and so on. Some of the measured spectra are presented in this article. The dependence of energetic electron population on mixing gas and extraction HV is also described. Additionally, we are looking forward to further measurements on SECRAL (Superconducting ECR Ion Source with Advanced design at Lanzhou)

  20. Ion Temperature Measurements in the Tore Supra Scrape-Off Layer Using a Retarding Field Analyzer

    International Nuclear Information System (INIS)

    Kocan, M.; Gunn, J.P.; Pascal, J.Y.; Gauthier, E.

    2010-01-01

    The retarding field analyzer (RFA) is one of the only widely accepted diagnostics for measuring the ion temperature T i )in the tokamak scrape-off layer. An overview of the outstanding RFA performance over ten years of operation in Tore Supra tokamak is given and the validation of T i measurements is addressed. The RFA measurements in Tore Supra are found to be well reproducible. The ion-to-electron temperature ratio is higher than one at low-to-moderate ion-electron collisionality regime and converges to unity at high collisionality regime. (authors)

  1. Evaluation of different methods for measuring the impedance of Lithium-ion batteries during ageing

    DEFF Research Database (Denmark)

    Stroe, Daniel Loan; Swierczynski, Maciej Jozef; Stroe, Ana-Irina

    2015-01-01

    The impedance represents one of the most important performance parameters of the Lithium-ion batteries since it used for power capability calculations, battery pack and system design, cooling system design and also for state-of-health estimation. In the literature, different approaches...... are presented for measuring the impedance of Lithium-ion batteries and electrochemical impedance spectroscopy and dc current pulses are the most used ones; each of these approaches has its own advantages and drawbacks. The goal of this paper is to investigate which of the most encountered impedance measurement...... approaches is the most suitable for measuring the impedance of Lithium-ion batteries during ageing....

  2. Measurement of the force on microparticles in a beam of energetic ions and neutral atoms

    International Nuclear Information System (INIS)

    Trottenberg, Thomas; Schneider, Viktor; Kersten, Holger

    2010-01-01

    The force on microparticles in an energetic ion beam is investigated experimentally. Hollow glass microspheres are injected into the vertically upward directed beam and their trajectories are recorded with a charge-coupled device camera. The net force on the particles is determined by means of the measured vertical acceleration. The resulting beam pressures are compared with Faraday cup measurements of the ion current density and calorimetric measurements of the beam power density. Due to the neutral gas background, the beam consists, besides the ions, of energetic neutral atoms produced by charge-exchange collisions. It is found that the measured composition of the drag force by an ion and a neutral atom component agrees with a beam model that takes charge-exchange collisions into account. Special attention is paid to the momentum contribution from sputtered atoms, which is shown to be negligible in this experiment, but should become measurable in case of materials with high sputtering yields.

  3. Doppler spectroscopic measurements of sheath ion velocities in radio-frequency plasmas

    International Nuclear Information System (INIS)

    Woodcock, B.K.; Busby, J.R.; Freegarde, T.G.; Hancock, G.

    1997-01-01

    We have measured the distributions of N 2 + ion velocity components parallel and perpendicular to the electrode in the sheath of a radio-frequency nitrogen reactive ion etching discharge, using pulsed laser-induced fluorescence. Parallel to the electrode, the ions have throughout a thermal distribution that is found to be consistent with the rotational temperature of 355 K. In the perpendicular direction, we see clearly the acceleration of the ions towards the electrode, and our results agree well with theoretical predictions although an unexpected peak of unaccelerated ions persists. We have also determined the absolute ion concentrations in the sheath, which we have calibrated by analyzing the decay in laser-induced fluorescence in the plasma bulk after discharge extinction. At 20 mTorr, the bulk concentration of 1.0x10 10 cm -3 falls to around 2x10 8 cm -3 at 2 mm from the electrode. copyright 1997 American Institute of Physics

  4. Advanced Quadrupole Ion Trap Instrumentation for Low Level Vehicle Emissions Measurements

    International Nuclear Information System (INIS)

    McLuckey, S.A.

    1997-01-01

    Quadrupole ion trap mass spectrometry has been evaluated for its potential use in vehicle emissions measurements in vehicle test facilities as an analyzer for the top 15 compounds contributing to smog generation. A variety of ionization methods were explored including ion trap in situ chemical ionization, atmospheric sampling glow discharge ionization, and nitric oxide chemical ionization in a glow discharge ionization source coupled with anion trap mass spectrometer. Emphasis was placed on the determination of hydrocarbons and oxygenated hydrocarbons at parts per million to parts per billion levels. Ion trap in situ water chemical ionization and atmospheric sampling glow discharge ionization were both shown to be amendable to the analysis of arenes, alcohols, aldehydes and, to some degree, alkenes. Atmospheric sampling glow discharge also generated molecular ions of methy-t-butyl ether (MTBE). Neither of these ionization methods, however, were found to generate diagnostic ions for the alkanes. Nitric oxide chemical ionization, on the other hand, was found to yield diagnostic ions for alkanes, alkenes, arenes, alcohols, aldehydes, and MTBE. The ability to measure a variety of hydrocarbons present at roughly 15 parts per billion at measurement rates of 3 Hz was demonstrated. All of the ions with potential to serve as parent ions in a tandem mass spectrometry experiment were found to yield parent-to-product conversion efficiencies greater than 75%. The flexibility afforded to the ion trap by use of tailored wave-forms applied to the end-caps allows parallel monitoring schemes to be devised that provide many of the advantages of tandem mass spectrometry without major loss in measurement rate. A large loss in measurement rate would ordinarily result from the use of conventional tandem mass spectrometry experiments carried out in series for a large number of targeted components. These results have demonstrated that the ion trap has an excellent combination of

  5. Measurements of actinometry and ions energy in a microwave discharge

    International Nuclear Information System (INIS)

    Becerril, F.; Camps, E.; Villagran, M.; Muhl, S.

    1998-01-01

    In the present work it is showed the implementation of the plasma diagnostic technique through actinometry which allows to determine the absolute density of excited species. It is showed the range of the technique application, for the case of N 2 -H 2 mixtures plasmas used for the metals nitridation. The effects of magnetic field and the work pressure over ions energy were determined, using a Faraday cup type energy analyser. The results showed that in our device it is possible to vary such energy in a range between 10-45 eV, which amplify the range of applications perceptibly in comparison with another type of discharges. (Author)

  6. Measurement of residual radioactivity in cooper exposed to high energy heavy ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eunjoo; Nakamura, Takashi [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Uwamino, Yoshitomo; Ito, Sachiko; Fukumura, Akifumi

    1999-03-01

    The residual radioactivities produced by high energy heavy ions have been measured using the heavy ion beams of the Heavy Ion Medical Accelerator (HIMAC) at National Institute of Radiological Sciences. The spatial distribution of residual radioactivities in 3.5 cm, 5.5 cm and 10 cm thick copper targets of 10 cm x 10 cm size bombarded by 290 MeV/u, 400 MeV/u-{sup 12}C ion beams and 400 MeV/u-{sup 20}Ne ion beam, respectively, were obtained by measuring the gamma-ray activities of 0.5 mm thick copper foil inserted in the target with a high purity Ge detector after about 1 hour to 6 hours irradiation. (author)

  7. On-line measurement of the microwave power in ECR ion source

    International Nuclear Information System (INIS)

    Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang

    2005-01-01

    It is a new technology that ECR ion source is applied in the neutron generator. Because of effect of the structure, working state of ECR ion source could not be judged by the color of gas discharging in discharging chamber as doing in high frequency ion source. Therefore, state adjusting of ECR ion source was difficult in running of the neutron generator. The method to resolve the question is described in this paper. The micro-wave power was measured in case of running by using the method of directional coupler adding small microwave power meter. Because both were in the direct proportion, the ion beam current could be educed from microwave incidence power measured, and discharge state in discharge chamber could be judged. Finally, the neutron generator might be operated in best running state. (authors)

  8. Variations of Low-energy Ion Distributions Measured in the Heliosheath

    International Nuclear Information System (INIS)

    Decker, R. B.; Roelof, E. C.; Hill, M. E.; Krimigis, S. M.

    2010-01-01

    This report is an update of low-energy ion intensities and angular distributions measured recently by the Low Energy Charged Particle instruments on the Voyager 1 and 2 spacecraft in the inner heliosheath.

  9. Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad; Han, Jie; Chahine, May; Selim, Hatem; Belhi, Memdouh; Sarathy, Mani; Bisetti, Fabrizio; Farooq, Aamir

    2016-01-01

    chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon

  10. Supplementary Material for: Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad B. S.; Han, Jie; Chahine, May; Selim, Hatem; Belhi, Memdouh; Sarathy, Mani; Bisetti, Fabrizio; Farooq, Aamir

    2017-01-01

    chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon

  11. High-resolution measurements of x rays from ion-atom collisions

    International Nuclear Information System (INIS)

    Knudson, A.R.

    1974-01-01

    High resolution measurements of K x-ray spectra produced by ion-atom collisions at MeV energies are presented. These measurements indicate that a distribution of L-shell vacancies accompanies K-shell excitation. The variation of these spectra as a function of incident ion energy and atomic number is discussed. Difficulties in the analysis of these spectra due to rearrangement of vacancies between the time of the collision and the time of x-ray emission are considered. The use of high resolution x-ray measurements to obtain information on projectile ion vacancy configurations is demonstrated by data for Ar ions in KCl. X-ray spectra from Al projectiles in a variety of targets were measured and the effect of target composition on these spectra is discussed

  12. Flow direction variations of low energy ions as measured by the ion electron sensor (IES) flying on board of Rosetta

    Science.gov (United States)

    Szegö, Karoly; Nemeth, Zoltan; Foldy, Lajos; Burch, James L.; Goldstein, Raymond; Mandt, Kathleen; Mokashi, Prachet; Broiles, Tom

    2015-04-01

    The Ion Electron Sensor (IES) simultaneously measures ions and electrons with two separate electrostatic plasma analyzers in the energy range of 4 eV- 22 keV for ions. The field of view is 90ox360o, with angular resolution 5ox45o for ions, with a sector containing the solar wind being further segmented to 5o × 5o. IES has operated continuously since early 2014. In the ion data a low energy (energy ions. Here we analyze the arrival direction of this low energy component. The origin of these low energy ions is certainly the ionized component of the neutral gas emitted due to solar activity from comet 67P/Churiumov-Gerasimenko. The low energy component in general shows a 6h periodicity due to cometary rotation. The data show, however, that the arrival direction of the low energy ions is smeared both in azimuth and elevation, due possibly to the diverse mechanisms affecting these ions. One of these effects is the spacecraft potential (~-10V), which accelerates the ions towards the spacecraft omnidirectionally. To characterize the flow direction in azimuth-elevation, we have integrated over the lowest 8 energy channels using weighted energy: sum(counts * energy)/sum(counts); and considered only cases when the counts are above 30. When we apply higher cut for counts, the flow direction became more definite. For this analysis we use data files where the two neighbouring energy values and elevation values are collapsed; and the azimuthal resolution is 45o, that is the solar wind azimuthal segmentation is also collapsed. Here we use day 2014.09.11. as illustration. On that day a solar wind shock reached the spacecraft at about ~10 UT. After the shock transition the energy of the solar wind became higher, and after ~12 UT the flow direction of the solar wind fluctuated, sometimes by 35o. On this day Rosetta flew at about 29.3-29.6 km from the nucleus. In the azimuth-elevation plots summed over "weighted energy" (as defined above) we were able to identify two flow directions

  13. A diagnostic for time-resolved spatial profiles measurements on the ion temperature on JET

    International Nuclear Information System (INIS)

    Brocken, H.J.B.M.; Ven, H.W van der.

    1980-05-01

    A neutral particle scattering experiment for a continuous measurement of the ion temperature and ion density of the JET plasma in the hydrogen and deuterium phase is proposed. Space- and time-resolved measurements are possible by injection of a mono-energetic particle beam into the plasma and from the analysis of the velocity distribution of the scattered particles. The requirements on the injection system are specified and a suitable analyzer system is described

  14. X ray and EUV spectroscopic measurements of highly charged tungsten ions relevant to fusion plasmas

    International Nuclear Information System (INIS)

    Radtke, R; Biedermann, C; Mandelbaum, P; Schwob, J L

    2007-01-01

    Using high-resolution x ray and extreme ultraviolet (EUV) spectrometry, the line emission of W 28+ - W 50+ ions was measured at the Berlin Electron Beam Ion Trap (EBIT). Our study encompasses a wide range of wavelengths (5-800 A) and includes the observation of electric and magnetic dipole lines. The results of our measurements are compared with predicted transition wavelengths from ab initioatomic structure calculations

  15. In situ recording of particle network formation in liquids by ion conductivity measurements.

    Science.gov (United States)

    Pfaffenhuber, Christian; Sörgel, Seniz; Weichert, Katja; Bele, Marjan; Mundinger, Tabea; Göbel, Marcus; Maier, Joachim

    2011-09-21

    The formation of fractal silica networks from a colloidal initial state was followed in situ by ion conductivity measurements. The underlying effect is a high interfacial lithium ion conductivity arising when silica particles are brought into contact with Li salt-containing liquid electrolytes. The experimental results were modeled using Monte Carlo simulations and tested using confocal fluorescence laser microscopy and ζ-potential measurements.

  16. Accurate measurements of visible M1 transitions of titanium-like ions using an electron beam ion trap

    International Nuclear Information System (INIS)

    Crosby, D.N.; Gaarde-Widdowson, K.; Silver, J.D.; Tarbutt, M.R.

    2001-01-01

    Magnetic dipole transitions between the fine structure levels (3d 4 ) 5 D 3 - 5 D 2 of titanium-like silver and tin have been observed as emission lines from the Oxford electron beam ion trap (EBIT). The precision of the measurement system is validated by observation and comparison of well known lines in Kr II and He I with the database values, justifying uncertainties of 4-12 ppm. (orig.)

  17. Accurate measurements of visible M1 transitions of titanium-like ions using an electron beam ion trap

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, D.N.; Gaarde-Widdowson, K.; Silver, J.D.; Tarbutt, M.R. [Oxford Univ. (United Kingdom). Dept. of Physics

    2001-07-01

    Magnetic dipole transitions between the fine structure levels (3d{sup 4}) {sup 5}D{sub 3}-{sup 5}D{sub 2} of titanium-like silver and tin have been observed as emission lines from the Oxford electron beam ion trap (EBIT). The precision of the measurement system is validated by observation and comparison of well known lines in Kr II and He I with the database values, justifying uncertainties of 4-12 ppm. (orig.)

  18. X-ray spectroscopic measurements of dielectronic recombination of highly charged krypton ions

    International Nuclear Information System (INIS)

    Biedermann, C.; Fuchs, T.; Liebisch, P.; Radtke, R.; Behar, E.; Doron, R.

    1999-01-01

    We have performed X-ray spectroscopic measurements of the dielectronic recombination (DR) resonance strengths for the KLn (n = 2, .., 5) series of He-, Li-, and Be-like krypton ions. The ions were produced with an electron beam ion trap, and the strengths were obtained from a fit procedure that compares the experimental excitation function for DR to theory. The results agree well with the predictions. By looking at the KLL resonance, the time evolution of different krypton charge states was measured with this technique and compared with a model of the trap inventory. (orig.)

  19. Transient field measurements on 56Fe- and 80Se-ions using segmented Fe-layers

    International Nuclear Information System (INIS)

    Busch, H.; Kremeyer, S.; Meens, A.; Maier-Komor, P.

    1996-01-01

    Measurements of transient magnetic fields (TF) were performed on swift heavy ions of 56 Fe and 80 Se, with Coulomb excitation of their first 2 + state as probe, traversing thin Fe layers with segmented and unsegmented structures. The 50 μm x 50 μm squares of the segments were accomplished applying the techniques of photolithography and ion etching. The magnitude of the TF deduced clearly shows that by segmentation of the targets the ion beam induced attenuations can be eliminated. This finding has direct applications to g-factor measurements. (orig.)

  20. Temperature dependent mobility measurements of alkali earth ions in superfluid helium

    Science.gov (United States)

    Putlitz, Gisbert Zu; Baumann, I.; Foerste, M.; Jungmann, K.; Riediger, O.; Tabbert, B.; Wiebe, J.; Zühlke, C.

    1998-05-01

    Mobility measurements of impurity ions in superfluid helium are reported. Alkali earth ions were produced with a laser sputtering technique and were drawn inside the liquid by an electric field. The experiments were carried out in the temperature region from 1.27 up to 1.66 K. The temperature dependence of the mobility of Be^+-ions (measured here for the first time) differs from that of the other alkali earth ions Mg^+, Ca^+, Sr^+ and Ba^+, but behaves similar to that of He^+ (M. Foerste, H. Günther, O. Riediger, J. Wiebe, G. zu Putlitz, Z. Phys. B) 104, 317 (1997). Theories of Atkins (A. Atkins, Phys. Rev.) 116, 1339 (1959) and Cole (M.W. Cole, R.A. Bachmann Phys. Rev. B) 15, 1388 (1977) predict a different defect structure for He^+ and the alkali earth ions: the helium ion is assumed to form a snowball like structure whereas for the alkali earth ions a bubble structure is assumed. If the temperature dependence is a characteristic feature for the different structures, then it seems likely that the Be^+ ion builds a snowball like structure.

  1. Supplementary Material for: Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad B. S.

    2017-01-01

    Cations and anions are formed as a result of chemi-ionization processes in combustion systems. Electric fields can be applied to reduce emissions and improve combustion efficiency by active control of the combustion process. Detailed flame ion chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon burner-stabilized atmospheric flames. Lean and stoichiometric flames are considered to assess the dependence of ion chemistry on flame stoichiometry. Relative ion concentration profiles are compared with numerical simulations using various temperature profiles, and good qualitative agreement was observed for the stoichiometric flame. However, for the lean flame, numerical simulations misrepresent the spatial distribution of selected ions greatly. Three modifications are suggested to enhance the ion mechanism and improve the agreement between experiments and simulations. The first two modifications comprise the addition of anion detachment reactions to increase anion recombination at low temperatures. The third modification involves restoring a detachment reaction to its original irreversible form. To our knowledge, this work presents the first detailed measurements of cations and flame temperature in canonical methane–oxygen-argon atmospheric flat flames. The positive ion profiles reported here may be useful to validate and improve ion chemistry models for methane-oxygen flames.

  2. Measurements of Positively Charged Ions in Premixed Methane-Oxygen Atmospheric Flames

    KAUST Repository

    Alquaity, Awad

    2016-08-22

    Cations and anions are formed as a result of chemi-ionization processes in combustion systems. Electric fields can be applied to reduce emissions and improve combustion efficiency by active control of the combustion process. Detailed flame ion chemistry models are needed to understand and predict the effect of external electric fields on combustion plasmas. In this work, a molecular beam mass spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane–oxygen argon burner-stabilized atmospheric flames. Lean and stoichiometric flames are considered to assess the dependence of ion chemistry on flame stoichiometry. Relative ion concentration profiles are compared with numerical simulations using various temperature profiles, and good qualitative agreement was observed for the stoichiometric flame. However, for the lean flame, numerical simulations misrepresent the spatial distribution of selected ions greatly. Three modifications are suggested to enhance the ion mechanism and improve the agreement between experiments and simulations. The first two modifications comprise the addition of anion detachment reactions to increase anion recombination at low temperatures. The third modification involves restoring a detachment reaction to its original irreversible form. To our knowledge, this work presents the first detailed measurements of cations and flame temperature in canonical methane–oxygen-argon atmospheric flat flames. The positive ion profiles reported here may be useful to validate and improve ion chemistry models for methane-oxygen flames.

  3. Momentum distributions in nuclei measured with relativistic heavy ions

    International Nuclear Information System (INIS)

    Hiller, B.; Huefner, J.; Heidelberg Univ.

    1982-01-01

    In a peripheral reaction between relativistic heavy ions, where one nucleon is knocked out of the projektile, the momentum distribution of the remaining fragment reflects the momentum distribution of the knocked out nucleon. This has been proven in a previous paper. Here we study how the final-state interaction between the knocked out nucleon and the observed fragment influences the result: The real part of the optical potential which describes the final-state interaction shifts the experimental momentum distribution by a value [ksub(||)] of a few tens of MeV/c and the imaginary part reduces the cross sections by a factor 2 roughly. We also derive the cross section for a proton as target. (orig.)

  4. Equivalent risky allocation: The new ERA of risk measurement for heterogeneous investors

    NARCIS (Netherlands)

    Plunus, S.; Gillet, R.; Hübner, G.M.B.J.

    2015-01-01

    This paper introduces an investor-specific risk measure derived from the linear-exponential (linex) utility function. It combines the notions of risk perception and risk aversion. To make this measure interpretable and comparable with others like variance or value-at-risk, it is translated into an

  5. Sample Heterogeneity and the Measurement Structure of the Multidimensional Students' Life Satisfaction Scale

    Science.gov (United States)

    Sawatzky, Richard; Ratner, Pamela A.; Johnson, Joy L.; Kopec, Jacek A.; Zumbo, Bruno D.

    2009-01-01

    Several measurement assumptions were examined with the goal of assessing the validity of the Multidimensional Students' Life Satisfaction Scale (MSLSS), a measure of adolescents' satisfaction with their family, friends, living environment, school, self, and general quality of life. The data were obtained via a cross-sectional survey of 8,225…

  6. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Murazaki, Minoru; Uno, Yuichi; Miyoshi, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of {+-}13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, {alpha}, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and {sup 3}He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, calculated value agreed well with measurement data of PSPC without Cd cover. (author)

  7. Micro-PIV measurements of multiphase flow of water and liquid CO2 in 2-D heterogeneous porous micromodels

    Science.gov (United States)

    Li, Yaofa; Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth T.

    2017-07-01

    We present an experimental study of pore-scale flow dynamics of liquid CO2 and water in a two-dimensional heterogeneous porous micromodel, inspired by the structure of a reservoir rock, at reservoir-relevant conditions (80 bar, 21°C). The entire process of CO2 infiltration into a water-saturated micromodel was captured using fluorescence microscopy and the micro-PIV method, which together reveal complex fluid displacement patterns and abrupt changes in velocity. The CO2 front migrated through the resident water in an intermittent manner, forming dendritic structures, termed fingers, in directions along, normal to, and even opposing the bulk pressure gradient. Such characteristics indicate the dominance of capillary fingering through the micromodel. Velocity burst events, termed Haines jumps, were also captured in the heterogeneous micromodel, during which the local Reynolds number was estimated to be ˜21 in the CO2 phase, exceeding the range of validity of Darcy's law. Furthermore, these drainage events were observed to be cooperative (i.e., across multiple pores simultaneously), with the zone of influence of such events extending beyond tens of pores, confirming, in a quantitative manner, that Haines jumps are nonlocal phenomena. After CO2 completely breaks through the porous section, shear-induced circulations caused by flowing CO2 were also observed, in agreement with previous studies using a homogeneous porous micromodel. To our knowledge, this study is the first quantitative measurement that incorporates both reservoir-relevant conditions and rock-inspired heterogeneity, and thus will be useful for pore-scale model development and validation.

  8. Detection of Diffusion Heterogeneity in Single Particle Tracking Trajectories Using a Hidden Markov Model with Measurement Noise Propagation

    Science.gov (United States)

    Slator, Paddy J.; Cairo, Christopher W.; Burroughs, Nigel J.

    2015-01-01

    We develop a Bayesian analysis framework to detect heterogeneity in the diffusive behaviour of single particle trajectories on cells, implementing model selection to classify trajectories as either consistent with Brownian motion or with a two-state (diffusion coefficient) switching model. The incorporation of localisation accuracy is essential, as otherwise false detection of switching within a trajectory was observed and diffusion coefficient estimates were inflated. Since our analysis is on a single trajectory basis, we are able to examine heterogeneity between trajectories in a quantitative manner. Applying our method to the lymphocyte function-associated antigen 1 (LFA-1) receptor tagged with latex beads (4 s trajectories at 1000 frames s−1), both intra- and inter-trajectory heterogeneity were detected; 12–26% of trajectories display clear switching between diffusive states dependent on condition, whilst the inter-trajectory variability is highly structured with the diffusion coefficients being related by D 1 = 0.68D 0 − 1.5 × 104 nm2 s−1, suggestive that on these time scales we are detecting switching due to a single process. Further, the inter-trajectory variability of the diffusion coefficient estimates (1.6 × 102 − 2.6 × 105 nm2 s−1) is very much larger than the measurement uncertainty within trajectories, suggesting that LFA-1 aggregation and cytoskeletal interactions are significantly affecting mobility, whilst the timescales of these processes are distinctly different giving rise to inter- and intra-trajectory variability. There is also an ‘immobile’ state (defined as D models within membranes incorporating aggregation, binding to the cytoskeleton, or traversing membrane microdomains. PMID:26473352

  9. 146Sm-142Nd systematics measured in enstatite chondrites reveals a heterogeneous distribution of 142Nd in the solar nebula.

    Science.gov (United States)

    Gannoun, Abdelmouhcine; Boyet, Maud; Rizo, Hanika; El Goresy, Ahmed

    2011-05-10

    The short-lived (146)Sm-(142)Nd chronometer (T(1/2) = 103 Ma) is used to constrain the early silicate evolution of planetary bodies. The composition of bulk terrestrial planets is then considered to be similar to that of primitive chondrites that represent the building blocks of rocky planets. However for many elements chondrites preserve small isotope differences. In this case it is not always clear to what extent these variations reflect the isotope heterogeneity of the protosolar nebula rather than being produced by the decay of parent isotopes. Here we present Sm-Nd isotopes data measured in a comprehensive suite of enstatite chondrites (EC). The EC preserve (142)Nd/(144)Nd ratios that range from those of ordinary chondrites to values similar to terrestrial samples. The EC having terrestrial (142)Nd/(144)Nd ratios are also characterized by small (144)Sm excesses, which is a pure p-process nuclide. The correlation between (144)Sm and (142)Nd for chondrites may indicate a heterogeneous distribution in the solar nebula of p-process matter synthesized in supernovae. However to explain the difference in (142)Nd/(144)Nd ratios, 20% of the p-process contribution to (142)Nd is required, at odds with the value of 4% currently proposed in stellar models. This study highlights the necessity of obtaining high-precision (144)Sm measurements to interpret properly measured (142)Nd signatures. Another explanation could be that the chondrites sample material formed in different pulses of the lifetime of asymptotic giant branch stars. Then the isotope signature measured in SiC presolar would not represent the unique s-process signature of the material present in the solar nebula during accretion.

  10. MOSFET dosimeter depth-dose measurements in heterogeneous tissue-equivalent phantoms at diagnostic x-ray energies

    International Nuclear Information System (INIS)

    Jones, A.K.; Pazik, F.D.; Hintenlang, D.E.; Bolch, W.E.

    2005-01-01

    The objective of the present study was to explore the use of the TN-1002RD metal-oxide-semiconductor field effect transistor (MOSFET) dosimeter for measuring tissue depth dose at diagnostic photon energies in both homogeneous and heterogeneous tissue-equivalent materials. Three cylindrical phantoms were constructed and utilized as a prelude to more complex measurements within tomographic physical phantoms of pediatric patients. Each cylindrical phantom was constructed as a stack of seven 5-cm-diameter and 1-cm-thick discs of materials radiographically representative of either soft tissue (S), bone (B), or lung tissue (L) at diagnostic photon energies. In addition to a homogeneous phantom of soft tissue (SSSSSSS), two heterogeneous phantoms were constructed: SSBBSSS and SBLLBSS. MOSFET dosimeters were then positioned at the interface of each disc, and the phantoms were then irradiated at 66 kVp and 200 mAs. Measured values of absorbed dose at depth were then compared to predicated values of point tissue dose as determined via Monte Carlo radiation transport modeling. At depths exceeding 2 cm, experimental results matched the computed values of dose with high accuracy regardless of the dosimeter orientation (epoxy bubble facing toward or away from the x-ray beam). Discrepancies were noted, however, between measured and calculated point doses near the surface of the phantom (surface to 2 cm depth) when the dosimeters were oriented with the epoxy bubble facing the x-ray beam. These discrepancies were largely eliminated when the dosimeters were placed with the flat side facing the x-ray beam. It is therefore recommended that the MOSFET dosimeters be oriented with their flat sides facing the beam when they are used at shallow depths or on the surface of either phantoms or patients

  11. Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Nielsen, Stefan Kragh; Porte, L.

    2007-01-01

    ) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also...

  12. Energy measurement of fast ions trapped in the toroidal field ripple of Tore Supra

    International Nuclear Information System (INIS)

    Basiuk, V.; Becoulet, A.; Hutter, T.; Martin, G.; Pecquet, A.L.; Saoutic, B.

    1993-09-01

    During additional heating in Tore Supra (ICRF or NBI) fast ion losses due to the toroidal field ripple were clearly measured by a set of graphite probes. This diagnostic collects the flow of fast ions entering a vertical port and usually shows a maximum flux for ions originating from the vicinity of surface δ * = 0. During the monster sawteeth regime, achieved with ICRF, a remarkable phenomenon was observed: the ejection of fast ions, not correlated with any measured MHD activity. The radial distribution of these ions is quite different from that usually observed exhibiting a peak located in the central section of the plasma. In order to measure the energy distribution of these ions, from 80 keV (energy of the neutral beam injected in Tore Supra) up to 1 MeV (expected during ICRF), a new diagnostic is under construction. The principle of the diagnostic is to discriminate the ions in energy using their Larmor radius (p = 1.3 cm for 100 keV → p = 3.6 cm for 700 keV, B = 4T). The detector is made of a hollow graphite cylinder with a small entrance slot, located in a vertical port on the ion drift side. An array of six metallic collectors placed inside the graphite cylinder intercepts the ions. The current on each collector was estimated at 10 → 100 nA, during ICRF heating. The energy resolution of this diagnostic is expected to be about 20 keV for the lowest energy range and 100 keV for the highest. This type of ruggedized detector might be extrapolated for the measurements of alpha particle losses in future DT experiments. It should also be suitable for the studies of stochastic ripple diffusion. (authors). 3 refs., 9 figs

  13. Friction and wear measurements of sputtered MoS/sub x/ films amorphized by ion bombardment

    International Nuclear Information System (INIS)

    Mikkelsen, N.J.; Chevallier, J.; Soerensen, G.; Straede, C.A.

    1988-01-01

    The present study presents an experimental evidence for amorphization of rf sputtered MoS/sub x/ films by ion bombardment. Even at low doses (3 x 10 15 ions/cm 2 ) of 400 keV argon ions a complete amorphization was confirmed by x-ray diffraction analysis and transmission electron microscopy. As a result of the ion bombardment the film density increased 100% to almost the bulk value for MoS 2 . The friction coefficient for ion beam amorphized MoS/sub x/ was measured to be 0.04 in agreement with the values reported for crystalline films but disagreeing considerably with the friction coefficient of 0.4 previously reported for amorphous films

  14. Temporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Bindslev, Henrik; Porte, L.

    2008-01-01

    reported [Bindslev , Phys. Rev. Lett. 97, 205005 2006]. Here we extend the discussion of these results which were obtained at the TEXTOR tokamak. The fast ions are generated by neutral-beam injection and ion-cyclotron resonance heating. The CTS system uses 100-150 kW of 110-GHz gyrotron probing radiation......Fast ions created in the fusion processes will provide up to 70% of the heating in ITER. To optimize heating and current drive in magnetically confined plasmas insight into fast-ion dynamics is important. First measurements of such dynamics by collective Thomson scattering (CTS) were recently...... of the velocity distribution after turnoff of the ion heating. These results are in close agreement with numerical simulations....

  15. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    CERN Document Server

    Murazaki, M; Uno, Y

    2003-01-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of +-13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, alpha, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and sup 3 He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, ...

  16. Fuel ion rotation measurement and its implications on H-mode theories

    International Nuclear Information System (INIS)

    Kim, J.; Burrell, K.H.; Gohil, P.; Groebner, R.J.; Hinton, F.L.; Kim, Y.B.; Seraydarian, R.; Mandl, W.

    1993-10-01

    Poloidal and toroidal rotation of the fuel ions (He 2+ ) and the impurity ions (C 6+ and B 5+ ) in H-mode helium plasmas have been investigated in the DIII-D tokamak by means of charge exchange recombination spectroscopy, resulting in the discovery that the fuel ion poloidal rotation is in the ion diamagnetic drift direction while the impurity ion rotation is in the electron diamagnetic drift direction. The radial electric field obtained from radial force balance analysis of the measured pressure gradients and rotation velocities is shown to be the same regardless of which ion species is used and therefore is a more fundamental parameter than the rotation flows in studying H-mode phenomena. It is shown that the three contributions to the radial electric field (diamagnetic, poloidal rotation, and toroidal rotation terms) are comparable and consequently the poloidal flow does not solely represent the E x B flow. In the high-shear edge region, the density scale length is comparable to the ion poloidal gyroradius, and thus neoclassical theory is not valid there. In view of this new discovery that the fuel and impurity ions rotate in opposite sense, L-H transition theories based on the poloidal rotation may require improvement

  17. Measurements of Ion Selective Containment on the RF Charge Breeder Device BRIC

    CERN Document Server

    Variale, Vincenzo; Batazova, Marina; Boggia, Antonio; Clauser, Tarcisio; Kuznetsov, Gennady I; Rainò, Antonio; Shiyankov, Sergey; Skarbo, Boris A; Valentino, Vincenzo; Verrone, Grazia

    2005-01-01

    The "charge state breeder" BRIC (BReeding Ion Charge) is based on an EBIS source and it is designed to accept Radioactive Ion Beam (RIB) with charge +1, in a slow injection mode, to increase their charge state up to +n. BRIC has been developed at the INFN section of Bari (Italy) during these last 3 years with very limited funds. Now, it has been assembled at the LNL (Italy) where are in progress the first tests as stand alone source. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion drift chamber, of a Radio Frequency (RF) Quadrupole aiming to filtering the unwanted elements and then making a more efficient containment of the wanted ions. In this contribution, the measurements of the selective effect on the ion charge state containement of the RF quadrupole field, applied on the ion chamber, will be reported and discussed. The ion charge state analisys of the ions trapped in BRIC seem confirm, as foreseen by simulation results carried out previously, that the s...

  18. Plasma rotation and ion temperature measurements by collective Thomson scattering at ASDEX Upgrade

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Nielsen, Stefan Kragh; Jacobsen, Asger Schou

    2015-01-01

    We present the first deuterium ion temperature and rotation measurements by collective Thomson scattering at ASDEX Upgrade. The results are in general agreement with boron-based charge exchange recombination spectroscopy measurements and consistent with neoclassical simulations for the plasma sce...... scenario studied here. This demonstration opens the prospect for direct non-perturbative measurements of the properties of the main ion species in the plasma core with applications in plasma transport and confinement studies.......We present the first deuterium ion temperature and rotation measurements by collective Thomson scattering at ASDEX Upgrade. The results are in general agreement with boron-based charge exchange recombination spectroscopy measurements and consistent with neoclassical simulations for the plasma...

  19. Measurement of the density profile of pure and seeded molecular beams by femtosecond ion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Congsen [LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Department of Physics, National University of Defense Technology, Changsha 410073 (China); Janssen, Maurice H. M. [LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1083, 1081 HV Amsterdam (Netherlands)

    2015-02-15

    Here, we report on femtosecond ion imaging experiments to measure the density profile of a pulsed supersonic molecular beam. Ion images are measured for both a molecular beam and bulk gas under identical experimental conditions via femtosecond multiphoton ionization of Xe atoms. We report the density profile of the molecular beam, and the measured absolute density is compared with theoretical calculations of the centre line beam density. Subsequently, we discuss reasons accounting for the differences between measurements and calculations and propose that strong skimmer interference is the most probable cause for the differences. Furthermore, we report on experiments measuring the centre line density of seeded supersonic beams. The femtosecond ion images show that seeding the heavy Xe atom at low relative seed fractions (1%-10%) in a light carrier gas like Ne results in strong relative enhancements of up to two orders of magnitude.

  20. Neutron measurements in the stray field produced by 158 GeV/c lead ion beams

    International Nuclear Information System (INIS)

    Agosteo, S.; Birattari, C.; Foglio Para, A.; Nava, E.; Silari, M.; Ulrici, L.

    1997-01-01

    This paper discusses measurements carried out at CERN in the stray radiation field produced by 158 GeV/c 208 Pb 82+ ions. The purpose was to test and intercompare the response of several detectors, mainly neutron measuring devices, and to determine the neutron spectral fluence as well as the microdosimetric (absorbed dose and dose equivalent) distributions in different locations around the shielding. Both active instruments and passive dosimeters were employed, including different types of Andersson-Braun rem counters, a tissue equivalent proportional counter, a set of superheated drop detectors, a Bonner sphere system and different types of ion chambers. Activation measurements with 12 C plastic scintillators and with 32 S pellets were also performed to assess the neutron yield of high energy lead ions interacting with a thin gold target. The results are compared with previous measurements and with measurements made during proton runs. (author)

  1. Surface potential measurement of the insulator with secondary electron caused by negative ion implantation

    International Nuclear Information System (INIS)

    Tsuji, Hiroshi; Toyota, Yoshitaka; Nagumo, Syoji; Gotoh, Yasuhito; Ishikawa, Junzo; Sakai, Shigeki; Tanjyo, Masayasu; Matsuda, Kohji.

    1994-01-01

    Ion implantation has the merit of the good controllability of implantation profile and low temperature process, and has been utilized for the impurity introduction in LSI production. However, positive ion implantation is carried out for insulator or insulated conductor substrates, their charged potential rises, which is a serious problem. As the requirement for them advanced, charge compensation method is not the effective means for resolving it. The negative ion implantation in which charging is little was proposed. When the experiment on the negative ion implantation into insulated conductors was carried out, it was verified that negative ion implantation is effective as the implantation process without charging. The method of determining the charged potential of insulators at the time of negative ion implantation by paying attention to the energy distribution of the secondary electrons emitted from substrates at the time was devised. The energy analyzer for measuring the energy distribution of secondary electrons was made, and the measurement of the charged potential of insulators was carried out. The principle of the measurement, the measuring system and the experimental results are reported. (K.I.)

  2. Measurements of fast ion spatial dynamics during magnetic activity in the RFP

    Science.gov (United States)

    Goetz, J. A.; Anderson, J. K.; Bonofiglo, P.; Kim, J.; McConnell, R.; Magee, R. M.

    2017-10-01

    Fast ions in the RFP are only weakly affected by a stochastic magnetic field and behave nearly classically in concentration too low to excite Alfvenic activity. At high fast ion concentration sourced by H-NBI in 300kA RFP discharges, a substantial drop in core-localized high pitch fast ions is observed during bursts of coupled EPM and IAE (magnetic island-induced Alfven eigenmode) activity (100-200kHz) through neutral particle analysis. Sourcing instead fast deuterium with NBI, the DD fusion products can measure the dynamics of the fast ion density profile. Both a collimated neutron detector and a new 3MeV fusion proton detector loaned by TriAlpha Energy measure the fast ion density profile with 5cm spatial resolution and 100 μs temporal resolution. In D-NBI, the bursting EPM is excited at slightly lower frequency and the IAE activity is nearly absent, likely due to an isotope effect and loss of wave-particle interaction. In these cases, neutral particle analysis shows little change in the core-localized high pitch fast ion content, and the fusion product profile indicates little change in the fast ion density profile, leaving unexplained the mechanism removing EPM drive. We measure a substantial redistribution of the fast ion profile due to strong lower-frequency ( 30kHz) MHD activity that accompanies the current profile relaxation in the RFP. Profile flattening is strongest in low bulk density discharges, which often occur with a total increase in global neutron flux from acceleration of the beam ions. Work supported by US DoE.

  3. Magnetically filtered Faraday probe for measuring the ion current density profile of a Hall thruster

    International Nuclear Information System (INIS)

    Rovey, Joshua L.; Walker, Mitchell L.R.; Gallimore, Alec D.; Peterson, Peter Y.

    2006-01-01

    The ability of a magnetically filtered Faraday probe (MFFP) to obtain the ion current density profile of a Hall thruster is investigated. The MFFP is designed to eliminate the collection of low-energy, charge-exchange (CEX) ions by using a variable magnetic field as an ion filter. In this study, a MFFP, Faraday probe with a reduced acceptance angle (BFP), and nude Faraday probe are used to measure the ion current density profile of a 5 kW Hall thruster operating over the range of 300-500 V and 5-10 mg/s. The probes are evaluated on a xenon propellant Hall thruster in the University of Michigan Large Vacuum Test Facility at operating pressures within the range of 4.4x10 -4 Pa Xe (3.3x10 -6 Torr Xe) to 1.1x10 -3 Pa Xe (8.4x10 -6 Torr Xe) in order to study the ability of the Faraday probe designs to filter out CEX ions. Detailed examination of the results shows that the nude probe measures a greater ion current density profile than both the MFFP and BFP over the range of angular positions investigated for each operating condition. The differences between the current density profiles obtained by each probe are attributed to the ion filtering systems employed. Analysis of the results shows that the MFFP, operating at a +5 A solenoid current, provides the best agreement with flight-test data and across operating pressures

  4. Measurement of refractive index by nanoparticle tracking analysis reveals heterogeneity in extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Chris Gardiner

    2014-11-01

    Full Text Available Introduction: Optical techniques are routinely used to size and count extracellular vesicles (EV. For comparison of data from different methods and laboratories, suitable calibrators are essential. A suitable calibrator must have a refractive index (RI as close to that of EV as possible but the RI of EV is currently unknown. To measure EV, RI requires accurate knowledge of size and light scattering. These are difficult to measure as most EVs cannot be resolved by light microscopy and their diameter is smaller than the wavelength of visible light. However, nanoparticle tracking analysis (NTA provides both size and relative light scattering intensity (rLSI values. We therefore sought to determine whether it was possible to use NTA to measure the RI of individual EVs. Methods: NTA was used to measure the rLSI and size of polystyrene and silica microspheres of known size and RI (1.470 and 1.633, respectively and of EV isolated from a wide range of cells. We developed software, based on Mie scattering code, to calculate particle RI from the rLSI data. This modelled theoretical scattering intensities for polystyrene and silica microspheres of known size (100 and 200 nm and RI. The model was verified using data from the polystyrene and silica microspheres. Size and rLSI data for each vesicle were processed by the software to generate RI values. Results: The following modal RI measurements were obtained: fresh urinary EV 1.374, lyophilised urinary EV 1.367, neuroblastoma EV 1.393, blood EV 1.398, EV from activated platelets 1.390, small placental EV 1.364–1.375 and 1.398–1.414 for large placental EV (>200 nm. Large placental EV had a significantly higher RI than small placental EV (p1.40 were observed for some large (>200 nm microvesicles. Conclusion: This method for measuring EV RI will be useful for developing appropriate calibrators for EV measurement.

  5. Measurement of asymmetric optical pumping of ions accelerating in a magnetic-field gradient

    International Nuclear Information System (INIS)

    Sun Xuan; Scime, Earl; Miah, Mahmood; Cohen, Samuel; Skiff, Frederick

    2004-01-01

    We report observations of asymmetric optical pumping of argon ions accelerating in a magnetic-field gradient. The signature is a difference in the laser-induced-fluorescence emission amplitude from a pair of Zeeman-split states. A model that reproduces the dependence of the asymmetry on magnetic-field and ion-velocity gradients is described. With the model, the fluorescence intensity ratio provides a new method of measuring ion collisionality. This phenomenon has implications for interpreting stellar plasma spectroscopy data which often exhibit unequal Zeeman state intensities

  6. Measurement of Asymmetric Optical Pumping of Ions Accelerating in a Magnetic-field Gradient

    Energy Technology Data Exchange (ETDEWEB)

    Xuan Sun; Earl Scime; Mahmood Miah; Samuel Cohen; Frederick Skiff

    2004-10-28

    We report observations of asymmetric optical pumping of argon ions accelerating in a magnetic field gradient. The signature is a difference in the laser-induced-fluorescence (LIF) emission amplitude from a pair of Zeeman-split states. A model that reproduces the dependence of the asymmetry on magnetic-field and ion-velocity gradients is described. With the model, the fluorescence intensity ratio provides a new method of measuring ion collisionality. This phenomenon has implications for interpreting stellar plasma spectroscopy data which often exhibit unequal Zeeman state intensities.

  7. '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.

  8. Measurements of hydrogen gas stopping efficiency for tin ions from laser-produced plasma

    Science.gov (United States)

    Abramenko, D. B.; Spiridonov, M. V.; Krainov, P. V.; Krivtsun, V. M.; Astakhov, D. I.; Medvedev, V. V.; van Kampen, M.; Smeets, D.; Koshelev, K. N.

    2018-04-01

    Experimental studies of stopping of ion fluxes from laser-produced plasma by a low-pressure gas atmosphere are presented. A modification of the time-of-flight spectroscopy technique is proposed for the stopping cross-sectional measurements in the ion energy range of 0.1-10 keV. The application of the proposed technique is demonstrated for Sn ion stopping by H2 gas. This combination of elements is of particular importance for the development of plasma-based sources of extreme ultraviolet radiation for lithographic applications.

  9. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe.

    Science.gov (United States)

    Chen, Y H; Yang, X Y; Lin, C; Wang, L; Xu, M; Wang, X G; Xiao, C J

    2014-11-01

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  10. Plasma flow measurement using directional Langmuir probe under weakly ion-magnetized conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Kenichi; Okamoto, Atsushi [Graduate School of Science, Nagoya Univ., Nagoya (Japan); Yoshimura, Shinji; Tanaka, Masayoshi Y. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-07-01

    It is both experimentally and theoretically demonstrated that ion flow velocity at an arbitrary angle with respect to the magnetic field can be measured with a directional Langmuir probe. Based on the symmetry argument, we show that the effect of magnetic field on directional probe current is exactly canceled in determining the ion flow velocity, and obtain the generalized relation between flow velocity and directional probe currents valid for any flowing direction. The absolute value of the flow velocity is determined by an in situ calibration method of the probe. The applicability limit of the present method to a strongly ion-magnetized plasma is experimentally examined. (author)

  11. Measurement of Asymmetric Optical Pumping of Ions Accelerating in a Magnetic-field Gradient

    International Nuclear Information System (INIS)

    Xuan Sun; Earl Scime; Mahmood Miah; Samuel Cohen; Frederick Skiff

    2004-01-01

    We report observations of asymmetric optical pumping of argon ions accelerating in a magnetic field gradient. The signature is a difference in the laser-induced-fluorescence (LIF) emission amplitude from a pair of Zeeman-split states. A model that reproduces the dependence of the asymmetry on magnetic-field and ion-velocity gradients is described. With the model, the fluorescence intensity ratio provides a new method of measuring ion collisionality. This phenomenon has implications for interpreting stellar plasma spectroscopy data which often exhibit unequal Zeeman state intensities

  12. Methods to determine fast-ion distribution functions from multi-diagnostic measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko

    -ion diagnostic views, it is possible to infer the distribution function using a tomography approach. Several inversion methods for solving this tomography problem in velocity space are implemented and compared. It is found that the best quality it obtained when using inversion methods which penalise steep......Understanding the behaviour of fast ions in a fusion plasma is very important, since the fusion-born alpha particles are expected to be the main source of heating in a fusion power plant. Preferably, the entire fast-ion velocity-space distribution function would be measured. However, no fast...

  13. Systematic measurements of transient fields for W, Os and Pt ions traversing Fe

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Heseltine, T.H.; Anderssen, S.S.; Bolotin, H.H.; Byrne, A.P.; Fabricius, B.; Kibedi, T.

    1994-01-01

    Transient magnetic fields were measured for W, Os and Pt ions traversing iron hosts with average velocities in the range from approximately 1.6 v 0 to 4.8 v 0 (v 0 = c/137, Bohr velocity). Transient fields for W and Os in Fe are consistent with behaviour found for lighter rare-earth ions and are about 20% stronger than those for Pt in Fe over the majority of the velocity range examined. A measurement was made to confirm that possible heavy-ion beam induced attenuations of the transient field are negligible for low-velocity Pt ions excited by Ni beams. Results are discussed in terms of both empirical and model-based parameterizations of the transient field strength. (orig.)

  14. Heavy ion beam probe development for the plasma potential measurement on the TUMAN-3M tokamak

    International Nuclear Information System (INIS)

    Askinazi, L.G.; Kornev, V.A.; Lebedev, S.V.; Tukachinsky, A.S.; Zhubr, N.A.; Dreval, N.B.; Krupnik, L.I.

    2004-01-01

    The peculiarities of the heavy ion beam probe implementation on the small aspect ratio tokamak TUMAN-3M are analyzed. The toroidal displacement of beam trajectory due to the high I pl /B tor ratio is taken into account when designing the layout of the diagnostic. Numerical calculation of beam trajectories using realistic configuration of TUMAN-3M magnetic fields and parabolic plasma current profile resulted in proper adjustment of probing and detection parameters (probing ion material, energy, entrance angles, detector location, and orientation). Secondary ion energy analyzer gain functions G and F were measured in situ using neutral hydrogen puffed in the tokamak vessel as a target for secondary ions production. The detector unit featured split-plate design and had additional electrodes for secondary electron emission suppression. As a result, the diagnostic is now capable of plasma potential evolution measurement and is sensitive enough to trace the potential profile evolution at the L-H mode transition

  15. Measurements of ion mobility in argon and neon based gas mixtures

    CERN Document Server

    INSPIRE-00507268

    2017-01-01

    As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection Chamber (TPC) will operate during LHC Run$\\,3$ with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility $K$ is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different $\\textrm{CO}_2$ fractions. A decrease of $K$ was measured for increasing water content.

  16. Brightness measurement of an electron impact gas ion source for proton beam writing applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, N.; Santhana Raman, P. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Xu, X.; Pang, R.; Kan, J. A. van, E-mail: phyjavk@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Khursheed, A. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore)

    2016-02-15

    We are developing a high brightness nano-aperture electron impact gas ion source, which can create ion beams from a miniature ionization chamber with relatively small virtual source sizes, typically around 100 nm. A prototype source of this kind was designed and successively micro-fabricated using integrated circuit technology. Experiments to measure source brightness were performed inside a field emission scanning electron microscope. The total output current was measured to be between 200 and 300 pA. The highest estimated reduced brightness was found to be comparable to the injecting focused electron beam reduced brightness. This translates into an ion reduced brightness that is significantly better than that of conventional radio frequency ion sources, currently used in single-ended MeV accelerators.

  17. Parallel ion flow velocity measurement using laser induced fluorescence method in an electron cyclotron resonance plasma

    International Nuclear Information System (INIS)

    Yoshimura, Shinji; Okamoto, Atsushi; Terasaka, Kenichiro; Ogiwara, Kohei; Tanaka, Masayoshi Y.; Aramaki, Mitsutoshi

    2010-01-01

    Parallel ion flow velocity along a magnetic field has been measured using a laser induced fluorescence (LIF) method in an electron cyclotron resonance (ECR) argon plasma with a weakly-diverging magnetic field. To measure parallel flow velocity in a cylindrical plasma using the LIF method, the laser beam should be injected along device axis; however, the reflection of the incident beam causes interference between the LIF emission of the incident and reflected beams. Here we present a method of quasi-parallel laser injection at a small angle, which utilizes the reflected beam as well as the incident beam to obtain the parallel ion flow velocity. Using this method, we observed an increase in parallel ion flow velocity along the magnetic field. The acceleration mechanism is briefly discussed on the basis of the ion fluid model. (author)

  18. Angular and mass resolved energy distribution measurements with a gallium liquid metal ion source

    International Nuclear Information System (INIS)

    Marriott, Philip

    1987-06-01

    Ionisation and energy broadening mechanisms relevant to liquid metal ion sources are discussed. A review of experimental results giving a picture of source operation and a discussion of the emission mechanisms thought to occur for the ionic species and droplets emitted is presented. Further work is suggested by this review and an analysis system for angular and mass resolved energy distribution measurements of liquid metal ion source beams has been constructed. The energy analyser has been calibrated and a series of measurements, both on and off the beam axis, of 69 Ga + , Ga ++ and Ga 2 + ions emitted at various currents from a gallium source has been performed. A comparison is made between these results and published work where possible, and the results are discussed with the aim of determining the emission and energy spread mechanisms operating in the gallium liquid metal ion source. (author)

  19. Integrated Microanalytical System for Simultaneous Voltammetric Measurements of Free Metal Ion Concentrations in Natural Waters

    OpenAIRE

    Noël, Stéphane; Tercier-Waeber, Mary-Lou; Lin, Lin; Buffle, Jacques; Guenat, Olivier; Koudelka-Hep, Milena

    2007-01-01

    A complexing gel integrated microelectrode (CGIME) for direct measurements of free metal ion concentrations in natural waters has been developed. It is prepared by the successive deposition of microlayers of a chelating resin, an antifouling agarose gel and Hg on a 100-interconnected Ir-based microelectrode array. The trace metals of interest are in a first step accumulated on the chelating resin in proportion to their free ion concentration in solution, then released in acidic solution and d...

  20. Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

    2008-10-09

    Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

  1. Cerenkov detector for heavy-ion velocity measurements

    International Nuclear Information System (INIS)

    Olson, D.L.; Baumgartner, M.; Dufour, J.P.; Girard, J.G.; Greiner, D.E.; Lindstrom, P.J.; Symons, T.J.M.; Crawford, H.J.

    1984-08-01

    We have developed a highly sensitive velocity measuring detector using total-internal-reflection Cerenkov counters of a type mentioned by Jelly in 1958. If the velocity of the particle is above the threshold for total-internal-reflection these counters have a charge resolution of sigma = 0.18e for a 3mm thick glass radiator. For the velocity measurement we use a fused silica radiator so that the velocity of the particles are near the threshold for total-internal reflection. For momentum-analyzed projectile fragments of 1.6 GeV/nucleon 40 Ar, we have measured a mass resolution of sigma = 0.1u for isotope identification

  2. A device for automated phase space measurement of ion beams

    International Nuclear Information System (INIS)

    Lukas, J.; Priller, A.; Steier, P.

    2007-01-01

    Equipment for automated phase-space measurements was developed at the VERA Lab. The measurement of the beam's intensity distribution, as well as its relative position with respect to the reference orbit is performed at two locations along the beam line. The device basically consists of moveable slits and a beam profile monitor, which are both coordinated and controlled by an embedded controller. The operating system of the controller is based on Linux with real-time extension. It controls the movement of the slits and records the data synchronized to the movement of the beam profile monitor. The data is sent via TCP/IP to the data acquisition system of VERA where visualization takes place. The duration of one phase space measurement is less than 10 s, which allows for using the device during routine beam tuning

  3. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging

    OpenAIRE

    Zuzana eBurdikova; Zdenek eSvindrych; Jan ePala; Cian eHickey; Martin G. Wilkinson; Jiri ePanek; Mark A. E. Auty; Ammasi ePeriasamy; Jeremiah J. Sheehan

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a signi...

  4. Measurement of pH micro-heterogeneity in natural cheese matrices by flourescence lifetime imaging

    OpenAIRE

    Burdikova, Suzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G.; Panek, Jiri; Auty, Mark A.E.; Periasamy, Ammasi; Sheehan, Jeremiah J.

    2015-01-01

    peer-reviewed Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level ther...

  5. Scrape-off layer ion temperature measurements at the divertor target during type III ELMs in MAST measured by RFEA

    Energy Technology Data Exchange (ETDEWEB)

    Elmore, S., E-mail: Sarah.Elmore@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Allan, S.Y.; Fishpool, G.; Kirk, A. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kočan, M. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Tamain, P. [Association Euratom-CEA, CEA/DSM/IRFM, CEA-Cadarache, F-13108 St Paul-lez-Durance Cedex (France); Thornton, A.J. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2015-08-15

    Edge-localised modes (ELMs) can carry significant fractions of their energy as far as main chamber plasma-facing components in divertor tokamaks. Since in future devices (e.g. ITER, DEMO) these energies could cause issues for material lifetime and impurity production, the energy and temperature of ions in ELMs needs to be investigated. In MAST, novel divertor measurements of T{sub i} during ELMs have been made using the divertor retarding field energy analyser (RFEA) probe. These measurements have shown instantaneous ion energy distributions corresponding to an effective T{sub i} at 5 cm from the strike point at the target that can be as high as 60 eV and that this decreases with time after the ELM start. This is consistent with the hottest, fastest ions arriving at the target first by parallel transport, followed by the lower end of the ion energy distribution. This analysis will form a basis for future data analysis of fast swept measurements of ion distributions in ELMs.

  6. Heterogeneity of wound outcome measures in RCTs of treatments for VLUs: a systematic review.

    Science.gov (United States)

    Gethin, G; Killeen, F; Devane, D

    2015-05-01

    Venous leg ulcers (VLUs) affect up to 4% of the population aged over 65 years. Outcomes of randomised controlled trials (RCTs) in VLUs are important to guide clinical and resource decision making. Our objective was to identify what endpoints and wound bed outcomes were assessed in RCTs in VLUs; how these were assessed and what reference was made to validity and reliability of methods used. A systematic review of all full text RCTs, published in English, from 1998-2013. Our criteria were met by 102 studies. There were 78 different endpoints recorded, the majority (n=34) related to healing and were evaluated at 12 different times points. Size was the most frequently reported outcome measure (n=99), with photographs, tissue type, exudate, odour and pain also recorded. There was poor reporting of methods used to assess outcomes. Visual analogue scales predominated as a method of assessment, but 95% of studies made no reference to the validity or reliability of assessment methods. Future research in VLUs requires standards for measuring outcomes with acceptable inter-rater reliability and validated measures of patient-reported outcomes.

  7. Beta Neutrino Correlation Measurement with Trapped Radioactive Ions

    International Nuclear Information System (INIS)

    Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Mery, A.; Rodriguez, D.; Thomas, J.-C.

    2010-01-01

    The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6 He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.

  8. An assessment of ion temperature measurements in the boundary of the Alcator C-Mod tokamak and implications for ion fluid heat flux limiters

    International Nuclear Information System (INIS)

    Brunner, D; LaBombard, B; Churchill, R M; Hughes, J; Lipschultz, B; Ochoukov, R; Theiler, C; Walk, J; Rognlien, T D; Umansky, M V; Whyte, D

    2013-01-01

    The ion temperature is not frequently measured in the boundary of magnetic fusion devices. Comparisons among different ion temperature techniques and simulations are even rarer. Here we present a comparison of ion temperature measurements in the boundary of the Alcator C-Mod tokamak from three different diagnostics: charge exchange recombination spectroscopy (CXRS), an ion sensitive probe (ISP), and a retarding field analyzer (RFA). Comparison between CXRS and the ISP along with close examination of the ISP measurements reveals that the ISP is space charge limited. It is thus unable to measure ion temperature in the high density (>10 19 m −3 ) boundary plasma of C-Mod with its present geometry. Comparison of ion temperatures measured by CXRS and the RFA shows fair agreement. Ion and electron parallel heat flow is analyzed with a simple 1D fluid code. The code takes divertor measurements as input and results are compared to the measured ratios of upstream ion to electron temperature, as inferred respectively by CXRS and a Langmuir probe. The analysis reveals the limits of the fluid model at high Knudsen number. The upstream temperature ratio is under predicted by a factor of 2. Heat flux limiters (kinetic corrections) to the fluid model are necessary to match experimental data. The values required are found to be close to those reported in kinetic simulations. The 1D code is benchmarked against the 2D plasma fluid code UEDGE with good agreement. (paper)

  9. An assessment of ion temperature measurements in the boundary of the Alcator C-Mod tokamak and implications for ion fluid heat flux limiters

    Science.gov (United States)

    Brunner, D.; LaBombard, B.; Churchill, R. M.; Hughes, J.; Lipschultz, B.; Ochoukov, R.; Rognlien, T. D.; Theiler, C.; Walk, J.; Umansky, M. V.; Whyte, D.

    2013-09-01

    The ion temperature is not frequently measured in the boundary of magnetic fusion devices. Comparisons among different ion temperature techniques and simulations are even rarer. Here we present a comparison of ion temperature measurements in the boundary of the Alcator C-Mod tokamak from three different diagnostics: charge exchange recombination spectroscopy (CXRS), an ion sensitive probe (ISP), and a retarding field analyzer (RFA). Comparison between CXRS and the ISP along with close examination of the ISP measurements reveals that the ISP is space charge limited. It is thus unable to measure ion temperature in the high density (>1019 m-3) boundary plasma of C-Mod with its present geometry. Comparison of ion temperatures measured by CXRS and the RFA shows fair agreement. Ion and electron parallel heat flow is analyzed with a simple 1D fluid code. The code takes divertor measurements as input and results are compared to the measured ratios of upstream ion to electron temperature, as inferred respectively by CXRS and a Langmuir probe. The analysis reveals the limits of the fluid model at high Knudsen number. The upstream temperature ratio is under predicted by a factor of 2. Heat flux limiters (kinetic corrections) to the fluid model are necessary to match experimental data. The values required are found to be close to those reported in kinetic simulations. The 1D code is benchmarked against the 2D plasma fluid code UEDGE with good agreement.

  10. An Antiproton Ion Collider (AIC) for Measuring Neutron and Proton Distributions in Stable and Radioactive Nuclei

    International Nuclear Information System (INIS)

    Kienle, Paul

    2005-01-01

    An antiproton-ion collider is proposed to independently determine mean square radii for protons and neutrons in stable and short lived nuclei by means of antiproton absorption at medium energies. The experiment makes use of the electron ion collider complex (ELISE) of the GSI FAIR project with appropriate modifications of the electron ring to store, cool and collide antiprotons of 30 MeV energy with 740A MeV energy ions.The total absorption cross-section of antiprotons by the stored ions will be measured by detecting their loss by means of the Schottky noise spectroscopy method. Cross sections for the absorption on protons and neutrons, respectively, will be studied by detection of residual nuclei with A-1 either by the Schottky method or by analysing them in recoil detectors after the first dipole stage of the NESR following the interaction zone. With a measurement of the A-1 fragment momentum distribution, one can test the momentum wave functions of the annihilated neutron and proton, respectively. Furthermore by changing the incident ion energy the tails of neutron and proton distribution can be measured.The absorption cross section is at asymptotic energies in leading order proportional to the mean square radius of the nucleus. Predicted cross sections and luminosities show that the method is applicable to nuclei with production rates of about 105 s-1 or lower, depending on the lifetime of the ions in the NESR, and for half-lives down to 1 second

  11. Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

    International Nuclear Information System (INIS)

    Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T.; Guharay, S.K.

    1997-01-01

    A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H - ) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

  12. Measurement Of The Heavy-Ion Collision Event Characteristics With The Atlas Experiment At The Lhc

    Directory of Open Access Journals (Sweden)

    Iwona Grabowska-Bołd

    2015-01-01

    Full Text Available Heavy-ion collisions at extreme energies can reproduce conditionspresent in the early Universe. The new state of very dense and hotmatter of deconfined quarks and gluons, called the Quark GluonPlasma~(QGP, is observed. This state is characterised by very lowviscosity resembling the properties of a perfect fluid. In suchmedium, the density fluctuations can be easily spread. In experimentalpractice, the size of these fluctuations is estimated by measuring theangular correlation of produced particles. The aim of this paper isto present measurements of the azimuthal anisotropy of chargedparticles produced in heavy-ion collisions using the ATLAS detector atthe LHC. Two measurement techniques are presented and compared.

  13. Measurements of Linac4 H$^{-}$ ion source beam with a magnetized Einzel lens electron dump

    CERN Document Server

    Midttun, O; Scrivens, R

    2014-01-01

    Linac4 is a part of the upgrade of CERN’s accelerator complex for increased luminosity in the LHC. A new system to extract the ion beam from the plasma generator has been designed and tested, in order to improve the reliability and beam optics of the pulsed H- ion source. This paper presents the successfully implemented extraction system and three different beam measurements. The simulations compare well to the measurements and show that the plasma density was too low for the extraction system design during the measurements.

  14. Interaction mean free path measurements for relativistic heavy ion fragments using CR39 plastic track detectors

    International Nuclear Information System (INIS)

    Drechsel, H.; Brechtmann, C.; Dreute, J.; Sonntag, S.; Trakowski, W.; Beer, J.; Heinrich, W.

    1984-01-01

    This paper describes an experiment measuring the interaction mean free paths for charge changing nuclear collisions of relativistic heavy ion fragments. We use a stack of CR39 plastic nuclear track detectors that was irradiated with 1.8 GeV/nucleon 40 Ar ions at the Berkeley Bevalac. About 1.5 x 10 7 etch cones were measured in this experiment using an automatic measuring system. By tracing the etch cones over successive plastic foils the particle trajectories in the stack were reconstructed. For 14185 trajectories with 6444 nuclear collisions of fragments with charge 9-15 the interaction mean free path in the plastic was determined. (orig.)

  15. Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

    Energy Technology Data Exchange (ETDEWEB)

    Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T. [National Inst. for Fusion Science, Nagoya (Japan); Guharay, S.K.

    1997-02-01

    A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H{sup -}) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

  16. Comparison of ion temperature and ion density measured during geomagnetically very quiet conditions on board of the geophysical rocket ''Vertical-6'' with the international reference ionosphere

    International Nuclear Information System (INIS)

    Bencze, P.; Kovacs, K.; Apathy, I.; Szemerey, I.; Afonin, V.; Bezrukih, V.; Shutte, N.

    1980-05-01

    Ion temperature and ion density, measured on October 25, 1977 during the flight of the geophyisical rocket ''Vertical-6'' by means of a group of five retarding potential analyzers looking into different directions of space, are compared with the International Reference Ionosphere 1978. The measurements were carried out in a geomagnetically quiet period to a height of 1500 km. The results show that both the ion temperature and the ion density are lower than the values predicted by the Reference Ionosphere, the difference is decreasing with increasing altitude. (author)

  17. Perfect additivity of microinterface arrays for liquid-liquid measurements: Application to cadmium ions quantification

    International Nuclear Information System (INIS)

    Mastouri, A.; Peulon, S.; Farcage, D.; Bellakhal, N.; Chaussé, A.

    2014-01-01

    Graphical abstract: - Highlights: • Confirmation of the perfect additivity of micropores independently of the geometry of arrays. • Study of assisted transfer of cadmium ions by 8-HQ at water/1,2-DCE. • Validation by cyclic and square wave voltammetry measurements for high and low concentrations. • Quantification of Cd(II) ions until 11 ppb in very simple conditions. • Highlighting of the very interesting use of arrays in a classical liquid-liquid microinterface device. - Abstract: For the first time, experimental measurements confirm the real additivity of the currents with micropore arrays, independently of the geometry (square, circular or in crosswise), from one single micropore until 256 micropores, in the case of the assisted transfer of cadmium ions by 8-hydroxyquinolinol (8-HQ). This result was obtained for measurements made by cyclic voltammetry at high concentration of cadmium ions (10 −4 M). At lower concentrations (until 10 −6 M), measurements performed by square wave voltammetry confirm also this additivity until 64 micropores. A calibration curve performed with a 64 micropores array allows us, in very simple conditions, the quantification of cadmium ions until 11 ppb (100 nM), which is lower than to the imposed limit for this specie in various fields, and in industrial effluents, in particular. The gain of sensitivity is close to 170 compared to measurements performed with one single micropore, illustrating the real interest of these arrays

  18. Janus: Graphical Software for Analyzing In-Situ Measurements of Solar-Wind Ions

    Science.gov (United States)

    Maruca, B.; Stevens, M. L.; Kasper, J. C.; Korreck, K. E.

    2016-12-01

    In-situ observations of solar-wind ions provide tremendous insights into the physics of space plasmas. Instrument on spacecraft measure distributions of ion energies, which can be processed into scientifically useful data (e.g., values for ion densities and temperatures). This analysis requires a strong, technical understanding of the instrument, so it has traditionally been carried out by the instrument teams using automated software that they had developed for that purpose. The automated routines are optimized for typical solar-wind conditions, so they can fail to capture the complex (and scientifically interesting) microphysics of transient solar-wind - such as coronal mass ejections (CME's) and co-rotating interaction regions (CIR's) - which are often better analyzed manually.This presentation reports on the ongoing development of Janus, a new software package for processing in-situ measurement of solar-wind ions. Janus will provide user with an easy-to-use graphical user interface (GUI) for carrying out highly customized analyses. Transparent to the user, Janus will automatically handle the most technical tasks (e.g., the retrieval and calibration of measurements). For the first time, users with only limited knowledge about the instruments (e.g., non-instrumentalists and students) will be able to easily process measurements of solar-wind ions. Version 1 of Janus focuses specifically on such measurements from the Wind spacecraft's Faraday Cups and is slated for public release in time for this presentation.

  19. Spectroscopic measurements of an H- ion source discharge

    International Nuclear Information System (INIS)

    Keller, R.; Smith, H.V. Jr.

    1985-01-01

    Spectral emission lines from an H - Penning surface-plasma source (SPS), the 4X source, are examined in the visible and near ultraviolet. Electron distribution temperatures are deduced from integral line-strength measurements. These temperatures are surprisingly low, about 0.5 eV. Electron density values of about 1.5 x 10 14 cm -3 and H-atom energies between 2 and 2.6 eV are determined from the measured Balmer-line profiles. Assuming the H - energy is identical to the H-atom energy, an emittance limit of 0.006 π x cm x mrad is deduced for this source with a 5.4-mm aperture

  20. Ion implanted Na22 source for positron lifetime measurements

    International Nuclear Information System (INIS)

    Fluss, M.J.; Smedeskjaer, L.C.

    1979-04-01

    A new positron source-sample fabrication technique, intended for high temperature positron annihilation measurements, was developed. The method makes use of a mass separator to implant pure Na 22 into the sample surface. The application of this technique to Cu is described. A brief discussion of the origin of the source component is given, and different possibilities of correcting for it are pointed out. 3 references

  1. Time-of-flight measurements of heavy ions using Si PIN diodes

    Energy Technology Data Exchange (ETDEWEB)

    Strekalovsky, A. O., E-mail: alex.strek@bk.ru; Kamanin, D. V. [Joint Institute for Nuclear Research (Russian Federation); Pyatkov, Yu. V. [National Nuclear Research University MEPhI (Moscow Engineering Physics Institute) (Russian Federation); Kondratyev, N. A.; Zhuchko, V. E. [Joint Institute for Nuclear Research (Russian Federation); Ilić, S. [University of Novi Sad (Serbia); Alexandrov, A. A.; Alexandrova, I. A. [Joint Institute for Nuclear Research (Russian Federation); Jacobs, N. [University of Stellenbosch, Faculty of Military Science, Military Academy (South Africa); Kuznetsova, E. A.; Mishinsky, G. V.; Strekalovsky, O. V. [Joint Institute for Nuclear Research (Russian Federation)

    2016-12-15

    A new off-line timing method for PIN diode signals is presented which allows the plasma delay effect to be suppressed. Velocities of heavy ions measured by the new method are in good agreement within a wide range of masses and energies with velocities measured by time stamp detectors based on microchannel plates.

  2. Determination of the Ion Velocity Distribution in a Rotating Plasma from Measurements of Doppler Broadening

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    The Doppler-broadened profile of the He II 4685.75 AA line was measured along a chord in a rotating plasma, transverse to the magnetic field. Using a single-particle orbit picture, the corresponding velocity spectrum of ions confirm the measurements, so it can be concluded that the single-particl...

  3. Beam-based measurements of persistent current decay in the Relativistic Heavy Ion Collider

    Directory of Open Access Journals (Sweden)

    W. Fischer

    2001-04-01

    Full Text Available The two rings of the Relativistic Heavy Ion Collider are equipped with superconducting dipole magnets. At injection, induced persistent currents in these magnets lead to a sextupole component. As the persistent currents decay with time, the horizontal and vertical chromaticities change. From magnet measurements of persistent current decays, chromaticity changes in the machine are estimated and compared with chromaticity measurements.

  4. Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

    International Nuclear Information System (INIS)

    Wieman, H.H.

    1994-05-01

    The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z

  5. Consistency between real and synthetic fast-ion measurements at ASDEX Upgrade

    DEFF Research Database (Denmark)

    Rasmussen, Jesper; Nielsen, Stefan Kragh; Pedersen, Morten Stejner

    2015-01-01

    that theory and measurements generally agree within these uncertainties for all three diagnostics during heating phases with either one or two neutral beam injection sources. This suggests that the measurements can be described by the same model assuming classical slowing down of fast ions. Since the three...

  6. Comparison of fast ion collective Thomson scattering measurements at ASDEX Upgrade with numerical simulations

    DEFF Research Database (Denmark)

    Salewski, Mirko; Meo, Fernando; Stejner Pedersen, Morten

    2010-01-01

    Collective Thomson scattering (CTS) experiments were carried out at ASDEX Upgrade to measure the one-dimensional velocity distribution functions of fast ion populations. These measurements are compared with simulations using the codes TRANSP/NUBEAM and ASCOT for two different neutral beam injecti...

  7. Oxygen Pickup Ions Measured by MAVEN Outside the Martian Bow Shock

    Science.gov (United States)

    Rahmati, A.; Cravens, T.; Larson, D. E.; Lillis, R. J.; Dunn, P.; Halekas, J. S.; Connerney, J. E. P.; Eparvier, F. G.; Thiemann, E.; Mitchell, D. L.; Jakosky, B. M.

    2015-12-01

    The MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft entered orbit around Mars on September 21, 2014 and has since been detecting energetic oxygen pickup ions by its SEP (Solar Energetic Particles) and SWIA (Solar Wind Ion Analyzer) instruments. The oxygen pickup ions detected outside the Martian bowshock and in the upstream solar wind are associated with the extended hot oxygen exosphere of Mars, which is created mainly by the dissociative recombination of molecular oxygen ions with electrons in the ionosphere. We use analytic solutions to the equations of motion of pickup ions moving in the undisturbed upstream solar wind magnetic and motional electric fields and calculate the flux of oxygen pickup ions at the location of MAVEN. Our model calculates the ionization rate of oxygen atoms in the exosphere based on the hot oxygen densities predicted by Rahmati et al. (2014), and the sources of ionization include photo-ionization, charge exchange, and electron impact ionization. The photo-ionization frequency is calculated using the FISM (Flare Irradiance Spectral Model) solar flux model, based on MAVEN EUVM (Extreme Ultra-Violet Monitor) measurements. The frequency of charge exchange between a solar wind proton and an oxygen atom is calculated using MAVEN SWIA solar wind proton flux measurements, and the electron impact ionization frequency is calculated based on MAVEN SWEA (Solar Wind Electron Analyzer) solar wind electron flux measurements. The solar wind magnetic field used in the model is from the measurements taken by MAVEN MAG (magnetometer) in the upstream solar wind. The good agreement between our predicted pickup oxygen fluxes and the MAVEN SEP and SWIA measured ones confirms detection of oxygen pickup ions and these model-data comparisons can be used to constrain models of hot oxygen densities and photochemical escape flux.

  8. Measurement of the effective plasma ion mass in large tokamaks

    International Nuclear Information System (INIS)

    Lister, J.B.; Villard, L.; Ridder, G. de

    1997-01-01

    There is not yet a straightforward method for the measurement of the D-T ratio in the centre of a tokamak plasma. One of the simpler measurements put forward in the past is the interpretation of the MHD spectrum in the frequency range of the Global Alfven Eigenmodes (GAE). However, the frequencies of these modes do not only depend on the plasma mass, but are also quite strongly dependent on the details of the current and density profiles, creating a problem of deconvolution of the estimate of the plasma mass from an implicit relationship between several measurable plasma parameters and the detected eigenmode frequencies. This method has been revised to assess its likely precision for the JET tokamak. The low n GAE modes are sometimes too close to the continuum edge to be detectable and the interpretation of the GAE spectrum is rendered less direct than had been hoped. We present a statistical study on the precision with which the D-T ratio could be estimated from the GAE spectrum on JET. (author) 4 figs., 8 refs

  9. Eddy covariance measurement of the spatial heterogeneity of surface energy exchanges over Heron Reef, Great Barrier Reef, Australia

    Science.gov (United States)

    MacKellar, M.; McGowan, H. A.; Phinn, S. R.

    2011-12-01

    Coral reefs cover 2.8 to 6.0 x 105 km2 of the Earth's surface and are warm, shallow regions that are believed to contribute enhanced sensible and latent heat to the atmosphere, relative to the surrounding ocean. To predict the impact of climate variability on coral reefs and their weather and climate including cloud, winds, rainfall patterns and cyclone genesis, accurate parameterisation of air-sea energy exchanges over coral reefs is essential. This is also important for the parameterisation and validation of regional to global scale forecast models to improve prediction of tropical and sub-tropical marine and coastal weather. Eddy covariance measurements of air-sea fluxes over coral reefs are rare due to the complexities of installing instrumentation over shallow, tidal water. Consequently, measurements of radiation and turbulent flux data for coral reefs have been captured remotely (satellite data) or via single measurement sites downwind of coral reefs (e.g. terrestrial or shipboard instrumentation). The resolution of such measurements and those that have been made at single locations on reefs may not capture the spatial heterogeneity of surface-atmosphere energy exchanges due to the different geomorphic and biological zones on coral reefs. Accordingly, the heterogeneity of coral reefs with regard to substrate, benthic communities and hydrodynamic processes are not considered in the characterization of the surface radiation energy flux transfers across the water-atmosphere interface. In this paper we present a unique dataset of concurrent in situ eddy covariance measurements made on instrumented pontoons of the surface energy balance over different geomorphic zones of a coral reef (shallow reef flat, shallow and deep lagoons). Significant differences in radiation transfers and air-sea turbulent flux exchanges over the reef were highlighted, with higher Bowen ratios over the shallow reef flat. Increasing wind speed was shown to increase flux divergence between

  10. Measurements and modelling of fast-ion redistribution due to resonant MHD instabilities in MAST

    International Nuclear Information System (INIS)

    Jones, O M; Cecconello, M; Klimek, I; McClements, K G; Akers, R J; Keeling, D L; Meakins, A J; Sharapov, S E; Boeglin, W U; Perez, R V; Turnyanskiy, M

    2015-01-01

    The results of a comprehensive investigation into the effects of toroidicity-induced Alfvén eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due to frequency-chirping TAE in the range 50 kHz–100 kHz and frequency-chirping energetic particle modes known as fishbones in the range 20 kHz–50 kHz, is observed. TAE and fishbones are also observed to cause losses of fast ions from the plasma. The spatial and temporal evolution of the fast-ion distribution is determined using a fission chamber, a radially-scanning collimated neutron flux monitor, a fast-ion deuterium alpha spectrometer and a charged fusion product detector. Modelling using the global transport analysis code Transp, with ad hoc anomalous diffusion and fishbone loss models introduced, reproduces the coarsest features of the affected fast-ion distribution in the presence of energetic particle-driven modes. The spectrally and spatially resolved measurements show, however, that these models do not fully capture the effects of chirping modes on the fast-ion distribution. (paper)

  11. Heavy ion beam measurement of the hydration of cementitious materials

    International Nuclear Information System (INIS)

    Livingston, R.A.; Schweitzer, J.S.; Rolfs, C.; Becker, H.-W.; Kubsky, S.; Spillane, T.; Zickefoose, J.; Castellote, M.; Viedma, P.G. de; Cheung, J.

    2010-01-01

    The setting and development of strength of Portland cement concrete depends upon the reaction of water with various phases in the Portland cement. Nuclear resonance reaction analysis (NRRA) involving the 1 H( 15 N,α,γ) 12 C reaction has been applied to measure the hydrogen depth profile in the few 100 nm thick surface layer that controls the early stage of the reaction. Specific topics that have been investigated include the reactivity of individual cementitious phases and the effects of accelerators and retarders.

  12. Impact of temperature on single event upset measurement by heavy ions in SRAM devices

    International Nuclear Information System (INIS)

    Liu Tianqi; Geng Chao; Zhang Zhangang; Gu Song; Tong Teng; Xi Kai; Hou Mingdong; Liu Jie; Zhao Fazhan; Liu Gang; Han Zhengsheng

    2014-01-01

    The temperature dependence of single event upset (SEU) measurement both in commercial bulk and silicon on insulator (SOI) static random access memories (SRAMs) has been investigated by experiment in the Heavy Ion Research Facility in Lanzhou (HIRFL). For commercial bulk SRAM, the SEU cross section measured by 12 C ions is very sensitive to the temperature. The temperature test of SEU in SOI SRAM was conducted by 209 Bi and 12 C ions, respectively, and the SEU cross sections display a remarkable growth with the elevated temperature for 12 C ions but keep constant for 209 Bi ions. The impact of temperature on SEU measurement was analyzed by Monte Carlo simulation. It is revealed that the SEU cross section is significantly affected by the temperature around the threshold linear energy transfer of SEU occurrence. As the SEU occurrence approaches saturation, the SEU cross section gradually exhibits less temperature dependency. Based on this result, the experimental data measured in HIRFL was analyzed, and then a reasonable method of predicting the on-orbit SEU rate was proposed. (semiconductor devices)

  13. Ion Flux Measurements in Electron Beam Produced Plasmas in Atomic and Molecular Gases

    Science.gov (United States)

    Walton, S. G.; Leonhardt, D.; Blackwell, D. D.; Murphy, D. P.; Fernsler, R. F.; Meger, R. A.

    2001-10-01

    In this presentation, mass- and time-resolved measurements of ion fluxes sampled from pulsed, electron beam-generated plasmas will be discussed. Previous works have shown that energetic electron beams are efficient at producing high-density plasmas (10^10-10^12 cm-3) with low electron temperatures (Te < 1.0 eV) over the volume of the beam. Outside the beam, the plasma density and electron temperature vary due, in part, to ion-neutral and electron-ion interactions. In molecular gases, electron-ion recombination plays a significant role while in atomic gases, ion-neutral interactions are important. These interactions also determine the temporal variations in the electron temperature and plasma density when the electron beam is pulsed. Temporally resolved ion flux and energy distributions at a grounded electrode surface located adjacent to pulsed plasmas in pure Ar, N_2, O_2, and their mixtures are discussed. Measurements are presented as a function of operating pressure, mixture ratio, and electron beam-electrode separation. The differences in the results for atomic and molecular gases will also be discussed and related to their respective gas-phase kinetics.

  14. Temperature measurement of {sup 6}He{sup + } ions confined in a transparent Paul trap

    Energy Technology Data Exchange (ETDEWEB)

    Flechard, X., E-mail: flechard@lpccaen.in2p3.fr; Ban, G.; Durand, D.; Lienard, E.; Mauger, F. [Universite de Caen, LPC Caen, ENSICAEN (France); Mery, A. [Universite de Caen, CIMAP, CEA/CNRS/ENSICAEN (France); Naviliat-Cuncic, O. [Universite de Caen, LPC Caen, ENSICAEN (France); Rodriguez, D. [Universitad de Granada, Departamento de Fisica Atomica, Molecular y Nuclear (Spain); Velten, P. [Universite de Caen, LPC Caen, ENSICAEN (France)

    2011-07-15

    The LPCTrap setup is a transparent Paul trap dedicated to the measurement of the {beta}-{nu} correlation coefficient a{sub {beta}{nu}} in the {beta} decay of trapped radioactive nuclides. In a first experiment, the system has been used to record {approx}10{sup 5} coincidences between the {beta} particles and recoiling ions emitted from the decay of {sup 6}He{sup + } ions. The analysis of the collected data has already shown that the size of the {sup 6}He{sup + } ion cloud confined in the Paul trap is a critical parameter, potentially limiting the accuracy on the a{sub {beta}{nu}} measurement. We report here the precise determination of the trapped ion cloud temperature and size. This was performed by extracting the trapped ions toward a position sensitive micro channel plate detector at different phases of the RF driving field. We find a temperature T{sub exp} = 0.107(7) eV, consistent with the temperature values inferred using two other observables but 20% higher than the temperature T{sub sim} = 0.09 eV predicted by realistic simulations of the ions interacting with the H{sub 2} buffer gas.

  15. E parallel B energy-mass spectrograph for measurement of ions and neutral atoms

    International Nuclear Information System (INIS)

    Funsten, H.O.; McComas, D.J.; Scime, E.E.

    1997-01-01

    Real-time measurement of plasma composition and energy is an important diagnostic in fusion experiments. The Thomson parabola spectrograph described here utilizes an electric field parallel to a magnetic field (E parallel B) and a two-dimensional imaging detector to uniquely identify the energy-per-charge and mass-per-charge distributions of plasma ions. An ultrathin foil can be inserted in front of the E parallel B filter to convert neutral atoms to ions, which are subsequently analyzed using the E parallel B filter. Since helium exiting an ultrathin foil does not form a negative ion and hydrogen isotopes do, this spectrograph allows unique identification of tritium ions and neutrals even in the presence of a large background of 3 He. copyright 1997 American Institute of Physics

  16. Degradation Behaviour of Lithium-Ion Batteries based on Field Measured Frequency Regulation Mission Profile

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stroe, Ana-Irina

    2015-01-01

    Energy storage systems based on Lithium-ion batteries have been proposed as an environmental friendly alternative to traditional conventional generating units for providing grid frequency regulation. One major challenge regarding the use of Lithium-ion batteries in such applications is their cost...... competitiveness in comparison to other storage technologies or with the traditional frequency regulation methods. In order to surpass this challenge and to allow for optimal sizing and proper use of the battery, accurate knowledge about the lifetime of the Lithium-ion battery and its degradation behaviour...... is required. This paper aims to investigate, based on a laboratory developed lifetime model, the degradation behaviour of the performance parameters (i.e., capacity and power capability) of a Lithium-ion battery cell when it is subjected to a field measured mission profile, which is characteristic...

  17. Precise measurements of energy loss straggling for swift heavy ions in polymers

    Science.gov (United States)

    Rani, Bindu; Neetu; Sharma, Kalpana; Diwan, P. K.; Kumar, Shyam

    2016-11-01

    The energy loss straggling measurements for heavy ions with Z = 3-22 (∼0.2-2.5 MeV/u) in PEN (C7H5O2) and PET (C10H8O4) polymers have been carried out utilizing the swift heavy ion beam facility from 15UD Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi, India. The recorded spectra are analyzed in such a way that the Straggling associated with energy loss process could be measured in a systematic manner at any selected value of energy, in terms of per unit thickness of the absorber, at any desired energy intervals. The measured values have been compared with the calculated values obtained from the most commonly used Bethe-Livingston formulations applicable for collisional straggling. The results are tried to be understood in terms of the effective charge on the impinging ion within the absorber. Some interesting trends are observed.

  18. Reconstruction of the ion plasma parameters from the current measurements: mathematical tool

    Directory of Open Access Journals (Sweden)

    E. Séran

    Full Text Available Instrument d’Analyse du Plasma (IAP is one of the instruments of the newly prepared ionospheric mission Demeter. This analyser was developed to measure flows of thermal ions at the altitude of ~ 750 km and consists of two parts: (i retarding potential analyser (APR, which is utilised to measure the energy distribution of the ion plasma along the sensor look direction, and (ii velocity direction analyser (ADV, which is used to measure the arrival angle of the ion flow with respect to the analyser axis. The necessity to obtain quick and precise estimates of the ion plasma parameters has prompted us to revise the existing mathematical tool and to investigate different instrumental limitations, such as (i finite angular aperture, (ii grid transparency, (iii potential depression in the space between the grid wires, (iv losses of ions during their passage between the entrance diaphragm and the collector. Simple analytical expressions are found to fit the currents, which are measured by the APR and ADV collectors, and show a very good agreement with the numerical solutions. It was proven that the fitting of the current with the model functions gives a possibility to properly resolve even minor ion concentrations and to find the arrival angles of the ion flow in the multi-species plasma. The discussion is illustrated by an analysis of the instrument response in the ionospheric conditions which are predicted by the International Reference Ionosphere (IRI model.

    Key words. Ionosphere (plasma convection; instruments and techniques – Space plasma physics (experimental and mathematical techniques

  19. Reconstruction of the ion plasma parameters from the current measurements: mathematical tool

    Directory of Open Access Journals (Sweden)

    E. Séran

    2003-05-01

    Full Text Available Instrument d’Analyse du Plasma (IAP is one of the instruments of the newly prepared ionospheric mission Demeter. This analyser was developed to measure flows of thermal ions at the altitude of ~ 750 km and consists of two parts: (i retarding potential analyser (APR, which is utilised to measure the energy distribution of the ion plasma along the sensor look direction, and (ii velocity direction analyser (ADV, which is used to measure the arrival angle of the ion flow with respect to the analyser axis. The necessity to obtain quick and precise estimates of the ion plasma parameters has prompted us to revise the existing mathematical tool and to investigate different instrumental limitations, such as (i finite angular aperture, (ii grid transparency, (iii potential depression in the space between the grid wires, (iv losses of ions during their passage between the entrance diaphragm and the collector. Simple analytical expressions are found to fit the currents, which are measured by the APR and ADV collectors, and show a very good agreement with the numerical solutions. It was proven that the fitting of the current with the model functions gives a possibility to properly resolve even minor ion concentrations and to find the arrival angles of the ion flow in the multi-species plasma. The discussion is illustrated by an analysis of the instrument response in the ionospheric conditions which are predicted by the International Reference Ionosphere (IRI model.Key words. Ionosphere (plasma convection; instruments and techniques – Space plasma physics (experimental and mathematical techniques

  20. Measured and simulated heavy-ion beam loss patterns at the CERN Large Hadron Collider

    Science.gov (United States)

    Hermes, P. D.; Bruce, R.; Jowett, J. M.; Redaelli, S.; Salvachua Ferrando, B.; Valentino, G.; Wollmann, D.

    2016-05-01

    The Large Hadron Collider (LHC) at CERN pushes forward to new regimes in terms of beam energy and intensity. In view of the combination of very energetic and intense beams together with sensitive machine components, in particular the superconducting magnets, the LHC is equipped with a collimation system to provide protection and intercept uncontrolled beam losses. Beam losses could cause a superconducting magnet to quench, or in the worst case, damage the hardware. The collimation system, which is optimized to provide a good protection with proton beams, has shown a cleaning efficiency with heavy-ion beams which is worse by up to two orders of magnitude. The reason for this reduced cleaning efficiency is the fragmentation of heavy-ion beams into isotopes with a different mass to charge ratios because of the interaction with the collimator material. In order to ensure sufficient collimation performance in future ion runs, a detailed theoretical understanding of ion collimation is needed. The simulation of heavy-ion collimation must include processes in which 82 + 208Pb ions fragment into dozens of new isotopes. The ions and their fragments must be tracked inside the magnetic lattice of the LHC to determine their loss positions. This paper gives an overview of physical processes important for the description of heavy-ion loss patterns. Loss maps simulated by means of the two tools ICOSIM [1,2] and the newly developed STIER (SixTrack with Ion-Equivalent Rigidities) are compared with experimental data measured during LHC operation. The comparison shows that the tool STIER is in better agreement.

  1. Characterizing functional lung heterogeneity in COPD using reference equations for CT scan-measured lobar volumes.

    Science.gov (United States)

    Come, Carolyn E; Diaz, Alejandro A; Curran-Everett, Douglas; Muralidhar, Nivedita; Hersh, Craig P; Zach, Jordan A; Schroeder, Joyce; Lynch, David A; Celli, Bartolome; Washko, George R

    2013-06-01

    CT scanning is increasingly used to characterize COPD. Although it is possible to obtain CT scan-measured lung lobe volumes, normal ranges remain unknown. Using COPDGene data, we developed reference equations for lobar volumes at maximal inflation (total lung capacity [TLC]) and relaxed exhalation (approximating functional residual capacity [FRC]). Linear regression was used to develop race-specific (non-Hispanic white [NHW], African American) reference equations for lobar volumes. Covariates included height and sex. Models were developed in a derivation cohort of 469 subjects with normal pulmonary function and validated in 546 similar subjects. These cohorts were combined to produce final prediction equations, which were applied to 2,191 subjects with old GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II to IV COPD. In the derivation cohort, women had smaller lobar volumes than men. Height positively correlated with lobar volumes. Adjusting for height, NHWs had larger total lung and lobar volumes at TLC than African Americans; at FRC, NHWs only had larger lower lobes. Age and weight had no effect on lobar volumes at TLC but had small effects at FRC. In subjects with COPD at TLC, upper lobes exceeded 100% of predicted values in GOLD II disease; lower lobes were only inflated to this degree in subjects with GOLD IV disease. At FRC, gas trapping was severe irrespective of disease severity and appeared uniform across the lobes. Reference equations for lobar volumes may be useful in assessing regional lung dysfunction and how it changes in response to pharmacologic therapies and surgical or endoscopic lung volume reduction.

  2. Comparison of measured and modelled negative hydrogen ion densities at the ECR-discharge HOMER

    Science.gov (United States)

    Rauner, D.; Kurutz, U.; Fantz, U.

    2015-04-01

    As the negative hydrogen ion density nH- is a key parameter for the investigation of negative ion sources, its diagnostic quantification is essential in source development and operation as well as for fundamental research. By utilizing the photodetachment process of negative ions, generally two different diagnostic methods can be applied: via laser photodetachment, the density of negative ions is measured locally, but only relatively to the electron density. To obtain absolute densities, the electron density has to be measured additionally, which induces further uncertainties. Via cavity ring-down spectroscopy (CRDS), the absolute density of H- is measured directly, however LOS-averaged over the plasma length. At the ECR-discharge HOMER, where H- is produced in the plasma volume, laser photodetachment is applied as the standard method to measure nH-. The additional application of CRDS provides the possibility to directly obtain absolute values of nH-, thereby successfully bench-marking the laser photodetachment system as both diagnostics are in good agreement. In the investigated pressure range from 0.3 to 3 Pa, the measured negative hydrogen ion density shows a maximum at 1 to 1.5 Pa and an approximately linear response to increasing input microwave powers from 200 up to 500 W. Additionally, the volume production of negative ions is 0-dimensionally modelled by balancing H- production and destruction processes. The modelled densities are adapted to the absolute measurements of nH- via CRDS, allowing to identify collisions of H- with hydrogen atoms (associative and non-associative detachment) to be the dominant loss process of H- in the plasma volume at HOMER. Furthermore, the characteristic peak of nH- observed at 1 to 1.5 Pa is identified to be caused by a comparable behaviour of the electron density with varying pressure, as ne determines the volume production rate via dissociative electron attachment to vibrationally excited hydrogen molecules.

  3. Measurement of secondary radiation during ion beam therapy with the pixel detector Timepix

    Science.gov (United States)

    Martišíková, Mária; Jakubek, Jan; Granja, Carlos; Hartmann, Bernadette; Opálka, Lukáš; Pospíšil, Stanislav; Jäkel, Oliver

    2011-11-01

    In ion beam therapy the finite range of the ion beams in tissue and the presence of the Bragg-peak are exploited. Unpredictable changes in the patient`s condition can alter the range of the ion beam in the body. Therefore it is desired to verify the actual ion range during the treatment, preferably in a non-invasive way. Positron emission tomography (PET) has been used successfully to monitor the applied dose distributions. This method however suffers from limited applicability and low detection efficiency. In order to increase the detection efficiency and to decrease the uncertainties, in this study we investigate the possibility to measure secondary charged particles emerging from the patient during irradiation. An initial experimental study to register the particle radiation coming out of a patient phantom during the therapy was performed at the Heidelberg Ion Beam Therapy Center (HIT) in Germany. A static narrowly-focused beam of carbon ions was directed into a head phantom. The emerging secondary radiation was measured with the position-sensitive Timepix detector outside of the phantom. The detector, developed by the Medipix Collaboration, consists of a silicon sensor bump bonded to a pixelated readout chip (256 × 256 pixels with 55 μm pitch). Together with the USB-based readout interface, Timepix can operate as an active nuclear emulsion registering single particles online with 2D-track visualization. In this contribution we measured the signal behind the head phantom and investigated its dependence on the beam energy (corresponding to beam range in water 2-30 cm). Furthermore, the response was measured at four angles between 0 and 90 degrees. At all investigated energies some signal was registered. Its pattern corresponds to ions. Differences in the total amount of signal for different beam energies were observed. The time-structure of the signal is correlated with that of the incoming beam, showing that we register products of prompt processes. Such

  4. Measurement of secondary radiation during ion beam therapy with the pixel detector Timepix

    International Nuclear Information System (INIS)

    Martišíková, Mária; Hartmann, Bernadette; Jäkel, Oliver; Jakubek, Jan; Granja, Carlos; Opálka, Lukáš; Pospíšil, Stanislav

    2011-01-01

    In ion beam therapy the finite range of the ion beams in tissue and the presence of the Bragg-peak are exploited. Unpredictable changes in the patient's condition can alter the range of the ion beam in the body. Therefore it is desired to verify the actual ion range during the treatment, preferably in a non-invasive way. Positron emission tomography (PET) has been used successfully to monitor the applied dose distributions. This method however suffers from limited applicability and low detection efficiency. In order to increase the detection efficiency and to decrease the uncertainties, in this study we investigate the possibility to measure secondary charged particles emerging from the patient during irradiation. An initial experimental study to register the particle radiation coming out of a patient phantom during the therapy was performed at the Heidelberg Ion Beam Therapy Center (HIT) in Germany. A static narrowly-focused beam of carbon ions was directed into a head phantom. The emerging secondary radiation was measured with the position-sensitive Timepix detector outside of the phantom. The detector, developed by the Medipix Collaboration, consists of a silicon sensor bump bonded to a pixelated readout chip (256 × 256 pixels with 55 μm pitch). Together with the USB-based readout interface, Timepix can operate as an active nuclear emulsion registering single particles online with 2D-track visualization. In this contribution we measured the signal behind the head phantom and investigated its dependence on the beam energy (corresponding to beam range in water 2–30 cm). Furthermore, the response was measured at four angles between 0 and 90 degrees. At all investigated energies some signal was registered. Its pattern corresponds to ions. Differences in the total amount of signal for different beam energies were observed. The time-structure of the signal is correlated with that of the incoming beam, showing that we register products of prompt processes. Such

  5. Beam profile measurement with CR-39 track detector for low-energy ions

    CERN Document Server

    Sato, F; Tanaka, T; Iida, T; Yamauchi, T; Oda, K

    1999-01-01

    A CR-39 track detector was successfully used to measure the outline of thin low-energy ion beams. After the etching, the surface of the detector was examined with an observation system composed of a Normarski microscope, a CCD camera and a digital image processing computer. Beam images obtained with the system were in good agreement on the outline of the beam formed with a beam aperture. Also, the resolving power in the beam outline measurement was roughly explained from the consideration of the ion range and the etch-pit growth in the chemical etching for the CR-39 detector.

  6. Measuring radiation damage dynamics by pulsed ion beam irradiation: 2016 project annual report

    Energy Technology Data Exchange (ETDEWEB)

    Kucheyev, Sergei O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-04

    The major goal of this project is to develop and demonstrate a novel experimental approach to access the dynamic regime of radiation damage formation in nuclear materials. In particular, the project exploits a pulsed-ion-beam method in order to gain insight into defect interaction dynamics by measuring effective defect interaction time constants and defect diffusion lengths. For Year 3, this project had the following two major milestones: (i) the demonstration of the measurement of thermally activated defect-interaction processes by pulsed ion beam techniques and (ii) the demonstration of alternative characterization techniques to study defect dynamics. As we describe below, both of these milestones have been met.

  7. Measurements of inelastic collisions between homonuclear ions: Na+, K+ and Rb+

    International Nuclear Information System (INIS)

    Peart, B.; Forrest, R.A.; Dolder, K.

    1981-01-01

    Cross sections have been measured for the formation of X 2+ by collisions between X + ions (X = Na, K or Rb) with centre of mass energies between 19.3 and 87.6 keV. The results were compared with similar measurements for Li + and Cs + previously made by Peart and coworkers (J. Phys. B.; 14:1655 and 3457 (1981)), but no simple empirical or theoretical scaling law could be found to relate results for the five single-charged alkali ions. (author)

  8. First Absolutely Calibrated Localized Measurements of Ion Velocity in the MST in Locked and Rotating Plasmas

    Science.gov (United States)

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; Munaretto, S.

    2015-11-01

    An Ion Doppler Spectrometer (IDS) is used on MST for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometer records data within 0.3 nm of the C+5 line of interest, and commercial calibration lamps do not produce lines in this narrow range . A novel optical system was designed to absolutely calibrate the IDS. The device uses an UV LED to produce a broad emission curve in the desired region. A Fabry-Perot etalon filters this light, cutting transmittance peaks into the pattern of the LED emission. An optical train of fused silica lenses focuses the light into the IDS with f/4. A holographic diffuser blurs the light cone to increase homogeneity. Using this light source, the absolute Doppler shift of ion emissions can be measured in MST plasmas. In combination with charge exchange recombination spectroscopy, localized ion velocities can now be measured. Previously, a time-averaged measurement along the chord bisecting the poloidal plane was used to calibrate the IDS; the quality of these central chord calibrations can be characterized with our absolute calibration. Calibration errors may also be quantified and minimized by optimizing the curve-fitting process. Preliminary measurements of toroidal velocity in locked and rotating plasmas will be shown. This work has been supported by the US DOE.

  9. The effects of spacecraft charging and outgassing on the LADEE ion measurements

    Science.gov (United States)

    Xie, Lianghai; Zhang, Xiaoping; Zheng, Yongchun; Guo, Dawei

    2017-05-01

    Abnormal ion signals can be usually seen in the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, including a suddenly enhanced current observed by the Lunar Dust Experiment (LDEX) near the sunlight-shadow boundary and an unexpected water ion measured by the neutral mass spectrometer (NMS), with their magnitudes insensitive to the convection electric field of solar wind but dependent on the SW density and the elapsed time of LADEE mission. By analyzing both the LDEX measurements and the NMS measurements, we find that the current enhancement can be caused by a negatively charged spacecraft in the shadow region while the significant water ions should be some artificial ions from spacecraft outgassing. The artificial water ions show a peak near 8:00 LT that may be related to a sunlight-controlled surface outgassing. In addition, the H2O flux can be enhanced near the end of the mission when the spacecraft has a lower altitude. It is found that the H2O enhancement is actually caused by an exosphere-contributed return flux, rather than a real water exosphere.

  10. Time-resolved measurements of the focused ion beams on PBFA II

    International Nuclear Information System (INIS)

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

    1992-01-01

    A time-resolved camera has been developed to image the intense ion beam focus on PBFA II. Focused ions from a sector of the ion diode are Rutherford scattered from a thin gold foil on the diode axis and pinhole imaged onto an array of up to 49 PIN detectors to obtain the spatially and temporally resolved images. The signals from these detectors are combined to provide a movie of the beam focus with a time resolution of about 3 ns and a spatial resolution of 2 mm over a 12 mm field of view. Monte Carlo simulations of the camera response are used with the measured ion energy to account for the time-of-flight dispersion of the beam and to convert the recorded signals to an intensity. From measurements on an 81 degree sector of the diode, average intensities on a 6 mm sphere of about 5 TW/cm 2 and energies approaching 80 kJ/cm 2 are calculated for standard proton diodes. Corresponding numbers for a lithium diode are less than those measured with protons. The details of the analysis and image reconstruction will be presented along with scaled images from recent ion focusing experiments

  11. Bayesian Integrated Data Analysis of Fast-Ion Measurements by Velocity-Space Tomography

    DEFF Research Database (Denmark)

    Salewski, M.; Nocente, M.; Jacobsen, A.S.

    2018-01-01

    Bayesian integrated data analysis combines measurements from different diagnostics to jointly measure plasma parameters of interest such as temperatures, densities, and drift velocities. Integrated data analysis of fast-ion measurements has long been hampered by the complexity of the strongly non...... framework. The implementation for different types of diagnostics as well as the uncertainties are discussed, and we highlight the importance of integrated data analysis of all available detectors....

  12. An apparatus for measuring the energy and angular distribution of electrons in ion-atom collisions

    International Nuclear Information System (INIS)

    Gibson, D.K.; Petersen, M.C.E.

    1978-07-01

    There is a need for further data on the energy and angular distribution of electrons ejected from atoms and molecules by ion impact. An apparatus in which simultaneous measurements can be made of the energy and angular distributions of such electrons is described. The advantages of the apparatus are the possibility of fast data collection and the ability to make measurements over the whole range of scattering angle. Preliminary tests and a trial measurement with the apparatus are described

  13. 3D ion velocity distribution function measurement in an electric thruster using laser induced fluorescence tomography

    Science.gov (United States)

    Elias, P. Q.; Jarrige, J.; Cucchetti, E.; Cannat, F.; Packan, D.

    2017-09-01

    Measuring the full ion velocity distribution function (IVDF) by non-intrusive techniques can improve our understanding of the ionization processes and beam dynamics at work in electric thrusters. In this paper, a Laser-Induced Fluorescence (LIF) tomographic reconstruction technique is applied to the measurement of the IVDF in the plume of a miniature Hall effect thruster. A setup is developed to move the laser axis along two rotation axes around the measurement volume. The fluorescence spectra taken from different viewing angles are combined using a tomographic reconstruction algorithm to build the complete 3D (in phase space) time-averaged distribution function. For the first time, this technique is used in the plume of a miniature Hall effect thruster to measure the full distribution function of the xenon ions. Two examples of reconstructions are provided, in front of the thruster nose-cone and in front of the anode channel. The reconstruction reveals the features of the ion beam, in particular on the thruster axis where a toroidal distribution function is observed. These findings are consistent with the thruster shape and operation. This technique, which can be used with other LIF schemes, could be helpful in revealing the details of the ion production regions and the beam dynamics. Using a more powerful laser source, the current implementation of the technique could be improved to reduce the measurement time and also to reconstruct the temporal evolution of the distribution function.

  14. A study of tritium behavior in lithium oxide by ion conductivity measurements

    International Nuclear Information System (INIS)

    Noda, Kenji; Ishii, Yoshinobu; Ohno, Hideo; Watanabe, Hitoshi

    1989-01-01

    Ion conductivity of lithium oxide (Li 2 O) irradiated with oxygen ions was measured to obtain information about the effects of irradiation on the behavior of lithium ions and tritium. The conductivity around 490 K decreased with the ion fluence, while around 440 K it increased. The decrease around 490 K and the increase around 440 K were assumed to be attributed to the F + centers and the unspecified radiation defects, respectively. From the point of view that the rate determinant in the mechanism of diffusion of lithium ions in Li 2 O leading to the ion conductivity is the same as that of tritium, the diffusivity of tritium is assumed to be as follows: the diffusivity of tritium is decreased by the F + centers in the range from 490 K to the temperature at which almost all of F + centers are recovered, while it is increased around 440 K by the unspecified radiation defects. In addition, effects of the irradiation on valence states of tritium (i.e., T + , T - ) were discussed in terms of the radiation defects. (orig.)

  15. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    Science.gov (United States)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  16. Towards a precise measurement of atomic parity violation in a single Ra+ ion

    International Nuclear Information System (INIS)

    Nuñez Portela, M.; Berg, J. E. van den; Bekker, H.; Böll, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W.

    2013-01-01

    A single trapped Ra  +  (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z 3 . This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba  +  ions as a precursor for radioactive Ra  +  . Online laser spectroscopy of the isotopes 209 − 214 Ra  +  in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra  +  ion could function as a very stable clock.

  17. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    International Nuclear Information System (INIS)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-01-01

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants

  18. Towards a precise measurement of atomic parity violation in a single Ra{sup +} ion

    Energy Technology Data Exchange (ETDEWEB)

    Nunez Portela, M., E-mail: nunez@kvi.nl; Berg, J. E. van den; Bekker, H.; Boell, O.; Dijck, E. A.; Giri, G. S.; Hoekstra, S.; Jungmann, K.; Mohanty, A.; Onderwater, C. J. G.; Santra, B.; Schlesser, S.; Timmermans, R. G. E.; Versolato, O. O.; Wansbeek, L. W.; Willmann, L.; Wilschut, H. W. [Kernfysisch Versneller Instituut (KVI) (Netherlands)

    2013-03-15

    A single trapped Ra{sup + } (Z = 88) ion provides a very promising route towards a most precise measurement of Atomic Parity Violation (APV), since APV effects grow faster than Z{sup 3}. This experiment promises the best determination of the electroweak coupling constant at the lowest accessible energies. Such a measurement provides a sensitive test of the Standard Model in particle physics. At the present stage of the experiment, we focus on trapping and laser cooling stable Ba{sup + } ions as a precursor for radioactive Ra{sup + }. Online laser spectroscopy of the isotopes {sup 209 - 214}Ra{sup + } in a linear Paul trap has provided information on transition wavelengths, fine and hyperfine structures and excited state lifetimes as test of atomic structure calculations. Additionaly, a single trapped Ra{sup + } ion could function as a very stable clock.

  19. Determination of the relative power density distribution in a heterogeneous reactor from the results of measurements of the reactivity effects and the neutron importance function

    International Nuclear Information System (INIS)

    Bobrov, A. A.; Glushkov, E. S.; Zimin, A. A.; Kapitonova, A. V.; Kompaniets, G. V.; Nosov, V. I.; Petrushenko, R. P.; Smirnov, O. N.

    2012-01-01

    A method for experimental determination of the relative power density distribution in a heterogeneous reactor based on measurements of fuel reactivity effects and importance of neutrons from a californium source is proposed. The method was perfected on two critical assembly configurations at the NARCISS facility of the Kurchatov Institute, which simulated a small-size heterogeneous nuclear reactor. The neutron importance measurements were performed on subcritical and critical assemblies. It is shown that, along with traditionally used activation methods, the developed method can be applied to experimental studies of special features of the power density distribution in critical assemblies and reactors.

  20. Time-resolved measurements of highly-polymerised negative ions in rf silane plasma deposition experiments

    International Nuclear Information System (INIS)

    Howling, A.A.; Sansonnens, L.; Dorier, J.L.; Hollenstein, C.

    1993-07-01

    The time-resolved fluxes of negative polysilicon hydride ions from a power-modulated rf silane plasma have been measured by quadrupole mass spectrometry and modeled using a simple polymerisation scheme. Experiments were performed with plasma parameters suitable for high-quality amorphous silicon deposition. Polysilicon hydride anions diffuse from the plasma with low energy (approximately 0.5 eV) during the afterglow after the electron density has decayed and the sheath fields have collapsed. The mass-dependence of the temporal behavior of the anion loss flux demonstrates that the plasma composition is influenced by the modulation frequency. The negative species attain much higher masses than the positive or neutral species, and anions containing as many as sixteen silicon atoms have been observed, corresponding to the 500 amu limit of the mass spectrometer. This suggests that negative ions could be the precursors to particle formation. Ion-molecule and ion-ion reactions are discussed and a simple negative ion polymerisation scheme is proposed which qualitatively reproduces the experimental results. The model shows that the densities of high mass negative ions in the plasma are strongly reduced by modulation frequencies near 1 kHz. Each plasma period is then too short for the polymerisation chain to propagate to high masses before the elementary anions are lost in each subsequent afterglow period. This explains why modulation of the rf power can reduce particle contamination. We conclude that, for the case of silane rf plasmas, the initiation steps which ultimately lead to particle contamination proceed by negative ion polymerisation. (author) 15 figs., 72 refs

  1. The measurements of light high-energy ions in NINA-2 experiment

    Directory of Open Access Journals (Sweden)

    A. Leonov

    2007-10-01

    Full Text Available The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluate radiation damages on space-borne instruments and on space mission crews. In spite of that, sources of data on the flux of energetic ions at LEO are roughly limited to the AP-8 model, CREME/CREME96 codes and the SAMPEX, NOAA/TIROS satellites. The existing and operational European SAC-C/ICARE and PROBA-1/SREM instruments could also be potential sources for proton data at LEO. Although AP-8 and SAMPEX/PSB97 may be publicly accessed through the SPENVIS, they exhibit an order of magnitude difference in low altitude proton fluxes and they do not contain helium fluxes. Therefore, improved light ion radiation models are still needed.

    In this paper we present a procedure to identify and measure the energy of ions that are not stopped in the NINA-2 instrument. Moreover, problems related to particles that cross the instrument in the opposite direction are addressed and shown to be a possible cause of particle misidentification. Measuring fluxes of low abundance elements like energetic helium ions requires a good characterisation of all possible sources of backgrounds in the detector. Hints to determine the several contributions to the background are presented herein and may be applied to extract an order of magnitude of energetic ions fluxes from existing data sets, while waiting for dedicated high performance instruments.

  2. The measurements of light high-energy ions in NINA-2 experiment

    Directory of Open Access Journals (Sweden)

    A. Leonov

    2007-10-01

    Full Text Available The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluate radiation damages on space-borne instruments and on space mission crews. In spite of that, sources of data on the flux of energetic ions at LEO are roughly limited to the AP-8 model, CREME/CREME96 codes and the SAMPEX, NOAA/TIROS satellites. The existing and operational European SAC-C/ICARE and PROBA-1/SREM instruments could also be potential sources for proton data at LEO. Although AP-8 and SAMPEX/PSB97 may be publicly accessed through the SPENVIS, they exhibit an order of magnitude difference in low altitude proton fluxes and they do not contain helium fluxes. Therefore, improved light ion radiation models are still needed. In this paper we present a procedure to identify and measure the energy of ions that are not stopped in the NINA-2 instrument. Moreover, problems related to particles that cross the instrument in the opposite direction are addressed and shown to be a possible cause of particle misidentification. Measuring fluxes of low abundance elements like energetic helium ions requires a good characterisation of all possible sources of backgrounds in the detector. Hints to determine the several contributions to the background are presented herein and may be applied to extract an order of magnitude of energetic ions fluxes from existing data sets, while waiting for dedicated high performance instruments.

  3. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Falabella, S.

    1988-05-11

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs.

  4. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Falabella, S.

    1988-01-01

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10 12 cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs

  5. Measurements of radial profiles of ion cyclotron resonance heating on the tandem mirror experiment

    International Nuclear Information System (INIS)

    Falabella, S.

    1988-01-01

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawrence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). This analyzer indicates an increase in ion temperature from ∼20 eV before ICRH to ∼150 eV during ICRH, with ∼60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial integral of n i T i as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma potential is seen to vary from axially peaked, to nearly flat, as the plasma conditions varied over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U

  6. Recent measurements of low energy charge exchange cross sections for collisions of multicharged ions on neutral atoms and molecules

    International Nuclear Information System (INIS)

    Havener, Charles C.

    2001-01-01

    At ORNL Multicharged Ion Research Facility (MIRF), charge exchange (CX) cross sections have been measured for multicharged ions (MCI) on neutral atoms and molecules. The ORNL ion-atom merged-beam apparatus was used to measure single electron capture by MCI from H at eV/amu energies. A gas cell was used to measure single and double electron capture by MCI from a variety of molecular targets at keV collision energies. The merged-beams experiment has been successful in providing benchmark total electron capture measurements for several collision systems with a variety of multicharged ions on H or D

  7. Ion temperature measurements of turbulently heated tokamak plasma by Doppler-broadening of visible lines in TRIAM-1

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, N; Nakamura, K; Toi, K; Itoh, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1981-01-01

    In the turbulent heating experiment of the high-field tokamak TRIAM-1, the bulk ion heating shown by the neutral energy analyzer measurement is confirmed by the Doppler broadening measurement of visible lines. The increasing rate and decay time of the Doppler ion temperature are almost the same as those derived from the neutral energy analyzer measurement. From both methods of ion temperature measurements, it is shown that the ion temperature has a parabolic profile within 50 ..mu..s after the application of the heating pulse.

  8. Plan of measurement experiment of correlation between ion beam and plasma

    Energy Technology Data Exchange (ETDEWEB)

    Oguri, Yoshiyuki; Abe, Satoru; Sakumi, Akira; Okazaki, Hisashi; Watanabe, Takeshi [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors

    1996-12-01

    The Research Laboratory, for Nuclear Reactors, Tokyo Institute of Technology has conducted experimental study on accelerating structure and beam behavior of high intensity heavy ion accelerator for a beam driver and its computer simulation study as a circle of fundamental study of the heavy ion inertial nuclear fusion. From last fiscal year, a preliminary study for measuring the correlation between beam and plasma using low speed heavy ion beam from 1.7 MV tandem accelerator was begun. As a result, a possibility of forming a plasma target with above 10 (exp 17)/cu cm in free electron density and about 100 ns in life possible to supply to measurement of the correlation between beam and plasma was obtained by formation of laser plasma target and development of diagnostic measurement system. According to the preliminary calculation, it is expected to be larger charging state of ion passing through plasma than that in normal temperature target, and stoppability is presumed to increase largely and to apply to electron stopper for accelerator. And, a plan of time resolution measurement of energy loss of beam passed through plasma target using magnetic field type spectrometer and high speed plastic scintillator is also preceeding. (G.K.)

  9. (n,p) emission channeling measurements on ion-implanted beryllium

    CERN Multimedia

    Jakubek, J; Uher, J

    2007-01-01

    We propose to perform emission-channeling measurements using thermal neutron induced proton emission from ion-implanted $^{7}$Be. The physics questions addressed concern the beryllium doping of III-V and II-VI semiconductors and the host dependence of the electron capture half-life of $^{7}$Be.

  10. Determination of fluoride ions by measuring ionic activities and using selective electrode

    International Nuclear Information System (INIS)

    Angelini, J.M.G.; Castro Miquelino, F.L. de

    1984-01-01

    Fluorides interfere adversely in electroplating baths of printed circuits and in other environments where it promotes corrosion. A calibration curve for its determination was drawn with standards of known concentrations. As the concentration of the fluorite ions in the sample did not follow the linearity of the curve, it was measured by means of the standard addition method. (C.L.B.) [pt

  11. Automated measurement of heterogeneity in CT images of healthy and diseased rat lungs using variogram analysis of an octree decomposition

    International Nuclear Information System (INIS)

    Jacob, Richard E; Carson, James P

    2014-01-01

    Assessing heterogeneity in lung images can be an important diagnosis tool. We present a novel and objective method for assessing lung damage in a rat model of emphysema. We combined a three-dimensional (3D) computer graphics method–octree decomposition–with a geostatistics-based approach for assessing spatial relationships–the variogram–to evaluate disease in 3D computed tomography (CT) image volumes. Male, Sprague-Dawley rats were dosed intratracheally with saline (control), or with elastase dissolved in saline to either the whole lung (for mild, global disease) or a single lobe (for severe, local disease). Gated 3D micro-CT images were acquired on the lungs of all rats at end expiration. Images were masked, and octree decomposition was performed on the images to reduce the lungs to homogeneous blocks of 2 × 2 × 2, 4 × 4 × 4, and 8 × 8 × 8 voxels. To focus on lung parenchyma, small blocks were ignored because they primarily defined boundaries and vascular features, and the spatial variance between all pairs of the 8 × 8 × 8 blocks was calculated as the square of the difference of signal intensity. Variograms–graphs of distance vs. variance–were constructed, and results of a least-squares-fit were compared. The robustness of the approach was tested on images prepared with various filtering protocols. Statistical assessment of the similarity of the three control rats was made with a Kruskal-Wallis rank sum test. A Mann-Whitney-Wilcoxon rank sum test was used to measure statistical distinction between individuals. For comparison with the variogram results, the coefficient of variation and the emphysema index were also calculated for all rats. Variogram analysis showed that the control rats were statistically indistinct (p = 0.12), but there were significant differences between control, mild global disease, and severe local disease groups (p < 0.0001). A heterogeneity index was calculated to describe the difference of an individual variogram from

  12. Thomson scattering measurements of ion interpenetration in cylindrically converging, supersonic magnetized plasma flows

    Science.gov (United States)

    Swadling, George

    2015-11-01

    Ion interpenetration driven by high velocity plasma collisions is an important phenomenon in high energy density environments such as the interiors of ICF vacuum hohlraums and fast z-pinches. The presence of magnetic fields frozen into these colliding flows further complicates the interaction dynamics. This talk focuses on an experimental investigation of ion interpenetration in collisions between cylindrically convergent, supersonic, magnetized flows (M ~10, Vflow ~ 100km/s, ni ~ 1017cm-3) . The flows used in this study were plasma ablation streams produced by tungsten wire array z-pinches, driven by the 1.4MA, 240ns Magpie facility at Imperial College, and diagnosed using a combination of optical Thomson scattering, Faraday rotation and interferometry. Optical Thomson scattering (TS) provides time-resolved measurements of local flow velocity and plasma temperature across multiple (7 to 14) spatial positions. TS spectra are recorded simultaneously from multiple directions with respect to the probing beam, resulting in separate measurements of the rates of transverse diffusion and slowing-down of the ion velocity distribution. The measurements demonstrate flow interpenetration through the array axis at early time, and also show an axial deflection of the ions towards the anode. This deflection is induced by a toroidal magnetic field (~ 10T), frozen into the plasma that accumulates near the axis. Measurements obtained later in time show a change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams, and rapid radial collapse of the magnetized plasma column. The quantitative nature of the spatial profiles of the density, flow velocities and ion temperatures measured in these experiments will allow detailed verification of MHD and PIC codes used by the HEDP community. Work Supported by EPSRC (Grant No. EP/G001324/1), DOE (Cooperative Agreement Nos. DE-F03-02NA00057 & DE-SC-0001063) & Sandia National

  13. Improved environmental and forensics measurements using multiple ion counters in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Goldberg, S.A.; Richter, S.; Schwieters, H.

    2002-01-01

    Full text: A new detector system designed for isotope ratio mass spectrometers provides improved precision on measurements of samples with very low amounts ( -11 grams) of analyte. An array of continuous dynode electron multipliers has been installed on a new ThermoFinnigan MAT Triton thermal ionization mass spectrometer acquired by the New Brunswick Laboratory. These ion counters are modifications of miniaturized, commercially-available continuous dynode electron multipliers. They can be readily installed to replace individual Faraday cups in a multi-detector mass spectrometer or bundled together and located along the detector plane with a set of Faraday cups. On the New Brunswick Laboratory mass spectrometer, nine Faraday cups, one conventional discrete dynode electron multiplier, and seven miniaturized ion counters were installed. Six of the small ion counters were bundled together and positioned on the high mass side of the Low 4 Faraday cup. One additional ion counter was positioned on the low mass side of the Low 4 Faraday cup. This arrangement allows for the simultaneous measurement of all uranium (including 233 U) or plutonium (including 244 Pu) isotopes, and allows for the measurement of larger 238 U intensities on the Faraday cup if needed. Unit mass spacing of U, Pu, or other actinides is readily achieved by the use of a mass dispersion zoom lens. The advantage of multiple ion counting is the simultaneous collection of isotopes. It overcomes many of the problems such as transient signal variation in sample emission and ionization. For a given sample, multiple ion counting generates a greater number of counts for each isotope relative to single detector ion counting and provides improved counting statistics by a factor of two or more. Initial tests indicate that the multiple ion counters exhibit high counting efficiency, a dark noise of less than 10 counts per minute and typically less than 1 count per minute, and show linear response characteristics over

  14. Probing the Martian Exosphere and Neutral Escape Using Pickup Ions Measured by MAVEN

    Science.gov (United States)

    Rahmati, A.; Larson, D. E.; Cravens, T.; Halekas, J. S.; Lillis, R. J.; McFadden, J. P.; Mitchell, D. L.; Thiemann, E.; Connerney, J. E. P.; Dunn, P.; DiBraccio, G. A.; Espley, J. R.; Eparvier, F. G.; Jakosky, B. M.

    2016-12-01

    Soon after the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft started orbiting Mars in September 2014, the SEP (Solar Energetic Particle), SWIA (Solar Wind Ion Analyzer), and STATIC (Supra-Thermal and Thermal Ion Composition) instruments onboard the spacecraft started detecting planetary pickup ions. SEP can measure energetic (>50 keV) oxygen pickup ions, the source of which is the extended hot oxygen exosphere of Mars. Model results show that these pickup ions originate from tens of Martian radii upstream of Mars and are energized by the solar wind motional electric field as they gyrate back towards Mars. SEP is blind to pickup hydrogen, as the low energy threshold for detection of hydrogen in SEP is 20 keV; well above the maximum pickup hydrogen energy, which is four times the solar wind proton energy. SWIA and STATIC, on the other hand, can detect both pickup oxygen and pickup hydrogen with energies below 30 keV and created closer to Mars. During the times when MAVEN is outside the Martian bow shock and in the upstream undisturbed solar wind, the solar wind velocity measured by SWIA and the solar wind (or interplanetary) magnetic field measured by the MAG (magnetometer) instrument can be used to model pickup oxygen and hydrogen fluxes near Mars. Solar wind flux measurements of the SWIA instrument are used in calculating charge-exchange frequencies, and data from the EUVM (Extreme Ultraviolet Monitor) and SWEA (Solar Wind Electron Analyzer) instruments are also used in calculating photo-ionization and electron impact frequencies of neutral species in the Martian exosphere. By comparing SEP, SWIA, and STATIC measured pickup ion fluxes with model results, the Martian thermal hydrogen and hot oxygen neutral densities can be probed outside the bow shock, which would place constraints on estimates of oxygen and hydrogen neutral escape rates. We will present model-data comparisons of pickup ions measured outside the Martian bow shock. Our analysis reveals an

  15. Measurements on Pb27+ Sources for the CERN Heavy Ion Injection Chain

    CERN Document Server

    Chamings, J A

    2004-01-01

    CERN, the world's largest particle physics laboratory near Geneva, is currently in the process of building the Large Hadron Collider (LHC). Lead-208 will be used in this accelerator and to meet the injection requirements much work is required to find a suitable and reliable heavy ion source. The work in this report covers two ion sources, the Laser Ion Source (LIS), and the Electron Cyclotron Resonance Ion Source (ECRIS). An emittance measurement, using a pepper pot and CCD camera, was completed on the recently re-installed LIS, measured and analysed to be 140mm.mrad un-normalised and 0.8mm.mrad normalised 4rms for the maximum intensity charge state, Pb27+. A Visual Basic Program was modified to allow Charge State Distribution (CSD) and other scans of the ECRIS at CERN to be taken. Chapter 5 presents the results of the CSD scans taken. This program provided a new method to take 1 dimensional transverse beam profiles. From this a direct emittance measurement was formed for the first time since the source was o...

  16. An Interlaboratory Evaluation of Drift Tube Ion Mobility–Mass Spectrometry Collision Cross Section Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Stow, Sarah M. [Department; Causon, Tim J. [Division; Zheng, Xueyun [Biological; Kurulugama, Ruwan T. [Agilent Technologies, Santa Clara, California 95051, United States; Mairinger, Teresa [Division; May, Jody C. [Department; Rennie, Emma E. [Agilent Technologies, Santa Clara, California 95051, United States; Baker, Erin S. [Biological; Smith, Richard D. [Biological; McLean, John A. [Department; Hann, Stephan [Division; Fjeldsted, John C. [Agilent Technologies, Santa Clara, California 95051, United States

    2017-08-14

    Collision cross section (CCS) measurements resulting from ion mobility-mass spectrometry (IM-MS) experiments provide a promising orthogonal dimension of structural information in MS-based analytical separations. As with any molecular identifier, interlaboratory standardization must precede broad range integration into analytical workflows. In this study, we present a reference drift tube ion mobility mass spectrometer (DTIM-MS) where improvements on the measurement accuracy of experimental parameters influencing IM separations provide standardized drift tube, nitrogen CCS values (DTCCSN2) for over 120 unique ion species with the lowest measurement uncertainty to date. The reproducibility of these DTCCSN2 values are evaluated across three additional laboratories on a commercially available DTIM-MS instrument. The traditional stepped field CCS method performs with a relative standard deviation (RSD) of 0.29% for all ion species across the three additional laboratories. The calibrated single field CCS method, which is compatible with a wide range of chromatographic inlet systems, performs with an average, absolute bias of 0.54% to the standardized stepped field DTCCSN2 values on the reference system. The low RSD and biases observed in this interlaboratory study illustrate the potential of DTIM-MS for providing a molecular identifier for a broad range of discovery based analyses.

  17. Charge-exchange recombination spectroscopy measurements of ion temperature and plasma rotation in PBX

    International Nuclear Information System (INIS)

    Jaehnig, K.P.; Fonck, R.J.; Ida, K.; Powell, E.T.

    1984-11-01

    The primary diagnostic on PBX for ion temperature measurements is charge-exchange recombination spectroscopy of low Z ions, wherein fast neutrals from the heating neutral beams excite spectral lines from highly excited states (n greater than or equal to 4) of hydrogenic 0, C, and He via charge-exchange collisions with the respective fully stripped ions. Since the neutral beams on PBX provide relatively low velocity neutrals (i.e., D 0 beams at 44 keV), the best signals are obtained using the near-uv lines of 0 7+ (e.g., n = 8-7, 2976 A). Off-line analysis of the Doppler broadened and shifted line profiles includes non-linear least squares fitting to a model line profile, while a simplified on-line fast analysis code permits between-shot data analysis

  18. Impact of beam ions on α-particle measurements by collective Thomson scattering in ITER

    DEFF Research Database (Denmark)

    Egedal, J.; Bindslev, H.; Budny, R.V.

    2005-01-01

    Collective Thomson scattering (CTS) has been proposed as a viable diagnostic for characterizing fusion born a-distributions in ITER. However, the velocities of the planned 1 MeV deuterium heating beam ions in 1TER are similar to that of fusion born a-particles and may therefore mask the measureme......Collective Thomson scattering (CTS) has been proposed as a viable diagnostic for characterizing fusion born a-distributions in ITER. However, the velocities of the planned 1 MeV deuterium heating beam ions in 1TER are similar to that of fusion born a-particles and may therefore mask...... and the alpha-particles are calculated. Our investigations show that the CTS measurements of alpha-particles will not be masked by the presence of the beam ions in H-mode plasmas. In lower density reversed shear plasmas, only a part of the CTS alpha-particle spectrum will be perturbed....

  19. Measurement of secondary particle production induced by particle therapy ion beams impinging on a PMMA target

    Directory of Open Access Journals (Sweden)

    Toppi M.

    2016-01-01

    Full Text Available Particle therapy is a technique that uses accelerated charged ions for cancer treatment and combines a high irradiation precision with a high biological effectiveness in killing tumor cells [1]. Informations about the secondary particles emitted in the interaction of an ion beam with the patient during a treatment can be of great interest in order to monitor the dose deposition. For this purpose an experiment at the HIT (Heidelberg Ion-Beam Therapy Center beam facility has been performed in order to measure fluxes and emission profiles of secondary particles produced in the interaction of therapeutic beams with a PMMA target. In this contribution some preliminary results about the emission profiles and the energy spectra of the detected secondaries will be presented.

  20. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Tapia Araya, Sebastian; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy-ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions , cold nuclear effects may also affect quarkonia production . Therefore, a full assessment requires detailed studies on the effects present in both A-A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt J/psi and psi(2S) productions as well as Upsilon production via the di-muon decay final states. The results are of the various measurements are discussed.

  1. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Kremer, Jakub Andrzej; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy-ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect quarkonia production. Therefore, a full assessment requires detailed studies on the effects present in both A-A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt J/psi and psi(2S) productions as well as Upsilon production via the di-muon decay final states. The results of the various measurements are discussed

  2. Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS)

    International Nuclear Information System (INIS)

    Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

    2012-01-01

    Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature. - Highlights: ► Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS) was developed to study electron attachment reaction. ► The rate constants of electron attachment to CCl 4 and CHCl 3 were determined. ► The present experimental results are in good agreement with the previously reported data.

  3. Measuring Heterogeneous Reaction Rates with ATR-FTIR Spectroscopy to Evaluate Chemical Fates in an Atmospheric Environment: A Physical Chemistry and Environmental Chemistry Laboratory Experiment

    Science.gov (United States)

    Roberts, Jason E.; Zeng, Guang; Maron, Marta K.; Mach, Mindy; Dwebi, Iman; Liu, Yong

    2016-01-01

    This paper reports an undergraduate laboratory experiment to measure heterogeneous liquid/gas reaction kinetics (ozone-oleic acid and ozone-phenothrin) using a flow reactor coupled to an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. The experiment is specially designed for an upper-level undergraduate Physical…

  4. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1-weighted perfusion MRI

    DEFF Research Database (Denmark)

    Larsson, Henrik B.W.; Vestergaard, Mark B.; Lindberg, Ulrich

    2017-01-01

    Purpose: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH...

  5. Ion energy distributions in bipolar pulsed-dc discharges of methane measured at the biased cathode

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, C; Rubio-Roy, M; Bertran, E; Portal, S; Pascual, E; Polo, M C; Andujar, J L, E-mail: corbella@ub.edu [FEMAN Group, IN2UB, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, c/ MartI i Franques 1, 08028 Barcelona (Spain)

    2011-02-15

    The ion fluxes and ion energy distributions (IED) corresponding to discharges in methane (CH{sub 4}) were measured in time-averaged mode with a compact retarding field energy analyser (RFEA). The RFEA was placed on a biased electrode at room temperature, which was powered by either radiofrequency (13.56 MHz) or asymmetric bipolar pulsed-dc (250 kHz) signals. The shape of the resulting IED showed the relevant populations of ions bombarding the cathode at discharge parameters typical in the material processing technology: working pressures ranging from 1 to 10 Pa and cathode bias voltages between 100 and 200 V. High-energy peaks in the IED were detected at low pressures, whereas low-energy populations became progressively dominant at higher pressures. This effect is attributed to the transition from collisionless to collisional regimes of the cathode sheath as the pressure increases. On the other hand, pulsed-dc plasmas showed broader IED than RF discharges. This fact is connected to the different working frequencies and the intense peak voltages (up to 450 V) driven by the pulsed power supply. This work improves our understanding in plasma processes at the cathode level, which are of crucial importance for the growth and processing of materials requiring controlled ion bombardment. Examples of industrial applications with these requirements are plasma cleaning, ion etching processes during fabrication of microelectronic devices and plasma-enhanced chemical vapour deposition of hard coatings (diamond-like carbon, carbides and nitrides).

  6. Surface characterization by energy distribution measurements of secondary electrons and of ion-induced electrons

    International Nuclear Information System (INIS)

    Bauer, H.E.; Seiler, H.

    1988-01-01

    Instruments for surface microanalysis (e.g. scanning electron or ion microprobes, emission electron or ion microscopes) use the current of emitted secondary electrons or of emitted ion-induced electrons for imaging of the analysed surface. These currents, integrating over all energies of the emitted low energy electrons, are however, not well suited to surface analytical purposes. On the contrary, the energy distribution of these electrons is extremely surface-sensitive with respect to shape, size, width, most probable energy, and cut-off energy. The energy distribution measurements were performed with a cylindrical mirror analyser and converted into N(E), if necessary. Presented are energy spectra of electrons released by electrons and argon ions of some contaminated and sputter cleaned metals, the change of the secondary electron energy distribution from oxidized aluminium to clean aluminium, and the change of the cut-off energy due to work function change of oxidized aluminium, and of a silver layer on a platinum sample. The energy distribution of the secondary electrons often shows detailed structures, probably due to low-energy Auger electrons, and is broader than the energy distribution of ion-induced electrons of the same object point. (author)

  7. Ion mobilities in diatomic gases: measurement versus prediction with non-specular scattering models.

    Science.gov (United States)

    Larriba, Carlos; Hogan, Christopher J

    2013-05-16

    Ion/electrical mobility measurements of nanoparticles and polyatomic ions are typically linked to particle/ion physical properties through either application of the Stokes-Millikan relationship or comparison to mobilities predicted from polyatomic models, which assume that gas molecules scatter specularly and elastically from rigid structural models. However, there is a discrepancy between these approaches; when specular, elastic scattering models (i.e., elastic-hard-sphere scattering, EHSS) are applied to polyatomic models of nanometer-scale ions with finite-sized impinging gas molecules, predictions are in substantial disagreement with the Stokes-Millikan equation. To rectify this discrepancy, we developed and tested a new approach for mobility calculations using polyatomic models in which non-specular (diffuse) and inelastic gas-molecule scattering is considered. Two distinct semiempirical models of gas-molecule scattering from particle surfaces were considered. In the first, which has been traditionally invoked in the study of aerosol nanoparticles, 91% of collisions are diffuse and thermally accommodating, and 9% are specular and elastic. In the second, all collisions are considered to be diffuse and accommodating, but the average speed of the gas molecules reemitted from a particle surface is 8% lower than the mean thermal speed at the particle temperature. Both scattering models attempt to mimic exchange between translational, vibrational, and rotational modes of energy during collision, as would be expected during collision between a nonmonoatomic gas molecule and a nonfrozen particle surface. The mobility calculation procedure was applied considering both hard-sphere potentials between gas molecules and the atoms within a particle and the long-range ion-induced dipole (polarization) potential. Predictions were compared to previous measurements in air near room temperature of multiply charged poly(ethylene glycol) (PEG) ions, which range in morphology from

  8. Flux threshold measurements of He-ion beam induced nanofuzz formation on hot tungsten surfaces

    International Nuclear Information System (INIS)

    Meyer, F W; Hijazi, H; Bannister, M E; Unocic, K A; Garrison, L M; Parish, C M

    2016-01-01

    We report measurements of the energy dependence of flux thresholds and incubation fluences for He-ion induced nano-fuzz formation on hot tungsten surfaces at UHV conditions over a wide energy range using real-time sample imaging of tungsten target emissivity change to monitor the spatial extent of nano-fuzz growth, corroborated by ex situ SEM and FIB/SEM analysis, in conjunction with accurate ion-flux profile measurements. The measurements were carried out at the multicharged ion research facility (MIRF) at energies from 218 eV to 8.5 keV, using a high-flux deceleration module and beam flux monitor for optimizing the decel optics on the low energy MIRF beamline. The measurements suggest that nano-fuzz formation proceeds only if a critical rate of change of trapped He density in the W target is exceeded. To understand the energy dependence of the observed flux thresholds, the energy dependence of three contributing factors: ion reflection, ion range and target damage creation, were determined using the SRIM simulation code. The observed energy dependence can be well reproduced by the combined energy dependences of these three factors. The incubation fluences deduced from first visual appearance of surface emissivity change were (2–4) × 10 23 m −2 at 218 eV, and roughly a factor of 10 less at the higher energies, which were all at or above the displacement energy threshold. The role of trapping at C impurity sites is discussed. (paper)

  9. Microstructured Optical Fiber-based Biosensors: Reversible and Nanoliter-Scale Measurement of Zinc Ions.

    Science.gov (United States)

    Heng, Sabrina; McDevitt, Christopher A; Kostecki, Roman; Morey, Jacqueline R; Eijkelkamp, Bart A; Ebendorff-Heidepriem, Heike; Monro, Tanya M; Abell, Andrew D

    2016-05-25

    Sensing platforms that allow rapid and efficient detection of metal ions would have applications in disease diagnosis and study, as well as environmental sensing. Here, we report the first microstructured optical fiber-based biosensor for the reversible and nanoliter-scale measurement of metal ions. Specifically, a photoswitchable spiropyran Zn(2+) sensor is incorporated within the microenvironment of a liposome attached to microstructured optical fibers (exposed-core and suspended-core microstructured optical fibers). Both fiber-based platforms retains high selectivity of ion binding associated with a small molecule sensor, while also allowing nanoliter volume sampling and on/off switching. We have demonstrated that multiple measurements can be made on a single sample without the need to change the sensor. The ability of the new sensing platform to sense Zn(2+) in pleural lavage and nasopharynx of mice was compared to that of established ion sensing methodologies such as inductively coupled plasma mass spectrometry (ICP-MS) and a commercially available fluorophore (Fluozin-3), where the optical-fiber-based sensor provides a significant advantage in that it allows the use of nanoliter (nL) sampling when compared to ICP-MS (mL) and FluoZin-3 (μL). This work paves the way to a generic approach for developing surface-based ion sensors using a range of sensor molecules, which can be attached to a surface without the need for its chemical modification and presents an opportunity for the development of new and highly specific ion sensors for real time sensing applications.

  10. Laser-induced fluorescence measurements of argon ion velocities near the sheath boundary of an argon-xenon plasma

    International Nuclear Information System (INIS)

    Lee, Dongsoo; Severn, Greg; Oksuz, Lutfi; Hershkowitz, Noah

    2006-01-01

    The Bohm sheath criterion in single- and two-ion species plasma is studied with laser-induced fluorescence using a diode laser. Xenon is added to a low pressure unmagnetized dc hot filament argon discharge confined by surface multidipole magnetic fields. The Ar II transition at 668.614 nm is adopted for optical pumping to detect the fluorescence from the plasma and to measure the argon ion velocity distribution functions with respect to positions relative to a negatively biased boundary plate. The structures of the plasma sheath and presheath are measured by an emissive probe. The ion concentrations of the two-species in the bulk plasma are calculated from ion acoustic wave experiments. Results are compared with previous experiments of Ar-He plasmas in which the argon ions were the heavier ion species. Unlike the previous results, the argon speed is slower than its own Bohm velocity near the sheath-presheath boundary in the Ar-Xe plasma where argon ions are the lighter ion species. We argue that this result is consistent with the behaviour of the helium ion required by the generalized Bohm criterion in the previous experiments with Ar-He plasmas. Further, our results suggest that the measured argon ion speed approaches the ion sound speed of the system

  11. Excited-level lifetimes and hyperfine-structure measurements on ions using collinear laser--ion-beam spectroscopy

    International Nuclear Information System (INIS)

    Jin, J.; Church, D.A.

    1994-01-01

    The mean lifetimes τ of the Ca II 4p 2 P 1/2 and 4p 2 P 3/2 levels, and the 35 Cl II 4p' 1 F 3 level, have been measured by a variant of the collinear laser--ion-beam lifetime technique applied previously to the Ar II 4p' 2 F 7/2 o level [Jian Jin and D. A. Church, Phys. Rev. A 47, 132 (1993)]. The present results are τ(Ca II, 4p 2 P 1/2 )=7.098(0.020) ns, τ(Ca II, 4p 2 P 3/2 )=6.924(0.019) ns, and τ(Cl II, 4p' 1 F 3 ) =11.17(0.06) ns. The experimental lifetimes of these, plus the Ar II 4p' 2 F 7/2 level, are compared with available recent many-electron calculations. Typically 1%--3% differences between measurement and ab initio theory are found, while certain semiempirical calculations are in better agreement with experiment. Data for other precise lifetime measurements on alkali-metal systems are compared with recent ab initio and semiempirical calculations to provide perspective on the Ca II results. The hyperfine structure of the 35 Cl II 3d' 1 G 4 --4p' 1 F 3 transition was also measured and analyzed in the course of the measurements, with the resulting hyperfine-structure constants: A( 1 F 3 )=301.9(0.5) MHz, B( 1 F 3 )=-6.7(0.8) MHz, A( 1 G 4 )=205.1(0.5) MHz, and B( 1 G 4 )=-3.9(2.4) MHz

  12. Scintillation screen materials for beam profile measurements of high energy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Krishnakumar, Renuka

    2016-06-22

    {sub 2}O{sub 3}:Cr screen over 1000 pulses while slight saturation effects was noticed from some other screens. No considerable radiation induced damage for an irradiation by maximal fluence of 1.7 x 10{sup 11} cm{sup -2} Uranium ions was seen in the samples except the formation of point defects and color centers. Among the investigated screens P43 (Gd{sub 2}O{sub 2}S:Tb) powder seems to be a good candidate up to certain energy deposition threshold while for very high intensity measurements Al{sub 2}O{sub 3}:Cr screens are recommended.

  13. Consideration of magnetic field fluctuation measurements in a torus plasma with heavy ion beam probe

    International Nuclear Information System (INIS)

    Shimizu, A.; Fujisawa, A.; Ohshima, S.; Nakano, H.

    2004-03-01

    The article discusses feasibility of magnetic fluctuation measurement with a heavy ion beam probe (HIBP) in an axisymmetric torus configuration. In the measurements, path integral fluctuation along the probing beam orbit should be considered as is similar to the density fluctuation measurements with HIBP. A calculation, based on an analytic formula, is performed to estimate the path integral effects for fluctuation patterns that have difference in profile, the correlation length, the radial wavelength, and the poloidal mode number. In addition, the large distance between the plasma and the detector is considered to lessen the path integral effect. As a result, it is found that local fluctuation of magnetic field can be properly detected with a heavy ion beam probe. (author)

  14. Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

    Energy Technology Data Exchange (ETDEWEB)

    Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

    1986-08-01

    The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs.

  15. Measurement of energy deposition near high energy, heavy ion tracks. Progress report, December 1982-April 1985

    International Nuclear Information System (INIS)

    Metting, N.F.; Braby, L.A.; Rossi, H.H.; Kliauga, P.J.; Howard, J.; Schimmerling, W.; Wong, M.; Rapkin, M.

    1986-08-01

    The microscopic spatial distribution of energy deposition in irradiated tissue plays a significant role in the final biological effect produced. Therefore, it is important to have accurate microdosimetric spectra of radiation fields used for radiobiology and radiotherapy. The experiments desribed here were designed to measure the distributions of energy deposition around high energy heavy ion tracks generated at Lawrence Berkeley Laboratory's Bevalac Biomedical Facility. A small proportional counter mounted in a large (0.6 by 2.5 m) vacuum chamber was used to measure energy deposition distributions as a function of the distance between detector and primary ion track. The microdosimetric distributions for a homogeneous radiation field were then calculated by integrating over radial distance. This thesis discusses the rationale of the experimental design and the analysis of measurements on 600 MeV/amu iron tracks. 53 refs., 19 figs

  16. Nanosensors for label-free measurement of sodium ion fluxes of neuronal cells

    Energy Technology Data Exchange (ETDEWEB)

    Gebinoga, Michael, E-mail: michael.gebinoga@tu-ilmenau.de [ZIK MacroNano Microfluidics and Biosensors, Technical University Ilmenau, P.O. Box 100565, D-98684 Ilmenau (Germany); Silveira, Liele; Cimalla, Irina [ZIK MacroNano Microfluidics and Biosensors, Technical University Ilmenau, P.O. Box 100565, D-98684 Ilmenau (Germany); Dumitrescu, Andreea [University of Pennsylvania - School of Engineering and Applied Science, Philadelphia, PA 19104-6391 (United States); Kittler, Mario; Luebbers, Benedikt; Becker, Annette [ZIK MacroNano Microfluidics and Biosensors, Technical University Ilmenau, P.O. Box 100565, D-98684 Ilmenau (Germany); Lebedev, Vadim [Fraunhofer Institute for Solid State Physics, Tullastr. 7, D-79108 Freiburg (Germany); Schober, Andreas [ZIK MacroNano Microfluidics and Biosensors, Technical University Ilmenau, P.O. Box 100565, D-98684 Ilmenau (Germany)

    2010-05-25

    Novel nanosensors based on aluminium gallium nitrides (AlGaN/GaN) high electron mobility transistors have been of high interest during the last years, especially for their electrical characteristics as open gate field effect transistors. These nanosensors provide a valuable tool for high content screening in drug discovery, cell monitoring and liquid analyses focusing on applications of electrochemical detection technology. Our own measurements with these sensors confirm their pH sensitivity and in addition the possibility of detection of other ions in aqueous media. These measurements deal with the reactions of NG 108-15 (mouse neuroblastoma x rat glioma hybrid) neuronal cells in response to different acetylcholinesterase inhibitors. Our experimental approach shows some advantages. The first advantage is the label-free measurement of ion fluxes, and another advantage is the possibility non-destructively to estimate cell signals.

  17. Nanosensors for label-free measurement of sodium ion fluxes of neuronal cells

    International Nuclear Information System (INIS)

    Gebinoga, Michael; Silveira, Liele; Cimalla, Irina; Dumitrescu, Andreea; Kittler, Mario; Luebbers, Benedikt; Becker, Annette; Lebedev, Vadim; Schober, Andreas

    2010-01-01

    Novel nanosensors based on aluminium gallium nitrides (AlGaN/GaN) high electron mobility transistors have been of high interest during the last years, especially for their electrical characteristics as open gate field effect transistors. These nanosensors provide a valuable tool for high content screening in drug discovery, cell monitoring and liquid analyses focusing on applications of electrochemical detection technology. Our own measurements with these sensors confirm their pH sensitivity and in addition the possibility of detection of other ions in aqueous media. These measurements deal with the reactions of NG 108-15 (mouse neuroblastoma x rat glioma hybrid) neuronal cells in response to different acetylcholinesterase inhibitors. Our experimental approach shows some advantages. The first advantage is the label-free measurement of ion fluxes, and another advantage is the possibility non-destructively to estimate cell signals.

  18. Fast-ion diffusion measurements from radial triton burn up studies

    International Nuclear Information System (INIS)

    McCauley, J.S.; Budny, R.; McCune, D.; Strachan, J.D.

    1993-08-01

    A fast-ion diffusion coefficient of 0.1 ± 0.1 m 2 s -1 has been deduced from the triton burnup neutron emission profile measured by a collimated array of helium-4 spectrometers. The experiment was performed with high-power deuterium discharges produced by Princeton University's Tokamak Fusion Test Reactor (TFTR). The fast ions monitored were the 1.0 MeV tritons produced from the d(d,t)p. These tritons ''burn up'' with deuterons and emit a 14 MeV neutron by the d(t,α)n reaction. The ratio of the measured to calculated DT yield is typically 70%. The measured DT profile width is comparable to that predicted by the TRANSP transport code during neutral beam heating and narrower after the beam heating ended

  19. A MEASUREMENT OF THE ADIABATIC COOLING INDEX FOR INTERSTELLAR HELIUM PICKUP IONS IN THE INNER HELIOSPHERE

    International Nuclear Information System (INIS)

    Saul, Lukas; Wurz, Peter; Kallenbach, Reinald

    2009-01-01

    Interstellar neutral gas enters the inner heliosphere where it is ionized and becomes the pickup ion population of the solar wind. It is often assumed that this population will subsequently cool adiabatically, like an expanding ideal gas due, to the divergent flow of the solar wind. Here, we report the first independent measure of the effective adiabatic cooling index in the inner heliosphere from SOHO CELIAS measurements of singly charged helium taken during times of perpendicular interplanetary magnetic field. We use a simple adiabatic transport model of interstellar pickup helium ions, valid for the upwind region of the inner heliosphere. The time averaged velocity spectrum of helium pickup ions measured by CELIAS/CTOF is fit to this model with a single free parameter which indicates an effective cooling rate with a power-law index of γ = 1.35 ± 0.2. While this average is consistent with the 'ideal-gas' assumption of γ = 1.5, the analysis indicates that such an assumption will not apply in general, and that due to observational constraints further measurements are necessary to constrain the cooling process. Implications are discussed for understanding the transport processes in the inner heliosphere and improving this measurement technique.

  20. Measurement of diffusion coefficient of thallium ion in H2O and D2O systems at different concentrations

    International Nuclear Information System (INIS)

    Das, A.; Changdar, S.N.

    1992-01-01

    Sliding cell method, developed in our laboratory, has been used to measure the inter diffusion coefficient of thallium ion in thallous sulphate solution over a wide concentration range using both water and heavy water as solvent at 35degC. The results have been analysed from the point of view of both ion-ion and ion-solvent interactions. The comparison of the diffusivities of the same ion in D 2 O and H 2 O electrolyte solutions at the same temperature indicate that the addition of salt affects the two solvent differently. (author). 8 refs., 1 fig., 1 tab

  1. Low energy RBS-channeling measurement system with the use of a time-of-flight scattered ion detector

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Masataka; Kobayashi, Naoto; Hayashi, Nobuyuki [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)

    1996-07-01

    We have developed a low energy Rutherford backscattering spectrometry-ion channeling measurement system for the analysis of thin films and solid surfaces with the use of several tens keV hydrogen ions and a time-of-flight particle energy spectrometer. For the detection of the scattered ions new TOF spectrometer has been developed, which consists of two micro-channel-plate detectors. The pulsing of the primary ion beam is not necessary for this type of TOF measurement, and it is possible to observe continues scattered ion beams. The dimension of whole system is very compact compared to the conventional RBS-channeling measurement system with the use of MeV He ions. The energy resolution, {delta} E/E, for 25 keV H{sup +} was 4.1%, which corresponds to the depth resolution of 4.8 nm for silicon. The depth resolution of our system is better than that of conventional RBS system with MeV helium ions and solid state detectors. We have demonstrated the ion channeling measurement by this system with 25 keV hydrogen ions. The system can be available well to the analysis of thin films and solid surfaces with the use of the ion channeling effect. The observation of the reaction between Fe and hydrogen terminated silicon surface was also demonstrated. (J.P.N.)

  2. Analysis of In Situ Thermal Ion Measurements from the MICA Sounding Rocket

    Science.gov (United States)

    Fernandes, P. A.; Lynch, K. A.; Zettergren, M. D.; Hampton, D. L.; Fisher, L. E.; Powell, S. P.

    2014-12-01

    The MICA sounding rocket launched on 19 Feb. 2012 into several discrete, localized arcs in the wake of a westward traveling surge. In situ and ground-based observations provide a measured response of the ionosphere to preflight and localized auroral drivers. Initial analysis of the in situ thermal ion data indicate possible measurement of an ion conic at low altitude (< 325 km). In the low-energy regime, the response of the instrument varies from the ideal because the measured thermal ion population is sensitive to the presence of the instrument. The plasma is accelerated in the frame of the instrument due to flows, ram, and acceleration through the sheath which forms around the spacecraft. The energies associated with these processes are large compared to the thermal energy. Correct interpretation of thermal plasma measurements requires accounting for all of these plasma processes and the non-ideal response of the instrument in the low-energy regime. This is an experimental and modeling project which involves thorough analysis of ionospheric thermal ion data from the MICA campaign. Analysis includes modeling and measuring the instrument response in the low-energy regime as well as accounting for the complex sheath formed around the instrument. This results in a forward model in which plasma parameters of the thermal plasma are propagated through the sheath and instrument models, resulting in an output which matches the in situ measurement. In the case of MICA, we are working toward answering the question of the initiating source processes that result, at higher altitudes, in well-developed conics and outflow on auroral field lines.

  3. Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

    International Nuclear Information System (INIS)

    Hermes, Pascal Dominik

    2016-01-01

    The CERN Large Hadron Collider (LHC) stores and collides proton and 208 Pb 82+ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new tracking

  4. Heavy-ion collimation at the Large Hadron Collider. Simulations and measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hermes, Pascal Dominik

    2016-12-19

    The CERN Large Hadron Collider (LHC) stores and collides proton and {sup 208}Pb{sup 82+} beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with the collimators. Previous simulation tools used simplified models for the simulation of particle-matter interaction and showed discrepancies compared to the measured loss patterns. This thesis describes the development and application of improved heavy-ion collimation simulation tools. Two different approaches are presented to provide these functionalities. In the first presented tool, called STIER, fragmentation at the primary collimator is simulated with the Monte-Carlo event generator FLUKA. The ion fragments scattered out of the primary collimator are subsequently tracked as protons with ion-equivalent rigidities in the existing proton tracking tool SixTrack. This approach was used to prepare the collimator settings for the 2015 LHC heavy-ion run and its predictions allowed reducing undesired losses. More accurate simulation results are obtained with the second presented simulation tool, in which SixTrack is extended to track arbitrary heavy ions. This new

  5. Dose profile monitoring with carbon ions by means of prompt-gamma measurements

    Energy Technology Data Exchange (ETDEWEB)

    Testa, E. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)], E-mail: e.testa@ipnl.in2p3.fr; Bajard, M.; Chevallier, M.; Dauvergne, D.; Le Foulher, F. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France); Freud, N.; Letang, J.M. [Institut National des Sciences Appliquees de Lyon, Laboratoire de Controle Non-Destructif par Rayonnements Ionisants (France); Poizat, J.C.; Ray, C.; Testa, M. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)

    2009-03-15

    A key point in the quality control of ion therapy is real-time monitoring and imaging of the dose delivered to the patient. Among the possible signals that can be used to make such a monitoring, prompt gamma-rays issued from nuclear fragmentation are possible candidates, provided the correlation between the emission profile and the primary beam range can be established. By means of simultaneous energy and time-of-flight discrimination, we could measure the longitudinal profile of the prompt gamma-rays emitted by 73 MeV/u carbon ions stopping inside a PMMA target. This technique allowed us to minimize the shielding against neutrons and scattered gamma rays, and to find a good correlation between the prompt-gamma profile and the ion range. This profile was studied as a function of the observation angle. By extrapolating our results to higher energies and realistic detection efficiencies, we showed that prompt gamma-ray measurements make it feasible to control in real time the longitudinal dose during ion therapy treatments.

  6. A method of measurement of lifetimes of excited ion levels, using orientation transfer by Penning collisions

    International Nuclear Information System (INIS)

    Hamel, J.; Barrat, J.-P.

    1978-01-01

    A method for measuring the lifetimes of ionic excited levels is described. This method uses the transfer of coherence in a Penning collision using metastable optically oriented He 2 3 S 1 atoms. If R.F. transitions are induced in the (2 3 S 1 )He level, a transverse component of the magnetic moment of this level is created, which precesses coherently at the angular frequency ω of the R.F. field. The helium transverse orientation is partially transferred to the ions produced by Penning collisions. After the collision, the orientation transferred precesses around the external magnetic field at the Larmor frequency ω 0 ' of the ion excited level. The degree of orientation of the excited ion level depends, in the stationary state, on the average phase shift, during the lifetime tau prime of this level, between the Larmor precession at angular frequency ω 0 ' and the forced precession of helium (at angular frequency ω). The orientation of the ions is monitored by the modulation of the light emitted during their radiative decay. It is possible to determine the lifetime tau prime by measuring the degree of modulation of the reemitted light as a function of ω [fr

  7. Comparison of measured and modelled negative hydrogen ion densities at the ECR-discharge HOMER

    Energy Technology Data Exchange (ETDEWEB)

    Rauner, D.; Kurutz, U.; Fantz, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); AG Experimentelle Plasmaphysik, Universität Augsburg, 86135 Augsburg (Germany)

    2015-04-08

    As the negative hydrogen ion density n{sub H{sup −}} is a key parameter for the investigation of negative ion sources, its diagnostic quantification is essential in source development and operation as well as for fundamental research. By utilizing the photodetachment process of negative ions, generally two different diagnostic methods can be applied: via laser photodetachment, the density of negative ions is measured locally, but only relatively to the electron density. To obtain absolute densities, the electron density has to be measured additionally, which induces further uncertainties. Via cavity ring-down spectroscopy (CRDS), the absolute density of H{sup −} is measured directly, however LOS-averaged over the plasma length. At the ECR-discharge HOMER, where H{sup −} is produced in the plasma volume, laser photodetachment is applied as the standard method to measure n{sub H{sup −}}. The additional application of CRDS provides the possibility to directly obtain absolute values of n{sub H{sup −}}, thereby successfully bench-marking the laser photodetachment system as both diagnostics are in good agreement. In the investigated pressure range from 0.3 to 3 Pa, the measured negative hydrogen ion density shows a maximum at 1 to 1.5 Pa and an approximately linear response to increasing input microwave powers from 200 up to 500 W. Additionally, the volume production of negative ions is 0-dimensionally modelled by balancing H{sup −} production and destruction processes. The modelled densities are adapted to the absolute measurements of n{sub H{sup −}} via CRDS, allowing to identify collisions of H{sup −} with hydrogen atoms (associative and non-associative detachment) to be the dominant loss process of H{sup −} in the plasma volume at HOMER. Furthermore, the characteristic peak of n{sub H{sup −}} observed at 1 to 1.5 Pa is identified to be caused by a comparable behaviour of the electron density with varying pressure, as n{sub e} determines

  8. Measurement of a 2D fast-ion velocity distribution function by tomographic inversion of fast-ion D-alpha spectra

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Jacobsen, Asger Schou

    2014-01-01

    We present the first measurement of a local fast-ion 2D velocity distribution function f(v‖, v⊥). To this end, we heated a plasma in ASDEX Upgrade by neutral beam injection and measured spectra of fast-ion Dα (FIDA) light from the plasma centre in three views simultaneously. The measured spectra ...... can measure spectra in up to seven views simultaneously in the next ASDEX Upgrade campaign which would further improve measurements of f(v‖, v⊥) by tomographic inversion.......We present the first measurement of a local fast-ion 2D velocity distribution function f(v‖, v⊥). To this end, we heated a plasma in ASDEX Upgrade by neutral beam injection and measured spectra of fast-ion Dα (FIDA) light from the plasma centre in three views simultaneously. The measured spectra...... agree very well with synthetic spectra calculated from a TRANSP/NUBEAM simulation. Based on the measured FIDA spectra alone, we infer f(v‖, v⊥) by tomographic inversion. Salient features of our measurement of f(v‖, v⊥) agree reasonably well with the simulation: the measured as well as the simulated f...

  9. Measurements of ion temperature and plasma hydrogenic composition by collective Thomson scattering in neutral beam heated discharges at TEXTOR

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Salewski, Mirko; Korsholm, Søren Bang

    2013-01-01

    A method is developed to perform plasma composition and ion temperature measurements across the plasma minor radius in TEXTOR based on ion cyclotron structures in collective Thomson scattering spectra. By gradually moving the scattering volume, we obtain measurements across the outer midplane of ...

  10. French experimental facilities for measurements of transverse flows and assessment of the corresponding risk of vibrations in heterogeneous cores

    International Nuclear Information System (INIS)

    Le Borgne, E.; Mattei, A.; Oceraies, Y.; Fardeau, P.

    1994-01-01

    Due to insertion of a limited number of new assemblies at each cycle, the cores in Pressurized Water Reactors are not homogeneous. Referring only to the impact on coolant flow, these differences can range from variable hydraulic resistances in the assembly, which depend on the geometric changes occurring during preceding cycles, to coexistence of assemblies with new design structures. Deviations in resistance between neighboring fuel assemblies causes the flow rates to be distributed differently between the assembly rods. This results in development of transverse flows from the main axial flow, and changes in the axial velocity gradients. These particularities of coolant flow have an effect on both vibration levels and cooling of the fuel rods, and also on the axial forces exerted on the assemblies in the core cavity. Since 1985, French Atomic Energy Commission (CEA) has gradually acquired experimental and measuring facilities that have allowed it to engage in research and development programs in these areas, in cooperation with industry partners in the nuclear field. Two complementary test loops have been constructed, called ARIANE and HERMES T. Use of these experimental facilities allows to obtain complete and detailed information on the hydraulic and vibratory phenomena specific to heterogeneous cores. In particular it is possible to establish a direct assessment of the actual compatibility between two different assemblies. By making a few specific changes, these facilities can also be used as a unique tool for assembly behaviour studies under seismic conditions with simulation of the flow effects. Also, a source of information in thus made available for qualification of computation codes for vibratory mechanics and multidimensional fluid mechanics under development at CEA and also used in the field of nuclear fuel. (authors). 6 figs., 1 ref

  11. The use of semantic similarity measures for optimally integrating heterogeneous Gene Ontology data from large scale annotation pipelines

    Directory of Open Access Journals (Sweden)

    Gaston K Mazandu

    2014-08-01

    Full Text Available With the advancement of new high throughput sequencing technologies, there has been an increase in the number of genome sequencing projects worldwide, which has yielded complete genome sequences of human, animals and plants. Subsequently, several labs have focused on genome annotation, consisting of assigning functions to gene products, mostly using Gene Ontology (GO terms. As a consequence, there is an increased heterogeneity in annotations across genomes due to different approaches used by different pipelines to infer these annotations and also due to the nature of the GO structure itself. This makes a curator's task difficult, even if they adhere to the established guidelines for assessing these protein annotations. Here we develop a genome-scale approach for integrating GO annotations from different pipelines using semantic similarity measures. We used this approach to identify inconsistencies and similarities in functional annotations between orthologs of human and Drosophila melanogaster, to assess the quality of GO annotations derived from InterPro2GO mappings compared to manually annotated GO annotations for the Drosophila melanogaster proteome from a FlyBase dataset and human, and to filter GO annotation data for these proteomes. Results obtained indicate that an efficient integration of GO annotations eliminates redundancy up to 27.08 and 22.32% in the Drosophila melanogaster and human GO annotation datasets, respectively. Furthermore, we identified lack of and missing annotations for some orthologs, and annotation mismatches between InterPro2GO and manual pipelines in these two proteomes, thus requiring further curation. This simplifies and facilitates tasks of curators in assessing protein annotations, reduces redundancy and eliminates inconsistencies in large annotation datasets for ease of comparative functional genomics.

  12. Experimental study of ion stopping power in warm dense matter: charge-state distribution measurements of ions leaving warm dense matter

    International Nuclear Information System (INIS)

    Gauthier, Maxence

    2013-01-01

    The determination if the ion slowing down process (or stopping power) in warm dense matter is essential especially in the frame of inertial confinement fusion. During my thesis, our interest was driven by the modification of the charge state of ion beam emerging from warm dense matter, this quantity playing a major role in ion stopping power calculation. We took advantage of the properties exhibited by ion beams produced by high intensity short pulse lasers to study during two experiments performed at ELFIE and TITAN facilities, the charge state modification of a carbon and helium ion beams emerging from an aluminum foil isochorically heated by an energetic proton beam. In the first two chapters are presented the major challenges regarding the subject from both a theoretical and experimental point of view. Here are exposed the different simulation tools used during the thesis. The third chapter is devoted to the study of the property of laser-produced ion beams in the scope of our experiments aiming at studying the stopping power. We have studied in particular ion beams generated using lower-than-solid density targets during two experiments: helium gas jet and laser-exploded target. In the last chapter are presented the set-ups and results of the two experiments on the charge state of ion beam emerging from warm dense matter. The data we measured in solid-density cold aluminum are successfully compared with the results already obtained in conventional accelerators. (author) [fr

  13. Visual classification of emphysema heterogeneity compared with objective measurements: HRCT vs spiral CT in candidates for lung volume reduction surgery

    International Nuclear Information System (INIS)

    Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B.; Bergstrand, L.; Tylen, U.; Aspelin, P.

    2002-01-01

    The aim of this study was to investigate whether spiral CT is superior to high-resolution computed tomography (HRCT) in evaluating the radiological morphology of emphysema, and whether the combination of both CT techniques improves the evaluation in patients undergoing lung volume reduction surgery (LVRS). The material consisted of HRCT (with 2-mm slice thickness) and spiral CT (with 10-mm slice thickness) of 94 candidates for LVRS. Selected image pairs from these examinations were evaluated. Each image pair consisted of one image from the cranial part of the lung and one image from the caudal part. The degree of emphysema in the two images was calculated by computer. The difference between the images determined the degree of heterogeneity. Five classes of heterogeneity were defined. The study was performed by visual classification of 95 image pairs (spiral CT) and 95 image pairs (HRCT) into one of five different classes of emphysema heterogeneity. This visual classification was compared with the computer-based classification. Spiral CT was superior to HRCT with 47% correct classifications of emphysema heterogeneity compared with 40% for HRCT-based classification (p<0.05). The combination of the techniques did not improve the evaluation (42%). Spiral CT is superior to HRCT in determining heterogeneity of emphysema visually, and should be included in the pre-operative CT evaluation of LVRS candidates. (orig.)

  14. Visual classification of emphysema heterogeneity compared with objective measurements: HRCT vs spiral CT in candidates for lung volume reduction surgery

    Energy Technology Data Exchange (ETDEWEB)

    Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B. [Department of Thoracic Radiology, Karolinska Hospital, Stockholm (Sweden); Bergstrand, L. [Department of Radiology, Danderyds Hospital, Danderyd (Sweden); Tylen, U. [Deparment of Radiology, Sahlgrenska University Hospital, Gothenberg (Sweden); Aspelin, P. [Department of Radiology, Huddinge University Hospital, Huddinge (Sweden)

    2002-05-01

    The aim of this study was to investigate whether spiral CT is superior to high-resolution computed tomography (HRCT) in evaluating the radiological morphology of emphysema, and whether the combination of both CT techniques improves the evaluation in patients undergoing lung volume reduction surgery (LVRS). The material consisted of HRCT (with 2-mm slice thickness) and spiral CT (with 10-mm slice thickness) of 94 candidates for LVRS. Selected image pairs from these examinations were evaluated. Each image pair consisted of one image from the cranial part of the lung and one image from the caudal part. The degree of emphysema in the two images was calculated by computer. The difference between the images determined the degree of heterogeneity. Five classes of heterogeneity were defined. The study was performed by visual classification of 95 image pairs (spiral CT) and 95 image pairs (HRCT) into one of five different classes of emphysema heterogeneity. This visual classification was compared with the computer-based classification. Spiral CT was superior to HRCT with 47% correct classifications of emphysema heterogeneity compared with 40% for HRCT-based classification (p<0.05). The combination of the techniques did not improve the evaluation (42%). Spiral CT is superior to HRCT in determining heterogeneity of emphysema visually, and should be included in the pre-operative CT evaluation of LVRS candidates. (orig.)

  15. Highly charged ions trapping for lifetime measurements; Piegeage d'ions tres charges pour la mesure de duree de vie d'etats metastables

    Energy Technology Data Exchange (ETDEWEB)

    Attia, D

    2007-10-15

    A new experimental setup dedicated to highly charged ion trapping is presented in this work. The final goal is to perform lifetime measurement of metastable states produced by our ECR (Electron Cyclotron Resonance) ion source. Lifetimes to be measured are in the range of a few ms and more. We have measured the lifetimes of the M1 transitions of the metastable states of Ar{sup 9+}, Ar{sup 13+} and Ar{sup 14+}. These measurements are useful to test the N-body problem in the relativistic range. The trap we have built, was designed a few years ago at the Weizman Institute in Israel, it allows ions with an energy of several keV to be trapped for lifetimes of about 1 second. This trap was originally designed to study the dynamics of excited molecules. We have shown for the first time how the trap operates and that it can operate with highly charged ions. We have studied the beam dynamics of highly charged ions and the trap has been tested with various species of ions and different charge states: from O{sup +} to O{sup 6+}, from Ar{sup 8+} to Ar{sup 13+}, and from Kr{sup 13+} to Kr{sup 20+}.

  16. Ion distribution dynamics near the Earth's bow shock: first measurements with the 2D ion energy spectrometer CORALL on the INTERBALL/Tail-probe satellite

    Directory of Open Access Journals (Sweden)

    Yu. I. Yermolaev

    1997-05-01

    Full Text Available The dynamics of the ion distribution function near the Earth's bow shock is studied on the basis of quasi-3D measurements of ion energy spectra in the range of 30–24200 eV/q with the Russian-Cuban CORALL instrument on the INTERBALL/Tail-probe satellite. The instrument was designed for observations of magnetospheric plasma and measures ions, in an angular range of 36°–144° from the Earth-Sun direction. Ion populations generated by the Earth bow shock are often observed upstream from the bow shock. In the solar-wind stream compressed and heated by the passing of very dense magnetic cloud (CME, two types of these ion populations were measured upstream and before the bow shock crossing on 25 August 1995 at 07:37 UT. Both populations were observed in the energy range above 2 keV. At ~06:20 UT, when the angle between the direction of the interplanetary magnetic field and normal to the bow shock VBn was ≃ 43° the instrument observed a narrow, fast (~800 km/s field-aligned beam moving from the Earth. At ~07:30, when Bn ≃ 28°, the wide ion pitch-angle distribution was observed. A similar suprathermal ion population is observed in the magnetosheath simultaneously with the solar-wind ion population being heated and deflected from the Sun-Earth direction. The similarity of observations during the mentioned time-interval and under usual solar-wind conditions allows us to conclude that types of suprathermal ion populations upstream and downstream from the bow shock do not depend on the solar-wind disturbance generated by magnetic cloud.

  17. Conserved charge fluctuations using the D measure in heavy-ion collisions

    Science.gov (United States)

    Mishra, D. K.; Netrakanti, P. K.; Garg, P.

    2017-05-01

    We study the net-charge fluctuation D -measure variable, in high-energy heavy-ion collisions in heavy-ion jet interaction generator (HIJING), ultrarelativistic quantum molecular dynamics (UrQMD), and hadron resonance gas (HRG) models for various center-of-mass energies (√{sNN}). The effects of kinematic acceptance and resonance decay, in the pseudorapidity acceptance interval (Δ η ) and lower transverse momentum (pTmin) threshold, on fluctuation measures are discussed. A strong dependence of D with the Δ η in HIJING and UrQMD models is observed as opposed to results obtained from the HRG model. The dissipation of fluctuation signal is estimated by fitting the D measure as a function of the Δ η . An extrapolated function for higher Δ η values at lower √{sNN} is different from the results obtained from models. Particle species dependence of D and the effect of the pTmin selection threshold are discussed in HIJING and HRG models. The comparison of D , at midrapidity, of net-charge fluctuations at various √{sNN} obtained from the models with the data from the A Large Ion Collider Experiment (ALICE) experiment is discussed. The results from the present paper as a function of Δ η and √{sNN} will provide a baseline for comparison to experimental measurements.

  18. Development of the temperature measurement device for the positive ion insensitive to the probe contamination

    International Nuclear Information System (INIS)

    Minami, Shigeyuki; Tsutsumi, Shiro; Takeya, Yoshio

    1978-01-01

    The contamination effect to the d.c. probe in the plasma diagnostics is quite serious in the low density plasma. It causes the distortion or hysterisis curves on the probe characteristics. In order to escape it, for the Langmuir probe measurements, methods of high speed sweeping of probe voltage and using the cleaned probe are reported. In this paper, we dealed with the results of experimental examinations of the possibilities and the limitation of the application of above sweeping to the ion temperature measurement. The essential difficulties of the ion parameter measurements to the d.c. probe of the electrons that very small signal currents and the strong capacitance of the electrodes makes the large time constant, is solved by the use of the neutralization circuits. By this neutralization, high speed voltage sweeping can be possible, and high time resolution of the parameters can be obtained. Using this merits, when the probe is boarded on the space craft, this high space resolution of this probe has additive merits about the possibilities of the aspect measurements of plasma flow and the probe. It is concluded that the high scan rate ion trap is useful of the space craft to the erronious probing by the use of uncleaned probe. (author)

  19. Numerical simulations of fast ion loss measurements induced by magnetic islands in the ASDEX Upgrade tokamak

    International Nuclear Information System (INIS)

    Gobbin, M.; Marrelli, L.; Martin, P.; Fahrbach, H.U.; Garcia-Munoz, M.; Guenter, S.; White, R.B.

    2009-01-01

    A test particle approach, implemented with the Hamiltonian code ORBIT, is used to simulate measurements of fast ion losses induced by magnetic islands in the ASDEX Upgrade tokamak. In particular, the numerical simulations reproduce the toroidal localization of losses and the lost ions pitch angle and energy distribution experimentally measured with the fast ion losses detector (FILD) in the presence of a neoclassical tearing mode (NTM). The simulated NTM induced losses occurring on time scales longer than 100 μs are composed of mainly trapped or barely passing particles, consistently with the slow decay of the experimental signal from one FILD channel after the beam switch-off. The numerical simulations have been performed by taking into account the D-shaped plasma geometry, the collision mechanisms, the losses due to ripple effects and the rotation of the mode. The radial profile of the magnetic perturbation is adjusted in order to match ECE measurements. While statistical properties of FILD measurements are rather well reproduced, the simulated total amount of losses is found to be significantly affected by edge details of the magnetic perturbation as it determines the loss mechanism.

  20. Prototype development or multi-cavity ion chamber for depth dose measurement

    International Nuclear Information System (INIS)

    Nayak, M.K.; Sahu, T.K.; Haridas, G.; Bandyopadhyay, Tapas; Tripathi, R.M.; Nandedkar, R.V.

    2016-01-01

    In high energy electron accelerators, when the electrons interact with vacuum chamber or surrounding structural material, Bremsstrahlung x-rays are produced. It is having a broad spectrum extending up to the electron energies. Dose measured as a function of depth due to electromagnetic cascade will give rise to depth dose curve. To measure the online depth dose profile in an absorber medium, when high energy electron or Bremsstrahlung is incident, a prototype Multi-Cavity Ion Chamber (MCIC) detector is developed. The paper describes the design and development of the MCIC for measurement of depth dose profile

  1. CW gain measurements in small-bore argon-ion laser discharges using a novel modulation technique

    International Nuclear Information System (INIS)

    Bennett, W.R. Jr.; Sze, R.C.

    1974-01-01

    A technique for small-signal gain measurements for cw laser systems is described. The method is applied to the measurement of multimode small-signal gain coefficients of small-bone argon-ion laser transitions. (U.S.)

  2. Characterization of aerosol photooxidation flow reactors: heterogeneous oxidation, secondary organic aerosol formation and cloud condensation nuclei activity measurements

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2011-03-01

    Full Text Available Motivated by the need to develop instrumental techniques for characterizing organic aerosol aging, we report on the performance of the Toronto Photo-Oxidation Tube (TPOT and Potential Aerosol Mass (PAM flow tube reactors under a variety of experimental conditions. The PAM system was designed with lower surface-area-to-volume (SA/V ratio to minimize wall effects; the TPOT reactor was designed to study heterogeneous aerosol chemistry where wall loss can be independently measured. The following studies were performed: (1 transmission efficiency measurements for CO2, SO2, and bis(2-ethylhexyl sebacate (BES particles, (2 H2SO4 yield measurements from the oxidation of SO2, (3 residence time distribution (RTD measurements for CO2, SO2, and BES particles, (4 aerosol mass spectra, O/C and H/C ratios, and cloud condensation nuclei (CCN activity measurements of BES particles exposed to OH radicals, and (5 aerosol mass spectra, O/C and H/C ratios, CCN activity, and yield measurements of secondary organic aerosol (SOA generated from gas-phase OH oxidation of m-xylene and α-pinene. OH exposures ranged from (2.0 ± 1.0 × 1010 to (1.8 ± 0.3 × 1012 molec cm−3 s. Where applicable, data from the flow tube reactors are compared with published results from the Caltech smog chamber. The TPOT yielded narrower RTDs. However, its transmission efficiency for SO2 was lower than that for the PAM. Transmission efficiency for BES and H2SO4 particles was size-dependent and was similar for the two flow tube designs. Oxidized BES particles had similar O/C and H/C ratios and CCN activity at OH exposures greater than 1011 molec cm−3 s, but different CCN activity at lower OH exposures. The O/C ratio, H/C ratio, and yield of m-xylene and α-pinene SOA was strongly affected by reactor design and

  3. Drift tube measurements of mobilities and longitudinal diffusion coefficients of ions in gases

    International Nuclear Information System (INIS)

    Chelf, R.D.

    1982-01-01

    The zero-field mobilities of Br - and NH 4+ in O 2 were determined as a function of gas temperature in a high pressure drift tube mass spectrometer. The mobilities and longitudinal diffusion coefficients of the ion-gas combinations Br - in Ne and Kr, Li + in Xe, and Tl/ + in Kr and Xe were determined as a function of E/N, where E is the electric field strength and N is the gas number density in a low pressure drift tube mass spectrometer. The measured longitudinal diffusion coefficients were used for a test and comparison of the generalized Einstein relations of Viehland-Mason and Waldman-Mason theories. The measured mobilities of Br - in Kr and Tl/ + in Kr were used in an iterative-inversion scheme from which the ion-neutral interaction potentials were determined

  4. Neutron activation system for spectral measurements of pulsed ion diode neutron production

    International Nuclear Information System (INIS)

    Hanson, D.L.; Kruse, L.W.

    1980-02-01

    A neutron energy spectrometer has been developed to study intense ion beam-target interactions in the harsh radiation environment of a relativistic electron beam source. The main component is a neutron threshold activation system employing two multiplexed high efficiency Ge(Li) detectors, an annihilation gamma coincidence system, and a pneumatic sample transport. Additional constraints on the neutron spectrum are provided by total neutron yield and time-of-flight measurements. A practical lower limit on the total neutron yield into 4π required for a spectral measurement with this system is approx. 10 10 n where the neutron yield is predominantly below 4 MeV and approx. 10 8 n when a significant fraction of the yield is above 4 MeV. Applications of this system to pulsed ion diode neutron production experiments on Hermes II are described

  5. Prospects for ion temperature measurements in JET by Thomson scattering of submillimetre waves

    International Nuclear Information System (INIS)

    Whitbourn, L.B.

    1975-03-01

    The Thomson scattering of submillimeter waves is envisaged as a possible means for measuring the ion temperature of the JET plasma. The present discussion is principally concerned with the practical limitations imposed to the method by the availability of high power pulsed sources and sensitive detectors and noise due to plasma emission at submillimeter wavelengths (bremsstrahlung and electron cyclotron emission). Coherent scattering from plasma wave (e.g. ion acoustic waves and electron drift waves) with millimeter and submillimeter waves are considered briefly. Further suitable development of lasers and heterodyne detectors would make such measurements possible. A pulsed HCN laser associated with a detectors with a lower heterodyne noise equivalent power could then be used to advantage. For scattering with CH 3 F laser the NEP of a Josephson junction would be adequate because a relatively high level of plasma emission is expected at 496 μm [fr

  6. Kappa distributions in Saturn's magnetosphere: energetic ion moments using Cassini/MIMI measurements

    Science.gov (United States)

    Dialynas, K.; Roussos, E.; Regoli, L.; Paranicas, C.; Krimigis, S. M.; Kane, M.; Mitchell, D. G.; Hamilton, D. C.

    2017-12-01

    Moments of the charged particle distribution function are a compact way of characterizing some of the properties of different magnetospheric regions. Following our previous analyses (Dialynas et al. 2009) and the techniques described in Dialynas et al. (2017), in the present study we use κ-Distribution fits to combine CHEMS (3 to 236 keV/e), LEMMS (0.024 220 keV) H+ and O+ energetic ion spectra covering measurements made in 2004-2016 to calculate the >20 keV energetic ion moments inside Saturn's magnetosphere. We use the Khurana et al. [2007] magnetic field model to map the ion measurements to the equatorial plane and produce the equatorial distributions of all ion integral moments, focusing on partial density (n), integral intensity (In), partial pressure (P), integral energy intensity (IE); as well as the characteristic energy (Ec=Ie/In), Temperature and κ-index of these ions as a function of Local Time (00:00 to 24:00 hrs) and L-Shell (5-20 Rs). The Roelof and Skinner [2000] model is then utilized to retrieve the equatorial H+ and O+ P, n and T in both local time and L-shell. We find that a) although the PH+ and PO+ are nearly comparable, H+ have higher IE and In at all radial distances (L>5) and local times; b) the 12Η+, ΓΟ+), are consistent with the Arridge et al. [2009] results. Dialynas K. et al. 2009, JGR, 114, A01212 Dialynas K. et al. 2017, Elsevier, ISBN: 9780128046388 Khurana K. K. et al. 2007, AGU, abstract #P44A-01 Roelof E. & A. Skinner 2000, SSR, 91, 437-459 Arridge C. S. et al. 2009, PSS, 57, 2032-2047

  7. Heavy ion effects on mammalian cells: Inactivation measurements with different cell lines

    International Nuclear Information System (INIS)

    Wulf, H.; Kraft-Weyrather, W.; Miltenburger, H.G.; Kraft, G.

    1985-07-01

    In track segment experiments, the inactivation of different mammalian cells by heavy charged particles between helium and uranium in the energy range between 1 and 1000 MeV/u has been measured at the heavy ion accelerator Unilac, Darmstadt, the Tandem Van de Graaf, Heidelberg and the Bevalac, Berkeley. The inactivation cross sections calculated from the final slope of the dose effect curves are given as a function of the particle energy and the LET. (orig.)

  8. A review of the methods to measure the ion temperature in a tokamak plasma

    International Nuclear Information System (INIS)

    Zurro Hernandez, B.; Perez-Navarro Gomez, A.

    1976-01-01

    The most important methods to measure the ion temperatu--re in a Tokamak plasma are reviewed, e.g. energy analysis of the fast neutrals which leave out the plasma, Doppler broadening of the emision spectral lines and fusion neutron analysis. It is discussed their bounds so as the advantages and drawbacks of each one. Other methods of some interest in the future are outlined. (author) [es

  9. Thermal conductivity measurement of the He-ion implanted layer of W using transient thermoreflectance technique

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Shilian; Li, Yuanfei [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang, Zhigang [Department of Electronic Engineering, Dalian University of Technology, Dalian 116024 (China); Jia, Yuzhen [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213 (China); Li, Chun [School of Mechanical and Materials Engineering, North China University of Technology, Beijing 100144 (China); Xu, Ben; Chen, Wanqi [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Bai, Suyuan [School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China); Huang, Zhengxing; Tang, Zhenan [Department of Electronic Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, Wei, E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2017-02-15

    Transient thermoreflectance method was applied on the thermal conductivity measurement of the surface damaged layer of He-implanted tungsten. Uniform damages tungsten surface layer was produced by multi-energy He-ion implantation with thickness of 450 nm. Result shows that the thermal conductivity is reduced by 90%. This technique was further applied on sample with holes on the surface, which was produced by the He-implanted at 2953 K. The thermal conductivity decreases to 3% from the bulk value.

  10. Direct measurement of the concentration of metastable ions produced from neutral gas particles using laser-induced fluorescence

    Science.gov (United States)

    Chu, Feng; Skiff, Fred; Berumen, Jorge; Mattingly, Sean; Hood, Ryan

    2017-10-01

    Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastables that are produced from neutral gas particles and existing ions in other electronic states. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal. The results show that under circumstances where the metastable ion population is coming directly from the ionization of neutrals (as opposed to the excitation of ground-state ions), the velocity distribution will only faithfully represent processes which act on the ion dynamics in a time shorter than the metastable lifetime. Therefore, it is important to know the ratio of metastable population coming from neutrals to that from existing ions to correct the LIF measurements of plasma ion temperature and electrostatic waves. In this paper, we experimentally investigate the ratio of these two populations by externally launching an ion acoustic wave and comparing the wave amplitudes that are measured with LIF and a Langmuir probe using a lock-in amplifier. DE-FG02-99ER54543.

  11. Measurements with vertically viewing charge exchange analyzers during ion cyclotron range of frequencies heating in TFTR

    International Nuclear Information System (INIS)

    Kaita, R.; Hammett, G.W.; Gammel, G.; Goldston, R.J.; Medley, S.S.; Scott, S.D.; Young, K.M.

    1988-01-01

    The utility of charge exchange neutral particle analyzers for studying energetic ion distributions in high-temperature plasmas has been demonstrated in a variety of tokamak experiments. Power deposition profiles have been estimated in the Princeton large torus (PLT) from particle measurements as a function of energy and angle during heating in the ion cyclotron range of frequencies (ICRF) and extensive studies of this heating mode are planned for the upcoming operational period in the tokamak fusion test reactor (TFTR). Unlike the horizontally scanning analyzer on PLT, the TFTR system consists of vertical sightlines intersecting a poloidal cross section of the plasma. A bounce-averaged Fokker--Planck program, which includes a quasilinear operator to calculate ICRF-generated energetic ions, is used to simulate the charge exchange flux expected during fundamental hydrogen heating. These sightlines also cross the trajectory of a diagnostic neutral beam (DNB), and it may be possible to observe the fast ion tail during 3 He minority heating, if the DNB is operated in helium for double charge exchange neutralization

  12. Precision Isotope Shift Measurements in Calcium Ions Using Quantum Logic Detection Schemes.

    Science.gov (United States)

    Gebert, Florian; Wan, Yong; Wolf, Fabian; Angstmann, Christopher N; Berengut, Julian C; Schmidt, Piet O

    2015-07-31

    We demonstrate an efficient high-precision optical spectroscopy technique for single trapped ions with nonclosed transitions. In a double-shelving technique, the absorption of a single photon is first amplified to several phonons of a normal motional mode shared with a cotrapped cooling ion of a different species, before being further amplified to thousands of fluorescence photons emitted by the cooling ion using the standard electron shelving technique. We employ this extension of the photon recoil spectroscopy technique to perform the first high precision absolute frequency measurement of the 2D(3/2)→2P(1/2) transition in calcium, resulting in a transition frequency of f=346 000 234 867(96)  kHz. Furthermore, we determine the isotope shift of this transition and the 2S(1/2)→2P(1/2) transition for 42Ca+, 44Ca+, and 48Ca+ ions relative to 40Ca+ with an accuracy below 100 kHz. Improved field and mass shift constants of these transitions as well as changes in mean square nuclear charge radii are extracted from this high resolution data.

  13. Measurements on rotating ion cyclotron range of frequencies induced particle fluxes in axisymmetric mirror plasmas

    International Nuclear Information System (INIS)

    Hatakeyama, R.; Hershkowitz, N.; Majeski, R.; Wen, Y.J.; Brouchous, D.B.; Proberts, P.; Breun, R.A.; Roberts, D.; Vukovic, M.; Tanaka, T.

    1997-01-01

    A comparison of phenomenological features of plasmas is made with a special emphasis on radio-frequency induced transport, which are maintained when a set of two closely spaced dual half-turn antennas in a central cell of the Phaedrus-B axisymmetric tandem mirror [J. J. Browning et al., Phys. Fluids B 1, 1692 (1989)] is phased to excite electromagnetic fields in the ion cyclotron range of frequencies (ICRF) with m=-1 (rotating with ions) and m=+1 (rotating with electrons) azimuthal modes. Positive and negative electric currents are measured to flow axially to the end walls in the cases of m=-1 and m=+1 excitations, respectively. These parallel nonambipolar ion and electron fluxes are observed to be accompanied by azimuthal ion flows in the same directions as the antenna-excitation modes m. The phenomena are argued in terms of radial particle fluxes due to a nonambipolar transport mechanism [Hojo and Hatori, J. Phys. Soc. Jpn. 60, 2510 (1991); Hatakeyama et al., J. Phys. Soc. Jpn. 60, 2815 (1991), and Phys. Rev. E 52, 6664 (1995)], which are induced when azimuthally traveling ICRF waves are absorbed in the magnetized plasma column. copyright 1997 American Institute of Physics

  14. Precise measurements of energy loss straggling for swift heavy ions in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Bindu [Department of Physics, Kurukshetra University, Kurukshetra 136 119 (India); Neetu [Department of Physics, S.D College, Panipat 132103 (India); Sharma, Kalpana [Department of Physics, CMR Institute of Technology, Bangalore 560037 (India); Diwan, P.K. [Department of Applied Sciences, UIET, Kurukshetra University, Kurukshetra 136 119 (India); Kumar, Shyam, E-mail: profshyam@gmail.com [Department of Physics, Kurukshetra University, Kurukshetra 136 119 (India)

    2016-11-15

    The energy loss straggling measurements for heavy ions with Z = 3–22 (∼0.2–2.5 MeV/u) in PEN (C{sub 7}H{sub 5}O{sub 2}) and PET (C{sub 10}H{sub 8}O{sub 4}) polymers have been carried out utilizing the swift heavy ion beam facility from 15UD Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi, India. The recorded spectra are analyzed in such a way that the Straggling associated with energy loss process could be measured in a systematic manner at any selected value of energy, in terms of per unit thickness of the absorber, at any desired energy intervals. The measured values have been compared with the calculated values obtained from the most commonly used Bethe-Livingston formulations applicable for collisional straggling. The results are tried to be understood in terms of the effective charge on the impinging ion within the absorber. Some interesting trends are observed.

  15. Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen

    Science.gov (United States)

    Draganic, I. N.; Havener, C. C.; Schultz, D. R.; Seely, D. G.; Schultz, P. C.

    2011-05-01

    Total cross sections of charge exchange (CX) for C5+, N6+, and O7+ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H+ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close-coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations. Work supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, and the Office of Basic Energy Sciences of the U.S. DoE.

  16. Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

    Science.gov (United States)

    Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

    2006-03-01

    We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

  17. Surface potential measurement of insulators in negative-ion implantation by secondary electron energy-peak shift

    International Nuclear Information System (INIS)

    Nagumo, Shoji; Toyota, Yoshitaka; Tsuji, Hiroshi; Gotoh, Yasuhito; Ishikawa, Junzo; Sakai, Shigeki; Tanjyo, Masayasu; Matsuda, Kohji.

    1993-01-01

    Negative-ion implantation is expected to realize charge-up free implantation. In this article, about a way to specify surface potential of negative-ion implanted insulator by secondary-electron-energy distribution, its principle and preliminary experimental results are described. By a measuring system with retarding field type energy analyzer, energy distribution of secondary electron from insulator of Fused Quartz in negative-carbon-ion implantation was measured. As a result the peak-shift of its energy distribution resulted according with the surface potential of insulator. It was found that surface potential of insulator is negatively charged by only several volts. Thus, negative-ion implanted insulator reduced its surface charge-up potential (without any electron supply). Therefore negative-ion implantation is considered to be much more effective method than conventional positive-ion implantation. (author)

  18. Measuring GAMMA 10 end-loss ions with an ELIS [end-loss-ion spectrometers] from TMX-U

    International Nuclear Information System (INIS)

    Foote, J.H.

    1987-01-01

    The author spent the period from March 22 to July 10, 1987, at the GAMMA 10 tandem-mirror experiment at the University of Tsukuba in Tsukuba, Japan. The purpose of this extended trip was to install on GAMMA 10 one of the end-loss-ion spectrometers (ELIS) used on TMX-U (Tandem Mirror Experiment-Upgrade) at LLNL and to make plasma measurements there with this diagnostic instrument. This report discusses the considerable planning and preparations that preceded the trip, the actual experience with the ELIS equipment at GAMMA 10, data and results obtained while the author was there, GAMMA 10 experimental procedures, the scientific and technical support during the stay, and some final comments and suggestions concerning an international exchange such as this one. The data acquired on GAMMA 10 while there, along with earlier data, present an encouraging picture of a plasma in a thermal-barrier mode in a tandem-mirror, magnetic-fusion machine. 6 refs

  19. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...

  20. Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Kaita, R.; Takahashi, H.; Gammel, G.; Hammett, G.W.; Kaye, S.

    1987-01-01

    During tangential injection of neutral beams into low density tokamak plasmas with β > 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists

  1. Measuring the radial density distribution of light emission around the track of fast ions in nitrogen

    International Nuclear Information System (INIS)

    Ibach, T.

    1983-01-01

    For analysing the emission and stopping of ionization electrons (σ-electrons) emitted by fast ions passing through a gas, the radial density distribution of the light emission of the (0,0) transition of two optical bands in nitrogen have been measured. The systems selected for the epxeriments are the 2nd positive system (2.PS) at 337.1 nm primarily excited by low-energy electrons of about 20 eV, and the first negative system (1.NS) at 391.4 nm excited by faster electrons and simultaneous ionization. The equipment developed for the experiments records the light emission with a telescope-type optical arrangement including interference filters, allowing high local resolution and dynamics of the measured range. The measurements have been carried out at pressures between 0.133 and 13.3 mbar, using photons of energies ranging from 270 keV to 2.8 MeV, helium 3 beams of 270 keV/u and 500 keV/u, and neon beams of 270 keV/u. Abel's inversion applied to the distance functions allows calculation of the spatial light emission density which is normalized for a gas density of 1 g/cm 3 . The profiles of the two bands indicate that the σ-electron spectrum gets harder in outward direction. Next to the beam the impact density decreases faster with increasing ion energy than the stopping power (increasing interaction range of the σ-electrons). With photon beams, about half of the whole light emission in the 1. NS, and of the ionization, is induced by primary interactions of the ion beam. This proportion decreases at constant energy per nucleon with increasing atomic number of the ions as compared with the σ-electrons. The primary σ-emission gets harder with higher atomic numbers. (orig./HP) [de

  2. Direct Measurement of Neutral/Ion Beam Power using Thermocouple Analysis

    International Nuclear Information System (INIS)

    Day, I.; Gee, S.

    2006-01-01

    Modern Neutral Beam Injection systems such as those used on JET and MAST routinely use thermocouples embedded close to the surface of beam stopping elements, such as calorimeters and ion dumps, coupled to high speed data acquisition systems to determine beam profile and position from temperature rise data. With the availability of low cost data acquisition and storage systems it is now possible to record data from all thermocouples in a fully instrumented calorimeter or ion dump on 20 ms timescales or better. This sample rate is sufficiently fast to enable the thermocouple data to be used to calculate the incident power density from 1d heat transfer theory. This power density data coupled with appropriate Gaussian fits enables the determination of the 2d beam profile and thus allows an instantaneous and direct measurement of beam power. The theory and methodology required to analyse the fast thermocouple data from the MAST calorimeter and residual ion dump thermocouples is presented and direct measurements of beam power density are demonstrated. The power of desktop computers allows such analysis to be carried out virtually instantaneously. The methods used to automate this analysis are discussed in detail. A code, utilising the theory and methodology, has been developed to allow immediate measurements of beam power on a pulse by pulse basis. The uncertainty in determining the beam power density is shown to be less than 10 %. This power density data is then fitted to a 2d Gaussian beam profile and integrated to establish the total beam power. Results of this automated analysis for the neutral beam and residual ion power of the MAST duopigatron and PINI NBI systems are presented. This technology could be applied to a beam power safety interlock system. The application to a beam shine through protection system for the inner wall of the JET Tokamak is discussed as an example. (author)

  3. A first comparison of irregularity and ion drift velocity measurements in the E-region

    Directory of Open Access Journals (Sweden)

    R. A. Makarevich

    2006-09-01

    Full Text Available E-region irregularity velocity measurements at large flow angles with the STARE Finland coherent VHF radar are considered in context of the ion and electron velocity data provided by the EISCAT tristatic radar system, CUTLASS Finland coherent HF radar, and IMAGE fluxgate magnetometers. The data have been collected during a special experiment on 27 March 2004 during which EISCAT was scanning between several E- and one F-region altitudes along the magnetic field line. Within the E-region, the EISCAT measurements at two altitudes of 110 and 115 km are considered while the electron velocity is inferred from the EISCAT ion velocity measurements at 278 km. The line-of-sight (l-o-s VHF velocity measured by STARE VHF los is compared to the ion and electron velocity components (Vi0 comp and Ve0 comp along the STARE l-o-s direction. The comparison with Ve0 comp for the entire event shows that the measurements exhibit large scatter and small positive correlation. The correlation with Ve0 comp was substantial in the first half of the interval under study when Ve0 comp was larger in magnitude. The comparison with Vi0 comp at 110 and 115 km shows a considerable positive correlation, with VHF velocity being typically larger (smaller in magnitude than Vi0 comp at 110 km (115 km so that VVHF los appears to be bounded by the ion velocity components at two altitudes. It is also demonstrated that the difference between VVHF los and Vi0 comp at 110 km can be treated, in the first approximation, as a linear function of the effective backscatter height heff also counted from 110 km; heff varies in the range 108–114 km due to the altitude integration effects in the scattering cross-section. Our results are consistent with the notion that VHF

  4. Winter nightime ion temperatures and energetic electrons from 0go 6 plasma measurements

    International Nuclear Information System (INIS)

    Sanatani, S.; Breig, E.L.

    1981-01-01

    This paper presents and discusses ion temperature and suprathermal electron flux data acquired with the retarding potential analyzer on board the ogo 6 satellite when it was in solar eclipse. Attention is directed to measurements in the 400- to 800-km height interval between midnight and predawn in the northern winter nonpolar ionosphere. Statistical analysis of data recorded during a 1-month time span permits a decoupling of horizontal and altitude effects. A distinct longitudinal variation is observed for ion temperature above 500 km, with a significant relative enhancement over the western North Altantic Altitude distributions of ion temperature are compatible with Millstone Hill profiles within the common region of this enhancement. Large fluxes of energetic electrons are observed and extend to mush lower geomagnetic latitudes in the same longitude sector. Both a direct correlation in magnitude and a strong similarity in spatial extent are demonstrated for these ion temperature and electron flux data. The location of the limiting low-altitude boundary for observation of the electron fluxes is variable, dependent on local time and season as well as longitude. Variations in this boundary are found to be consistent with a calculated conjugate solar zenith angle of 99 0 +- 2 0 describing photoproduction of energetic electrons in the southern hemisphere. The ogo 6 data are considered to be indicative of an energy source originating in the sunlit summer hemisphere and providing heat via transport of photoelectrons to a broad but preferential segment of the winter nighttime mid-latitude ionosphere. Ions at other longitudes are without access to this energy source and cool to near the neutral temperature at heights to above 800 km inthe predawn hours

  5. Basic experimental preparation for the measurement of the stopping power of heavy ions in matter

    International Nuclear Information System (INIS)

    Carvalho Brito Brum, H. de.

    1976-02-01

    To measure the stopping power of heavy ions in solid matter one must develop both an experimental apparatus and a data analysis program. This thesis discusses these preparatory works and the methods to be employed. The design, building and testing of a scattering chamber with many detectors; the preparation of thin solid films, their analysis by electron diffraction and their thickness measurements; the testing of the electronic system; the calibration of the 4 MeV Van de Graaf accelerator at PUC/RJ; and the development of an original data analysis computer program are presented. (Author) [pt

  6. Density and potential measurements in an intense ion-beam-generated plasma

    International Nuclear Information System (INIS)

    Abt, N.E.

    1982-05-01

    Neutral beams are created by intense large area ion beams which are neutralized in a gas cell. The interaction of the beam with the gas cell creates a plasma. Such a plasma is studied here. The basic plasma parameters, electron temperature, density, and plasma potential, are measured as a function of beam current and neutral gas pressure. These measurements are compared to a model based on the solution of Poisson's equation. Because of the cylindrical geometry the equation cannot be solved analytically. Details of the numerical method are presented

  7. Calibration of the photometric method of heavy ion charge measurements in emulsion using a CCD camera

    International Nuclear Information System (INIS)

    Kudzia, D.; Wilczynska, B.; Wilczynski, H.

    2002-01-01

    A previously developed method of heavy ion charge measurements in emulsion has been significantly improved. The charge measurements are based on analysis of photometric profiles of the particle tracks in emulsion. These profiles are obtained using a CCD camera mounted on an optical microscope. So far, the manual charge determination by delta ray counting had to be used for calibration of the photometric method. In this paper a complete procedure for calibration of the photometric method is shown, without resorting to the manual method

  8. Measurement of mobility profile in ion-implanted silicon layers using electroreflection spectroscopy

    International Nuclear Information System (INIS)

    Galiev, G.B.; Kapaev, V.V.; Mokerov, V.G.

    1986-01-01

    The possibility is shown of the application of the low field linearized electroreflection spectroscopy for the measurement of profiles of carriers mobilities μ(x) simultaneously with the concentration profiles N(x) in thin ion-implanted silicon layers. The μ(χ) value is determined from the calibration curve of the dependence of the phenomenological broadening parameter γ on the mobility for uniformly doped samples. The results are presented for the measurements of the profiles μ(x) for boron- and arsenic-implanted silicon

  9. Electric field simulation and measurement of a pulse line ion accelerator

    International Nuclear Information System (INIS)

    Shen Xiaokang; Zhang Zimin; Cao Shuchun; Zhao Hongwei; Zhao Quantang; Liu Ming; Jing Yi; Wang Bo; Shen Xiaoli

    2012-01-01

    An oil dielectric helical pulse line to demonstrate the principles of a Pulse Line Ion Accelerator (PLIA) has been designed and fabricated. The simulation of the axial electric field of an accelerator with CST code has been completed and the simulation results show complete agreement with the theoretical calculations. To fully understand the real value of the electric field excited from the helical line in PLIA, an optical electric integrated electric field measurement system was adopted. The measurement result shows that the real magnitude of axial electric field is smaller than that calculated, probably due to the actual pitch of the resister column which is much less than that of helix. (authors)

  10. Ion source plasma parameters measurement based on Langmuir probe with commercial frequency sweep

    International Nuclear Information System (INIS)

    Xie, Y.H.; Hu, C.D.; Liu, S.; Shong, S.H.; Jiang, C.C.; Liu, Z.M.

    2010-01-01

    Langmuir probe is one of the main diagnostic tools to measure the plasma parameters in the ion source. In this article, the commercial frequency power, which is sine wave of 50 Hz, was supplied on the Langmuir probe to measure the plasma parameters. The best feature of this probe sweep voltage is that it does not need extra design. The probe I-V characteristic curve can be got in less than 5 ms and the plasma parameters, the electron temperature and the electron density, varying with the time can be got in one plasma discharge of 400 ms.

  11. Measurement of the energy loss of heavy ions in laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch-Maas, Renate

    2009-11-25

    The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10{sup 22} cm{sup -3}. With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a

  12. Measurement of the energy loss of heavy ions in laser-produced plasmas

    International Nuclear Information System (INIS)

    Knobloch-Maas, Renate

    2009-01-01

    The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10 22 cm -3 . With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a diameter of only

  13. Measurement of the lifetime and the proportion of 12C3+ ions in stored relativistic ion beams as a preparation for laser cooling experiments at the CSRe

    Science.gov (United States)

    Wang, H. B.; Wen, W. Q.; Huang, Z. K.; Zhang, D. C.; Hai, B.; Zhu, X. L.; Zhao, D. M.; Yang, J.; Li, J.; Li, X. N.; Mao, L. J.; Mao, R. S.; Wu, J. X.; Yang, J. C.; Yuan, Y. J.; Eidam, L.; Winters, D.; Beck, T.; Kiefer, D.; Rein, B.; Walther, Th.; Loeser, M.; Schramm, U.; Siebold, M.; Bussmann, M.; Ma, X.

    2017-10-01

    We report on an experiment that was conducted in preparation of laser cooling experiments at the heavy-ion storage ring CSRe. The lifetimes of ion beams made up of 12C3+ and 16O4+ ions stored at an energy of 122 MeV/u in the CSRe were determined by two independent methods, firstly via a DC current transformer (DCCT) and secondly via a Schottky resonator. Using electron-cooling, the signals of the 12C3+ and 16O4+ ions could be separated and clearly observed in the Schottky spectrum. The obtained individual lifetimes of the 12C3+ and 16O4+ components were 23.6 s and 17.8 s, respectively. The proportion of 12C3+ ions in the stored ion beam was measured to be more than 70% at the beginning of the injection and increasing as a function of time. In addition to these measurements, the operation and remote control of a pulsed laser system placed directly next to the storage ring was tested in a setup similar to the one envisaged for future laser experiments.

  14. Precise measurements and theoretical calculations of He-like ion resonance line satellites radiated from Be-, B-, C-, N-, O-, and F-like ions

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Pikuz, S.A.; Shlyaptseva, A.S.

    1994-01-01

    Spectra with spectral resolution λ/Δλ∼ =3000-7000 in the vicinity of the He-like ion resonance lines Mg, Al, Si, P, S were obtained in CO 2 laser-produced plasma. The wavelengths of these satellites were measured and compared with numerical calculations. Identification of lines or a group of overlapping lines was performed. Twenty-two transitions of dielectronic satellites for Be-like ions, 41 transitions for B-like, 40 transitions for C-like, 22 transitions for N-like, 12 transitions for O-like ions and 2 transitions for F-like ions were identified. The average between theoretical and experimental wavelengths was ±(0.0005-0.001) A, but in some cases it was ±(0.002-0.003) A. (orig.)

  15. Precise measurements and theoretical calculations of He-like ion resonance line satellites radiated from Be-, B-, C-, N-, O-, and F-like ions

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya. [MISDC, NPO `VNIIFTRI`, Mendeleevo (Russian Federation); Pikuz, S.A. [P.N. Lebedev Physical Inst., Russian Academy of Sciences, Moscow (Russian Federation); Shlyaptseva, A.S. [Inst. of Technical Glasses, Moscow (Russian Federation)

    1994-01-01

    Spectra with spectral resolution {lambda}/{Delta}{lambda}{approx} =3000-7000 in the vicinity of the He-like ion resonance lines Mg, Al, Si, P, S were obtained in CO{sub 2} laser-produced plasma. The wavelengths of these satellites were measured and compared with numerical calculations. Identification of lines or a group of overlapping lines was performed. Twenty-two transitions of dielectronic satellites for Be-like ions, 41 transitions for B-like, 40 transitions for C-like, 22 transitions for N-like, 12 transitions for O-like ions and 2 transitions for F-like ions were identified. The average between theoretical and experimental wavelengths was {+-}(0.0005-0.001) A, but in some cases it was {+-}(0.002-0.003) A. (orig.).

  16. Ion cyclotron waves: Direct compariosn between ground-based measurements and observations in the source region

    International Nuclear Information System (INIS)

    Perraut, S.; Gendrin, R.; Roux, A.; de Villedary, C.

    1984-01-01

    Simultaneous measurements of ion cyclotron waves (ICW's) were performed on GEOS spacecraft and in the vicinity of their magnetic footprints with the French Mobile station. The detailed comparison between the two sets of data shown that while ICW's having F + gyrofrequency at the equator, generally propagate to the ground, only 50% of those generated above F/sub He/ can reach the ground station. It is shown that these results are in good agreement with the conclusions that Rauch and Roux [1982] drew on the basis of measurements reported by Young et al 1981]. In an He + -rich plasma, ICW's with F>F/sub He/ suffer a reflection where the frequency locally matches the local bi-ion hybrid frequency. We extend the calculations of Rauch and Roux and calculate, as a function of the He + concentration, the tunneling of ICW's through the stopband induced by the presence of minor He + ions. It is shown that the transmission coefficient strongly depends upon the wave frequency for a given He + abundance ratio. The results obtained are shown to be supported by existing observations

  17. Noncontact measurement of electrostatic fields: Verification of modeled potentials within ion mobility spectrometer drift tube designs

    International Nuclear Information System (INIS)

    Scott, Jill R.; Tremblay, Paul L.

    2007-01-01

    The heart of an ion mobility spectrometer is the drift region where ion separation occurs. While the electrostatic potentials within a drift tube design can be modeled, no method for independently validating the electrostatic field has previously been reported. Two basic drift tube designs were modeled using SIMION 7.0 to reveal the expected electrostatic fields: (1) A traditional alternating set of electrodes and insulators and (2) a truly linear drift tube. One version of the alternating electrode/insulator drift tube and two versions of linear drift tubes were then fabricated. The stacked alternating electrodes/insulators were connected through a resistor network to generate the electrostatic gradient in the drift tube. The two linear drift tube designs consisted of two types of resistive drift tubes with one tube consisting of a resistive coating within an insulating tube and the other tube composed of resistive ferrites. The electrostatic fields within each type of drift tube were then evaluated by a noncontact method using a Kelvin-Zisman type electrostatic voltmeter and probe (results for alternative measurement methods provided in supplementary material). The experimental results were then compared with the electrostatic fields predicted by SIMION. Both the modeling and experimental measurements reveal that the electrostatic fields within a stacked ion mobility spectrometer drift tube are only pseudo-linear, while the electrostatic fields within a resistive drift tube approach perfect linearity

  18. Spectroscopic Measurements of the Ion Velocity Distribution at the Base of the Fast Solar Wind

    Science.gov (United States)

    Jeffrey, Natasha L. S.; Hahn, Michael; Savin, Daniel W.; Fletcher, Lyndsay

    2018-03-01

    In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons, and minor ions extending from 0.3 au to the heliopause. The physical mechanisms responsible for these non-thermal properties and the location where these properties originate remain open questions. Here, we present spectroscopic evidence, from extreme ultraviolet spectroscopy, that the velocity distribution functions (VDFs) of minor ions are already non-Gaussian at the base of the fast solar wind in a coronal hole, at altitudes of thermal equilibrium, (b) fluid motions such as non-Gaussian turbulent fluctuations or non-uniform wave motions, or (c) some combination of both. These observations provide important empirical constraints for the source region of the fast solar wind and for the theoretical models of the different acceleration, heating, and energy deposition processes therein. To the best of our knowledge, this is the first time that the ion VDF in the fast solar wind has been probed so close to its source region. The findings are also a timely precursor to the upcoming 2018 launch of the Parker Solar Probe, which will provide the closest in situ measurements of the solar wind at approximately 0.04 au (8.5 solar radii).

  19. Measurement of charmonium production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00511724; The ATLAS collaboration

    2017-01-01

    The suppression of heavy charmonia states in heavy-ion collisions is a phenomenon understood as a consequence of quark gluon plasma formation in the hot, dense system formed in heavy ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect heavy charmonia production. Therefore, a full assessment requires detailed studies on the effects present in both A+A and p+A collisions. Based on p+Pb data collected in 2013 and pp and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt $J/\\psi$ and $\\psi$(2S) productions via the dimuon decay final states. The production and excited-to-ground state ratios of heavy charmonia measured in both p+Pb and Pb+Pb collision data with respect to that measured in pp collision data will be presented in intervals of transverse momentum, rapidity and centrality.

  20. Large-eddy simulations of surface-induced turbulence and its implications to the interpretation of eddy-covariance measurements in heterogeneous landscapes

    Science.gov (United States)

    Bohrer, G.; Kenny, W.; Morin, T. H.

    2015-12-01

    We used the RAMS-based Forest Large Eddy Simulations (RAFLES) to evaluate the sensitivity of eddy covariance measurements to land-surface discontinuity. While the sensitivity of eddy covariance measurements to surface heterogeneity is well known, it is, in most cases, no feasible to restrict measurements only to sites where the surface include undisturbed and homogeneous land cover over vast distances around the observation tower. The common approach to handle surface heterogeneity is to use a footprint model and reject observations obtained while the source of observed signal is from a mixture of land-use types, and maintain only measurements where the signal originates mostly from the land-use type of interest. We simulated two scenarios - measurements of fluxes from a small forest-surrounded lake, and measurements near a forest edge. These are two very common scenarios where measurements are bound to be affected by heterogeneity - measurements in small lakes, will, by definition, be in some non-negligible proximity or the lake edge; forest edges are common in any forest, near the forest patch edge but also around disturbed patches and forest gaps. We identify regions where the surface heterogeneity is creating persistent updraft or downdraft. A non-zero mean vertical wind is typically neglected in eddy-covariance measurements. We find that these circulations lead to both vertical and horizontal advection that cannot be easily measured by a single eddy-covariance tower. We identify downwind effects, which are well known, but also quantify the upwind effects. We find that surface-induced circulations may affect the flux measured from a tower up to several canopy heights ahead of the discontinuity. We used the High-resolution Volatile Organic Compound Atmospheric Chemistry in Canopies (Hi-VACC) model to determine the actual measurement footprints throughout the RAFLES domain. We estimated the land-cover type distribution of the source signal at different virtual

  1. Scale dependence of cirrus horizontal heterogeneity effects on TOA measurements – Part I: MODIS brightness temperatures in the thermal infrared

    Directory of Open Access Journals (Sweden)

    T. Fauchez

    2017-07-01

    Full Text Available This paper presents a study on the impact of cirrus cloud heterogeneities on MODIS simulated thermal infrared (TIR brightness temperatures (BTs at the top of the atmosphere (TOA as a function of spatial resolution from 50 m to 10 km. A realistic 3-D cirrus field is generated by the 3DCLOUD model (average optical thickness of 1.4, cloud-top and base altitudes at 10 and 12 km, respectively, consisting of aggregate column crystals of Deff = 20 µm, and 3-D thermal infrared radiative transfer (RT is simulated with the 3DMCPOL code. According to previous studies, differences between 3-D BT computed from a heterogenous pixel and 1-D RT computed from a homogeneous pixel are considered dependent at nadir on two effects: (i the optical thickness horizontal heterogeneity leading to the plane-parallel homogeneous bias (PPHB and the (ii horizontal radiative transport (HRT leading to the independent pixel approximation error (IPAE. A single but realistic cirrus case is simulated and, as expected, the PPHB mainly impacts the low-spatial-resolution results (above ∼ 250 m with averaged values of up to 5–7 K, while the IPAE mainly impacts the high-spatial-resolution results (below ∼ 250 m with average values of up to 1–2 K. A sensitivity study has been performed in order to extend these results to various cirrus optical thicknesses and heterogeneities by sampling the cirrus in several ranges of parameters. For four optical thickness classes and four optical heterogeneity classes, we have found that, for nadir observations, the spatial resolution at which the combination of PPHB and HRT effects is the smallest, falls between 100 and 250 m. These spatial resolutions thus appear to be the best choice to retrieve cirrus optical properties with the smallest cloud heterogeneity-related total bias in the thermal infrared. For off-nadir observations, the average total effect is increased and the minimum is shifted to coarser spatial

  2. A direct-measurement technique for estimating discharge-chamber lifetime. [for ion thrusters

    Science.gov (United States)

    Beattie, J. R.; Garvin, H. L.

    1982-01-01

    The use of short-term measurement techniques for predicting the wearout of ion thrusters resulting from sputter-erosion damage is investigated. The laminar-thin-film technique is found to provide high precision erosion-rate data, although the erosion rates are generally substantially higher than those found during long-term erosion tests, so that the results must be interpreted in a relative sense. A technique for obtaining absolute measurements is developed using a masked-substrate arrangement. This new technique provides a means for estimating the lifetimes of critical discharge-chamber components based on direct measurements of sputter-erosion depths obtained during short-duration (approximately 1 hr) tests. Results obtained using the direct-measurement technique are shown to agree with sputter-erosion depths calculated for the plasma conditions of the test. The direct-measurement approach is found to be applicable to both mercury and argon discharge-plasma environments and will be useful for estimating the lifetimes of inert gas and extended performance mercury ion thrusters currently under development.

  3. High-resolution spectroscopy diagnostics for measuring impurity ion temperature and velocity on the COMPASS tokamak

    International Nuclear Information System (INIS)

    Weinzettl, Vladimir; Shukla, Gaurav; Ghosh, Joydeep; Melich, Radek; Panek, Radomir; Tomes, Matej; Imrisek, Martin; Naydenkova, Diana; Varju, Josef; Pereira, Tiago; Gomes, Rui; Abramovic, Ivana; Jaspers, Roger; Pisarik, Michael; Odstrcil, Tomas; Van Oost, Guido

    2015-01-01

    Highlights: • We built a new diagnostic of poloidal plasma rotation on the COMPASS tokamak. • Improvements in throughput via toroidal integration and fiber optimizations shown. • Poloidal rotation and ion temperature measured in L- and H-mode and during RMP. • Design and parameters of a new CXRS diagnostic for COMPASS are introduced. - Abstract: High-resolution spectroscopy is a powerful tool for the measurement of plasma rotation as well as ion temperature using the Doppler shift of the emitted spectral lines and their Doppler broadening, respectively. Both passive and active diagnostic variants for the COMPASS tokamak are introduced. The passive diagnostic focused on the C III lines at about 465 nm is utilized for the observation of the poloidal plasma rotation. The current set-up of the measuring system is described, including the intended high-throughput optics upgrade. Different options to increase the fiber collection area are mentioned, including a flower-like fiber bundle, and the use of micro-lenses or tapered fibers. Recent measurements of poloidal plasma rotation of the order of 0–6 km/s are shown. The design of the new active diagnostic using a deuterium heating beam and based on charge exchange recombination spectroscopy (C VI line at 529 nm) is introduced. The tool will provide both space (0.5–5 cm) and time (10 ms) resolved toroidal plasma rotation and ion temperature profiles. The results of the Simulation of Spectra code used to examine the feasibility of charge exchange measurements on COMPASS are shown and connected with a selection of the spectrometer coupled with the CCD camera.

  4. High-resolution spectroscopy diagnostics for measuring impurity ion temperature and velocity on the COMPASS tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Weinzettl, Vladimir, E-mail: vwei@ipp.cas.cz [Institute of Plasma Physics ASCR, Prague (Czech Republic); Shukla, Gaurav [Institute of Plasma Physics ASCR, Prague (Czech Republic); Department of Applied Physics, Ghent University, Ghent (Belgium); Faculty of Mathematics and Physics, Charles University in Prague, Prague (Czech Republic); Ghosh, Joydeep [Institute for Plasma Research, Bhat, Gandhinagar (India); Melich, Radek; Panek, Radomir [Institute of Plasma Physics ASCR, Prague (Czech Republic); Tomes, Matej; Imrisek, Martin; Naydenkova, Diana [Institute of Plasma Physics ASCR, Prague (Czech Republic); Faculty of Mathematics and Physics, Charles University in Prague, Prague (Czech Republic); Varju, Josef [Institute of Plasma Physics ASCR, Prague (Czech Republic); Pereira, Tiago [Instituto de Plasmas e Fusão Nuclear, Lisboa (Portugal); Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Gomes, Rui [Instituto de Plasmas e Fusão Nuclear, Lisboa (Portugal); Abramovic, Ivana; Jaspers, Roger [Eindhoven University of Technology, Eindhoven (Netherlands); Pisarik, Michael [SQS Vlaknova optika a.s., Nova Paka (Czech Republic); Department of Electromagnetic Field, Faculty of Electrical Engineering, Czech Technical University in Prague (Czech Republic); Odstrcil, Tomas [Max-Planck-Institut fur Plasmaphysik, Garching (Germany); Van Oost, Guido [Department of Applied Physics, Ghent University, Ghent (Belgium)

    2015-10-15

    Highlights: • We built a new diagnostic of poloidal plasma rotation on the COMPASS tokamak. • Improvements in throughput via toroidal integration and fiber optimizations shown. • Poloidal rotation and ion temperature measured in L- and H-mode and during RMP. • Design and parameters of a new CXRS diagnostic for COMPASS are introduced. - Abstract: High-resolution spectroscopy is a powerful tool for the measurement of plasma rotation as well as ion temperature using the Doppler shift of the emitted spectral lines and their Doppler broadening, respectively. Both passive and active diagnostic variants for the COMPASS tokamak are introduced. The passive diagnostic focused on the C III lines at about 465 nm is utilized for the observation of the poloidal plasma rotation. The current set-up of the measuring system is described, including the intended high-throughput optics upgrade. Different options to increase the fiber collection area are mentioned, including a flower-like fiber bundle, and the use of micro-lenses or tapered fibers. Recent measurements of poloidal plasma rotation of the order of 0–6 km/s are shown. The design of the new active diagnostic using a deuterium heating beam and based on charge exchange recombination spectroscopy (C VI line at 529 nm) is introduced. The tool will provide both space (0.5–5 cm) and time (10 ms) resolved toroidal plasma rotation and ion temperature profiles. The results of the Simulation of Spectra code used to examine the feasibility of charge exchange measurements on COMPASS are shown and connected with a selection of the spectrometer coupled with the CCD camera.

  5. Measurements of beam current density and proton fraction of a permanent-magnet microwave ion source

    Energy Technology Data Exchange (ETDEWEB)

    Waldmann, Ole; Ludewigt, Bernhard [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2011-11-15

    A permanent-magnet microwave ion source has been built for use in a high-yield, compact neutron generator. The source has been designed to produce up to 100 mA of deuterium and tritium ions. The electron-cyclotron resonance condition is met at a microwave frequency of 2.45 GHz and a magnetic field strength of 87.5 mT. The source operates at a low hydrogen gas pressure of about 0.15 Pa. Hydrogen beams with a current density of 40 mA/cm{sup 2} have been extracted at a microwave power of 450 W. The dependence of the extracted proton beam fraction on wall materials and operating parameters was measured and found to vary from 45% for steel to 95% for boron nitride as a wall liner material.

  6. Measurements of beam current density and proton fraction of a permanent-magnet microwave ion source.

    Science.gov (United States)

    Waldmann, Ole; Ludewigt, Bernhard

    2011-11-01

    A permanent-magnet microwave ion source has been built for use in a high-yield, compact neutron generator. The source has been designed to produce up to 100 mA of deuterium and tritium ions. The electron-cyclotron resonance condition is met at a microwave frequency of 2.45 GHz and a magnetic field strength of 87.5 mT. The source operates at a low hydrogen gas pressure of about 0.15 Pa. Hydrogen beams with a current density of 40 mA/cm(2) have been extracted at a microwave power of 450 W. The dependence of the extracted proton beam fraction on wall materials and operating parameters was measured and found to vary from 45% for steel to 95% for boron nitride as a wall liner material. © 2011 American Institute of Physics

  7. A New Efficient Analytical Method for Picolinate Ion Measurements in Complex Aqueous Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Parazols, M.; Dodi, A. [CEA Cadarache, Lab Anal Radiochim and Chim, DEN, F-13108 St Paul Les Durance (France)

    2010-07-01

    This study focuses on the development of a new simple but sensitive, fast and quantitative liquid chromatography method for picolinate ion measurement in high ionic strength aqueous solutions. It involves cation separation over a chromatographic CS16 column using methane sulfonic acid as a mobile phase and detection by UV absorbance (254 nm). The CS16 column is a high-capacity stationary phase exhibiting both cation exchange and RP properties. It allows interaction with picolinate ions which are in their zwitterionic form at the pH of the mobile phase (1.3-1.7). Analysis is performed in 30 min with a detection limit of about 0.05 {mu}M and a quantification limit of about 0.15 {mu}M. Moreover, this analytical technique has been tested efficiently on complex aqueous samples from an effluent treatment facility. (authors)

  8. Progress toward a microsecond duration, repetitive, intense-ion beam for active spectroscopic measurements on ITER

    International Nuclear Information System (INIS)

    Davis, H.A.; Bartsch, R.R.; Barnes, C.W.

    1996-01-01

    The authors describe the design of an intense, pulsed, repetitive, neutral beam based on magnetically insulated diode technology for injection into ITER for spectroscopic measurements of thermalizing alpha particle and thermal helium density profiles, ion temperature, plasma rotation, and low Z impurity concentrations in the confinement region. The beam is being developed to enhance low signal-to-noise ratios expected with conventional steady-state ion beams because of severe beam attenuation and intense bremstrahlung emission. A 5 GW (e.g., 100 keV, 50 kA) one-microsecond-duration beam would increase the signal by 10 3 compared to a conventional 5 MW beam with signal-to-noise ratios comparable to those from a chopped conventional beam in one second

  9. Electron cloud measurements in heavy-ion driver for HEDP and inertial fusion energy

    International Nuclear Information System (INIS)

    Kireeff Covo, Michel; Molvik, Arthur W.; Friedman, Alex; Cohen, Ronald; Vay, Jean-Luc; Bieniosek, Frank; Baca, David; Seidl, Peter A.; Logan, Grant; Vujic, Jasmina L.

    2007-01-01

    The high-current experiment (HCX) at LBNL is a driver scale single beam injector that provides a 1 MeV K + ion beam current of 0.18 A for 5 μs. It transports high-current beams with large fill factor (ratio of the maximum beam envelope radius to the beam pipe radius) and low emittance growth that are required to keep the cost of the power plant competitive and to satisfy the target requirements of focusing ion beams to high-power density. Beam interaction with the background gas and walls desorbs electrons that can multiply and accumulate, creating an electron cloud. This ubiquitous effect grows at higher fill factors and degrades the quality of the beam. We review simulations and diagnostics tools used to measure electron production, accumulation and its properties

  10. Measurement of quarkonia production in heavy-ion collisions with the ATLAS detector

    CERN Document Server

    Kremer, Jakub Andrzej; The ATLAS collaboration

    2017-01-01

    The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in nucleus-nucleus collisions at the LHC. In addition to hot matter effects in heavy-ion collisions, cold nuclear effects may also affect quarkonia production. Therefore, a full assessment requires detailed studies on the effects present in both A+A and $\\textit{p}$+A collisions. Based on $\\textit{p}$+Pb data collected in 2013 and $\\textit{pp}$ and Pb+Pb data collected in 2015 at the LHC, the ATLAS experiment has studied prompt and non-prompt $J/\\psi$ and $\\psi\\left(2\\mathrm{S}\\right)$ productions as well as $\\Upsilon\\left(n\\mathrm{S}\\right)$ production via the di-muon decay final states. The results of the various measurements are discussed.

  11. Comet 73P Measurements of Solar Wind Interactions, Cometary Ion Pickup, and Spatial Distribution

    Science.gov (United States)

    Gilbert, J. A.; Lepri, S. T.; Rubin, M.; Combi, M. R.; Zurbuchen, T.

    2015-12-01

    Several fragments of Comet 73P/Schwassmann-Wachmann 3 passed near the Earth following a 2006 disintegration episode. Unique measurements regarding the charge state composition and the elemental abundances of both cometary and heliospheric plasma were made during this time by both the ACE/SWICS and Wind/STICS sensors. As the solar wind passed through the neutral cometary coma, it experienced charge exchange that was observed as an increase in the ratio of He+/He++. In addition, particles originating from fragments trailing the major cometary objects were ionized and picked up by the solar wind. The cometary material can be identified by the concentrations of water-group pickup ions having a mass-per-charge ratio of 16-18 amu/e, indicating that these are actively sublimating fragments. Here we present an analysis of cometary composition, spatial distribution, directionality, and heliospheric interactions with a focus on Helium, Carbon (C/O), and water-group ions.

  12. The measurement of acetanilide in plasma by spectrophotometric and selected ion monitoring methods.

    Science.gov (United States)

    Baty, J D; Playfer, J; Evans, D A; Lamb, J

    1977-08-01

    Plasma samples from volunteers who had received an oral dose of acetanilide have been analysed by gas chromatography mass spectrometry and ultraviolet absorption techniques. The gas chromatography mass spectrometry method involved extraction of the plasma and analysis of the acetanilide using selected ion monitoring with a deuterated internal standard. In the ultraviolet method the plasma was hydrolysed with acid to convert the acetanilide to aniline, and this compound was diazotized and coupled with N-1-naphthylethylene-diamine. The absorbance of the resulting complex was read at 550 nm. Acetanilide levels in plasma determined by the selected ion monitoring method were significantly lower than those measured by spectrophotometry. Pharmacokinetic data calculated from the results obtained using these two assays are very different and illustrate the need for an accurate and specific method of analysis. The major metabolites of acetanilide are shown not to interfere with these assays and the results suggest the possible presence of a new metabolite of acetanilide.

  13. Towards a Measurement of the n=2 Lamb Shift in Hydrogen-like Nitrogen Using an Electron Beam Ion Trap

    International Nuclear Information System (INIS)

    Hosaka, K.; Crosby, D. N.; Gaarde-Widdowson, K.; Smith, C. J.; Silver, J. D.; Myers, E. G.; Kinugawa, T.; Ohtani, S.

    2003-01-01

    Using a 14 C 16 O 2 laser the 2s 1/2 -2p 3/2 (fine structure - Lamb shift) transition has been induced in 14 N 6+ ions trapped in an electron beam ion trap. Prospects for a measurement of the Lamb shift in hydrogen-like nitrogen are discussed.

  14. Fast-ion redistribution due to sawtooth crash in the TEXTOR tokamak measured by collective Thomson scattering

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Bindslev, Henrik; Salewski, Mirko

    2010-01-01

    Here we present collective Thomson scattering measurements of 1D fast-ion velocity distribution functions in neutral beam heated TEXTOR plasmas with sawtooth oscillations. Up to 50% of the fast ions in the centre are redistributed as a consequence of a sawtooth crash. We resolve various directions...

  15. BRIEF COMMUNICATION: Fast-ion redistribution due to sawtooth crash in the TEXTOR tokamak measured by collective Thomson scattering

    Science.gov (United States)

    Nielsen, S. K.; Bindslev, H.; Salewski, M.; Bürger, A.; Delabie, E.; Furtula, V.; Kantor, M.; Korsholm, S. B.; Leipold, F.; Meo, F.; Michelsen, P. K.; Moseev, D.; Oosterbeek, J. W.; Stejner, M.; Westerhof, E.; Woskov, P.; TEXTOR Team

    2010-09-01

    Here we present collective Thomson scattering measurements of 1D fast-ion velocity distribution functions in neutral beam heated TEXTOR plasmas with sawtooth oscillations. Up to 50% of the fast ions in the centre are redistributed as a consequence of a sawtooth crash. We resolve various directions to the magnetic field. The fast-ion distribution is found to be anisotropic as expected. For a resolved angle of 39° to the magnetic field we find a drop in the fast-ion distribution of 20-40%. For a resolved angle of 83° to the magnetic field the drop is no larger than 20%.

  16. Measurement of the electron and ion temperatures by the x-ray imaging crystal spectrometer on joint Texas experimental tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Yan, W.; Chen, Z. Y., E-mail: zychen@hust.edu.cn; Huang, D. W.; Tong, R. H.; Wang, S. Y.; Wei, Y. N.; Ma, T. K.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Jin, W. [Center of Interface Dynamics for Sustainability, China Academy of Engineering Physics, Chengdu, Sichuan 610200 (China); Lee, S. G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Shi, Y. J. [Department of Nuclear Engineering, Seoul National University, Seoul 08826 (Korea, Republic of)

    2016-11-15

    An x-ray imaging crystal spectrometer has been developed on joint Texas experimental tokamak for the measurement of electron and ion temperatures from the K{sub α} spectra of helium-like argon and its satellite lines. A two-dimensional multi-wire proportional counter has been applied to detect the spectra. The electron and ion temperatures have been obtained from the Voigt fitting with the spectra of helium-like argon ions. The profiles of electron and ion temperatures show the dependence on electron density in ohmic plasmas.

  17. High Time-Resolved Kinetic Temperatures of Solar Wind Minor Ions Measured with SOHO/CELIAS/CTOF

    Science.gov (United States)

    Janitzek, N. P.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Solar wind heavy ions with an atomic number Z > 2 are referred to as minor ions since they represent a fraction of less than one percent of all solar wind ions. They can be therefore regarded as test particles, only reacting to but not driving the dynamics of the solar wind plasma, which makes them a unique diagnostic tool for plasma wave phenomena both in the solar atmosphere and the extended heliosphere. In the past, several studies have investigated the kinetic temperatures of minor ions, but due to low counting statistics these studies are based on ion velocity distribution functions (VDFs) recorded over time periods of several hours. The Charge Time-Of-Flight (CTOF) mass spectrometer as part of the Charge, ELement and Isotope Analysis System (CELIAS) onboard the SOlar and Heliospheric Observatory (SOHO) provides solar wind heavy ion 1D radial VDFs with excellent charge state separation, an unprecedented cadence of 5 minutes and very high counting statistics, exceeding similar state-of-the-art instruments by a factor of ten. In our study, based on CTOF measurements at Langrangian point L1 between DOY 150 and DOY 220 in 1996, we investigate systematically the influence of the VDF time resolution on the derived kinetic temperatures for solar wind silicon and iron ions. The selected ion set spans a wide range of mass-per-charge from 3 amu/e heavy ions with ion-cyclotron waves.

  18. A Microfluidic Long-Period Fiber Grating Sensor Platform for Chloride Ion Concentration Measurement

    Directory of Open Access Journals (Sweden)

    Jian-Neng Wang

    2011-09-01

    Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0

  19. Measurement of the mean radial position of a lead ion beam in the CERN PS

    CERN Document Server

    Belleman, J; González, J; Johnston, S; Schulte, E C; Thivent, E

    1996-01-01

    The intensity of the lead ion beam in the PS, nominally 4×108 charges of Pb53+ per bunch, is too low for the closed orbit measurement system. However, for successful acceleration it is sufficient to know the mean radial position (MRP). A system was thus designed for simultaneous acquisition of revolution frequency and magnetic field. The frequency measurement uses a direct digital synthesiser (DDS), phase-locked to the beam signal from a special high-sensitivity pick-up. The magnetic field is obtained from the so-called B-train. From these two values, the MRP is calculated. The precision depends on the frequency measurement and on the accuracy of the value for the magnetic field. Furthermore, exact knowledge of the transition energy is essential. This paper describes the hardware and software developed for the MRP system, and discusses the issue of calibration, with a proton beam, of the B measurement.

  20. Range measurements of keV hydrogen ions in solid oxygen and carbon monoxide

    International Nuclear Information System (INIS)

    Schou, J.; Soerensen, H.; Andersen, H.H.; Nielsen, M.; Rune, J.

    1984-01-01

    Ranges of 1.3-3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen. The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees with that previously found for solid nitrogen. (orig.)

  1. Validation of Am-241 measurement in ion chamber type smoke detector by using gamma spectrometry system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Khairul Nizam Razali

    2005-01-01

    Smoke detectors are useful devices in modern days that able to save many lives. Even though, the use of ion chamber type smoke detector (usually contain Americium-241) was exempted in Malaysia, but the trading of this device was controlled by regulation, under the Atomic Energy Licensing Act (Act 304). The activity of the Am-241 can be measured by using the Gamma Spectrometry System since it was much easier, compared to Alpha Spectrometry System. To do so, the system was first need to be calibrated using the standard reference source to find the efficiency of the germanium detector. The method used for the measurement was first validated for several relevant parameters, which include specificity, precision (repeatability), bias (accuracy), linearity, working range, detection limit, robustness and ruggedness to ensure it was fit for the purpose. The measured Am-241 activity inside the smoke detector will be reported together with a reasonable expanded uncertainty arise from the measurement. (Author)

  2. First measurements of the ion energy distribution at the divertor strike point during DIII-D disruptions

    International Nuclear Information System (INIS)

    Parks, P.B.; Brooks, N.H.; West, W.P.; Wong, C.P.C.; Bastasz, R.; Wampler, W.R.; Whyte, D.

    1995-12-01

    Plasma/wall interaction studies are being carried out using the Divertor Materials Exposure System (DiMES) on DIII-D. The objective of the experiment is to determine the kinetic energy and flux of deuterium ions reaching the divertor target during argon-induced radiative disruptions. The experiment utilizes a special slotted ion analyzer mounted over a Si sample to collect the fast charge-exchange (CX) deuterium neutrals emitted within the recycled cold neutral layer (CNL) which serves as a CX target for the incident ions. A theoretical interpretation of the experiment reveals a strong forward pitch-angle dependence in the approaching ion distribution function. The depth distribution of the trapped D in the Si sample was measured using low-energy direct recoil spectroscopy. Comparison with the TRIM code using monoenergetic ions indicated that the best fit to the data was obtained for an ion energy of 100 eV

  3. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    International Nuclear Information System (INIS)

    Park, Sae-Hoon; Kim, Yu-Seok; Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub

    2015-01-01

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber

  4. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Gyeonju (Korea, Republic of); Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Multipurpose Accelerator Complex, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber.

  5. EUCAARI ion spectrometer measurements at 12 European sites – analysis of new particle formation events

    Directory of Open Access Journals (Sweden)

    H. E. Manninen

    2010-08-01

    Full Text Available We present comprehensive results on continuous atmospheric cluster and particle measurements in the size range ~1–42 nm within the European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI project. We focused on characterizing the spatial and temporal variation of new particle formation events and relevant particle formation parameters across Europe. Different types of air ion and cluster mobility spectrometers were deployed at 12 field sites across Europe from March 2008 to May 2009. The measurements were conducted in a wide variety of environments, including coastal and continental locations as well as sites at different altitudes (both in the boundary layer and the free troposphere. New particle formation events were detected at all of the 12 field sites during the year-long measurement period. From the data, nucleation and growth rates of newly formed particles were determined for each environment. In a case of parallel ion and neutral cluster measurements, we could also estimate the relative contribution of ion-induced and neutral nucleation to the total particle formation. The formation rates of charged particles at 2 nm accounted for 1–30% of the corresponding total particle formation rates. As a significant new result, we found out that the total particle formation rate varied much more between the different sites than the formation rate of charged particles. This work presents, so far, the most comprehensive effort to experimentally characterize nucleation and growth of atmospheric molecular clusters and nanoparticles at ground-based observation sites on a continental scale.

  6. Ion microprobe assessment of the heterogeneity of Mg/Ca, Sr/Ca and Mn/Ca ratios in Pecten maximus and Mytilus edulis (bivalvia shell calcite precipitated at constant temperature

    Directory of Open Access Journals (Sweden)

    P. S. Freitas

    2009-07-01

    Full Text Available Small-scale heterogeneity of biogenic carbonate elemental composition can be a significant source of error in the accurate use of element/Ca ratios as geochemical proxies. In this study ion microprobe (SIMS profiles showed significant small-scale variability of Mg/Ca, Sr/Ca and Mn/Ca ratios in new shell calcite of the marine bivalves Pecten maximus and Mytilus edulis that was precipitated during a constant-temperature culturing experiment. Elevated Mg/Ca, Sr/Ca and Mn/Ca ratios were found to be associated with the deposition of elaborate shell features, i.e. a shell surface stria in P. maximus and surface shell disturbance marks in both species, the latter a common occurrence in bivalve shells. In both species the observed small-scale elemental heterogeneity most likely was not controlled by variable transport of ions to the extra-pallial fluid, but by factors such as the influence of shell organic content and/or crystal size and orientation, the latter reflecting conditions at the shell crystal-solution interface. In the mid and innermost regions of the P. maximus shell the lack of significant small-scale variation of Mg/Ca ratios, which is consistent with growth at constant temperature, suggest a potential application as a palaeotemperature proxy. Cross-growth band element/Ca ratio profiles in the interior of bivalve shells may provide more promising palaeo-environmental tools than sampling from the outer region of bivalve shells.

  7. Precision mass measurements using the Phase-Imaging Ion-Cyclotron-Resonance detection technique

    CERN Document Server

    Karthein, Jonas

    This thesis presents the implementation and improvement of the Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR) detection technique at the ISOLTRAP experiment, located at the ISOLDE / CERN, with the purpose of on-line high-precision and high-resolution mass spectrometry. Extensive simulation studies were performed with the aim of improving the phase-imaging resolution and finding the optimal position for detector placement. Following the outcome of these simulations, the detector was moved out of a region of electric-field distortion and closer to the center of the Penning trap, showing a dramatic improvement in the quality and reproducibility of the phase-imaging measurements. A new image reconstitution and analysis software for the MCP-PS detector was written in Python and ROOT and introduced in the framework of PI-ICR mass measurements. The state of the art in the field of time-of-flight ion-cyclotron-resonance measurements is illustrated through an analysis of on-line measurements of the mirror nuclei $...

  8. Fuzzy logic modeling of EIS measurements on lithium-ion batteries

    International Nuclear Information System (INIS)

    Singh, Pritpal; Vinjamuri, Ramana; Wang, Xiquan; Reisner, David

    2006-01-01

    A fuzzy logic-based state of health (SOH) meter is being developed for lithium-ion (Li-ion) batteries for potential use in portable defibrillators. Electrochemical impedance spectroscopy (EIS) measurements have been made from which input parameters for a fuzzy logic model to estimate the state of charge (SOC) and SOH are derived. The batteries are discharged continuously at a 1.4 A load current to simulate the constant current draw during the monitoring and recording of a patient's EKG, and periodically interrupted by 10 A pulses to simulate the battery discharge to charge up the capacitor that is in turn discharged to supply high voltage to the electrodes for the defibrillation of the patient. The test procedures included both voltage recovery and EIS measurements, and were made as the batteries were being discharged and over 30 charge/discharge cycles. Accurate models have been developed to estimate the number of pulses that the battery pack can deliver at various stages of its cycle life (SOC measure) and the number of charge/discharge cycles (SOH measure) that it had undergone

  9. Automatable lipid bilayer formation and ion channel measurement using sessile droplets

    Energy Technology Data Exchange (ETDEWEB)

    Poulos, J L [Librede Inc., Sherman Oaks, CA (United States); Portonovo, S A; Schmidt, J J [Department of Bioengineering, University of California, Los Angeles, Los Angeles (United States); Bang, H, E-mail: schmidt@seas.ucla.ed [School of Mechanical and Aerospace Engineering, Seoul National University (Korea, Republic of)

    2010-11-17

    Artificial lipid bilayer membranes have been used to reconstitute ion channels for scientific and technological applications. Membrane formation has traditionally involved slow, labor intensive processes best suited to small scale laboratory experimentation. We have recently demonstrated a high throughput method of membrane formation using automated liquid-handling robotics. We describe here the integration of membrane formation and measurement with two methods compatible with automation and high throughput liquid-handling robotics. Both of these methods create artificial lipid bilayers by joining lipid monolayers self-assembled at the interface of aqueous and organic phases using sessile aqueous droplets in contact with a measurement electrode; one using a pin tool, commonly employed in high throughput fluid handling assays, and the other using a positive displacement pipette. Membranes formed with both methods were high quality and supported measurement of ion channels at the single molecule level. Full automation of bilayer production and measurement with the positive displacement pipette was demonstrated by integrating it with a motion control platform.

  10. Picosecond resolution on relativistic heavy ions' time-of-flight measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ebran, A., E-mail: adeline.ebran@cea.fr; Taieb, J., E-mail: julien.taieb@cea.fr; Belier, G.; Chatillon, A.; Laurent, B.; Martin, J.-F.; Pellereau, E.

    2013-11-11

    We developed a time-of-flight measurement system for relativistic heavy ions with a requested resolution of 40 ps Full Width Half Maximum. Such a resolution is mandatory to assign the correct mass number to every fission fragment, identified using the Bρ-ToF-ΔE method with the recoil spectrometer designed for the SOFIA experiment—which hold very recently at GSI. To achieve such a performance, fast plastic scintillators read-out by dedicated photomultiplier tubes were chosen among other possible options. We have led several test-measurements from 2009 to 2011, in order to investigate: the effect of the addition of a quenching molecule in the scintillator's matrix, the influence of the detector's size and the impact of the photomultiplier tube. The contribution of the dedicated electronics is also characterized. Time-of-flight measurements were performed realized with electron pulses and relativistic heavy ions, respectively provided by the LASER driven electron–accelerator (ELSA) at CEA–DAM Ile-de-France and by the SIS18/FRS facility at GSI. The reported results exhibit a time resolution better than 20 ps Full Width Half Maximum reached with the last prototype at GSI with an Uranium beam. These results confirm that the SOFIA experiment should enable the measurement of the relativistic fission fragments' time-of-flight with the requested resolution.

  11. Picosecond resolution on relativistic heavy ions' time-of-flight measurement

    International Nuclear Information System (INIS)

    Ebran, A.; Taieb, J.; Belier, G.; Chatillon, A.; Laurent, B.; Martin, J.-F.; Pellereau, E.

    2013-01-01

    We developed a time-of-flight measurement system for relativistic heavy ions with a requested resolution of 40 ps Full Width Half Maximum. Such a resolution is mandatory to assign the correct mass number to every fission fragment, identified using the Bρ-ToF-ΔE method with the recoil spectrometer designed for the SOFIA experiment—which hold very recently at GSI. To achieve such a performance, fast plastic scintillators read-out by dedicated photomultiplier tubes were chosen among other possible options. We have led several test-measurements from 2009 to 2011, in order to investigate: the effect of the addition of a quenching molecule in the scintillator's matrix, the influence of the detector's size and the impact of the photomultiplier tube. The contribution of the dedicated electronics is also characterized. Time-of-flight measurements were performed realized with electron pulses and relativistic heavy ions, respectively provided by the LASER driven electron–accelerator (ELSA) at CEA–DAM Ile-de-France and by the SIS18/FRS facility at GSI. The reported results exhibit a time resolution better than 20 ps Full Width Half Maximum reached with the last prototype at GSI with an Uranium beam. These results confirm that the SOFIA experiment should enable the measurement of the relativistic fission fragments' time-of-flight with the requested resolution

  12. Continuous measurement of the radon concentration in water using electret ion chamber method

    International Nuclear Information System (INIS)

    Dua, S.K.; Hopke, P.K.

    1992-10-01

    A radon concentration of 300 pCi/L has been proposed by the US Environmental Protection Agency as a limit for radon dissolved in municipal drinking water supplies. There is therefore a need for a continuous monitor to insure that the daily average concentration does not exceed this limit. In order to calibrate the system, varying concentrations of radon in water have been generated by bubbling radon laden air through a dynamic flowthrough water system. The value of steady state concentration of radon in water from this system depends on the concentration of radon in air, the air bubbling rate, and the water flow rate. The measurement system has been designed and tested using a 1 L volume electret ion chamber to determine the radon in water. In this dynamic method, water flows directly through the electret ion chamber. Radon is released to the air and measured with the electret. A flow of air is maintained through the chamber to prevent the build-up of high radon concentrations and too rapid discharge of the electret. It was found that the system worked well when the air flow was induced by the application of suction. The concentration in the water was calculated from the measured concentration in air and water and air flow rates. Preliminary results suggest that the method has sufficient sensitivity to measure concentrations of radon in water with acceptable accuracy and precision

  13. Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013 Ohm resistors

    International Nuclear Information System (INIS)

    Koornneef, J.M.; Bouman, C.; Schwieters, J.B.; Davies, G.R.

    2014-01-01

    Highlights: • First data are presented using 10 13 Ohm resistors connected to Faraday collectors. • 5 prototype 10 13 Ohm resistors were installed in a TRITON-Plus TIMS. • Performance was tested by measuring Sr and Nd isotope ratios on  13 Ohm resistors perform better than ion counting and 10 11 Ohm resistors. • Fourth decimal variability can be resolved for Nd isotope ratios on 10 pg samples. - Abstract: We tested 5 newly manufactured – prototype – 10 13 Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 10 11 Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2 × 10 −16 to 1 × 10 −12 A, corresponding to intensities of 32 μV to 100 mV on a default 10 11 Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 10 13 compared 10 12 Ohm resistors and to the default 10 11 Ohm resistors. At an 87 Sr ion current of 3 × 10 −14 A (3 mV on a 10 11 Ohm amplifier) the internal precision (2 SE) of 87 Sr/ 86 Sr is 5 times better for 10 13 Ohm resistors compared to 10 11 Ohm resistors. The external reproducibility (2 SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low 87 Sr/ 86 Sr compared to the long term average (e.g. 10 pg average = 0.710083 ± 164 (n = 11) instead of 0.710244 ± 12, n = 73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the

  14. A Lagrangian model for laser-induced fluorescence and its application to measurements of plasma ion temperature and electrostatic waves

    Science.gov (United States)

    Chu, F.; Skiff, F.

    2018-01-01

    Extensive information can be obtained on wave-particle interactions and wave fields by a direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastable states that are produced from neutral gas particles and ions in other electronic states. If the laser intensity is increased to obtain a better LIF signal, then optical pumping can produce systematic effects depending on the collision rates which control metastable population and lifetime. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal for the case where metastables are produced directly from neutrals. This case requires more strict precautions and is important for discharges with energetic primary electrons and a high density of neutrals. Some of the results also apply to metastables produced from pre-existing ions. The simulations show that optical pumping broadening affects the ion velocity distribution function f0(v) and its first-order perturbation f1(v,t) when the laser intensity is increased above a certain level. The results also suggest that ion temperature measurements are only accurate when the metastable ions can live longer than the ion-ion collision mean free time. For the purposes of wave detection, the wave period has to be significantly shorter than the lifetime of metastable ions for a direct interpretation. It is more generally true that metastable ions may be viewed as test-particles. As long as an appropriate model is available, LIF can be extended to a range of environments.

  15. Experimental ion mobility measurements in Xe-C2H6

    Science.gov (United States)

    Perdigoto, J. M. C.; Cortez, A. F. V.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

    2017-10-01

    In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon (Xe) with ethane (C2H6) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 Td to 25 Td range (2.4-6.1 kVṡcm-1ṡ bar-1), at room temperature. The time of arrival spectra revealed two peaks throughout the entire range studied which were attributed to ion species with 3-carbons (C3H5+, C3H6+ C3H8+ and C3H9+) and with 4-carbons (C4H7+, C4H9+ and C4H10+). Besides these, and for Xe concentrations above 70%, a bump starts to appear at the right side of the main peak for reduced electric fields higher than 20 Td, which was attributed to the resonant charge transfer of C2H6+ to C2H6 that affects the mobility of its ion products (C3H8+ and C3H9+). The time of arrival spectra for Xe concentrations of 20%, 50%, 70% and 90% are presented, together with the reduced mobilities as a function of the Xe concentration calculated from the peaks observed for the low reduced electric fields and pressures studied.

  16. Ion temperature measurement by neutral energy analyzer in high-field tokamak TRIAM-1

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K; Hiraki, N; Toi, K; Itoh, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1980-02-01

    The measurement of the ion temperature of the TRIAM-1 tokamak plasma is carried out by using a seven-channel neutral energy analyzer. The temporal and spatial variations of the ion temperature have been obtained with the spatial resolution of +-4.3 mm and the temporal resolution of 100 ..mu..sec. The energy range of the analyzed neutral particles is from 0.2 to 8 keV. The energy spectrum in the TRIAM-1 plasma without the strong gas puffing usually consists of two-component Maxwellian; the one represents the thermal part which is a superposition of the contribution from a hot region (T sub(i) = 100 - 300 eV) and that from an edge region (T sub(i) asymptotically equals 50 eV), and the other represents the superthermal part (T sub(i) asymptotically equals 1 keV). The neutral particle energy spectra at several vertical positions are obtained by scanning the analyzer in the vertical direction. From those spectra, the radial profile of the ion temperature is derived by means of the nonlinear optimization method.

  17. Non-destructive profile measurement of intensive heavy ion beams; Zerstoerungsfreie Profilmessung intensiver Schwerionenstrahlen

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Frank

    2010-02-08

    Within the framework of the FAIR-project (Facility for Antiproton and Ion Research) at GSI (Helmholtz Center for Heavy Ion Research), high intensity beams from protons to uranium ions with kinetic energies up to 30 AGeV are foreseen. Present GSI-accelerators like the UNILAC and the Heavy Ion Synchrotron (SIS-18) with a magnetic rigidity of 18 Tm will be used as injectors for the future synchrotron (SIS-100). Their beam current will be increased by up to two orders of magnitude. An accurate beam position and beam profile measurement is mandatory for a safe operation of transport sections, in particular in front of production targets (Fragment Separator (FRS)-target, anti p-production-target and Warm Dense Matter (WDM)-targets). Conventional intercepting profile monitors will not withstand the thermal stress of intensive ion beams, particularly for low energy applications or focused beams. For transverse profile determination a non-intercepting Beam Induced Fluorescence (BIF)-monitor was developed, working with residual gas. The BIF-monitor exploits fluorescence light emitted by residual gas molecules after atomic collisions with beam ions. Fluorescence-images were recorded with an image-intensified camera system, and beam profiles were obtained by projecting these images. Within the scope of this dissertation the following topics have been investigated: The photon yield, profile shape and background contribution were determined for different ion species (H{sup +}, S{sup 6+}, Ar{sup 18+}, K{sup +}, Ni{sup 9+}, Xe{sup 48+}, Ta{sup 24+}, Au{sup 65+}, U{sup 73+}), beam energies (7.7 AkeV-750 AMeV), gas pressures (10{sup -6}-3 mbar) and gas species (N{sub 2}, He, Ne, Ar, Kr, Xe). Applying an imaging spectrograph and narrowband 10 nm interference filters, the spectral response was mapped and associated with the corresponding gas transitions. Spectrally resolved beam profiles were also obtained form the spectrographic images. Major results are the light yield showing a

  18. Validation of fast-ion D-alpha spectrum measurements during EAST neutral-beam heated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J., E-mail: juan.huang@ipp.ac.cn; Wu, C. R.; Hou, Y. M.; Chang, J. F.; Ding, S. Y.; Chen, Y. J.; Jin, Z.; Xu, Z.; Gao, W.; Wang, J. F.; Lyu, B.; Zang, Q.; Zhong, G. Q.; Hu, L.; Wan, B. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui (China); Heidbrink, W. W.; Stagner, L.; Zhu, Y. B. [University of California, Irvine, California 92697 (United States); Hellermann, M. G. von [Diagnostic Team, ITER Organization, Route de Vinon-sur-Verdon 13067 St. Paul Lez Durance (France)

    2016-11-15

    To investigate the fast ion behavior, a fast ion D-alpha (FIDA) diagnostic system has been installed on EAST. Fast ion features can be inferred from the Doppler shifted spectrum of Balmer-alpha light from energetic hydrogenic atoms. This paper will focus on the validation of FIDA measurements performed using MHD-quiescent discharges in 2015 campaign. Two codes have been applied to calculate the D{sub α} spectrum: one is a Monte Carlo code, Fortran 90 version FIDASIM, and the other is an analytical code, Simulation of Spectra (SOS). The predicted SOS fast-ion spectrum agrees well with the measurement; however, the level of fast-ion part from FIDASIM is lower. The discrepancy is possibly due to the difference between FIDASIM and SOS velocity distribution function. The details will be presented in the paper to primarily address comparisons of predicted and observed spectrum shapes/amplitudes.

  19. First β-ν correlation measurement from the recoil-energy spectrum of Penning trapped Ar35 ions

    Science.gov (United States)

    Van Gorp, S.; Breitenfeldt, M.; Tandecki, M.; Beck, M.; Finlay, P.; Friedag, P.; Glück, F.; Herlert, A.; Kozlov, V.; Porobic, T.; Soti, G.; Traykov, E.; Wauters, F.; Weinheimer, Ch.; Zákoucký, D.; Severijns, N.

    2014-08-01

    We demonstrate a novel method to search for physics beyond the standard model by determining the β-ν angular correlation from the recoil-ion energy distribution after β decay of ions stored in a Penning trap. This recoil-ion energy distribution is measured with a retardation spectrometer. The unique combination of the spectrometer with a Penning trap provides a number of advantages, e.g., a high recoil-ion count rate and low sensitivity to the initial position and velocity distribution of the ions and completely different sources of systematic errors compared to other state-of-the-art experiments. Results of a first measurement with the isotope Ar35 are presented. Although currently at limited precision, we show that a statistical precision of about 0.5% is achievable with this unique method, thereby opening up the possibility of contributing to state-of-the-art searches for exotic currents in weak interactions.

  20. A phase-imaging ion-cyclotron-resonance technique for mass measurements of short-lived nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, Sergey; Blaum, Klaus; Doerr, Andreas; Eronen, Tommi; Goncharov, Mikhail; Hoecker, Martin; Ketter, Jochen; Ramirez, Enrique Minaya; Simon, Vanessa [Max-Planck Institute for Nuclear Physics (Germany); Block, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Chenmarev, Stanislav; Filjanin, Pavel; Nesterenko, Dmitriy; Novikov, Yuri [Petersburg Nuclear Physics Institute (Russian Federation); Droese, Christian; Schweikhard, Lutz [Institute for Physics, Ernst-Moritz-Arndt-University (Germany)

    2014-07-01

    A novel approach to mass measurements on the sub-ppb level even for short-lived nuclides with half-lives well below one second is presented. It is based on the projection of the radial ion motion in a Penning trap onto a position sensitive detector. Compared to the presently employed time-of-flight ion-cyclotron-resonance technique, the novel approach is 25-times faster and provides a 40-fold gain in resolving power. With the new technique low-lying isomeric states with excitation energy on the 10-keV level can be separated from the ground state. Moreover, the new technique possesses a substantially higher sensitivity since just two ions are sufficient to determine the ion cyclotron frequency. A measurement of the mass difference of singly charged ions of {sup 132}Xe and {sup 131}Xe with an uncertainty of 25 eV has demonstrated the great potential of the new approach.