WorldWideScience

Sample records for beam energy spectrum

  1. Full Spectrum Diffused and Beamed Solar Energy Application Using Optical Fibre

    OpenAIRE

    Majumdar, M. R. Dutta; Das, Debasish

    2007-01-01

    Existing solar energy application systems use small fraction of full spectrum of solar energy. So attempts are made to show how full spectrum solar energy can be used for diffused and beamed form of incident solar energy. Luminescent Solar Concentrator (LSC) principle with optical fibre in diffused sun light and dielectric mirror separation technique with optical fibre in beamed form are discussed. Comparison of both the cases are done. Keywords: full spectrum, solar photonics, diffused solar...

  2. Time-resolved energy spectrum of a pseudospark-produced electron beam

    International Nuclear Information System (INIS)

    For the first time a time-resolved energy spectrum of a pseudospark-produced electron beam is constructed. A small portion of electron beam sampled at its axis is injected into a vacuum and the electrons passed through a negatively biased electrode are measured by a Faraday cup. The time-resolved energy spectrum is determined by analyzing the Faraday cup current waveforms measured at various bias voltages. The resultant spectrum reveals that the instantaneous beam energy is nearly monoenergetic. The energy is monotonically decreasing in time and resembles the anode-cathode voltage waveform. This suggests that electrons are accelerated by the full instantaneous anode-cathode voltage

  3. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    International Nuclear Information System (INIS)

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator

  4. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    Science.gov (United States)

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  5. Presumption of the energy-spectrum of high-energy electron beam based on the beta-distribution model

    International Nuclear Information System (INIS)

    The energy spectra of high-energy electron beams used in radiotherapy are the most important data for evaluating absorbed doses and/or dose distributions in the body of a patient. However, it is impossible to measure the actual spectra of a high-energy electron beam. In this study, we suggest a method to presume the spectra of high-energy electron beams by use of the beta distribution model. The procedure of this method is as follows: (1) the spectrum of the high-energy electron beam was assumed to have a maximum energy Emax, and α, β parameters of the beta probability density function. (2) The percentage depth dose (PDD) based on the assumed spectrum was calculated by a Monte Carlo simulation. (3) The best matching energy spectrum was searched in comparison with the experimental PDD curves. Finally, the optimal energy spectrum of the electron beam was estimated after reiterating the process from (1) to (3). With our method, the measured PDD curves were optimally simulated following the experimental data. It appeared that the assumed spectra approximated well to the actual spectra. However, the error between the assumed and experimental data was observed in the region under the incident surface. We believe this was due to the influence of low-energy electrons scattered at installed collimators, etc. In order to simulate PDDs in this region accurately, a further correction process is required for a spectrum based on the beta distribution model. (author)

  6. Energy spectrum of electron beam at its multiple scattering from target

    International Nuclear Information System (INIS)

    The effect of the inelastically reflected electrons, returning to the target after reflection from the acceleration area, on the energy spectrum of the pulse electron beam, formed in the direct action diode and transported to the target in the leading magnetic field, is considered. The formulas for the general and differential flows of reflected and absorbed electrons of various orders are presented. It is shown that accounting for the electrons multiple reflection leads to essential change in the profile of the normalized function of thermal sources in the target: the energy release at the irradiated target surface is noticeably increased on the account of energy release in the deep-seated layers of the material

  7. An approach to an accurate determination of the energy spectrum of high-energy electron beams using magnetic spectrometry

    International Nuclear Information System (INIS)

    At the national metrology institute of Germany, the Physikalisch-Technische Bundesanstalt, a research accelerator for dosimetry in radiation therapy has been installed. Magnetic spectrometry is used to determine the spectrum of high-energy electrons generated by this accelerator. Regarding the intended experiments at the accelerator, a high accuracy for the energy determination of the electron beam is required. For this purpose, an experimental setup is used that has a number of additional devices assembled around the spectrometer to determine geometric characteristics of the electron beam, which influence the energy analysis. For the analysis of the acquired data, a software was developed which meets specific needs. One important aspect is that the software is based on an algorithm for energy determination which considers the measured magnetic flux density of the spectrometer and geometric details of the beam and the spectrometer. The software also meets the demand that it can be used to estimate the uncertainty assigned to the energy. This paper covers the experimental and analytical background of magnetic spectrometry at the high-energy beamline of PTB's research accelerator. A comparison of results calculated with the specific algorithm for energy determination which was developed for this experimental setup and with well-known algorithms is given to show the advantage of the specific method. Results of measurements and their analysis with the algorithm are presented as well

  8. Spectrum analysis in beam diagnostics

    International Nuclear Information System (INIS)

    In this article, we discuss fundamentals of the spectrum analysis in beam diagnostics, where several important particle motions in a circular accelerator are considered. The properties of the Fourier transform are presented. Then the coasting and the bunched beam motion in both longitudinal and transverse are studied. The discussions are separated for the signal particle, multiple particle, and the Schottky noise cases. To demonstrate the interesting properties of the beam motion spectrum, time domain functions are generated, and then the associated spectra are calculated and plotted. In order to show the whole picture in a single plot, some data have been scaled, therefore they may not be realistic in an accelerator

  9. Preliminary Research of Neutron Energy Spectrum of Thermal Neutron Beam Port for IHNI

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    IHNI with 30 kW is specially designed for Boron Neutron Capture Therapy (BNCT), it is the pool-tank reactor, UO2 with enrichment of 12.5% 235U as fuel, beryllium as reflector, light water as moderator and coolant. There are two neutron beams in the opposite side

  10. Determination Of Some Specific Parameters In Energy Spectrum Of Electron Beams From The Radiation Therapy Linear Accelerator Siemens PRIMUS

    International Nuclear Information System (INIS)

    Mean energy E0 and maximum probability energy Ep,0 of electron beams on the patient skin are important parameters using in radiotherapy. This report presents the experimental method assessing quality of 12 MeV electron beam from Radiation therapy Linac-SIEMENS Primus at the National Cancer Hospital (K Hospital). Absorbed dose distribution and absorbed curve of a certain field size at the depths in medium have been defined by absorbed measurement technique in water phantom. The determination of Ep,0 and E0 is based on the use of semi- empirical relationships between electron energy and range parameters, which are determined in percentage depth dose curve for electron beam in water phantom. (author)

  11. TAILORING X-RAY BEAM ENERGY SPECTRUM TO ENHANCE IMAGE QUALITY OF NEW RADIOGRAPHY CONTRAST AGENTS BASED ON GD OR OTHER LANTHANIDES

    International Nuclear Information System (INIS)

    Gadovist, a 1.0-molar Gd contrast agent from Schering AG, Berlin Germany, in use in clinical MPI in Europe, was evaluated as a radiography contrast agent. In a collaboration with Brookhaven National Laboratory (BNL), Schering AG is developing several such lanthanide-based contrast agents, while BNL evaluates them using different x-my beam energy spectra. These energy spectra include a ''truly'' monochromatic beam (0.2 keV energy bandwidth) from the National Synchrotron Light Source (NSLS), BNL, tuned above the Gd K-edge, and x-ray-tube beams from different kVp settings and beam filtrations. Radiographs of rabbits' kidneys were obtained with Gadovist at the NSLS. Furthermore, a clinical radiography system was used for imaging rabbits' kidneys comparing Gadovist and Conray, an iodinated contrast agent. The study, using 74 kVp and standard Al beam filter for Conray and 66 kVp and an additional 1.5 mm Cu beam filter for Gadovist, produced comparable images for Gadovist and Conray; the injection volumes were the same, while the radiation absorbed dose for Gadovist was slightly smaller. A bent-crystal silicon monochromator operating in the Laue diffraction mode was developed and tested with a conventional x-ray tube beam; it narrows the energy spectrum to about 4 keV around the anode tungsten's Ku line. Preliminary beam-flux results indicate that the method could be implemented in clinical CT if x-ray tubes with approximately twice higher output become available

  12. TAILORING X-RAY BEAM ENERGY SPECTRUM TO ENHANCE IMAGE QUALITY OF NEW RADIOGRAPHY CONTRAST AGENTS BASED ON GD OR OTHER LANTHANIDES.

    Energy Technology Data Exchange (ETDEWEB)

    DILMANIAN,F.A.; WEINMANN,H.J.; ZHONG,Z.; BACARIAN,T.; RIGON,L.; BUTTON,T.M.; REN,B.; WU,X.Y.; ZHONG,N.; ATKINS,H.L.

    2001-02-17

    Gadovist, a 1.0-molar Gd contrast agent from Schering AG, Berlin Germany, in use in clinical MPI in Europe, was evaluated as a radiography contrast agent. In a collaboration with Brookhaven National Laboratory (BNL), Schering AG is developing several such lanthanide-based contrast agents, while BNL evaluates them using different x-my beam energy spectra. These energy spectra include a ''truly'' monochromatic beam (0.2 keV energy bandwidth) from the National Synchrotron Light Source (NSLS), BNL, tuned above the Gd K-edge, and x-ray-tube beams from different kVp settings and beam filtrations. Radiographs of rabbits' kidneys were obtained with Gadovist at the NSLS. Furthermore, a clinical radiography system was used for imaging rabbits' kidneys comparing Gadovist and Conray, an iodinated contrast agent. The study, using 74 kVp and standard Al beam filter for Conray and 66 kVp and an additional 1.5 mm Cu beam filter for Gadovist, produced comparable images for Gadovist and Conray; the injection volumes were the same, while the radiation absorbed dose for Gadovist was slightly smaller. A bent-crystal silicon monochromator operating in the Laue diffraction mode was developed and tested with a conventional x-ray tube beam; it narrows the energy spectrum to about 4 keV around the anode tungsten's Ku line. Preliminary beam-flux results indicate that the method could be implemented in clinical CT if x-ray tubes with {approximately} twice higher output become available.

  13. KAMINI beam tube unfolded neutron spectrum

    International Nuclear Information System (INIS)

    Least squared minimization procedure based on simplex method was adapted to unfold neutron energy spectra from foil activation measurements at KAMINI beam tube end. An expansion of the neutron energy distribution on a set of parameters are fitted to minimize the square sum of differences between the measured and calculated activities. (author)

  14. Use achromatic beam line for Hall C beam energy measurement

    International Nuclear Information System (INIS)

    There are several different methods to measure accelerator beam energy, for example, from frequency spectrum measurement and calculation of orbit length from accurate measurement of magnetic field in a reference dipole magnet from high precision floating wire analogue, and from detecting the synchrotron radiation emitted from kicker magnets. In this report an achromatic spectrometer method combined with calibrating a reference magnet and determining the deflection angle of spectrometer is proposed. The similar method will be used to measure beam energy in Bates Linear Accelerator Center, a 10-3 accuracy of beam energy measurement is expected

  15. Proton Beam Energy Characterization

    OpenAIRE

    Marus, Lauren A.; Engle, J.W.; John, K. D.; Birnbaum, E. R.; Nortier, F. M.

    2015-01-01

    Introduction The Los Alamos Isotope Production Facility (IPF) is actively engaged in the development of isotope production technologies that can utilize its 100 MeV proton beam. Characterization of the proton beam energy and current is vital for optimizing isotope production and accurately conducting research at the IPF. Motivation In order to monitor beam intensity during research irradiations, aluminum foils are interspersed in experimental stacks. A theoretical yield of 22Na from...

  16. Comparison of activation in fission and fusion spectrum neutron beams

    International Nuclear Information System (INIS)

    The materials used in the construction of fusion reactors have to satisfy a number of criterions, one of the important being low activation due to neutron irradiation. Experimental analysis of the activation of candidate materials for the first wall is performed with the irradiation of samples in various neutron fields, frequently in the field of a fission reactor. In the present work a calculation is performed to compare the expected activation of candidate materials intended to be used for the first wall in fusion reactors with the activation of a sample of the same material in a fission reactor beam. The FISPACT code is used for activation calculations. An investigation, to what extent the results of activation in a fission spectrum neutron beam, where most neutrons have energies of less than 2 MeV, mimic the real situation in a fusion reactor with the peak neutron energy around 14 MeV, is performed. (author)

  17. Electron Beam Spectrum Diagnostics with Optical Transition Radiation on the Beijing Free-Electron Laser

    Institute of Scientific and Technical Information of China (English)

    李泉凤; 吴频; 高建江; 吴刚

    2004-01-01

    A measurement system was developed to measure the electron beam spectrum of the Beijing free-electron laser based on the optical transition radiation (OTR). This paper describes the system, which consists of a 32-channel high resolution of 0.02% OTR detector, especially the spectrometer. The OTR angular-distribution pattern at the focal plane has two apexes, but the two apexes are smoothed out due to the electron beam energy distribution. The energy spectrum can be measured if the magnet energy resolution is higher than 0.7% to distinguish the electron beam energy distribution.

  18. Joint opportunistic beam and spectrum selection schemes for spectrum sharing systems with limited feedback

    KAUST Repository

    Sayed, Mostafa M.

    2014-11-01

    Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing an unlicensed secondary user (SU) to share the spectrum with a licensed primary user (PU) under acceptable interference levels to the primary receiver (PU-Rx). In this paper, we consider a secondary link composed of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx). The secondary link is allowed to share the spectrum with a primary network composed of multiple PUs communicating over distinct frequency spectra with a primary base station. We develop a transmission scheme where the SU-Tx initially broadcasts a set of random beams over all the available primary spectra for which the PU-Rx sends back the index of the spectrum with the minimum interference level, as well as information that describes the interference value, for each beam. Based on the feedback information on the PU-Rx, the SU-Tx adapts the transmitted beams and then resends the new beams over the best primary spectrum for each beam to the SU-Rx. The SU-Rx selects the beam that maximizes the received signal-to-interference-plus-noise ratio (SINR) to be used in transmission over the next frame. We consider three cases for the level of feedback information describing the interference level. In the first case, the interference level is described by both its magnitude and phase; in the second case, only the magnitude is considered; and in the third case, we focus on a q-bit description of its magnitude. In the latter case, we propose a technique to find the optimal quantizer thresholds in a mean-square-error sense. We also develop a statistical analysis for the SINR statistics and the capacity and bit error rate of the secondary link and present numerical results that study the impact of the different system parameters.

  19. Interference-aware random beam selection for spectrum sharing systems

    KAUST Repository

    Abdallah, Mohamed M.

    2012-09-01

    Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

  20. Consequences of the angular spectrum decomposition of a focused beam, including slower than c beam propagation

    Science.gov (United States)

    Gouesbet, Gérard; Lock, James A.

    2016-07-01

    When dealing with light scattering and propagation of an electromagnetic beam, there are essentially two kinds of expansions which have been used to describe the incident beam (i) a discrete expansion involving beam shape coefficients and (ii) a continuous expansion in terms of an angular spectrum of plane waves. In this paper, we demonstrate that the angular spectrum decomposition readily leads to two important consequences, (i) laser light beams travel in free space with an effective velocity that is smaller than the speed of light c, and (ii) the optical theorem does not hold for arbitrary shaped beams, both in the case of electromagnetic waves and scalar waves, e.g. quantum and acoustical waves.

  1. Energy spectrum of muon in EAS

    International Nuclear Information System (INIS)

    The compact extensive air shower (EAS) array which consists of 8 scintillation counters, and the solid iron magnet spectrometer (the Okayama muon telescope) have been used to measure energy spectrum of muons in EAS from January 2004 in Okayama University. We compared the result of the muon energy spectrum tagged by EAS trigger signals with EAS simulations which agreed with higher energy hadronic interaction models such as QGSJET and SYBILL, and lower energy hadronic ones such as Hillas Splitting Algorithm, GHEISHA and UrQMD, in order to verify the influence of the hadronic interaction model upon properties of EAS particles, especially the energy spectrum of muons

  2. Energy spectrum of muon in EAS

    Science.gov (United States)

    Matsumoto, H.; Iyono, A.; Noda, C.; Masuda, M.; Yamamoto, I.; Wada, T.; Okei, K.; Tsuji, S.; Morita, T.; Okita, M.; Takahashi, N.; Liang, S.; Yamashita, Y.; Nakatsuka, T.; Ochi, N.

    2008-01-01

    The compact extensive air shower (EAS) array which consists of 8 scintillation counters, and the solid iron magnet spectrometer (the Okayama muon telescope) have been used to measure energy spectrum of muons in EAS from January 2004 in Okayama University. We compared the result of the muon energy spectrum tagged by EAS trigger signals with EAS simulations which agreed with higher energy hadronic interaction models such as QGSJET and SYBILL, and lower energy hadronic ones such as Hillas Splitting Algorithm, GHEISHA and UrQMD, in order to verify the influence of the hadronic interaction model upon properties of EAS particles, especially the energy spectrum of muons.

  3. Joint random beam and spectrum selection for spectrum sharing systems with partial channel state information

    KAUST Repository

    Abdallah, Mohamed M.

    2013-11-01

    In this work, we develop joint interference-aware random beam and spectrum selection scheme that provide enhanced performance for the secondary network under the condition that the interference observed at the primary receiver is below a predetermined acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a set of primary links composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes jointly select a beam, among a set of power-optimized random beams, as well as the primary spectrum that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint. In particular, we consider the case where the interference level is described by a q-bit description of its magnitude, whereby we propose a technique to find the optimal quantizer thresholds in a mean square error (MSE) sense. © 2013 IEEE.

  4. High energy beam manufacturing technologies

    International Nuclear Information System (INIS)

    Technological progress continues to enable us to utilize ever widening ranges of physical and chemical conditions for material processing. The increasing cost of energy, raw materials and environmental control make implementation of advanced technologies inevitable. One of the principal avenues in the development of material processing is the increase of the intensity, accuracy, flexibility and stability of energy flow to the processing site. The use of different forms of energy beams is an effective way to meet these sometimes incompatible requirements. The first important technological applications of high energy beams were welding and flame cutting. Subsequently a number of different kinds of beams have been used to solve different problems of part geometry control and improvement of surface characteristics. Properties and applications of different specific beams were subjects of a number of fundamental studies. It is important now to develop a generic theory of beam based manufacturing. The creation of a theory dealing with general principles of beam generation and beam-material interaction will enhance manufacturing science as well as practice. For example, such a theory will provide a format approach for selection and integration of different kinds of beams for a particular application. And obviously, this theory will enable us to integrate the knowledge bases of different manufacturing technologies. The War of the Worlds by H. G. Wells, as well as a number of more technical, although less exciting, publications demonstrate both the feasibility and effectiveness of the generic approach to the description of beam oriented technology. Without any attempt to compete with Wells, we still hope that this volume will contribute to the creation of the theory of beam oriented manufacturing

  5. Energy spectrum of C60 fullerene

    Science.gov (United States)

    Mironov, G. I.; Murzashev, A. I.

    2011-11-01

    The energy spectrum of the C60 fullerene has been calculated in terms of the Shubin-Vonsovskii-Hubbard model using an approximation of static fluctuations. Based on the spectrum, the optical absorption bands at 4.84, 5.88, and 6.30 eV observed experimentally have been successfully explained. It has been concluded that the model used is applicable for the calculation of the energy spectrum and the energy properties of other nanosystems, such as fullerenes of higher orders, carbon nanotubes, and grafen planes.

  6. The beam energy calibration system for the BEPC-II collider

    CERN Document Server

    Achasov, M N; Mo, Xiaohu; Muchnoi, N Yu; Qin, Qing; Qu, Huamin; Wang, Yifang; Xu, Jinqiang

    2008-01-01

    This document contains a proposal of the BEPC-II collider beam energy calibration system (IHEP, Beijing). The system is based on Compton backscattering of carbon dioxide laser radiation, producing a beam of high energy photons. Their energy spectrum is then accurately measured by HPGe detector. The high-energy spectrum edge will allow to determine the average electron or positron beam energy with relative accuracy about 3x10^-5.

  7. Calculated LET spectrum from antiproton beams stopping in water

    CERN Document Server

    Bassler, Niels

    2009-01-01

    Antiprotons have been proposed as a potential modality for radiotherapy because the annihilation at the end of range leads to roughly a doubling of physical dose in the Bragg peak region. So far it has been anticipated that the radiobiology of antiproton beams is similar to that of protons in the entry region of the beam, but very different in the annihilation region, due to the expected high-LET components resulting from the annihilation. On closer inspection we find that calculations of dose averaged LET in the entry region may suggest that the RBE of antiprotons in the plateau region could significantly differ from unity, which seems to warrant closer inspection of the radiobiology in this region. Materials and Methods. Monte Carlo simulations using FLUKA were performed for calculating the entire particle spectrum of a beam of 126 MeV antiprotons hitting a water phantom. Results and Discussion. In the plateau region of the simulated antiproton beam we observe a dose-averaged unrestrict...

  8. Intense low energy positron beams

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, K.G.; Jacobsen, F.M.

    1993-12-31

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e{sup +} beams exist producing of the order of 10{sup 8} {minus} 10{sup 9} e{sup +}/sec. Several laboratories are aiming at high intensity, high brightness e{sup +} beams with intensities greater than 10{sup 9} e{sup +}/sec and current densities of the order of 10{sup 13} {minus} 10{sup 14} e{sup +} sec{sup {minus}} {sup 1}cm{sup {minus}2}. Intense e{sup +} beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B{sup +} moderators or by increasing the available activity of B{sup +} particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e{sup +} collisions with atoms and molecules. Within solid state physics high intensity, high brightness e{sup +} beams are in demand in areas such as the re-emission e{sup +} microscope, two dimensional angular correlation of annihilation radiation, low energy e{sup +} diffraction and other fields. Intense e{sup +} beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies.

  9. Beam-beam studies for the High-Energy LHC

    CERN Document Server

    Ohmi, K; Zimmermann, F

    2011-01-01

    LHC upgrades are being considered both towards higher luminosity (HL-LHC) and towards higher energy (HE-LHC). In this paper we report initial studies of the beam-beam effects in the HE-LHC [1]. The HE-LHC aims at beam energies of 16.5 TeV, where the transverse emittance decreases due to synchrotron radiation with a 2-hour damping time. As a result of this emittance, shrinkage the beam-beam parameter increases with time, during a physics store. The beam-beam limit in the HE-LHC is explored using computer simulations.

  10. Energy Spectrum of Buoyancy-Driven Turbulence

    OpenAIRE

    Kumar, Abhishek; Chatterjee, Anando G.; Verma, Mahendra K.

    2014-01-01

    Using high-resolution direct numerical simulation and arguments based on the kinetic energy flux $\\Pi_u$, we demonstrate that for stably stratified flows, the kinetic energy spectrum $E_u(k) \\sim k^{-11/5}$, the entropy spectrum $E_\\theta(k) \\sim k^{-7/5}$, and $\\Pi_u(k) \\sim k^{-4/5}$, consistent with the Bolgiano-Obukhov scaling. This scaling arises due to the conversion of kinetic energy to the potential energy by buoyancy. For weaker buoyancy, this conversion is weak, hence $E_u(k)$ follo...

  11. Energy spectrum of Buoyancy-driven Flows

    CERN Document Server

    Kumar, Abhishek; Verma, Mahendra K

    2014-01-01

    Using high-resolution direct numerical simulation and arguments based on the kinetic energy flux $\\Pi_u$, we demonstrate that for stably stratified flows, the kinetic energy spectrum $E_u(k) \\sim k^{-11/5}$, the entropy spectrum $E_\\theta(k) \\sim k^{-7/5}$, and $\\Pi_u(k) \\sim k^{-4/5}$ (Bolgiano-Obukhov scaling). This scaling is due to the depletion of kinetic energy because of buoyancy. For weaker buoyancy in stratified flows, $E_u(k)$ follows Kolmgorov's spectrum with a constant energy flux. We also argue that for Rayleigh B\\'{e}nard convection, the Bolgiano-Obukhov scaling will not hold for the bulk flow due to the positive energy supply by buoyancy and non-decreasing $\\Pi_u(k)$.

  12. Beam-beam interaction in high energy linear electron-positron colliders

    International Nuclear Information System (INIS)

    The interaction of high energy electron and positron beams in a linear collider has been investigated using a macroparticle Monte Carlo method based on a Cloud-In-Cells plasma simulation scheme. Density evolutions, luminosities, energy and angular distributions for electrons (positrons) and synchrotron photons are calculated. Beside beams with a symmetric transverse profile also flat beams are considered. A reasonably good agreement to alternative computer calculations as well as to an analytical approximation for the energy spectrum of synchrotron photons has been obtained. (author)

  13. THE PAIR BEAM PRODUCTION SPECTRUM FROM PHOTON-PHOTON ANNIHILATION IN COSMIC VOIDS

    International Nuclear Information System (INIS)

    Highly beamed relativistic e ±-pair energy distributions result in double photon collisions of the beamed gamma rays from TeV blazars at cosmological distances with the isotropically distributed extragalactic background light (EBL) in the intergalactic medium. The typical energies k 0 ≅ 10–7 in units of mec 2 of the EBL are more than 10 orders of magnitude smaller than the observed gamma-ray energies k 1 ≥ 107. Using the limit k 0 1, we demonstrate that the angular distribution of the generated pairs in the lab frame is highly beamed in the direction of the initial gamma-ray photons. For the astrophysically important case of power-law distributions of the emitted gamma-ray beam up to the maximum energy M interacting with Wien-type N(k 0)∝kq0exp (– k 0/Θ) soft photon distributions with total number density N 0, we calculate analytical approximations for the electron production spectrum. For distant objects with luminosity distances dL >> r 0 = (σ T N 0)–1 = 0.49N –10 Mpc (with Thomson cross section σ T), the implied large values of the optical depth τ0 = dL /r 0 indicate that the electron production spectra differ at energies inside and outside the interval [(Θln τ0)–1, τ0/Θ], given the maximum gamma-ray energy M >> Θ–1. In the case M >> Θ–1, the production spectrum is strongly peaked near E ≅ Θ–1, being exponentially reduced at small energies and decreasing with the steep power law ∝E –1–p up to the maximum energy E = M – (1/2).

  14. The Pair Beam Production Spectrum from Photon-Photon Annihilation in Cosmic Voids

    Science.gov (United States)

    Schlickeiser, R.; Elyiv, A.; Ibscher, D.; Miniati, F.

    2012-10-01

    Highly beamed relativistic e ±-pair energy distributions result in double photon collisions of the beamed gamma rays from TeV blazars at cosmological distances with the isotropically distributed extragalactic background light (EBL) in the intergalactic medium. The typical energies k 0 ~= 10-7 in units of mec 2 of the EBL are more than 10 orders of magnitude smaller than the observed gamma-ray energies k 1 >= 107. Using the limit k 0 Lt k 1, we demonstrate that the angular distribution of the generated pairs in the lab frame is highly beamed in the direction of the initial gamma-ray photons. For the astrophysically important case of power-law distributions of the emitted gamma-ray beam up to the maximum energy M interacting with Wien-type N(k 0)vpropkq 0exp (- k 0/Θ) soft photon distributions with total number density N 0, we calculate analytical approximations for the electron production spectrum. For distant objects with luminosity distances dL Gt r 0 = (σ T N 0)-1 = 0.49N -1 0 Mpc (with Thomson cross section σ T ), the implied large values of the optical depth τ0 = dL /r 0 indicate that the electron production spectra differ at energies inside and outside the interval [(Θln τ0)-1, τ0/Θ], given the maximum gamma-ray energy M Gt Θ-1. In the case M Gt Θ-1, the production spectrum is strongly peaked near E ~= Θ-1, being exponentially reduced at small energies and decreasing with the steep power law vpropE -1 - p up to the maximum energy E = M - (1/2).

  15. High energy ion beam mixing

    International Nuclear Information System (INIS)

    Experimental investigations have been made on the parameters which can be used to control the mixing profiles, and the width of intermixed layers in film-substrate systems being irradiated by high energy heavy ion beams. The samples were irradiated by ion beams of Au, Cu, and Si with energies of 1.5 to 3 MeV. Typical examples of the RBS spectra are presented and discussions are made on the extent of contribution of binary collisions on the interfacial mixing. The experimental and simulation results show that the interfacial mixing is dominated by the binary collisions. (author)

  16. Neutron spectrum measurements in the aluminum oxide filtered beam facility at the Brookhaven Medical Research Reactor

    International Nuclear Information System (INIS)

    Neutron spectrum measurements were performed on the aluminum oxide filter installed in the Brookhaven Medical Research Reactor (BMRR). For these measurements, activation foils were irradiated at the exit port of the beam facility. A technique based on dominant resonances in selected activation reactions was used to measure the epithermal neutron spectrum. The fast and intermediate-energy ranges of the neutron spectrum were measured by threshold reactions and 10B-shielded 235U fission reactions. Neutron spectral data were derived from the activation data by two approaches: (1) a short analysis which yields neutron flux values at the energies of the dominant or primary resonances in the epithermal activation reactions and integral flux data for neutrons above corresponding threshold or pseudo-threshold energies, and (2) the longer analysis which utilized all the activation data in a full-spectrum, unfolding process using the FERRET spectrum adjustment code. This paper gives a brief description of the measurement techniques, analysis methods, and the results obtained

  17. Energy spectrum of lightning gamma emission

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, A.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Karashtin, A.N. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Ryabov, V.A., E-mail: ryabov@x4u.lebedev.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shepetov, A.L. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Antonova, V.P.; Kryukov, S.V. [Ionosphere Institute, Almaty (Kazakhstan); Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Ptitsyn, M.O., E-mail: ptitsyn@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shalamova, S.Ya. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shlyugaev, Yu.V. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Vildanova, L.I. [Tien-Shan Mountain Cosmic Ray Station, Almaty (Kazakhstan); Zybin, K.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Gurevich, A.V., E-mail: alex@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation)

    2009-08-10

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10{sup -3}-10{sup -2} J. The experimental results are in an agreement with the runaway breakdown mechanism.

  18. Energy spectrum of lightning gamma emission

    International Nuclear Information System (INIS)

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10-3-10-2 J. The experimental results are in an agreement with the runaway breakdown mechanism.

  19. Hofstadter's butterfly energy spectrum of ultracold fermions on the two-dimensional triangular optical lattice

    International Nuclear Information System (INIS)

    We study the energy spectrum of ultracold fermionic atoms on the two-dimensional triangular optical lattice subjected to a perpendicular effective magnetic field, which can be realized with laser beams. We derive the generalized Harper's equations and numerically solve them, then we obtain the Hofstadter's butterfly-like energy spectrum, which has a novel fractal structure. The observability of the Hofstadter's butterfly spectrum is also discussed

  20. Is LEP beam-beam limited at its highest energy?

    CERN Document Server

    Brandt, D; Meddahi, Malika; Verdier, A

    1999-01-01

    The operation of LEP at 45.6 GeV was limited by beam-beam effects and the vertical beam-beam parameter xy never exceeded 0.045. At the highest energy of 94.5 GeV, the increased damping allows higher beam-beam parameters xy . Values above 0.07 in the vertical plane averaged over four experiments have been obtained frequently with peak values up to 0.075 in a single experiment. Although the maximum intensity in LEP is presently limited by technical considerations, some observations indicate that the beam-beam limit is close and the question of the maximum possible values can be raised. These observations are shown in this paper and possible consequences are presented. The optimum operation of LEP in the neighbourhood of the beam-beam limit is discussed.

  1. Energy Spectrum of Buoyancy-driven Turbulence

    CERN Document Server

    Verma, Mahendra K; Chatterjee, Anando G

    2014-01-01

    Using direct numerical simulation we demonstrate that stably stratified flows with large Richardson number follow Bolgiano-Obukhov scaling, i.e, the kinetic energy spectrum $E_u(k) \\sim k^{-11/5}$, the entropy spectrum $E_\\theta(k) \\sim k^{-7/5}$, and kinetic energy flux $\\Pi_u(k) \\sim k^{-4/5}$. This is due to the conversion of kinetic energy to potential energy because of buoyancy. We also demonstrate that $E_u(k) \\sim k^{-5/3}$ for stratified flow with weaker buoyancy or smaller Richardson number. We argue that due to the positive energy supply by buoyancy and non-decreasing $\\Pi_u(k)$, Rayleigh B\\'{e}nard convection should follow Kolmogorov-Obukhov scaling ($E_u(k) \\sim k^{-5/3}$).

  2. Energy spectrum of buoyancy-driven turbulence

    KAUST Repository

    Kumar, Abhishek

    2014-08-25

    Using high-resolution direct numerical simulation and arguments based on the kinetic energy flux Πu, we demonstrate that, for stably stratified flows, the kinetic energy spectrum Eu(k)∼k-11/5, the potential energy spectrum Eθ(k)∼k-7/5, and Πu(k)∼k-4/5 are consistent with the Bolgiano-Obukhov scaling. This scaling arises due to the conversion of kinetic energy to the potential energy by buoyancy. For weaker buoyancy, this conversion is weak, hence Eu(k) follows Kolmogorov\\'s spectrum with a constant energy flux. For Rayleigh-Bénard convection, we show that the energy supply rate by buoyancy is positive, which leads to an increasing Πu(k) with k, thus ruling out Bolgiano-Obukhov scaling for the convective turbulence. Our numerical results show that convective turbulence for unit Prandt number exhibits a constant Πu(k) and Eu(k)∼k-5/3 for a narrow band of wave numbers. © 2014 American Physical Society.

  3. High performance hybrid slow positron beam and its user application spectrum

    Science.gov (United States)

    Waeber, W. B.; Shi, M.

    1997-05-01

    A true hybrid beam is operational at PSI. From a β+ radioisotope source and a premoderation of the positrons to medium energies in a high magnetic field confinement of Tesla order, a 3 keV wide spectrum of positrons is extracted and adiabatically guided to low fields of less than 100 G allowing extraction in a highly efficient and quasi-divergency-free way into field free space by increasing the positron's transverse energy spread by less than 20 eV. Double electrostatic focussing followed each time by W-remoderators (air lock anneal is possible) results in a beam diameter of μm dimensions. The microbeam is then transported through a cylindrical mirror beam switch device to five different user ports (one at a time, within minutes). The first target station is equipped with a retractable beam gun and a high precision sample manipulator with six movements for low (-200°C) and high (+950°C) temperatures (sample introduction by an air lock system). At the target chamber a UHV of 3.5 × 10 -11 mbar has been reached and the chamber can be equipped for surface physics experiments, for example to perform PAES. The sample is always at ground potential and the beam energy can be tuned between a few eV and 60 keV. The facility, initially equipped with a source of 500 mCi 58Co, produces a monoenergetic beam intensity (energy spread 10 10e+/ s, pulsing, repolarization) will be outlined.

  4. Numerical analysis of the beam quality and spectrum of wavelength-beam-combined laser diode arrays

    Science.gov (United States)

    Tang, Xuan; Wang, Xiao-Jun; Ke, Wei-Wei

    2015-02-01

    In this paper, a numerical model is presented to simulation the performance of the wavelength-beam-combined laser diode arrays (LDA) system. The eigen mode expansion method is used to describe the two-dimensional optical amplification and the strength of field feedback of external cavity. To describe the mode competition in laser diodes, the gain saturation effect is considered. The two-dimension distributions of the carrier concentration, recombination rates, and optical gain are calculated for solving the laser dynamic equation. The Fresnel integration, grating equation and mode overlap integration are used to obtain the feedback coefficient of extent cavity diffraction. Quantum noise is considered to evaluate the spectral linewidth of semiconductor laser. Based on the numerical model, the impact of the mutual optical feedback on the beam quality and spectrum of the LDA is present and analysis.

  5. Analyzer of energy spectra of a magnetized relativistic electron beam

    International Nuclear Information System (INIS)

    Analyzer of magnetized REB instant energy spectrum is described. The analyzer operation principle is based on the application of a sharp change of the direction of force lines of a magnetic field which is non-adiabatic for the beam electrons. The analyzer design is described, the main factors effecting the energy resolution are considered. The analyzer serviceability is examined in the course of experiments on plasma heating using a heavy-current microsecond REB at the GOL-3 device. The analyzer energy resolution which does not exceed 10% at 0.8 MeV energy and 20% at 0.3 MeV is determined. Beam energy spectra are obtained in one of the regimes of beam interaction with plasma. The efficiency of beam interaction with plasma determined using the analyzer achieves 30%. 10 refs.; 7 figs

  6. A new approach for beam hardening correction based on the local spectrum distributions

    Energy Technology Data Exchange (ETDEWEB)

    Rasoulpour, Naser; Kamali-Asl, Alireza, E-mail: a_kamali@sbu.ac.ir; Hemmati, Hamidreza

    2015-09-11

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called “beam hardening”. The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile. - Highlights: • A novel Beam Hardening (BH) correction approach was described. • A new concept named Local Spectrum Distributions (LSDs) was used to BH

  7. A new approach for beam hardening correction based on the local spectrum distributions

    International Nuclear Information System (INIS)

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called “beam hardening”. The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile. - Highlights: • A novel Beam Hardening (BH) correction approach was described. • A new concept named Local Spectrum Distributions (LSDs) was used to BH

  8. Tolerance of ion beam etching on multilayer dielectric thin film reflector for spectrum reshaping

    International Nuclear Information System (INIS)

    Lots of attentions have been paid to spatial distribution, temporal profile, as well as spectrum reshapings in the design of kilojoule peta watt chirped pulse amplification(CPA) systems. The multilayer dielectric thin film reflector fabricated by top-down nano-fabrication processes can be used to realize the spectral reshaping of high power chirped pulses. In the design and fabrication of the reflector, it is necessary to determine the tolerance of ion beam etching appropriately based on the designed reflectivity. Therefore, the analytical expression for the tolerance of ion beam etching has been derived for the multilayer dielectric thin film reflector for spectral reshaping of the chirped pulse laser in the large energy and high power Nd:glass CPA system. The error limitation of ion beam etching for each film has been analyzed, and the tolerance of ion beam etching for the multilayer dielectric thin film reflector has been proposed. Study shows that: etching high refractive index material layer, the etching tolerance is 35 nm; for low refractive index one is 62 nm. Furthermore, according to application requirement and fabrication capability, etching methods have also been discussed. For the ease of processing, reactive ion beam etching is preferred especially with the scheme of etching and leaving low refractive index media. (authors)

  9. The Complex Energy Spectrum of Isomeric Reactions

    OpenAIRE

    Ugulavaa, A.; Toklikishvilia, Z.; Chkhaidze, S.; Chotorlishvili, L.; Abramishvilia, R.

    2011-01-01

    The internal motion in a molecule, in which isomerization processes occur, is characterized by two essentially different modes of motion - oscillatory and rotational. The quantum equation of motion which describes an isomerization process is reduced to the Mathieu-Hill equation. As is known, this equation is able to describe both modes. In the paper, it is shown that the chaotic region of the energy spectrum characterizing an isomerization process corresponds to the region where two modes of ...

  10. End of the cosmic neutrino energy spectrum

    CERN Document Server

    Anchordoqui, L A; Goldberg, H; Learned, J G; Marfatia, D; Pakvasa, S; Paul, T C; Weiler, T J

    2014-01-01

    There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe the Standard Model Glashow-resonance events expected at 6.3 PeV. There are also no higher-energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates models with a fundamental restriction on neutrino energies above a few PeV. The simplest scenario to terminate the neutrino spectrum is Lorentz-invariance violating with a limiting neutrino velocity that is smaller than the speed of light. A consequence is that charged pions are stable above four times the maximum neutrino energy and may serve as a cosmic ray primary.

  11. THE PAIR BEAM PRODUCTION SPECTRUM FROM PHOTON-PHOTON ANNIHILATION IN COSMIC VOIDS

    Energy Technology Data Exchange (ETDEWEB)

    Schlickeiser, R.; Ibscher, D. [Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Elyiv, A. [Institut d' Astrophysique et de Geophysique, Universite de Liege, B-4000 Liege (Belgium); Miniati, F., E-mail: rsch@tp4.rub.de, E-mail: ibscher@tp4.rub.de, E-mail: elyiv@astro.ulg.ac.be, E-mail: fm@phys.ethz.ch [Physics Department, Wolfgang-Pauli-Strasse 27, ETH-Zuerich, CH-8093 Zuerich (Switzerland)

    2012-10-20

    Highly beamed relativistic e {sup {+-}}-pair energy distributions result in double photon collisions of the beamed gamma rays from TeV blazars at cosmological distances with the isotropically distributed extragalactic background light (EBL) in the intergalactic medium. The typical energies k {sub 0} {approx_equal} 10{sup -7} in units of m{sub e}c {sup 2} of the EBL are more than 10 orders of magnitude smaller than the observed gamma-ray energies k {sub 1} {>=} 10{sup 7}. Using the limit k {sub 0} << k {sub 1}, we demonstrate that the angular distribution of the generated pairs in the lab frame is highly beamed in the direction of the initial gamma-ray photons. For the astrophysically important case of power-law distributions of the emitted gamma-ray beam up to the maximum energy M interacting with Wien-type N(k {sub 0}){proportional_to}k{sup q} {sub 0}exp (- k {sub 0}/{Theta}) soft photon distributions with total number density N {sub 0}, we calculate analytical approximations for the electron production spectrum. For distant objects with luminosity distances d{sub L} >> r {sub 0} = ({sigma} {sub T} N {sub 0}){sup -1} = 0.49N {sup -1} {sub 0} Mpc (with Thomson cross section {sigma} {sub T}), the implied large values of the optical depth {tau}{sub 0} = d{sub L} /r {sub 0} indicate that the electron production spectra differ at energies inside and outside the interval [({Theta}ln {tau}{sub 0}){sup -1}, {tau}{sub 0}/{Theta}], given the maximum gamma-ray energy M >> {Theta}{sup -1}. In the case M >> {Theta}{sup -1}, the production spectrum is strongly peaked near E {approx_equal} {Theta}{sup -1}, being exponentially reduced at small energies and decreasing with the steep power law {proportional_to}E {sup -1-p} up to the maximum energy E = M - (1/2).

  12. Parton distributions with high energy proton beams

    International Nuclear Information System (INIS)

    The opportunities for using high energy proton beams to advance our current knowledge in parton distributions are discussed. Highlights from some Fermilab dimuon production experiments with 800 GeV proton beams are presented. Possible future directions are discussed

  13. Determination of the LEP beam energy

    CERN Document Server

    Torrence, E

    2000-01-01

    This article describes the determination of the LEP beam energy above the production threshold for W boson pairs. A brief overview of the magnetic extrapolation method is presented which is currently used to determine the LEP beam energy to a relative precision of 2*10/sup -4 /. A new method for beam energy measurements based on an in-line energy spectrometer is presented, and current developments in the commissioning of this device are outlined. (2 refs).

  14. Effect of Coma Aberration on Orbital Angular Momentum Spectrum of Vortex Beams

    Institute of Scientific and Technical Information of China (English)

    CHEN Zi-Yang; PU Ji-Xiong

    2009-01-01

    Spiral spectra of vortex beams with coma aberration are studied.It is shown that the orbital angular momentum (OAM) states of vortex beams with coma aberration are different from those aberration-free vortex beams.Spiral spectra of beams with coma aberration are spreading.It is found that in the presence of coma aberration,the vortex beams contain not only the original OAM component but also other components.A larger coma aberration coefficient and/or a larger beam waist will lead to a wider spreading of the spiral spectrum. The results may have potential applications in information encoding and transmittance.

  15. FreeNet: Spectrum and Energy Harvesting Wireless Networks

    OpenAIRE

    Ansari, Nirwan; Han, Tao

    2015-01-01

    The dramatic mobile data traffic growth is not only resulting in the spectrum crunch but is also leading to exorbitant energy consumption. It is thus desirable to liberate mobile and wireless networks from the constraint of the spectrum scarcity and to rein in the growing energy consumption. This article introduces FreeNet, figuratively synonymous to "Free Network", which engineers the spectrum and energy harvesting techniques to alleviate the spectrum and energy constraints by sensing and ha...

  16. Beam energy online measurement of BEPCII LINAC

    CERN Document Server

    Wang, Shao-Zhe; Chi, Yun-Long

    2015-01-01

    This paper describes beam energy online measurement of BEPCII linac, presents the calculation formula and some of the results. The method mentioned here measures the beam energy by acquiring beam positions in the horizontal direction with three beam position monitors (BPM) eliminating the effect of orbit fluctuation, which is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in the end of this paper.

  17. Determination of neutron energy spectrum at KAMINI shielding experiment location.

    Science.gov (United States)

    Sen, Sujoy; Bagchi, Subhrojit; Prasad, R R; Venkatasubramanian, D; Mohanakrishnan, P; Keshavamurty, R S; Haridas, Adish; Arul, A John; Puthiyavinayagam, P

    2016-09-01

    The neutron spectrum at KAMINI reactor south beam tube end has been determined using multifoil activation method. This beam tube is being used for characterizing neutron attenuation of novel shield materials. Starting from a computed guess spectrum, the spectrum adjustment/unfolding procedure makes use of minimization of a modified constraint function representing (a) least squared deviations between the measured and calculated reaction rates, (b) a measure of sharp fluctuations in the adjusted spectrum and (c) the square of the deviation of adjusted spectrum from the guess spectrum. The adjusted/unfolded spectrum predicts the reaction rates accurately. The results of this new procedure are compared with those of widely used SAND-II code. PMID:27389881

  18. An energy-based beam hardening model in tomography

    Energy Technology Data Exchange (ETDEWEB)

    Casteele, E van de; Dyck, D van; Sijbers, J; Raman, E [Vision Lab, Physics Departement, University of Antwerp (RUCA) (Belgium)

    2002-12-07

    As a consequence of the polychromatic x-ray source, used in micro-computer tomography ({mu}CT) and in medical CT, the attenuation is no longer a linear function of absorber thickness. If this nonlinear beam hardening effect is not compensated, the reconstructed images will be corrupted by cupping artefacts. In this paper, a bimodal energy model for the detected energy spectrum is presented, which can be used for reduction of artefacts caused by beam hardening in well-specified conditions. Based on the combination of the spectrum of the source and the detector efficiency, the assumption is made that there are two dominant energies which can describe the system. The validity of the proposed model is examined by fitting the model to the experimental datapoints obtained on a microtomograph for different materials and source voltages.

  19. Residual Energy Spectrum of Solar Wind Turbulence

    CERN Document Server

    Chen, C H K; Salem, C S; Maruca, B A

    2013-01-01

    It has long been known that the energy in velocity and magnetic field fluctuations in the solar wind is not in equipartition. In this paper, we present an analysis of 5 years of Wind data at 1 AU to investigate the reason for this. The residual energy (difference between energy in velocity and magnetic field fluctuations) was calculated using both the standard magnetohydrodynamic (MHD) normalization for the magnetic field and a kinetic version, which includes temperature anisotropies and drifts between particle species. It was found that with the kinetic normalization, the fluctuations are closer to equipartition, with a mean normalized residual energy of sigma_r = -0.19 and mean Alfven ratio of r_A = 0.71. The spectrum of residual energy, in the kinetic normalization, was found to be steeper than both the velocity and magnetic field spectra, consistent with some recent MHD turbulence predictions and numerical simulations, having a spectral index close to -1.9. The local properties of residual energy and cros...

  20. ADAPTIVE FULL-SPECTRUM SOLOR ENERGY SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Byard D. Wood

    2004-04-01

    This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports solar light from a paraboloidal dish concentrator to a luminaire via a large core polymer fiber optic. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of solar lighting and electric lighting. A benchmark prototype system has been developed to evaluate the HSL system. Sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. A secondary mirror consisting of eight planar-segmented mirrors directs the visible part of the spectrum to eight fibers (receiver) and subsequently to eight luminaires. This results in about 8,200 lumens incident at each fiber tip. Each fiber can illuminate about 16.7 m{sup 2} (180 ft{sup 2}) of office space. The IR spectrum is directed to a thermophotovoltaic (TPV) array to produce electricity. During this reporting period, the project team made advancements in the design of the second generation (Alpha) system. For the Alpha system, the eight individual 12 mm fibers have been replaced with a centralized bundle of 3 mm fibers. The TRNSYS Full-Spectrum Solar Energy System model has been updated and new components have been added. The TPV array and nonimaging device have been tested and progress has been made in the fiber transmission models. A test plan was developed for both the high-lumen tests and the study to determine the non-energy benefits of daylighting. The photobioreactor team also made major advancements in the testing of model scale and bench top lab-scale systems.

  1. Compact 180 deg magnetic energy analyzer for relativistic electron beams

    International Nuclear Information System (INIS)

    A compact, 180 deg deflection magnetic energy analyzer has been designed and used to measure the energy spectrum of the beam produced by the Tesla Transformer-Pulse forming line type Relativistic Electron Beam (REB) generator being used in the FEL experiments that are currently underway at Institute for Plasma Research. Relativistic electron beams have been used in many applications ranging from free-electron lasers to virtual cathode oscillators and other high power microwave devices. In all these cases, it is required that the electron beam is propagated without considerable loss across a drift region and it is also imperative that accurate energy measurements are required for dependable estimates and analysis regarding the output parameters of the system. In the case of a free-electron laser, the output wavelength of the FEL has a strong dependence on the beam energy and hence it is important to determine as accurately as possible, the energy of the electron beam in order to accurately estimate the FEL radiation frequency

  2. Discrimination of a crack in the Ultrasonic Spectrum signal of multi laser beams

    International Nuclear Information System (INIS)

    A laser ultrasonic inspection system is a non-contact inspection device which generates and measures ultrasounds by using a laser beam. A laser ultrasonic inspection system provides a high measurement resolution because the ultrasonic signal generated by a pulse laser beam has a wide-band spectrum and the ultrasonic signal is measured from a focused small spot of a measuring laser beam. In this paper, we have studied a discrimination technique for a crack by a spectrum analysis of multi laser ultrasonic signals. We experimentally confirmed that the defect information can be extracted through observing the frequency of the attenuation variation of coefficients

  3. A new approach for beam hardening correction based on the local spectrum distributions

    Science.gov (United States)

    Rasoulpour, Naser; Kamali-Asl, Alireza; Hemmati, Hamidreza

    2015-09-01

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called "beam hardening". The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile.

  4. Calculated LET Spectrum from Antiproton Beams Stopping in Water

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael

    2009-01-01

    Antiprotons have been proposed as a potential modality for radiotherapy because the annihilation at the end of range leads to roughly a doubling of physical dose in the Bragg peak region. So far it has been anticipated that the radiobiology of antiproton beams is similar to that of protons in the...

  5. Beam dynamics in high energy particle accelerators

    CERN Document Server

    Wolski, Andrzej

    2014-01-01

    Particle accelerators are essential tools for scientific research in fields as diverse as high energy physics, materials science and structural biology. They are also widely used in industry and medicine. Producing the optimum design and achieving the best performance for an accelerator depends on a detailed understanding of many (often complex and sometimes subtle) effects that determine the properties and behavior of the particle beam. Beam Dynamics in High Energy Particle Accelerators provides an introduction to the concepts underlying accelerator beam line design and analysis, taking an approach that emphasizes the elegance of the subject and leads into the development of a range of powerful techniques for understanding and modeling charged particle beams.

  6. Measurements of effective total macroscopic cross sections and effective energy of continuum beam

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hisao [Rikkyo Univ., Yokosuka, Kanagawa (Japan). Inst. for Atomic Energy

    1998-03-01

    Two practically useful quantities are introduced in this study to characterize a continuum neutron beam and to describe transmission phenomena of the beam in field of quantitative neutron radiography: an effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section defined at the monochromatic energy. The effective energy was evaluated by means of energy dependence of ETM cross section. To realize the method a beam quality indicator (BQI) has been proposed recently. Several effective energies were measured for non-filtered, filtered neutron beams, and outputs of neutron guide tubes in world by the BQI. A thermal neutron beam and three beams modulated by Pb filters with different thicknesses are studied to measure ETM cross sections for various materials and summarized in a table. Validity of the effective energy determined by the BQI is discussed relating with ETM cross sections of materials. (author)

  7. Ion Beam Energy Calibration Method for Accelerator

    International Nuclear Information System (INIS)

    Ion beam energy calibration methods, i e : nuclear reaction method, magnetic field method and calorimeter method were elaborated and studied from its advantage and disadvantage in this paper. Ion beam energy calibration method for accelerator using the method of magnetic field on 3 MV Tandem Accelerator have been carried out at Tiara, JAERI, Japan. The result showed that the energy of ion beam current is 43.56 keV. The result of study conclude that nuclear reaction method generally used to calibrate ion beam energy at the accelerator of energy larger than 2 MeV, calorimetric method for the accelerator electron including linac, magnetic field method for all particle type of accelerator. (author)

  8. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    International Nuclear Information System (INIS)

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  9. On the whole spectrum of Timoshenko beams. Part I: a theoretical revisitation

    Science.gov (United States)

    Cazzani, Antonio; Stochino, Flavio; Turco, Emilio

    2016-04-01

    The problem of free vibrations of the Timoshenko beam model is here addressed. A careful analysis of the governing equations allows identifying that the vibration spectrum consists of two parts, separated by a transition frequency, which, depending on the applied boundary conditions, might be itself part of the spectrum. For both parts of the spectrum, the values of natural frequencies are computed and the expressions of eigenmodes are provided. This allows to acknowledge that the nature of vibration modes changes when moving across the transition frequency. Among all possible combination of end constraints which can be applied to single-span beams, the case of a simply supported beam is considered. These theoretical results can be used as benchmarks for assessing the correctness of the numerical values provided by several numerical techniques, e.g. traditional Lagrangian-based finite element models or the newly developed isogeometric approach.

  10. Spectrum shaping of accelerator-based neutron beams for BNCT

    CERN Document Server

    Montagnini, B; Esposito, J; Giusti, V; Mattioda, F; Varone, R

    2002-01-01

    We describe Monte Carlo simulations of three facilities for the production of epithermal neutrons for Boron Neutron Capture Therapy (BNCT) and examine general aspects and problems of designing the spectrum-shaping assemblies to be used with these neutron sources. The first facility is based on an accelerator-driven low-power subcritical reactor, operating as a neutron amplifier. The other two facilities have no amplifier and rely entirely on their primary sources, a D-T fusion reaction device and a conventional 2.5 MeV proton accelerator with a Li target, respectively.

  11. Spectrum analysis of hydrogen plasma in spherically convergent beam fusion

    International Nuclear Information System (INIS)

    Spectroscopic analysis of spherical glow discharge fusion device was carried out using hydrogen gas. Effects of the discharge current and cathode voltage on spectrum profiles of hydrogen Balmar lines were measured. The profiles of all hydrogen lines were broadened with the cathode voltage. From the relationship between the maximum broadening width and the cathode voltage, it was indicated that the broadening was caused by the Doppler effect. From the spatial distribution of emission intensity, it was found that plasma core size became larger with discharge current and smaller with cathode voltage. (author)

  12. Spectrum analysis of hydrogen plasma in spherically convergent beam fusion

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, Kazuki; Yamauchi, Kunihito; Watanabe, Masato; Sunaga, Yoshitaka; Hotta, Eiki [Tokyo Institute of Technology, Dept. of Energy Sciences, Yokohama, Kanagawa (Japan); Okino, Akitoshi [Tokyo Institute of Technology, Dept. of Electrical and Electronic Engineering, Tokyo (Japan)

    2001-09-01

    Spectroscopic analysis of spherical glow discharge fusion device was carried out using hydrogen gas. Effects of the discharge current and cathode voltage on spectrum profiles of hydrogen Balmar lines were measured. The profiles of all hydrogen lines were broadened with the cathode voltage. From the relationship between the maximum broadening width and the cathode voltage, it was indicated that the broadening was caused by the Doppler effect. From the spatial distribution of emission intensity, it was found that plasma core size became larger with discharge current and smaller with cathode voltage. (author)

  13. Low energy beam transport system developments

    International Nuclear Information System (INIS)

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H− beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H− beams, but such gas densities cause unacceptably high H− beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H− beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed

  14. Low energy beam transport system developments

    Science.gov (United States)

    Dudnikov, V.; Han, B.; Stockli, M.; Welton, R.; Dudnikova, G.

    2015-04-01

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H- beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H- beams, but such gas densities cause unacceptably high H- beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H- beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  15. Calibration of a proton beam energy monitor.

    Science.gov (United States)

    Moyers, M F; Coutrakon, G B; Ghebremedhin, A; Shahnazi, K; Koss, P; Sanders, E

    2007-06-01

    Delivery of therapeutic proton beams requires an absolute energy accuracy of +/-0.64 to 0.27 MeV for patch fields and a relative energy accuracy of +/-0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  16. Effects of synchrotron radiation spectrum energy on polymethyl methacrylate photosensitivity to deep x-ray lithography

    CERN Document Server

    Mekaru, H; Hattori, T

    2003-01-01

    Since X-ray lithography requires a high photon flux to achieve deep resist exposure, a synchrotron radiation beam, which is not monochromatized, is generally used as a light source. If the synchrotron radiation beam is monochromatized, photon flux will decrease rapidly. Because of this reason, the wavelength dependence of the resist sensitivity has not been investigated for deep X-ray lithography. Measuring the spectrum of a white beam with a Si solid-state detector (SSD) is difficult because a white beam has a high intensity and an SSD has a high sensitivity. We were able to measure the spectrum and the photocurrent of a white beam from a beam line used for deep X-ray lithography by keeping the ring current below 0.05 mA. We evaluated the characteristics of the output beam based on the measured spectrum and photocurrent, and used them to investigate the relationship between the total exposure energy and the dose-processing depth with polymethyl methacrylate (PMMA). We found that it is possible to guess the p...

  17. Low-energy beam line at KVI

    NARCIS (Netherlands)

    Toprek, D.; Formanoy, I.; Brandenburg, S.

    2006-01-01

    This paper describes the redesign of the low-energy beam line at KVI. Redesigned and properties of the optical elements of the transport beam line is done by using the code COSY INFINITY in the third-order of approximation. The effects of fringe fields of the optical elements are also taken into acc

  18. NSPEC - A neutron spectrum code for beam-heated fusion plasmas

    International Nuclear Information System (INIS)

    A 3-dimensional computer code is described, which computes neutron spectra due to beam heating of fusion plasmas. Three types of interactions are considered; thermonuclear of plasma-plasma, beam-plasma and beam-beam interactions. Beam deposition is modelled by the NFREYA code. The applied steady state beam distribution as a function of pitch angle and velocity contains the effects of energy diffusion, friction, angular scattering, charge exchange, electric field and source pitch angle distribution. The neutron spectra, generated by Monte-Carlo methods, are computed with respect to given lines of sight. This enables the code to be used for neutron diagnostics. (author)

  19. Invariance of spectrum and polarization of electromagnetic Gaussian Schell-model beams propagating in free space

    Institute of Scientific and Technical Information of China (English)

    Jixiong Pu

    2006-01-01

    @@ The propagation of polychromatic electromagnetic Gaussian Schell-model (EGSM) beams in free space is investigated. It is shown that the spectral degree of polarization, spectral degree of coherence, and normalized spectrum change generally on propagation. The conditions of keeping the spectral invariance and keeping polarization invariance for the polychromatic EGSM beams are derived respectively. The results indicate that the constraints on the parameters of EGSM source to keep polarization invariance on propagation are more rigorous than those to keep invariance of the normalized spectrum.

  20. Neutralization of low energy broad ion beam

    International Nuclear Information System (INIS)

    The paper is devoted to experimental and theoretical investigation of a low energy broad ion beam space charge and current compensation and ion-beam plasma (IBP), which would be created in transport space of the beam. The beam had cylindrical symmetry. The continuous uniform and hole tube like ion beams are used in the experiments. Different channels of electron appearing have been investigated for cases of neutralization due to secondary γ-electrons from the target and by electrons from glow cathode-neutralizer with metal or dielectric target. Results of neutralizing electrons energy distributions function measurements are presented as well as dependences of electron temperature and self-consisted plasma potential vs. beam parameters, ambient gas pressure, neutralizer parameters. Role of the thermoelectrons and dependence of IBP parameters on neutralizer area, location and potential are discussed. Significant role in neutralization of spatial collisional processes has been revealed even in neutralization by thermocathode. On the base of the experimental results self-consistent theoretical model have been developed, which describes the behavior of intense ion beam passing through the neutral gas at low pressure within conductive walls. The collisionless approach is used which means absence of collisional relaxation of the beam. This theory is used to derive the plasma potential and electron temperature within the beam

  1. Compressed beam directed particle nuclear energy generator

    International Nuclear Information System (INIS)

    This invention relates to the generation of energy from the fusion of atomic nuclei which are caused to travel towards each other along collision courses, orbiting in common paths having common axes and equal radii. High velocity fusible ion beams are directed along head-on circumferential collision paths in an annular zone wherein beam compression by electrostatic focusing greatly enhances head-on fusion-producing collisions. In one embodiment, a steady radial electric field is imposed on the beams to compress the beams and reduce the radius of the spiral paths for enhancing the particle density. Beam compression is achieved through electrostatic focusing to establish and maintain two opposing beams in a reaction zone

  2. Nuclear spectroscopy and apparatus for stabilization of an energy spectrum

    International Nuclear Information System (INIS)

    Nuclear spectroscopy method and apparatus for the stabilization of an energy spectrum, made from a signal emitted by a radiation detector, and containing nuclear events, represented by pulses, whose amplitude is a measure of the energy of the particles, such as gamma rays, collected by the detector the spectrum including at least a first reference energy peak coming from an ancillary nuclear source, wherein the method comprises: detecting the radiation under analysis by two detectors between which is placed the ancillary source; establishing at least one coincident spectrum corresponding to pairs of events simultaneously detected in both detectors and originating from the ancillary source; and stabilizing the coincident spectrum by using one energy peak of said spectrum as said first reference energy peak. 8 refs

  3. LINAC4 low energy beam measurements

    CERN Document Server

    Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

    2012-01-01

    Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

  4. Effect of beam spectrum on quantitativeness of cold neutron computed tomography

    International Nuclear Information System (INIS)

    In case of radiography by a cold neutron beam having a continuous beam spectrum, neutron attenuation coefficients of many materials decrease with increasing the transmitting path length. As a result, quantitative analyses, such as determining the composition and density of the object quantitatively, with cold neutron computed tomography (CN-CT) has been difficult. In order to improve quantitativeness of CN-CT, we examined two procedures for reducing the effect of the thickness-dependent attenuation coefficient, and confirmed their effectiveness experimentally. One procedure is modifying projected images by using the neutron transmission curve as a kind of calibration curve, which is called the inverse function method. Another, the spectrum-narrowing method, is depressing change of the attenuation coefficient by making the width of the neutron beam spectrum narrower with a neutron filter. Each procedure was demonstrated experimentally to enable quantitative CN-CT. The inverse function method is simple, but it emphasizes noises of the projected image in, especially, the low neutron transmittance region. The spectrum-narrowing method has an advantage of obtaining the simple exponential attenuation property on neutron radiograph, though the longer exposure time was required because of beam intensity loss. (author)

  5. Calculation of energy spectra for the therapeutic electron beams from depth-dose curves

    International Nuclear Information System (INIS)

    In this note the algorithm for calculation of the electron energy spectrum from the depth-dose curve was tested by data on a 4 MeV linear accelerator with scanning beam. A Perspex phantom with cellulose triacetate dosimetric films was irradiated on a conveyor moving perpendicularly to the area of beam scanning, thus simulating irradiation by broad beam. Excellent agreement between measured and calculated spectra is claimed. (U.K.)

  6. Internal flows and energy circulation in light beams

    International Nuclear Information System (INIS)

    We review optical phenomena associated with the internal energy redistribution which accompany propagation and transformations of monochromatic light fields in homogeneous media. The total energy flow (linear-momentum density, Poynting vector) can be divided into a spin part associated with the polarization and an orbital part associated with the spatial inhomogeneity. We give a general description of the internal flows in the coordinate and momentum (angular spectrum) representations for both nonparaxial and paraxial fields. This enables one to determine local densities and integral values of the spin and orbital angular momenta of the field. We analyse patterns of the internal flows in standard beam models (Gaussian, Laguerre–Gaussian, flat-top beam, etc), which provide an insightful picture of the energy transport. Emphasis is given to the singular points of the flow fields. We describe the spin–orbit and orbit–orbit interactions in the processes of beam focusing and symmetry breakdown. Finally, we consider how the energy flows manifest themselves in the mechanical action on probing particles and in the transformations of a propagating beam subjected to a transverse perturbation. (review article)

  7. Pxie low energy beam transport commissioning

    CERN Document Server

    Prost, L; Andrews, R; Carneiro, J -P; Hanna, B; Scarpine, V; Shemyakin, A; D'Arcy, R; Wiesner, C

    2015-01-01

    The Proton Improvement Plan II (PIP-II) at Fermilab is a program of upgrades to the injection complex. At its core is the design and construction of a CW-compatible, pulsed H- superconducting RF linac. To validate the concept of the front-end of such machine, a test accelerator (a.k.a. PXIE) is under construction. It includes a 10 mA DC, 30 KeV H- ion source, a 2 m-long Low Energy Beam Transport (LEBT), a 2.1 MeV CW RFQ, followed by a Medium Energy Beam Transport (MEBT) that feeds the first of 2 cryomodules increasing the beam energy to ~25 MeV, and a High Energy Beam Transport section (HEBT) that takes the beam to a dump. The ion source and LEBT, which includes 3 solenoids, several clearing electrodes/collimators and a chopping system, have been built, installed, and commissioned to full specification parameters. This report presents the outcome of our commissioning activities, including phase-space measurements at the end of the beam line under various neutralization schemes obtained by changing the electro...

  8. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Haitao, E-mail: ren@frib.msu.edu; Pozdeyev, Eduard; Lund, Steven M.; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn [Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-02-15

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  9. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    Science.gov (United States)

    Ren, Haitao; Pozdeyev, Eduard; Lund, Steven M.; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn

    2016-02-01

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  10. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    International Nuclear Information System (INIS)

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper

  11. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  12. Evaluation of crystal implantation technique for the measurement of neutral beam composition and energy spectra

    International Nuclear Information System (INIS)

    A promising method of measuring a neutral beam's energy spectrum and impurity content is to implant beam high purity silicon crystals. The depth distribution of the beam particles into the crystal surface is then measured by SIMS (secondary ion mass spectroscopy); the penetration distance is a function of the incident particle energy. The inferred beam energy spectrum can be used to determine the percentages of atomic and molecular ions that comprise the source plasma. Moreover, other elements are analyzed by mass and compared with the total amount of implanted hydrogen in order to obtain a beam impurity content. Previous analysis of a 40 keV ORNL hydrogen beam gave a source species composition that agreed with that obtained by magnetic momentum analysis of the residual ion beam to within the accuracy of the momentum analysis. Crystals have already been irradiated by a 78 keV hydrogen beam from the LBL 30-sec ion source at their Neutral Beam Engineering Test Facility (NBETF); similar exposures are made with the ORNL 30 sec source at the same test stand. Use of the NBETF allows direct comparison with the spectra obtained from the LBL Doppler-shift spectrometer. Although increasing particle energy allows greater peak resolution and increased accuracy, the increasing power density makes proper exposure more difficult. An exposure technique used at ORNL to measure a 70 keV beam is also discussed

  13. Energy distribution of projectile fragment particles in heavy ion therapeutic beam

    Energy Technology Data Exchange (ETDEWEB)

    Matsufuji, Naruhiro; Tomura, Hiromi; Futami, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)] [and others

    1998-03-01

    Production of fragment particles in a patient`s body is one of important problems for heavy charged particle therapy. It is required to know the yield and the energy spectrum for each fragment element - so called `beam quality` to understand the effect of therapeutic beam precisely. In this study, fragment particles produced by practical therapeutic beam of HIMAC were investigated with using tissue-equivalent material and a detector complex. From the results, fragment particles were well identified by difference of their atomic numbers and the beam quality was derived. Responses of the detectors in this energy region were also researched. (author)

  14. Energy spectrum of stably-stratified and convective turbulent flows

    Science.gov (United States)

    Verma, Mahendra; Kumar, Abhishek

    2015-11-01

    In the inertial range of fluid turbulence, the energy flux is constant, while the energy spectrum scales as k - 5 / 3 (k=wavenumber). The buoyancy however could change the phenomenology dramatically. Bolgiano and Obukhov (1959) had conjectured that stably stratified flows (as in atmosphere) exhibits a decrease in the energy flux as k - 4 / 5 due to the conversion of kinetic energy to the potential energy, consequently, the energy spectrum scales as k - 11 / 5. We show using detailed numerical analysis that the stably stratified flows indeed exhibit k - 11 / 5 energy spectrum for Froude numbers Fr near unity. The flow becomes anisotropic for small Froude numbers. For weaker buoyancy (large Fr), the kinetic energy follows Kolmogorov's spectrum with a constant energy flux. However, in convective turbulence, the energy flux is a nondecreasing function of wavenumber since the buoyancy feeds positively into the kinetic energy. Hence, the kinetic energy spectrum is Kolmogorov-like (k - 5 / 3) or shallower. We also demonstrate the above scaling using a shell model of buoyancy-driven turbulence.

  15. Interference-aware random beam selection schemes for spectrum sharing systems

    KAUST Repository

    Abdallah, Mohamed

    2012-10-19

    Spectrum sharing systems have been recently introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this work, we develop interference-aware random beam selection schemes that provide enhanced performance for the secondary network under the condition that the interference observed by the receivers of the primary network is below a predetermined/acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a primary link composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes select a beam, among a set of power-optimized random beams, that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the SINR statistics as well as the capacity and bit error rate (BER) of the secondary link.

  16. Fluidic energy harvesting beams in grid turbulence

    Science.gov (United States)

    Danesh-Yazdi, A. H.; Goushcha, O.; Elvin, N.; Andreopoulos, Y.

    2015-08-01

    Much of the recent research involving fluidic energy harvesters based on piezoelectricity has focused on excitation through vortex-induced vibration while turbulence-induced excitation has attracted very little attention, and virtually no previous work exists on excitation due to grid-generated turbulence. The present experiments involve placing several piezoelectric cantilever beams of various dimensions and properties in flows where turbulence is generated by passive, active, or semi-passive grids, the latter having a novel design that significantly improves turbulence generation compared to the passive grid and is much less complex than the active grid. We experimentally show for the first time that the average power harvested by a piezoelectric cantilever beam placed in decaying isotropic, homogeneous turbulence depends on mean velocity, velocity and length scales of turbulence as well as the electromechanical properties of the beam. The output power can be modeled as a power law with respect to the distance of the beam from the grid. Furthermore, we show that the rate of decay of this power law closely follows the rate of decay of the turbulent kinetic energy. We also introduce a forcing function used to model approximately the turbulent eddies moving over the cantilever beam and observe that the feedback from the beam motion onto the flow is virtually negligible for most of the cases considered, indicating an effectively one-way interaction for small-velocity fluctuations.

  17. Impulsive solar X-ray bursts. III - Polarization, directivity, and spectrum of the reflected and total bremsstrahlung radiation from a beam of electrons directed toward the photosphere

    Science.gov (United States)

    Langer, S. H.; Petrosian, V.

    1977-01-01

    The paper presents the spectrum, directivity, and state of polarization of the bremsstrahlung radiation expected from a beam of high-energy electrons spiraling along radial magnetic field lines toward the photosphere. A Monte Carlo method is then described for evaluation of the spectrum, directivity, and polarization of X-rays diffusely reflected from stellar photospheres. The accuracy of the technique is evaluated through comparison with analytic results. The calculated characteristics of the incident X-rays are used to evaluate the spectrum, directivity, and polarization of the reflected and total X-ray fluxes. The results are compared with observations.

  18. THERMO-MECHANICAL MODELLING OF METAL STRUCTURES SUBJECTED TO HIGH ENERGY PARTICLE BEAM IMPACTS

    CERN Document Server

    Peroni, L; Dallocchio, A

    2011-01-01

    Particle accelerators [Wiedemann 1993] act as microscopes for such a complex research; these large machines accelerate charged elementary particles (electrons, protons or ionized atoms) to high kinetic energies. A high energy particle beam can be brought into collision against a fixed target or against another beam and from this encounter a multitude of short life sub-atomic particles is originated. The higher the energy of the colliding beams and the event rate, the wider the spectrum of the generable sub-atomic particles.

  19. A correlated study between effective total macroscopic cross sections and effective energies for neutron beams with continuous spectra

    CERN Document Server

    Kobayashi, H

    1999-01-01

    Two practically useful quantities have been introduced to characterize a continuous-energy-spectrum neutron beam and to describe transmission phenomena of the beam in the field of quantitative neutron radiography. These quantities are the effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section as defined for a monochromatic energy. Four neutron beams have been used to measure ETM cross sections at effective energies of 29.8, 17.2, 9.8 meV, and at the In resonance energy of 1.46 eV. Results are studied as a function of estimated effective energy, where the effective energy was estimated by a beam quality indicator (BQI) which has been proposed recently. Validity of ETM cross sections as a function of the effective energy is discussed and correlated with recent nuclear data.

  20. Energy detection for spectrum sensing in cognitive radio

    CERN Document Server

    Atapattu, Saman; Jiang, Hai

    2014-01-01

    This Springer Brief focuses on the current state-of-the-art research on spectrum sensing by using energy detection, a low-complexity and low-cost technique. It includes a comprehensive summary of recent research, fundamental theories, possible architectures, useful performance measurements of energy detection and applications of energy detection. Concise, practical chapters explore conventional energy detectors, alternative forms of energy detectors, performance measurements, diversity techniques and cooperative networks. The careful analysis enables reader to identify the most efficient techn

  1. ABSOLUTE MEASUREMENT OF THE GANIL BEAM ENERGY

    NARCIS (Netherlands)

    CASANDJIAN, JM; MITTIG, W; BEUNARD, R; GAUDARD, L; LEPINESZILY, A; VILLARI, ACC; AUGER, G; BIANCHI, L; CUNSOLO, A; FOTI, A; LICHTENTHALER, R; PLAGNOL, E; SCHUTZ, Y; SIEMSSEN, RH; WIELECZKO, JP

    1993-01-01

    The energy of the GANIL cyclotron beam was measured on-line during the Pb-208 + Pb-208 elastic scattering experiment ''Search for Color van der Waals Force in the Pb-208 + Pb-208 Mott scattering'' with an absolute precision of 7 x 10(-5) at approximately 1.0 GeV, which represents an improvement of o

  2. Superintense ion beam with high energy density

    Science.gov (United States)

    Dudnikov, Vadim; Dudnikova, Galina

    2008-04-01

    The energy density of ion beam accumulated in a storage ring can be increased dramatically with using of space charge compensation as was demonstrated in experiments [1]. The intensity of said superintense beam can be far greater than a space charge limit without space charge compensation. The model of secondary plasma build up with secondary ion-electron emission as a source of delayed electrons has been presented and discussed. This model can be used for explanation of bunched beam instability with electron surviving after gap, for prediction of e-cloud generation in coasting and long bunches beam, and can be important for pressure rise in worm and cold sections of storage rings. A fast desorption by ion of physically adsorbed molecules can explain a ``first pulse Instability''. Application of this model for e-p instability selfstabilization and superintense circulating beam accumulation is considered. Importance of secondary plasma for high perveance ion beam stabilization in ion implantation will be considered. Preliminary results of simulation of electron and ion accumulation will be presented. [1]. Belchenko et al., Xth International Particle Accelerator Conference, Protvino, 1977, Vol. 2, p. 287.

  3. The High Energy Spectrum of NGC 4151

    CERN Document Server

    Beckmann, V; Gehrels, N; Soldi, S; Lubinski, P; Zdziarski, A A; Petrucci, P O; Malzac, J

    2005-01-01

    We present the first INTEGRAL observations of the type 1.5 Seyfert galaxy NGC 4151. Combining several INTEGRAL observations performed during 2003, totaling about 400 ks of exposure time, allows us to study the spectrum in the 2 - 300 keV range. The measurements presented here reveal an overall spectrum from X-rays up to soft gamma-rays that can be described by an absorbed (NH = 6.9e22 1/cm**2) model based on a Compton continuum from a hot electron population (kT = 94 keV) from an optically thick (tau = 1.3) corona, reflected on cold material (R=0.7), consistent with earlier claims. The time resolved analysis shows little variation of the spectral parameters over the duration of the INTEGRAL observations. The comparison with CGRO/OSSE data shows that the same spectral model can be applied over a time span of 15 years, with flux variations of the order of a factor of 2 and changes in the underlying continuum reflected by the temperature of the electron population (kT = 50 - 100 keV). When modeled with an expone...

  4. Mass Spectrum Analysis of CO2 and N2 Using Ion Beam Separator System

    International Nuclear Information System (INIS)

    The main purpose of this research is to study investigate the massspectrum profile of CO2 and N2 emitted from Penning ion source using ionbeam separator. Besides that, it is also identified the compositions of CO2and N2 ion gas and their abundances through their mass spectrum profile,because as we know that these ions are consist of ion of atom or molecule aswell as the their abundances. To get these profiles, the ion beam acceleratedin accelerating tube are passed through magnet separator. After passing themagnet separator, the ion current beam was detected using microampere meter.By scanning the strength of magnetic field, it will be found the currentspectrum profile as a function of magnetic field. From this current spectrum,we can make a mass spectrum profile. From experiment done, it was found thatthe mass spectrum peak of CO2 and N2 were C+ with m/z = (12.00 ± 0.10)amu, O2+ = (31.96 ± 0.29) amu, CO2+ = (43.93 ± 0.31) amu, N+(13.97 ± 0.33) amu, and N2+ = (28.05 ± 0.18) amu. (author)

  5. Analytical solution for beam with time-dependent boundary conditions versus response spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Gou, P.F.; Panahi, K.K. [GE Nuclear Energy, San Jose, CA (United States)

    2001-07-01

    This paper studies the responses of a uniform simple beam for which the supports are subjected to time-dependent conditions. Analytical solution in terms of series was presented for two cases: (1) Two supports of a simple beam are subjected to a harmonic motion, and (2) One of the two supports is stationary while the other is subjected to a harmonic motion. The results of the analytical solution were investigated and compared with the results of conventional response spectrum method using the beam finite element model. One of the applications of the results presented in this paper can be used to assess the adequacy and accuracy of the engineering approaches such as response spectra methods. It has been found that, when the excitation frequency equals the fundamental frequency of the beam, the results from response spectrum method are in good agreement with the exact calculation. The effects of initial conditions on the responses are also examined. It seems that the non-zero initial velocity has pronounced effects on the displacement time histories but it has no effect on the maximum accelerations. (author)

  6. Energy Absorption Capacity of Composite Beams

    Directory of Open Access Journals (Sweden)

    Arivalagan

    2009-01-01

    Full Text Available Local buckling may occur in the compression flange of rectangular hollow-section beams under cyclic repeated loadingarising from earthquakes. Once a local mechanism forms, residual strength rapidly reduces within a few cycles. This is trueeven for compact sections under static bending. This paper aims to study the experimental behaviour and ultimate momentcapacity of unfilled and concrete-filled rectangular hollow sections subjected to cyclic reversible loading. Two types offiller material were used - normal mix concrete and fly ash concrete. The effect of filler materials, section slenderness, loaddeflectionresponse, moment-strain behaviour, first cycle peak load, ductility, stiffness degradation and energy absorption ofconcrete –filled RHS beams are studied.

  7. Energy recovery in high energy neutral beam injectors

    International Nuclear Information System (INIS)

    One way to heat the plasma of thermonuclear fusion experiments, is to inject high energy (50 to 100 KeV per nucleon), neutral particles (hydrogen or deuterium). Neutral beam elaboration consists in ion production and acceleration, neutralisation by charge exchange on gas target, disposal of unneutralized ions. But, in the case of positive ion based neutral beam injection, the neutralisation efficiency is limited to 50% at 100 KeV, and decreases rapidly with energy. The energy recovery is a new method for disposing of the unneutralized ions: these are electrostatically decelerated and collected on electrodes which are polarized at low voltage, close to the ion source potential. An energy recovery system was studied and experimented with positive ion beams of 50 and 100 KeV. In the framework of a french-japanese collaboration, we measured a relative power reduction of about 20%, with 100 KeV, 1,5 MW deuterium beams. We have also studied theoretically an energy recovery system for negative ion beams, which will be utilized at high energy (1 MeV). A relative power reduction of 20% can be expected in the best conditions

  8. NREL Spectrum of Clean Energy Innovation: Issue 3 (Book)

    Energy Technology Data Exchange (ETDEWEB)

    2012-11-01

    This quarterly magazine is dedicated to stepping beyond the technical journals to reveal NREL's vital work in a real-world context for our stakeholders. Continuum provides insights into the latest and most impactful clean energy innovations, while spotlighting those talented researchers and unique facilities that make it all happen. This edition focuses on the NREL Spectrum of Clean Energy Innovation.

  9. Ultra High Energy Cosmic Rays Propagation and Spectrum

    OpenAIRE

    Aloisio, Roberto

    2011-01-01

    The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on earth will be presented, applying such scheme to interpret the experimental results. The phenomenological scenarios favored by HiRes and Auger in terms of chemical composition and spectrum will be also presented.

  10. Interaction of turbulence with flexible beams in fluidic energy harvesting

    Science.gov (United States)

    Danesh Yazdi, Amir Hossein

    Advances in the development and fabrication of microelectronics have enhanced the energy efficiency of these devices to such an extent that they can now operate at very low power levels, typically on the order of a few microwatts or less. Batteries are primarily thought of as the most convenient source of power for electronic devices, but in instances where a device needs to be deployed in a difficult-to-access location such as under water, the added weight and especially maintenance of such a power source becomes costly. A solution that avoids this problem and is particularly attractive in a "deploy & forget" setting involves designing a device that continuously harvests energy from the surrounding environment. Piezoelectric energy harvesters, which employ the direct piezoelectric effect to convert mechanical strain into electrical energy, have garnered a great deal of attention in the literature. This work presents an overview of the experimental and analytical results related to fluidic energy extraction from vortex and turbulent flow using piezoelectric cantilever beams. In particular, the development of the FTGF (Fourier Transform-Green's Function) solution approach to the coupled, continuous electromechanical equations governing piezoelectric cantilever beams and the associated TFB (Train of Frozen Boxcars) method, which models the flow of vortices and turbulent eddies over the beams, is discussed. In addition, the behavior of fluidic energy harvesters in decaying isotropic, homogeneous grid turbulence generated by passive, semi-passive and active grids is examined and a novel grid-turbulence forcing model is introduced. An expression for the expected power output of the piezoelectric beam is obtained by utilizing this forcing function model in the single degree-of-freedom electromechanical equations. Furthermore, approximate, closed-form solutions to the theoretical expected power are derived from deterministic turbulence forcing models and are compared with

  11. On the whole spectrum of Timoshenko beams. Part II: further applications

    Science.gov (United States)

    Cazzani, Antonio; Stochino, Flavio; Turco, Emilio

    2016-04-01

    The problem of free vibrations of the Timoshenko beam model has been addressed in the first part of this paper. A careful analysis of the governing equations has shown that the vibration spectrum consists of two parts, separated by a transition frequency, which, depending on the applied boundary conditions, might be itself part of the spectrum. Here, as an extension, the case of a doubly clamped beam is considered. For both parts of the spectrum, the values of natural frequencies are computed and the expressions of eigenmodes are provided: this allows to acknowledge that the nature of vibration modes changes when moving across the transition frequency. This case is a meaningful example of more general ones, where the wave-numbers equation cannot be written in a factorized form and hence must be solved by general root-finding methods for nonlinear transcendental equations. These theoretical results can be used as further benchmarks for assessing the correctness of the numerical values provided by several numerical techniques, e.g. finite element models.

  12. Energy verification in Ion Beam Therapy

    CERN Document Server

    Moser, F; Dorda, U

    2011-01-01

    The adoption of synchrotrons for medical applications necessitates a comprehensive on-line verification of all beam parameters, autonomous of common beam monitors. In particular for energy verification, the required precision of down to 0.1MeV in absolute terms, poses a special challenge regarding the betatron-core driven 3rd order extraction mechanism which is intended to be used at MedAustron [1]. Two different energy verification options have been studied and their limiting factors were investigated: 1) A time-of-flight measurement in the synchrotron, limited by the orbit circumference information and measurement duration as well as extraction uncertainties. 2) A calorimeter-style system in the extraction line, limited by radiation hardness and statistical fluctuations. The paper discusses in detail the benefits and specific aspects of each method.

  13. Bayesian modelling of the emission spectrum of the Joint European Torus Lithium Beam Emission Spectroscopy system.

    Science.gov (United States)

    Kwak, Sehyun; Svensson, J; Brix, M; Ghim, Y-C

    2016-02-01

    A Bayesian model of the emission spectrum of the JET lithium beam has been developed to infer the intensity of the Li I (2p-2s) line radiation and associated uncertainties. The detected spectrum for each channel of the lithium beam emission spectroscopy system is here modelled by a single Li line modified by an instrumental function, Bremsstrahlung background, instrumental offset, and interference filter curve. Both the instrumental function and the interference filter curve are modelled with non-parametric Gaussian processes. All free parameters of the model, the intensities of the Li line, Bremsstrahlung background, and instrumental offset, are inferred using Bayesian probability theory with a Gaussian likelihood for photon statistics and electronic background noise. The prior distributions of the free parameters are chosen as Gaussians. Given these assumptions, the intensity of the Li line and corresponding uncertainties are analytically available using a Bayesian linear inversion technique. The proposed approach makes it possible to extract the intensity of Li line without doing a separate background subtraction through modulation of the Li beam. PMID:26931843

  14. Energy Production Demonstrator for Megawatt Proton Beams

    CERN Document Server

    Pronskikh, Vitaly S; Novitski, Igor; Tyutyunnikov, Sergey I

    2014-01-01

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however...

  15. Multislot Simultaneous Spectrum Sensing and Energy Harvesting in Cognitive Radio

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2016-07-01

    Full Text Available In cognitive radio (CR, the spectrum sensing of the primary user (PU may consume some electrical power from the battery capacity of the secondary user (SU, resulting in a decrease in the transmission power of the SU. In this paper, a multislot simultaneous spectrum sensing and energy harvesting model is proposed, which uses the harvested radio frequency (RF energy of the PU signal to supply the spectrum sensing. In the proposed model, the sensing duration is divided into multiple sensing slots consisting of one local-sensing subslot and one energy-harvesting subslot. If the PU is detected to be present in the local-sensing subslot, the SU will harvest RF energy of the PU signal in the energy-harvesting slot, otherwise, the SU will continue spectrum sensing. The global decision on the presence of the PU is obtained through combining local sensing results from all the sensing slots by adopting “Or-logic Rule”. A joint optimization problem of sensing time and time splitter factor is proposed to maximize the throughput of the SU under the constraints of probabilities of false alarm and detection and energy harvesting. The simulation results have shown that the proposed model can clearly improve the maximal throughput of the SU compared to the traditional sensing-throughput tradeoff model.

  16. Interference Energy Spectrum of the Infinite Square Well

    Directory of Open Access Journals (Sweden)

    Mordecai Waegell

    2016-04-01

    Full Text Available Certain superposition states of the 1-D infinite square well have transient zeros at locations other than the nodes of the eigenstates that comprise them. It is shown that if an infinite potential barrier is suddenly raised at some or all of these zeros, the well can be split into multiple adjacent infinite square wells without affecting the wavefunction. This effects a change of the energy eigenbasis of the state to a basis that does not commute with the original, and a subsequent measurement of the energy now reveals a completely different spectrum, which we call the interference energy spectrum of the state. This name is appropriate because the same splitting procedure applied at the stationary nodes of any eigenstate does not change the measurable energy of the state. Of particular interest, this procedure can result in measurable energies that are greater than the energy of the highest mode in the original superposition, raising questions about the conservation of energy akin to those that have been raised in the study of superoscillations. An analytic derivation is given for the interference spectrum of a given wavefunction Ψ ( x , t with N known zeros located at points s i = ( x i , t i . Numerical simulations were used to verify that a barrier can be rapidly raised at a zero of the wavefunction without significantly affecting it. The interpretation of this result with respect to the conservation of energy and the energy-time uncertainty relation is discussed, and the idea of alternate energy eigenbases is fleshed out. The question of whether or not a preferred discrete energy spectrum is an inherent feature of a particle’s quantum state is examined.

  17. High Energy Atmospheric Neutrino Fluxes From a Realistic Primary Spectrum

    Science.gov (United States)

    Campos Penha, Felipe; Dembinski, Hans; Gaisser, Thomas K.; Tilav, Serap

    2016-03-01

    Atmospheric neutrino fluxes depend on the energy spectrum of primary nucleons entering the top of the atmosphere. Before the advent of AMANDA and the IceCube Neutrino Observatory, measurements of the neutrino fluxes were generally below ~ 1TeV , a regime in which a simple energy power law sufficed to describe the primary spectrum. Now, IceCube's muon neutrino data extends beyond 1PeV , including a combination of neutrinos from astrophysical sources with background from atmospheric neutrinos. At such high energies, the steepening at the knee of the primary spectrum must be accounted for. Here, we describe a semi-analytical approach for calculating the atmospheric differential neutrino fluxes at high energies. The input is a realistic primary spectrum consisting of 4 populations with distinct energy cutoffs, each with up to 7 representative nuclei, where the parameters were extracted from a global fit. We show the effect of each component on the atmospheric neutrino spectra, above 10TeV . The resulting features follow directly from recent air shower measurements included in the fit. Felipe Campos Penha gratefully acknowledges financial support from CAPES (Processo BEX 5348/14-5), CNPq (Processo 142180/2012-2), and the Bartol Research Institute.

  18. Low energy beam transport for HIDIF

    Energy Technology Data Exchange (ETDEWEB)

    Meusel, O. E-mail: o.meusel@iap.uni-frankfurt.de; Pozimski, J.; Jakob, A.; Lakatos, A

    2001-05-21

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe{sup +} beam are presented and the results of numerical simulations are shown.

  19. Electron beam accelerator energy control system

    International Nuclear Information System (INIS)

    A control system has been developed for the energy control of the electron beam accelerator using PLC. The accelerating voltage of 3 MV has been obtained by using parallel coupled voltage multiplier circuit. A autotransformer controlled variable 0-10 KV DC is fed to a tube based push pull oscillator to generate 120 Khz, 10 KV AC. Oscillator output voltage is stepped up to 0-300 KV/AC using a transformer. 0-300 KVAC is fed to the voltage multiplier column to generate the accelerating voltage at the dome 0-3 MV/DC. The control system has been designed to maintain the accelerator voltage same throughout the operation by adjusting the input voltage in close loop. Whenever there is any change in the output voltage either because of beam loading or arcing in the accelerator. The instantaneous accelerator voltage or energy is a direct proportional to 0-10 KVDC obtained from autotransformer. A PLC based control system with user settable energy level has been installed for 3 MeV, EB accelerator. The PLC takes the user defined energy value through a touch screen and compares it to the actual accelerating voltage (obtained using resistive divider). Depending upon the error the PLC generates the pulses to adjust the autotransformer to bring the actual voltage to the set value within the window of error (presently set to +/- 0.1%). (author)

  20. Energy Spectrum of Anyons in a Magnetic Field

    CERN Document Server

    Illuminati, F

    1993-01-01

    For the many-anyon system in external magnetic field, we derive the energy spectrum as an exact solution of the quantum eigenvalue problem with particular topological constraints. Our results agree with the numerical spectra recently obtained for the 3- and the 4-anyon systems.

  1. Energy Spectrum of Anyons in a Magnetic Field

    OpenAIRE

    Illuminati, Fabrizio

    1992-01-01

    For the many-anyon system in external magnetic field, we derive the energy spectrum as an exact solution of the quantum eigenvalue problem with particular topological constraints. Our results agree with the numerical spectra recently obtained for the 3- and the 4-anyon systems.

  2. Energy Spectrum Of Nonthermal Electrons Accelerated At A Plane Shock

    CERN Document Server

    Kang, Hyesung

    2011-01-01

    We calculate the energy spectra of cosmic ray (CR) protons and electrons at a plane shock with quasi-parallel magnetic fields, using time-dependent, diffusive shock acceleration (DSA) simulations, including energy losses via synchrotron emission and Inverse Compton (IC) scattering. A thermal leakage injection model and a Bohm type diffusion coefficient are adopted. The electron spectrum at the shock becomes steady after the DSA energy gains balance the synchrotron/IC losses, and it cuts off at the equilibrium momentum p_{eq}. In the postshock region the cutoff momentum of the electron spectrum decreases with the distance from the shock due to the energy losses and the thickness of the spatial distribution of electrons scales as p^{-1}. Thus the slope of the downstream integrated spectrum steepens by one power of p for p_{br}spectrum exhibit a concave curvature and...

  3. Faraday Cup - it is used to measure beam intensities at low energy beams.

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    A Faraday Cup is used to measure beam intensities at low energy beams. An electrically isolated metallic electrode intercepts the beam and captures all its charges. These charges are integrated using an current sensitive amplifier. When the beam impinges onto the electrode surface low energy electrons are liberated. In order to prevent these electrons from escaping the cup and thus falsifying the measurement, a repeller electrode with negative potential pushes the electrons back onto the electrode.

  4. Exact energy spectrum for models with equally spaced point potentials

    OpenAIRE

    Caudrelier, V.; Crampe, N.

    2006-01-01

    We describe a non-perturbative method for computing the energy band structures of one-dimensional models with general point potentials sitting at equally spaced sites. This is done thanks to a Bethe ansatz approach and the method is applicable even when periodicity is broken, that is when Bloch's theorem is not valid any more. We derive the general equation governing the energy spectrum and illustrate its use in various situations. In particular, we get exact results for boundary effects. We ...

  5. Measurement of the energy spectrum of cosmic ray hadrons

    International Nuclear Information System (INIS)

    In the course of the air shower experiment KASCADE a prototype of the central calorimeter was built. The construction of the TMS-ionization chambers and the trigger system are described in detail. With the prototype calorimeter single cosmic ray hadrons were measured. The identification of hadronic showers in the calorimeter and the determination of the hadron energy are explained. With about 50000 reconstructed single hadrons the differential energy spectrum in the energy range between 3 GeV and 15 TeV and the energy dependence of the inelastic proton-air cross section could be determined. The results are compared with those of earlier experiments. (orig.)

  6. Aspects on the optimal photon beam energy for radiation therapy

    International Nuclear Information System (INIS)

    The selection of optimal photon beam energy is investigated both for realistic clinical bremsstrahlung beams and for monoenergetic photon beams. The photon energies covered in this investigation range from 60Co to bremsstrahlung and monoenergetic beams with maximum energies up to 50 MeV. One head and neck tumor and an advanced cervix tumor are investigated and the influence of beam direction is considered. It is shown that the use of optimized intensity modulated photon beams significantly reduces the need of beam energy selection. The most suitable single accelerator potential will generally be in the range 6-15 MV for both superficially located and deep-seated targets, provided intensity-modulated dose delivery is employed. It is also shown that a narrow penumbra region of a photon beam ideally should contain low-energy photons (≤4 MV), whereas the gross tumor volume, particularly when deep-seated targets are concerned, should be irradiated by high-energy photons. The regions where low photon energies are most beneficial are where organs at risk are laterally close to the target volume. The situation is completely changed when uniform or wedged beams are used. The selection of optimal beam energy then becomes a very important task in line with the experience from traditional treatment techniques. However, even with a large number of uniform beam portals, the treatment outcome is substantially lower than with a few optimized intensity-modulated beams. (orig.)

  7. Broad energy spectrum of laser-accelerated protons for spallation-related physics

    International Nuclear Information System (INIS)

    A beam of MeV protons, accelerated by ultraintense laser-pulse interactions with a thin target foil, is used to investigate nuclear reactions of interest for spallation physics. The laser-generated proton beam is shown (protons were measured) to have a broad energy distribution, which closely resembles the expected energy spectrum of evaporative protons (below 50 MeV) produced in GeV-proton-induced spallation reactions. The protons are used to quantify the distribution of residual radioisotopes produced in a representative spallation target (Pb), and the results are compared with calculated predictions based on spectra modeled with nuclear Monte Carlo codes. Laser-plasma particle accelerators are shown to provide data relevant to the design and development of accelerator driven systems

  8. Electrostatic energy analyzers for high energy charged particle beams

    International Nuclear Information System (INIS)

    The electrostatic energy analyzers for high energy charged particle beams emitted from extended large-size objects as well as from remote point sources are proposed. Results of the analytical trajectory solutions in ideal cylindrical field provide focusing characteristics for both configurations. The instruments possess of simple compact design, based on an ideal cylindrical field with entrance window arranged in the end-boundary between electrodes and can be used for measurements in space technologies, plasma and nuclear physics

  9. Neutron spectrum measurements at a radial beam port of the NUR research reactor using a Bonner spheres spectrometer.

    Science.gov (United States)

    Mazrou, H; Nedjar, A; Seguini, T

    2016-08-01

    This paper describes the measurement campaign held around the neutron radiography (NR) facility of the Algerian 1MW NUR research reactor. The main objective of this work is to characterize accurately the neutron beam provided at one of the radial channels of the NUR research reactor taking benefit of the acquired CRNA Bonner spheres spectrometer (BSS). The specific objective was to improve the image quality of the NR facility. The spectrometric system in use is based on a central spherical (3)He thermal neutron proportional counter combined with high density polyethylene spheres of different diameters ranging from 3 to 12in. This counting system has good gamma ray discrimination and is able to cover an energy range from thermal to 20MeV. The measurements were performed at the sample distance of 0.6m from the beam port and at a height of 1.2m from the facility floor. During the BSS measurements, the reactor was operating at low power (100W) to avoid large dead times, pulse pileup and high level radiation exposures, in particular, during spheres handling. Thereafter, the neutron spectrum at the sample position was unfolded by means of GRAVEL and MAXED computer codes. The thermal, epithermal and fast neutron fluxes, the total neutron flux, the mean energy and the Cadmium ratio (RCd) were provided. A sensitivity analysis was performed taking into account various defaults spectra and ultimately a different response functions in the unfolding procedure. Overall, from the obtained results it reveals, unexpectedly, that the measured neutron spectrum at the sample position of the neutron radiography of the NUR reactor is being harder with a predominance of fast neutrons (>100keV) by about 60%. Finally, those results were compared to previous and more recent measurements obtained by activation foils detectors. The agreement was fairly good highlighting thereby the consistency of our findings. PMID:27203706

  10. Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Vedantham, Srinivasan; Shi, Linxi; Glick, Stephen J.; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2013-01-15

    Purpose: To determine the x-ray photon energy dependence of the anatomic power spectrum of the breast when imaged with dedicated breast computed tomography (CT). Methods: A theoretical framework for scaling the empirically determined anatomic power spectrum at one x-ray photon energy to that at any given x-ray photon energy when imaged with dedicated breast CT was developed. Theory predicted that when the anatomic power spectrum is fitted with a power curve of the form k f{sup -{beta}}, where k and {beta} are fit coefficients and f is spatial frequency, the exponent {beta} would be independent of x-ray photon energy (E), and the amplitude k scales with the square of the difference in energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues. Twenty mastectomy specimens based numerical phantoms that were previously imaged with a benchtop flat-panel cone-beam CT system were converted to 3D distribution of glandular weight fraction (f{sub g}) and were used to verify the theoretical findings. The 3D power spectrum was computed in terms of f{sub g} and after converting to linear attenuation coefficients at monoenergetic x-ray photon energies of 20-80 keV in 5 keV intervals. The 1D power spectra along the axes were extracted and fitted with a power curve of the form k f{sup -{beta}}. The energy dependence of k and {beta} were analyzed. Results: For the 20 mastectomy specimen based numerical phantoms used in the study, the exponent {beta} was found to be in the range of 2.34-2.42, depending on the axis of measurement. Numerical simulations agreed with the theoretical predictions that for a power-law anatomic spectrum of the form k f{sup -{beta}}, {beta} was independent of E and k(E) =k{sub 1}[{mu}{sub g}(E) -{mu}{sub a}(E)]{sup 2}, where k{sub 1} is a constant, and {mu}{sub g}(E) and {mu}{sub a}(E) represent the energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues, respectively. Conclusions: Numerical

  11. Scaling-law for the energy dependence of anatomic power spectrum in dedicated breast CT

    International Nuclear Information System (INIS)

    Purpose: To determine the x-ray photon energy dependence of the anatomic power spectrum of the breast when imaged with dedicated breast computed tomography (CT). Methods: A theoretical framework for scaling the empirically determined anatomic power spectrum at one x-ray photon energy to that at any given x-ray photon energy when imaged with dedicated breast CT was developed. Theory predicted that when the anatomic power spectrum is fitted with a power curve of the form k f−β, where k and β are fit coefficients and f is spatial frequency, the exponent β would be independent of x-ray photon energy (E), and the amplitude k scales with the square of the difference in energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues. Twenty mastectomy specimens based numerical phantoms that were previously imaged with a benchtop flat-panel cone-beam CT system were converted to 3D distribution of glandular weight fraction (fg) and were used to verify the theoretical findings. The 3D power spectrum was computed in terms of fg and after converting to linear attenuation coefficients at monoenergetic x-ray photon energies of 20–80 keV in 5 keV intervals. The 1D power spectra along the axes were extracted and fitted with a power curve of the form k f−β. The energy dependence of k and β were analyzed. Results: For the 20 mastectomy specimen based numerical phantoms used in the study, the exponent β was found to be in the range of 2.34–2.42, depending on the axis of measurement. Numerical simulations agreed with the theoretical predictions that for a power-law anatomic spectrum of the form k f−β, β was independent of E and k(E) =k1[μg(E) −μa(E)]2, where k1 is a constant, and μg(E) and μa(E) represent the energy-dependent linear attenuation coefficients of fibroglandular and adipose tissues, respectively. Conclusions: Numerical simulations confirmed the theoretical predictions that in dedicated breast CT, the spatial frequency

  12. Measurement of the BESSY II electron beam energy by Compton-backscattering of laser photons

    CERN Document Server

    Klein, R; Thornagel, R; Brandt, G; Görgen, R; Ulm, G

    2002-01-01

    Accurate knowledge of all storage ring parameters is essential for the Physikalisch-Technische Bundesanstalt (PTB) to operate the electron storage ring BESSY II as a primary source standard. One parameter entering the Schwinger equation for the calculation of the spectral photon flux of bending magnet radiation is the electron beam energy. So at BESSY II the electron beam energy is measured by two independent techniques one of which is described in this paper: the photons from a CO sub 2 -laser are scattered in a head-on collision with the stored electrons. From the spectrum of the backscattered photons that are detected by an energy-calibrated HPGe detector the electron beam energy can be determined. The experimental set-up at the BESSY II electron storage ring as well as the current experimental status are described for operation of the storage ring at the energies of 900 and 1700 MeV.

  13. Radon measurement in α energy spectrum and its influence factors

    International Nuclear Information System (INIS)

    Background: Radon is one radioactive gas which should be monitored. Purpose: High sensitivity, good stability for distinguishing the characteristics of radon and thorium in air radon content measurement are required. Methods: One alpha energy spectrum measuring device was designed based on diffusion-accumulation theory. And the major influence factors were discussed. At the same time, the preliminary solution was proposed and testing was progressed. Results: We have got the results of energy calibration curve, energy resolution, sensitivity and other important information by standard radon chamber calibration. Conclusions: The experimental results show that this scheme is feasible and the performance is suited to the national standards for air radon measurement requirements. (authors)

  14. Spectrum sensing using single-radio switched-beam antenna systems

    DEFF Research Database (Denmark)

    Tsakalaki, Elpiniki; Wilcox, David; De Carvalho, Elisabeth;

    2012-01-01

    of the reactive loads rotate the narrowband beampattern to different angular positions dividing the whole space around the cognitive receiver into several angular subspaces. The beampattern directionality leverages the performance of spectrum sensing algorithms like the energy detection by enhancing...... the receive signal-to-noise ratio. Moreover, the selection combining across the weakly correlated beampatterns gives rise to a diversity action further boosting the probability of detection....

  15. Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2.

  16. Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum

    International Nuclear Information System (INIS)

    In order to study the mechanism of irradiation-induced damage of botanic samples caused by low energy heavy ions, transmission energy spectrum measurement was performed. Kidney bean slice samples 100 μm in thickness were irradiated by 50 keV N+ ions. The irradiation beam current density was about 30 μA/cm2, and the irradiation ion doses were 1 x 1015, 1 x 1016, 3 x 1016 and 1 x 1017 ions·cm-2, respectively. A target set up that could greatly reduce the incident ion current density was designed to achieve the damage-free measurement. The 3.2 MeV H+ transmitted ion energy spectrum measurement was carried out before and after the irradiation. From the transmission ion energy spectrum, it was found that the kidney bean slice itself was structurally inhomogeneous compared with the PET films (C10H8O4). The results indicated that the average mass thickness changed little when the N+ ion dose was below 3 x 1016 ions·cm-2, but changed obviously when ion dose was beyond 3 x 1016 ions·cm-2

  17. Decay energy of 55Fe from its inner Bremsstrahlung spectrum

    Indian Academy of Sciences (India)

    S L Keshava; K Gopala; P Venkataramaiah

    2001-06-01

    Several measurements of decay energy using the inner Bremsstrahlung spectrum (IB) due to radiative electron capture in 55Fe has been made. But the results are not uniform. Hence another attempt has been made at the same. Experimental data was obtained with a 4.445 cm. dia × 5.08 cm thick NaI (Tl) detector. It was subjected to suitable statistical treatment and various corrections using Liden and Starfelt procedure. The corrected spectrum agrees well with the Glauber and Martin theory for 1s electron capture beyond 100 keV. From the Jauch plot, the decay energy of 232.36 ± 0.64 keV was obtained.

  18. Energy Beam Highways Through the Skies

    Science.gov (United States)

    Myrabo, Leik N.

    1996-01-01

    The emergence of Energy Beam Flight Transportation Systems could dramatically change the way we travel in the 21st Century. A framework for formulating 'Highways of Light' and the top level architectures that invoke radically new Space Power Grid infrastructure, are introduced. Basically, such flight systems, hereafter called Lightcraft, would employ off-board energy beam sources (either laser or microwave) to energize on-board dependent 'motors' -- instead of the traditional autonomous 'engines' with their on-board energy sources (e.g., chemical fuels). Extreme reductions in vehicle dry mass appear feasible with the use of off-board power and a high degree of on-board artificial intelligence. Such vehicles may no longer need airports for refueling (since they require no propellant), and could possibly pick up travelers at their homes -- before motoring over to one of many local boost stations, for the flight out. With off-board power, hyper-energetic acceleration performance and boost-glide trajectories become feasible. Hypersonic MS airbreathing propulsion can enable boosts up to twice escape velocity, which will cut trip times to the moon down to 5.5 hours. The predominant technological, environmental and social factors that will result from such transportation systems will be stressed. This presentation first introduces the remote source siting options for the space power system infrastructure, and then provides three representative laser/microwave Lightcraft options (derived from historical Case Studies): i.e., 'Acorn', 'Toy Top', and 'Disc.' Next the gamut of combined-cycle engine options developed for these Lightcraft are examined -- to illuminate the 'emerging technologies' that must be harnessed to produce flight hardware. Needed proof-of concept experiments are identified, along with the Macro-Level Issues that can springboard these revolutionary concepts into hardware reality.

  19. Energy-Efficient Spectrum Sensing for Cognitive Radio Networks

    NARCIS (Netherlands)

    Maleki, S.

    2013-01-01

    Dynamic spectrum access employing cognitive radios has been proposed, in order to opportunistically use underutilized spectrum portions of a heavily licensed electromagnetic spectrum. Cognitive radios opportunistically share the spectrum, while avoiding any harmful interference to the primary licens

  20. Exact energy spectrum for models with equally spaced point potentials

    Science.gov (United States)

    Caudrelier, V.; Crampé, N.

    2006-03-01

    We describe a non-perturbative method for computing the energy band structures of one-dimensional models with general point potentials sitting at equally spaced sites. This is done thanks to a Bethe ansatz approach and the method is applicable even when periodicity is broken, that is when Bloch's theorem is not valid any more. We derive the general equation governing the energy spectrum and illustrate its use in various situations. In particular, we get exact results for boundary effects. We also study non-perturbatively the effects of impurities in such systems. Finally, we discuss the possibility of including interactions between the particles of these systems.

  1. Molecular Ion Beam Transportation for Low Energy Ion Implantation

    International Nuclear Information System (INIS)

    A joint research and development of steady state intense boron ion sources for 100's of electron-volt ion implanters has been in progress for the past five years. Current density limitation associated with extracting and transporting low energy ion beams result in lower beam currents that in turn adversely affects the process throughput. The transport channel with electrostatic lenses for decaborane (B10H14) and carborane (C2B10H12) ion beams transportation was developed and investigated. The significant increase of ion beam intensity at the beam transport channel output is demonstrated. The transport channel simulation, construction and experimental results of ion beam transportation are presented.

  2. Induction of Micronuclei in Human Fibroblasts from the Los Alamos High Energy Neutron Beam

    Science.gov (United States)

    Cox, Bradley

    2009-01-01

    The space radiation field includes a broad spectrum of high energy neutrons. Interactions between these neutrons and a spacecraft, or other material, significantly contribute to the dose equivalent for astronauts. The 15 degree beam line in the Weapons Neutron Research beam at Los Alamos Nuclear Science Center generates a neutron spectrum relatively similar to that seen in space. Human foreskin fibroblast (AG1522) samples were irradiated behind 0 to 20 cm of water equivalent shielding. The cells were exposed to either a 0.05 or 0.2 Gy entrance dose. Following irradiation, micronuclei were counted to see how the water shield affects the beam and its damage to cell nuclei. Micronuclei induction was then compared with dose equivalent data provided from a tissue equivalent proportional counter.

  3. The energy spectrum and the optical absorption spectrum of C{sub 60} fullerene within the Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Silant’ev, A. V., E-mail: kvvant@rambler.ru [Mari State University (Russian Federation)

    2015-10-15

    Anticommutator Green’s functions and the energy spectrum of C{sub 60} fullerene are calculated in the approximation of static fluctuations within the Hubbard model. On the basis of this spectrum, an interpretation is proposed for the experimentally observed optical absorption bands of C{sub 60} fullerene. The parameters of C{sub 60} fullerene that characterize it within the Hubbard model are calculated by the optical absorption spectrum.

  4. Simultaneous recording of high energy photon spectrum in phoswich detectors

    International Nuclear Information System (INIS)

    Phoswich detector with PSD electronics has been routinely used for lung counting at RSD, Indira Gandhi Centre for Atomic Research. The PSD electronics has been optimized for obtaining only low energy photon (LEP) spectrum upto 200 keV. The pulses resulting from the NaI(Tl) portion i.e, mainly LEP interaction are selected by the PSD and used for the measurement. The pulses from the CsI portion i.e, mainly high energy photon (HEP) interactions are utilized only for the PSD electronics and are not being utilized for any spectral measurements. But processing of pulses originating from the CsI can also provide valuable information about HEP photon emitters if any during the in vivo monitoring. This requires modification the PSD electronics and two multichannel analysers for simultaneous recording the energy spectra derived. While the modification is done, care was taken not sacrifice the quality and fidelity of low energy monitoring. The phoswich detector with modified PSD electronics configuration enabled us to simultaneously record both LE photon and HE photon spectra from a single phoswich detector. The system performance evaluation showed that the system with new PSD configuration has very good gamma spectrometry characteristics. Analysis of recorded room background REP spectrum brought out the trace level detector contamination of 137Cs. The interference of 41Ar could be easily identified and its contribution to lower energy regions is quantified

  5. Electron beam energy QA - a note on measurement tolerances.

    Science.gov (United States)

    Meyer, Juergen; Nyflot, Matthew J; Smith, Wade P; Wottoon, Landon S; Young, Lori; Yang, Fei; Kim, Minsun; Hendrickson, Kristi R G; Ford, Eric; Kalet, Alan M; Cao, Ning; Dempsey, Claire; Sandison, George A

    2016-01-01

    Monthly QA is recommended to verify the constancy of high-energy electron beams generated for clinical use by linear accelerators. The tolerances are defined as 2%/2 mm in beam penetration according to AAPM task group report 142. The practical implementation is typically achieved by measuring the ratio of readings at two different depths, preferably near the depth of maximum dose and at the depth corresponding to half the dose maximum. Based on beam commissioning data, we show that the relationship between the ranges of energy ratios for different electron energies is highly nonlinear. We provide a formalism that translates measurement deviations in the reference ratios into change in beam penetration for electron energies for six Elekta (6-18 MeV) and eight Varian (6-22 MeV) electron beams. Experimental checks were conducted for each Elekta energy to compare calcu-lated values with measurements, and it was shown that they are in agreement. For example, for a 6 MeV beam a deviation in the measured ionization ratio of ± 15% might still be acceptable (i.e., be within ± 2 mm), whereas for an 18 MeV beam the corresponding tolerance might be ± 6%. These values strongly depend on the initial ratio chosen. In summary, the relationship between differences of the ionization ratio and the corresponding beam energy are derived. The findings can be translated into acceptable tolerance values for monthly QA of electron beam energies. PMID:27074488

  6. Low energy ion beam dynamics of NANOGAN ECR ion source

    Science.gov (United States)

    Kumar, Sarvesh; Mandal, A.

    2016-04-01

    A new low energy ion beam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ion beams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ion beams. Higher emittance at low energy of intense ion beam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ion beam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ion beams similar to the trend observed theoretically.

  7. ILC Beam Energy Measurement by means of Laser Compton Backscattering

    OpenAIRE

    Muchnoi, N.; Schreiber, H. J.; Viti, M

    2008-01-01

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered $\\gamma$-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitiv...

  8. Compact Measurement Station for Low Energy Proton Beams

    CERN Document Server

    Yildiz, H; Oz, S; Yasatekin, B; Turemen, G; Ogur, S; Sunar, E; Aydin, Y A; Dimov, V A; Unel, G; Alacakir, A

    2016-01-01

    A compact, remote controlled, cost efficient diagnostic station has been developed to measure the charge, the profile and the emittance for low energy proton beams. It has been installed and tested in the proton beam line of the Project Prometheus at SANAEM of the Turkish Atomic Energy Authority.

  9. Universal Raising and Lowering Operators for a Discrete Energy Spectrum

    Science.gov (United States)

    Torres-Vega, Gabino

    2016-06-01

    We consider the first-order finite-difference expression of the commutator between d / dx and x. This is the appropriate setting in which to propose commutators and time operators for a quantum system with an arbitrary potential function and a discrete energy spectrum. The resulting commutators are identified as universal lowering and raising operators. We also find time operators which are finite-difference derivations with respect to the energy. The matrix elements of the commutator in the energy representation are analyzed, and we find consistency with the equality [hat{T},hat{H}]=ihbar . We apply the theory to the particle in an infinite well and for the Harmonic oscillator as examples.

  10. Electron beam directed energy device and methods of using same

    Science.gov (United States)

    Retsky, Michael W.

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  11. ENERGY EFFICIENT COOPERATIVE SPECTRUM SENSING IN COGNITIVE RADIO

    Directory of Open Access Journals (Sweden)

    Ramzi Saifan

    2016-03-01

    Full Text Available Sensing in cognitive radio (CR protects the primary user (PU from bad interference. Therefore, it is assumed to be a requirement. However, sensing has two main challenges; first the CR is required to sense the PU under very low signal to noise ratios which will take longer sensing time, and second, some CR nodes may suffer from deep fading and shadowing effects. Cooperative spectrum sensing (CSS is supposed to solve these challenges. However, CSS adds extra energy consumption due to CRs send the sensing result to the fusion center and receive the final decision from the fusion center. This is in addition to the sensing energy itself. Therefore, CSS may consume considerable energy out of the battery of the CR node. Therefore in this paper, we try to find jointly the sensing time required from each CR node and the number of CR nodes who should perform sensing such that the energy and energy efficiency (i.e., ratio of throughput to energy consumed are optimized. Simulation results show that the joint optimization achieves better in terms of energy efficiency than other approaches that perform separate optimization.

  12. The toes of the ultra high energy cosmic ray spectrum

    OpenAIRE

    Harari, Diego; Mollerach, Silvia; Roulet, Esteban

    1999-01-01

    We study the effects of the galactic magnetic field on the ultra high energy cosmic ray propagation. We show that the deflections of the cosmic ray trajectories can have many important implications such as (de)magnification of the cosmic ray fluxes by lensing effects (which can modify the spectrum of individual sources), the formation of multiple images of a source or the existence of regions of the sky to which the Earth is almost blind. The appearance of image pairs is related to the existe...

  13. The high energy spectrum of 3C 273

    OpenAIRE

    Esposito, V; R. Walter(ISDC); Jean, P.; Tramacere, A.; M. Türler; A. Lähteenmäki(Aalto University Metsähovi Radio Observatory, Kylmälä, Finland); Tornikoski, M.

    2015-01-01

    Aims. The high energy spectrum of 3C 273 is usually understood in terms of inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays that could be tested with simultaneous observations from the radio to the GeV range. Methods. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE, and LAT on board Fermi have enough sensitivity to follow the spectral variability of 3C 273 from the keV to the GeV. We looked for correlations betw...

  14. Neutron energy spectrum from 120 GeV protons on a thick copper target

    CERN Document Server

    Shigyo, Nobuhiro; Kajimoto, Tsuyoshi; Iwamoto, Yosuke; Hagiwara, Masayuki; Saito, Kiwamu; Ishibashi, Kenji; Nakashima, Hiroshi; Sakamoto, Yukio; Lee, Hee-Seock; Ramberg, Erik; Meyhoefer, Aria A; Coleman, Rick; Jensen, Doug; Leveling, Anthony F; Boehnlein, David J; Mokhov, Nikolai V

    2012-01-01

    Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, proton-induced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30^{\\circ} and 5 m 90^{\\circ} with respect to the...

  15. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    Science.gov (United States)

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  16. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Hyojae, E-mail: lkcom@ibs.re.kr; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2016-02-15

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  17. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    International Nuclear Information System (INIS)

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described

  18. Energy spectrum and arrival direction distribution of cosmic rays with energies above 1019 electrovolts

    International Nuclear Information System (INIS)

    Results from three experiments provide evidence that the cosmic-ray spectrum flattens above 1019 eV; no ''cutoff'' in the spectrum is observed to at least 1.6 x 1020 eV. Below 1019 eV the differential slope of the power-law spectrum is -3.09 +- 0.002 while at higher energies it is -2.31 +- 0.10. An analysis of the arrival direction distribution of over 4700 primaries above 1018 eV and 142 above 1019 recorded at Haverah Park suggests that the mean galactic latitude of these events increases beyond the energy at which the spectrum flattens. The implications of these results for theories of the origin of the highest-energy cosmic rays are discussed

  19. Study on electron beam in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Muhammad Zubair, E-mail: mzubairkhan-um76@yahoo.com [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia and Department of Physics, Federal Urdu University of Arts, Science and Technology, 45320 Islamabad (Pakistan); Ling, Yap Seong; San, Wong Chiow [Plasma Technology Research Center, Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05

    Electron beam emission was investigated in a low energy plasma focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma focus device.

  20. Study on electron beam in a low energy plasma focus

    International Nuclear Information System (INIS)

    Electron beam emission was investigated in a low energy plasma focus device (2.2 kJ) using copper hollow anode. Faraday cup was used to estimate the energy of the electron beam. XR100CR X-ray spectrometer was used to explore the impact of the electron beam on the target observed from top-on and side-on position. Experiments were carried out at optimized pressure of argon gas. The impact of electron beam is exceptionally notable with two different approaches using lead target inside hollow anode in our plasma focus device

  1. Characterization of low energy radioactive beams using direct reactions

    DEFF Research Database (Denmark)

    Johansen, J.G.; Fraser, M.A.; Bildstein, V.;

    2013-01-01

    We demonstrate a new technique to determine the beam structure of low energy radioactive beams using coincidence events from a direct reaction. The technique will be described and tested using Geant4 simulations. We use the technique to determine for the first time the width, divergence and energy...... of an accelerated radioactive beam produced at ISOLDE. We use data from an experiment with an 11Be beam incident on a deuteron target producing 10Be from a (d,t) reaction. The T-REX Si detector array was used for particle detection, but the technique is applicable for other setups....

  2. Sensitivity of EAS measurements to the energy spectrum of muons

    CERN Document Server

    Espadanal, J; Conceição, R

    2016-01-01

    We have studied how the energy spectrum of muons at production affects some of the most common measurements related to muons in extensive air shower studies, namely, the number of muons at the ground, the slope of the lateral distribution of muons, the apparent muon production depth, and the arrival time delay of muons at ground. We found that by changing the energy spectrum by an amount consistent with the difference between current models (namely EPOS-LHC and QGSjet-II.04), the muon surface density at ground increases $5\\%$ at $20^\\circ$ zenith angle and $17\\%$ at $60^\\circ$ zenith angle. This effect introduces a zenith angle dependence on the reconstructed number of muons which might be experimentally observed. The maximum of the muon production depth distribution at $40^\\circ$ increases $\\sim10\\text{ g/cm}^2$ and $\\sim0\\text{ g/cm}^2$ at $60^\\circ$, which, from pure geometrical considerations, increases the arrival time delay of muons. There is an extra contribution to the delay due to the subluminal velo...

  3. Chandra High Energy Transmission Grating Spectrum of AE Aquarii

    CERN Document Server

    Mauche, Christopher W

    2009-01-01

    (Abridged) The results of a Chandra X-ray Observatory High-Energy Transmission Grating (HETG) observation of the nova-like cataclysmic binary AE Aqr are described. First, the X-ray spectrum is that of an optically thin multi-temperature thermal plasma; the X-ray emission lines are broad, with widths that increase with the line energy, from sigma~1 eV for O VIII to sigma~5.5 eV for Si XIV; the X-ray spectrum is reasonably well fit by a plasma model with a Gaussian emission measure distribution that peaks at log T(K)=7.16, has a width sigma=0.48, an Fe abundance equal to 0.44 times solar, and other metal (primarily Ne, Mg, and Si) abundances equal to 0.76 times solar; and for a distance d=100 pc, the total emission measure EM=8.0E53 cm^-3 and the 0.5-10 keV luminosity L_X=1.1E31 erg/s. Second, based on the f/(i+r) flux ratios of the forbidden (f), intercombination (i), and recombination (r) lines of the He alpha triplets of N VI, O VII, and Ne IX measured by Itoh et al. in the XMM-Newton Reflection Grating Spec...

  4. Beam Loss Calibration Studies for High Energy Proton Accelerators

    CERN Document Server

    Stockner, M

    2007-01-01

    CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....

  5. Linac4 Low Energy Beam Measurements with Negative Hydrogen

    CERN Document Server

    Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

    2014-01-01

    Linac4, a 160 MeV normal-conducting H- 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 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- 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.

  6. Alpha-particle diagnostics with high energy neutral beams

    International Nuclear Information System (INIS)

    We have examined the feasibility of alpha-particle diagnostics using a high energy neutral beam on the R-tokamak, a planned device at IPP-Nagoya, Japan, for reacting plasma experiments. In this method, injected neutral particles neutralize alpha particles so as to escape from the magnetically confined plasma through double charge exchange processes, He++ + A0 -- → He0 + A++. Requirements for a probing beam are dis cussed from viewpoints of penetration of an injected beam in the plasma and a neutralization efficiency of alpha particles in a wide velocity range. Either a Li0 beam or a He0 beam in the ground state, produced from a negative ion beam is suitable. A method to neutralize a He- beam into the ground state through an auto-detachment process is proposed. (author)

  7. Piezoelectric energy harvester having planform-tapered interdigitated beams

    Science.gov (United States)

    Kellogg, Rick A.; Sumali, Hartono

    2011-05-24

    Embodiments of energy harvesters have a plurality of piezoelectric planform-tapered, interdigitated cantilevered beams anchored to a common frame. The plurality of beams can be arranged as two or more sets of beams with each set sharing a common sense mass affixed to their free ends. Each set thus defined being capable of motion independent of any other set of beams. Each beam can comprise a unimorph or bimorph piezoelectric configuration bonded to a conductive or non-conductive supporting layer and provided with electrical contacts to the active piezoelectric elements for collecting strain induced charge (i.e. energy). The beams are planform tapered along the entirety or a portion of their length thereby increasing the effective stress level and power output of each piezoelectric element, and are interdigitated by sets to increase the power output per unit volume of a harvester thus produced.

  8. Possible dark energy imprints in gravitational wave spectrum of mixed neutron-dark-energy stars

    OpenAIRE

    Yazadjiev, Stoytcho S.; Doneva, Daniela D.

    2011-01-01

    In the present paper we study the oscillation spectrum of neutron stars containing both ordinary matter and dark energy in different proportions. Within the model we consider, the equilibrium configurations are numerically constructed and the results show that the properties of the mixed neuron-dark-energy star can differ significantly when the amount of dark energy in the stars is varied. The oscillations of the mixed neuron-dark-energy stars are studied in the Cowling approximation. As a re...

  9. Australian Science and Technology with Relevance to Beamed Energy Propulsion

    International Nuclear Information System (INIS)

    Although Australia has no Beamed Energy Propulsion programs at the present time, it is accomplishing significant scientific and technological activity that is of potential relevance to Beamed Energy Propulsion (BEP). These activities include: continual upgrading and enhancement of the Woomera Test Facility, Which is ideal for development and test of high power laser or microwave systems and the flight vehicles they would propel; collaborative development and test, with the US and UK of hypersonic missiles that embody many features needed by beam-propelled flight vehicles; hypersonic air breathing propulsion systems that embody inlet-engine-nozzle features needed for beam-riding agility by air breathing craft; and research on specially conditioned EM fields that could reduce beamed energy lost during atmospheric propagation

  10. Evaluation of beam energy fluctuation caused by phase noise

    International Nuclear Information System (INIS)

    The stability of RF signal sources is quite important for accelerators which have to provide very high quality beams. The RF sources for XFELs, for example, have to satisfy the integrated phase fluctuation less than several tens femtoseconds. The SSB noises of RF reference signal dominate the short-term instabilities of the RF phase of the carrier RF. This phase modulation finally results in the beam energy fluctuation. This presentation gives a quantitative evaluation of the beam energy fluctuations in an electron linear accelerator caused by phase noises comparing a theoretical analysis and experimental results: A simple model, which represents actual RF phase transmission in transmission lines of an electron linac, was introduced to understand how phase noises result the relative phase deference between a beam bunch and accelerating RF fields. In the experiments, we measured the enhanced beam energy fluctuations by modulating the phase of the reference RF signals with an external signal. (author)

  11. ILC Beam Energy Measurement by means of Laser Compton Backscattering

    CERN Document Server

    Muchnoi, N; Viti, M

    2008-01-01

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered $\\gamma$-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of $10^{-4}$ or bette...

  12. Development of multi-bunch beam energy compensation method

    International Nuclear Information System (INIS)

    A method to compensate for beam loading effects in a multi-bunch beam is under development at Accelerator Test Facility (ATF) in KEK. In this paper we describe the rf high power test for ΔT energy compensation by using the SLED cavities. In this ΔT (early injection and amplitude modulation) energy compensation method, the input waveform into accelerating structure is changed by controlling the rf phase and combining the rf-power from two klystrons with a 3 dB hybrid combiner to compensate multi-bunch beam energy for various beam currents. In this test, an arbitrary waveform was generated by changing the rotating speed of the each klystron phase into the opposite direction and the beam test will be done soon. (author)

  13. Effects of the D-T fusion neutron energy spectrum on high energy reaction rates

    International Nuclear Information System (INIS)

    The fusion neutron energy spectrum can affect the predicted average cross sections for neutron reactions with thresholds near 14 MeV. For vacuum wall materials, the high energy reactions leading to He production are important for wall life predictions. The effect of the fusion neutron spectrum on a few reactions and materials has been investigated by D. W. Muir. In the present work the effects of the fusion neutron spectrum on 19 high energy reactions for all of the naturally occurring isotopes of Ti, V, stainless steel, Nb, and Mo have been studied. The fusion neutron energy spectrum was determined using the ''exact'' equation given by G. Lehner. This equation was derived by assuming that the fusioning species could be adequately described by isotropic Maxwellian distributions at some characteristic plasma temperature. The D--T fusion reaction cross section data were taken from the recent compilation by G. Miley, H. Towner, and N. Ivich. Neutron energy spectra have been calculated and used to compute spectrum average cross sections for plasma temperatures of 4, 10, 20, 40, 100, 200, and 400 keV

  14. Measuring the electron beam energy in a magnetic bunch compressor

    International Nuclear Information System (INIS)

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 μm precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  15. Low energy photon mimic of the tritium beta decay energy spectrum

    Science.gov (United States)

    Malabre-O'Sullivan, Neville

    Tritium is a radioactive hydrogen isotope that is typically produced via neutron interaction with heavy water (D2O), producing tritiated water (DTO). As a result of this, tritium accounts for roughly a third of all occupational exposures at a CANDU type nuclear power plant. This identifies a need to study the biological effects associated with tritium (and low energy electrons in general). However, there are complications regarding the dosimetry of tritium, as well as difficulties in handling and using tritium for the purposes of biophysics experiments. To avoid these difficulties, an experiment has been proposed using photons to mimic the beta decay energy spectrum of tritium. This would allow simulation of the radiation properties of tritium, so that a surrogate photon source can be used for biophysics experiments. Through experimental and computational means, this work has explored the use of characteristic x-rays of various materials to modify the output spectrum of an x-ray source, such that it mimics the tritium beta decay spectrum. Additionally, the resultant primary electron spectrum generated in water from an x-ray source was simulated. The results from this research have indicated that the use of characteristic x-rays is not a viable method for simulating a tritium source. Also, the primary electron spectrum generated in water shows some promise for simulating tritium exposure, however further work must be done to investigate the slowing down electron spectrum. Keywords: Tritium, MCNP, low energy electrons, biophysics, characteristic x-rays.

  16. High energy density in matter produced by heavy ion beams

    International Nuclear Information System (INIS)

    This annual report summarizes the results of research carried out in 1986 within the framework of the program 'High Energy Density in Matter Produced by Heavy Ion Beams' which is funded by the Federal Ministry for Research and Technology. Its initial motivation and its ultimate goal is the question whether inertial confinement can be achieved by intense beams of heavy ions. (orig./HSI)

  17. Structuring of silicon with low energy focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Nebiker, P.W.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muehle, R. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    The defect production in silicon induced by focused ion beam irradiation as a function of energy and projectile mass has been investigated and compared to the measured sputter yield. The aim was to find optimal beam parameters for the structuring of semiconductors with a minimum amount of defects produced per removed atom. (author) 2 figs., 2 refs.

  18. Energy Harvesting-Aided Spectrum Sensing and Data Transmission in Heterogeneous Cognitive Radio Sensor Network

    OpenAIRE

    Zhang, Deyu; Ren, Zhigang Chen Ju; Zhang, Ning; Awad, Mohamad Khattar; Zhou, Haibo; Xuemin; Shen

    2016-01-01

    The incorporation of Cognitive Radio (CR) and Energy Harvesting (EH) capabilities in wireless sensor networks enables spectrum and energy efficient heterogeneous cognitive radio sensor networks (HCRSNs). The new networking paradigm of HCRSNs consists of EH-enabled spectrum sensors and battery powered data sensors. Spectrum sensors can cooperatively scan the licensed spectrum for available channels, while data sensors monitor an area of interest and transmit sensed data to the sink over those ...

  19. Energy Spectrum Extraction and Optimal Imaging via Dual-Energy Material Decomposition

    CERN Document Server

    Zhao, Wei; Zhang, Bo; Zhang, Qiude; Niu, Tianye

    2015-01-01

    Inferior soft-tissue contrast resolution is a major limitation of current CT scanners. The aim of the study is to improve the contrast resolution of CT scanners using dual-energy acquisition. Based on dual-energy material decomposition, the proposed method starts with extracting the outgoing energy spectrum by polychromatic forward projecting the material-selective images. The extracted spectrum is then reweighted to boost the soft-tissue contrast. A simulated water cylinder phantom with inserts that contain a series of six solutions of varying iodine concentration (range, 0-20 mg/mL) is used to evaluate the proposed method. Results show the root mean square error (RMSE) and mean energy difference between the extracted energy spectrum and the spectrum acquired using an energy-resolved photon counting detector(PCD), are 0.044 and 0.01 keV, respectively. Compared to the method using the standard energy-integrating detectors, dose normalized contrast-to-noise ratio (CNRD) for the proposed method are improved fro...

  20. Turbulent kinetic energy spectrum in very anisothermal flows

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Sylvain, E-mail: sylvain_serra@bbox.fr [PROcedes, Materiaux et Energie Solaire, UPR CNRS 8521, Rambla de la thermodynamique, Tecnosud, 66100 Perpignan (France); Toutant, Adrien, E-mail: adrien.toutant@univ-Perp.fr [PROcedes, Materiaux et Energie Solaire, UPR CNRS 8521, Rambla de la thermodynamique, Tecnosud, 66100 Perpignan (France); Bataille, Françoise, E-mail: francoise.bataille@promes.cnrs.fr [PROcedes, Materiaux et Energie Solaire, UPR CNRS 8521, Rambla de la thermodynamique, Tecnosud, 66100 Perpignan (France); Zhou, Ye, E-mail: yezhou@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2012-10-01

    In this Letter, we find that the Kolmogorov scaling law is no longer valid when the flow is submitted to strong dilatational effects caused by high temperature gradients. As a result, in addition to the nonlinear time scale, there is a much shorter “temperature gradients” time scale. We propose a model that estimates the time scale of the triple decorrelation incorporating the influences of the temperature gradient. The model agrees with the results from the thermal large-eddy simulations of different Reynolds numbers and temperature gradients. This Letter provides a better understanding of the very anisothermal turbulent flow. -- Highlights: ► Turbulent flows subject to high temperature gradients are considered. ► The new “temperature gradients” time scale is determined. ► A generalized energy spectrum is developed to incorporate the effects of temperature gradient.

  1. Neutron energy spectrum in graphite blankets of fusion reactors

    International Nuclear Information System (INIS)

    Neutron flux measurements were performed in a graphite stack and compared with calculations made with a two dimensional transport computer code. In the present work it is observed that the calculated spectrum in the elastic and inelastic scattering ranges (the first collision range in both cases), is sensitive to details of the angular distribution of these neutrons. Regarding the discrepancies in the elastic scattering range it is concluded that the microscopic cross section library ENDF/B-IV overestimates the large angle scattering (back scattering) as can be seen from comparison of measured and calculated spectra. The two most important conclusions of the present work are: 1. Inelastic scattering interaction of D-T neutrons in graphite cannot be calculated without a proper account of energy-angle correlation. 2. An experimental setup supplying monoenergetic collimated D-T neutrons constitutes a sensitive although indirect means for measuring angular distributions in inelastic and elastic scattering

  2. Turbulent kinetic energy spectrum in very anisothermal flows

    International Nuclear Information System (INIS)

    In this Letter, we find that the Kolmogorov scaling law is no longer valid when the flow is submitted to strong dilatational effects caused by high temperature gradients. As a result, in addition to the nonlinear time scale, there is a much shorter “temperature gradients” time scale. We propose a model that estimates the time scale of the triple decorrelation incorporating the influences of the temperature gradient. The model agrees with the results from the thermal large-eddy simulations of different Reynolds numbers and temperature gradients. This Letter provides a better understanding of the very anisothermal turbulent flow. -- Highlights: ► Turbulent flows subject to high temperature gradients are considered. ► The new “temperature gradients” time scale is determined. ► A generalized energy spectrum is developed to incorporate the effects of temperature gradient.

  3. Processes leading to enhanced energy deposition by particle beams

    International Nuclear Information System (INIS)

    Range shortening of electron and proton beams due to target temperature and density effects is calculated. The effect on target hydrodynamics is calculated for a proton beam. The effect of the penetration of an electron beam self magnetic field into the target is shown to cause effective range shortening. Enhanced energy deposition by a pinched electron beam in a foil target is studied numerically and experimentally. The target expansion velocity measured by laser flash photography is used to determine the enhancement factor. Bremsstrahlung measurements are used to study the electron trajectories

  4. Unprecedented intensity of a low-energy positron beam

    Energy Technology Data Exchange (ETDEWEB)

    Hugenschmidt, C. [Technische Universitaet Muenchen, ZWEFRM II/E21, Lichtenbergstrasse 1, 85747 Garching (Germany)], E-mail: Christoph.Hugenschmidt@frm2.tum.de; Loewe, B.; Mayer, J.; Piochacz, C.; Pikart, P.; Repper, R.; Stadlbauer, M.; Schreckenbach, K. [Technische Universitaet Muenchen, ZWEFRM II/E21, Lichtenbergstrasse 1, 85747 Garching (Germany)

    2008-08-11

    A new in-pile {gamma}-converter and Pt-moderator was recently installed at the neutron induced positron source NEPOMUC. The intensity of the moderated positron beam is unprecedented and amounts to (9.0{+-}0.8)x10{sup 8} moderated positrons per second at an energy of 1 keV. Hence, the beam facility NEPOMUC provides the world highest intensity of a monoenergetic positron beam reported so far. Up to now, no degradation of the positron yield has been observed for several weeks of operation. Thus, the long-term stability of the positron beam enables experiments with high reliability.

  5. Cross-Beam Energy Transfer Driven by Incoherent Laser Beams with Frequency Detuning

    Science.gov (United States)

    Maximov, A.; Myatt, J. F.; Short, R. W.; Igumenshchev, I. V.; Seka, W.

    2015-11-01

    In the direct-drive method of the inertial confinement fusion (ICF), the coupling of laser energy to target plasmas is strongly influenced by the effect of cross-beam energy transfer (CBET) between multiple driving laser beams. The laser -plasma interaction (LPI) model of CBET is based on the nonparaxial laser light propagation coupled with the low-frequency ion-acoustic-domain plasma response. Common ion waves driven by multiple laser beams play a very important role in CBET. The effect of the frequency detuning (colors) in the driving laser beams is studied and it is shown to significantly reduce the level of common ion waves and therefore the level of CBET. The differences between the LPI-based CBET model and the ray-based CBET model used in hydrocodes are discussed. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  6. An online, energy-resolving beam profile detector for laser-driven proton beams.

    Science.gov (United States)

    Metzkes, J; Zeil, K; Kraft, S D; Karsch, L; Sobiella, M; Rehwald, M; Obst, L; Schlenvoigt, H-P; Schramm, U

    2016-08-01

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source. PMID:27587116

  7. The FiR 1 photon beam model adjustment according to in-air spectrum measurements with the Mg(Ar) ionization chamber

    International Nuclear Information System (INIS)

    The mixed neutron–photon beam of FiR 1 reactor is used for boron–neutron capture therapy (BNCT) in Finland. A beam model has been defined for patient treatment planning and dosimetric calculations. The neutron beam model has been validated with an activation foil measurements. The photon beam model has not been thoroughly validated against measurements, due to the fact that the beam photon dose rate is low, at most only 2% of the total weighted patient dose at FiR 1. However, improvement of the photon dose detection accuracy is worthwhile, since the beam photon dose is of concern in the beam dosimetry. In this study, we have performed ionization chamber measurements with multiple build-up caps of different thickness to adjust the calculated photon spectrum of a FiR 1 beam model. - Highlights: • In order to verify the photon beam model of the FiR 1 BNCT facility in Finland, the photon beam spectrum is determined experimentally through ionization chamber measurements with multiple build-up caps of different thickness. • Large discrepancy is found between free in air measurements with the ionization chamber and the Monte Carlo calculations indicating that the initial beam model needs to be adjusted. • The unfolded spectrum and photon beam intensity may be applicable as a more correct photon beam model

  8. Electron Beam Energy Compensation by Controlling RF Pulse Shape

    CERN Document Server

    Kii, T; Kusukame, K; Masuda, K; Nakai, Y; Ohgaki, H; Yamazaki, T; Yoshikawa, K; Zen, H

    2005-01-01

    We have studied on improvement of electron beam macropulse properties from a thermionic RF gun. Though a thermionic RF gun has many salient features, there is a serious problem that back-bombardment effect worsens quality of the beam. To reduce beam energy degradation by this effect, we tried to feed non-flat RF power into the gun. As a result, we successfully obtained about 1.5 times longer macropulse and two times larger total charge per macropulse. On the other hand, we calculated transient evolution of RF power considering non-constant beam loading. The beam loading is evaluated from time evolution of cathode temperature, by use of one dimensional heat conduction model and electron trajectories' calculations by a particle simulation code. Then we found good agreement between the experimental and calculation results. Furthermore, with the same way, we studied the electron beam output dependence on the cathode radius.

  9. Characterization of different beam shapes for piezoelectric energy harvesting

    International Nuclear Information System (INIS)

    This paper deals with the analysis of different beam shapes for piezoelectric energy harvesters. The theory is based on the well-established Rayleigh–Ritz method for piezoelectric compound structures. It is validated by experiments with triangular-shaped and rectangular-shaped beams. It turns out that triangular-shaped beams are more effective than rectangular-shaped ones in terms of curvature homogeneity independent of the proof mass. This effect is opposed by the adverse mass distribution and the increased stiffness of triangular-shaped beams. Therefore, the overall efficiency is only weakly influenced by the beam shape. Nevertheless triangular-shaped beams drastically outperform rectangular ones in terms of tolerable excitation amplitude and maximum output power

  10. Effect of the fragment excitation energy distribution on the prompt fission neutron spectrum

    International Nuclear Information System (INIS)

    The effects of cascade emission of neutrons from a nucleus and of distribution of the initial excitation energy upon characteristics of the emission spectrum are studied. Calculations of the emission spectrum are made in the Weisskopf form in the constant temperature approximation. It has been elucidated that the cascade character of particle emission is not sufficient for the total spectrum to approach the maxwellian one. A dependence of the distorting function upon energy has been obtained. The calculation spectrum is compared with the experimental and with the Weisskopf spectra. A conclusion is drawn that the temperature dependence upon excitation energy is predominant in formation of a fission neutron spectrum

  11. Design study of low-energy beam transport for multi-charge beams at RAON

    Science.gov (United States)

    Bahng, Jungbae; Qiang, Ji; Kim, Eun-San

    2015-12-01

    The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

  12. Energy Spread of the Proton Beam in the Fermilab Booster at its Injection Energy

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chase, B. E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chaurize, S. J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Garcia, F. G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Seiya, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Pellico, W. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sullivan, T. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Triplett, A. K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-04-27

    We have measured the energy spread of the Booster beam at its injection energy of 400 MeV by three different methods: (1) creating a notch of about 40 nsec wide in the beam immediately after multiple turn injection and measuring the slippage time required for high and low momentum particles for a grazing touch in line-charge distribution, (2) injecting partial turn beam and letting it to debunch, and (3) comparing the beam profile monitor data with predictions from MAD simulations for the 400 MeV injection beam line. The measurements are repeated under varieties of conditions of rf systems in the ring and in the beam transfer line.

  13. Channeling of high energy beams in nanotubes

    CERN Document Server

    Bellucci, S; Chesnokov, Yu A; Guidi, V; Scandale, Walter; Chesnokov, Yu. A.

    2003-01-01

    We present simulations of particle beam channeling in carbon nanotubes and evaluate the possibilities for experimental observation of channeling effect in straight and bent nanotubes at IHEP and LNF. Different particle species are considered: protons of 1.3 and 70 GeV, and positrons of 0.5 GeV. Predictions are made for the experiments, with analysis of requirements on the quality of nanosamples and resolution of the experimental set-up. Based on Monte Carlo simulations, the capabilities of nanotube channeling technique for particle beam steering are discussed.

  14. Low Energy Scanned Electron-Beam Dose Distribution in Thin Layers

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Hjortenberg, P. E.; Pedersen, Walther Batsberg

    1975-01-01

    Thin radiochromic dye film dosimeters, calibrated by means of calorimetry, make possible the determination of absorbed-dose distributions due to low-energy scanned electron beam penetrations in moderately thin coatings and laminar media. For electrons of a few hundred keV, calibrated dosimeters of...... different backings (wood, aluminum, and iron) for scanned electron beams (Emax = 400 keV) having a broad energy spectrum and diffuse incidence, such as those used in radiation curing of coatings, textiles, plastics, etc. Theoretical calculations of such distributions of energy depositions are relatively...... about 30–60 μm thickness may be used in stacks or interleaved between layers of materials of interest and supply a sufficient number of experimental data points throughout the depth of penetration of electrons to provide a depth-dose curve. Depth doses may be resolved in various polymer layers on...

  15. Anomalous broadening of energy distributions in photoemitted electron beams

    Science.gov (United States)

    Guidi, Vincenzo

    1996-06-01

    Photoemission is widely used to generate electron beams with an energy spread lower than by thermoemission. However, when a photocathode is illuminated by a multimode laser this feature is lost and an electron beam with several eV of energy spread is produced. We have developed an explanation for this anomalous behavior pointing out its origin in the combined effect of charge relaxation, taking place within the beam, together with the modulation of the laser power imposed by laser modes. The model permits a correct interpretation overall experimental evidences.

  16. Uncorrelated Energy Spread and Longitudinal Emittance of a Photoinjector Beam

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z; Dowell, D.; Emma, P.; Limborg-Deprey, C.; Stupakov, G.; Wu, J.; /SLAC

    2005-05-25

    Longitudinal phase space properties of a photoinjector beam are important in many areas of high-brightness beam applications such as bunch compression, transverse-to-longitudinal emittance exchange, and high-gain free-electron lasers. In this paper, we discuss both the rf and the space charge contributions to the uncorrelated energy spread of the beam generated from a laser-driven rf gun. We compare analytical expressions for the uncorrelated energy spread and the longitudinal emittance with numerical simulations and recent experimental results.

  17. Beam dynamics simulations of post low energy beam transport section in RAON heavy ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyunchang, E-mail: hcjin@ibs.re.kr; Jang, Ji-Ho; Jang, Hyojae; Hong, In-Seok [Institute for Basic Science, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon (Korea, Republic of)

    2016-02-15

    RAON (Rare isotope Accelerator Of Newness) heavy ion accelerator of the rare isotope science project in Daejeon, Korea, has been designed to accelerate multiple-charge-state beams to be used for various science programs. In the RAON accelerator, the rare isotope beams which are generated by an isotope separation on-line system with a wide range of nuclei and charges will be transported through the post Low Energy Beam Transport (LEBT) section to the Radio Frequency Quadrupole (RFQ). In order to transport many kinds of rare isotope beams stably to the RFQ, the post LEBT should be devised to satisfy the requirement of the RFQ at the end of post LEBT, simultaneously with the twiss parameters small. We will present the recent lattice design of the post LEBT in the RAON accelerator and the results of the beam dynamics simulations from it. In addition, the error analysis and correction in the post LEBT will be also described.

  18. Computer simulations of a low energy proton beam tomograph

    International Nuclear Information System (INIS)

    This work presents the recent development of a low energy proton beam tomograph. The proton tomograph prototype (involving UTFPR, UERJ, UFRJ and IEN/CNEN) has been installed and tested at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to optimize the performance of the scattered proton beam and its aluminum collimator energy losses. The computer code simulates the tomographic measurements with two aluminum collimators (variable aperture from 0.2 mm to 0.4 mm in diameter and variable thickness from 4 mm to 8 mm), a water phantom and a Si(Li) detector. The analysis of the exit beam energy spectra in comparison with a perfectly collimated proton beam made it possible to achieve the best quality of reconstructed tomographic images of water phantom. (author)

  19. CSR routine for low energy electron beam in GPT

    International Nuclear Information System (INIS)

    General Particle Tracer (GPT) is a particle tracking code, which includes 3D space charge effect based on nonequidistant multigrid Poisson solver or point-to-point method. It is used to investigate beam dynamics in ERL and FEL injectors. We have developed a new routine to simulate coherent synchrotron radiation (CSR) in GPT based on the formalism of Sagan. The routine can calculate 1D-wake functions for arbitrary beam trajectories as well as CSR shielding effect. In particular, the CSR routine does not assume ultrarelativistic electron beam and is therefore applicable at low beam energies in the injector. Energy loss and energy spread caused by CSR effect were checked for a simple circular orbit, and compared with analytic formulas. (author)

  20. Computer simulations of a low energy proton beam tomograph

    Energy Technology Data Exchange (ETDEWEB)

    Milhoretto, E.; Schelin, H.R.; Setti, J.A.P.; Denyak, V.; Paschuk, S.A.; Basilio, A.C.; Rocha, R.; Ribeiro Junior, S. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Curso de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial (CPGEI)]. E-mails: sergei@utfpr.edu.br; edneymilhoretto@yahoo.com; schelin@cpgei.cefetpr.br; Evseev, I.; Yevseyeva, O. [Universidade Estadual do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil)]. E-mail: evseev@iprj.uerj.br; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graducao em Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mail: ricardo@lin.ufrj.br; Vinagre Filho, U.M. [Instituto de Energia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2007-07-01

    This work presents the recent development of a low energy proton beam tomograph. The proton tomograph prototype (involving UTFPR, UERJ, UFRJ and IEN/CNEN) has been installed and tested at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to optimize the performance of the scattered proton beam and its aluminum collimator energy losses. The computer code simulates the tomographic measurements with two aluminum collimators (variable aperture from 0.2 mm to 0.4 mm in diameter and variable thickness from 4 mm to 8 mm), a water phantom and a Si(Li) detector. The analysis of the exit beam energy spectra in comparison with a perfectly collimated proton beam made it possible to achieve the best quality of reconstructed tomographic images of water phantom. (author)

  1. Preparation of a beam quality indicator for effective energy determinations of continuum beams: establishment of traceability

    CERN Document Server

    Matsubayashi, M; Kobayashi, H

    1999-01-01

    A new beam quality indicator (BQI) was designed and fabricated to determine effective energies of beams extracted from neutron radiography facilities. Performances of the five new BQIs were compared with the original BQI which was recently proposed and tested by various beams. Non-filtered thermal neutrons, filtered thermal neutrons, and cold neutrons from a guide tube were used in the performance test program. The new BQIs were also examined by four different detection systems using a combination of a Gd converter and a X-ray film, a neutron imaging plate, a cooled charge coupled device camera, and a silicon intensified target tube camera.

  2. Energy harvesting from controlled buckling of piezoelectric beams

    Science.gov (United States)

    Ansari, M. H.; Karami, M. Amin

    2015-11-01

    A piezoelectric vibration energy harvester is presented that can generate electricity from the weight of passing cars or crowds. The energy harvester consists of a piezoelectric beam, which buckles when the device is stepped on. The energy harvester can have a horizontal or vertical configuration. In the vertical (direct) configuration, the piezoelectric beam is vertical and directly sustains the weight of the vehicles or people. In the horizontal (indirect) configuration, the vertical weight is transferred to a horizontal axial force through a scissor-like mechanism. Buckling of the beam results in significant stresses and, thus, large power production. However, if the beam’s buckling is not controlled, the beam will fracture. To prevent this, the axial deformation is constrained to limit the deformations of the beam. In this paper, the energy harvester is analytically modeled. The considered piezoelectric beam is a general non-uniform beam. The natural frequencies, mode shapes, and the critical buckling force corresponding to each mode shape are calculated. The electro-mechanical coupling and the geometric nonlinearities are included in the model. The design criteria for the device are discussed. It is demonstrated that a device, realized with commonly used piezoelectric patches, can generate tens of milliwatts of power from passing car traffic. The proposed device could also be implemented in the sidewalks or integrated in shoe soles for energy generation. One of the key features of the device is its frequency up-conversion characteristics. The piezoelectric beam undergoes free vibrations each time the weight is applied to or removed from the energy harvester. The frequency of the free vibrations is orders of magnitude larger than the frequency of the load. The device is, thus, both efficient and insensitive to the frequency of the force excitations.

  3. Upgrade of Beam Energy Measurement System at BEPC-II

    CERN Document Server

    Zhang, Jian-Yong; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M N; Krasnov, A A; Muchnoi, N Yu; Pyata, E E; Mamoshkina, E V; Harris, F A

    2015-01-01

    The beam energy measurement system is of great importance and profit for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. Many advanced techniques and precise instruments are employed to realize the highly accurate measurement of positron/electron beam energy. During five year's running period, in order to meet the requirement of data taking and improve the capacity of measurement itself, the upgradation of system is continued, which involve the component reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the purchase of electric cooling system for high purity germanium detector, and the improvement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and efficient measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.

  4. Thermo-mechanical modelling of high energy particle beam impacts

    CERN Document Server

    Scapin, M; Dallocchio, A

    2010-01-01

    The unprecedented energy intensities of modern hadron accelerators yield special problems with the materials that are placed close to or into the high intensity beams. The energy stored in LHC in a single beam is equivalent to about 80 kg of TNT explosive, stored in a transverse beam area of 0.2 mm×0.2 mm. The materials placed close to the beam are used at, or even beyond, their damage limits. However, it is very difficult to predict structural efficiency and robustness accurately: beam-induced damage occurs in a regime where practical experience does not exist. This study is performed in order to estimate the damage on a copper component due to the impact with a 7 TeV proton beam generated by LHC. The case study represents an accidental case consequent to an abnormal release of the beam, in which 8 bunches irradiate the target directly. The energy delivered on the component is calculated using the FLUKA code and then used as input in the numerical simulations, that are carried out via the FEM code LS-DYNA. ...

  5. Beam dynamics and commissioning of low and medium energy H- beam at Linac4

    CERN Document Server

    Satri, Masoomeh Yarmohammadi; Lamehi-Rachti , Mohammad

    The First step of the CERN Large Hadron Collider injectors upgrade (LIU) project is Linac4. It accelerates H- ions to 160 MeV in an 80 m long accelerator housed in a tunnel 12 m underground, presently under construction. It will replace the present 50 MeV proton Linac2 as injector of the proton accelerator complex to increase the LHC luminosity. It consists of a 45 keV RF volume source, a twosolenoid Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) accelerating the beam to 3 MeV, a Medium Energy Beam Transport (MEBT) line. The MEBT houses a fast chopper to selectively remove unwanted micro-bunches in the 352 MHz sequence and avoid losses at capture in the CERN PSB (1 MHz). After chopping, the beam acceleration continues by a 50 MeV Drift Tube Linac (DTL), a 100 MeV Cell-Coupled Drift Tube Linac and a Pi-Mode Structure bringing the beam to the final energy of 160 MeV. Linac4 has been commissioned with a temporary source up to 12 MeV. The beam commissioning stages of Linac4 in LEBT...

  6. On the propagation of a low energy oxygen ion beam

    International Nuclear Information System (INIS)

    Positive ion beams, in the range from about tens eV to several hundred eV are frequently used in RIE and RIBE etching systems. The experimental limitations in this energy range are severe and there are still many unsolved problems. Optimal ion beam focusing and maximum current beam at the substrate target are assured by the adequate ion beam neutralization. The electrons from the target plasma and also the secondary ones resulted from the ion-grid and ion-neutral interactions form a negative space charge that is involved in the ion beam neutralization. After the extraction, both the angular divergence and damping of the beam are essential to settle the position of the substrate. The beam angular divergence is established by the ion trajectories in the extraction region and also is strongly influenced by the ion beam neutralization. The shape and thickness of the space charge near the grid, which in turn is determined by the beam intensity, grid characteristics and target plasma parameters is necessary to be investigated. Positive ion bombardment plays an important role in the plasma treatments of polymers. This was the reason that investigations about the surface modifications of polymers in a positive oxygen ion beam-low density plasma (IB-LDP) system were carried out by our group [2-6]. In such system the electrons of the low-density target plasma neutralize the positive space charge of the beam and also that brought by the beam onto the polymer (insulator) surface. Results concerning the investigations of the IB-LDP system, in oxygen, by Langmuir probe method, in different experimental conditions are given in the present paper. They are compared with those obtained by using Monte Carlo method for elementary processes (ion charge transfer, electronic ionisation) in 'particle in cell' numerical simulation. (authors)

  7. Energy Absorption Capacity of Composite Beams

    OpenAIRE

    Arivalagan; Kandasamy

    2009-01-01

    Local buckling may occur in the compression flange of rectangular hollow-section beams under cyclic repeated loadingarising from earthquakes. Once a local mechanism forms, residual strength rapidly reduces within a few cycles. This is trueeven for compact sections under static bending. This paper aims to study the experimental behaviour and ultimate momentcapacity of unfilled and concrete-filled rectangular hollow sections subjected to cyclic reversible loading. Two types offiller material we...

  8. PHENIX Experiment Results from the RHIC Beam Energy Scan Program

    CERN Document Server

    ,

    2013-01-01

    The PHENIX Experiment at RHIC has conducted a beam energy scan at several collision energies in order to search for signatures of the QCD critical point and the onset of deconfinement. PHENIX has conducted measurements of transverse energy production, muliplicity fluctuations, the skewness and kurtosis of net charge distributions, Hanbury-Brown Twiss correlations, charged hadron flow, and energy loss. The data analyzed to date show no significant indications of the presence of the critical point.

  9. Broad energy range neutron spectroscopy using a liquid scintillator and a proportional counter: Application to a neutron spectrum similar to that from an improvised nuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yanping, E-mail: yx2132@cumc.columbia.edu; Randers-Pehrson, Gerhard; Marino, Stephen A.; Garty, Guy; Harken, Andrew; Brenner, David J.

    2015-09-11

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n){sup 3}He and D(d,n){sup 3}He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the {sup 9}Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  10. Broad energy range neutron spectroscopy using a liquid scintillator and a proportional counter: Application to a neutron spectrum similar to that from an improvised nuclear device

    Science.gov (United States)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A.; Garty, Guy; Harken, Andrew; Brenner, David J.

    2015-09-01

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)3He and D(d,n)3He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  11. The energy spectrum of high energy gamma rays observed at an airplane altitude

    International Nuclear Information System (INIS)

    In order to get some knowledge of altitude variation of high energy cosmic rays in the atmosphere, an emulsion chamber (EC) has been flown at the atmospheric depth of 260 g/cm2 on an airplane jet cargo. The total amount of exposure is 165 m2hour. Approximately 400 showers with energy greater than 1.0 TeV are observed. The energy spectrum of high energy gamma rays is presented. The comparison with similar measurement at greater depth is made. (orig.)

  12. Study of absorbed dose distribution to high energy electron beams

    International Nuclear Information System (INIS)

    The depth absorbed dose distribution by electron beams was studied. The influence of the beam energy, the energy spread, field size and design characteristics of the accelerator was relieved. Three accelerators with different scattering and collimation systems were studied leading todifferent depth dose distributions. A theoretical model was constructed in order to explain the increase in the depth dose in the build-up region with the increase of the energy. The model utilizes a three-dimensional formalism based on the Fermi-Eyges multiple scattering theory, with the introduction of modifications that takes into account the criation of secondary electrons. (Author)

  13. Electron beam pumping of CdZnSe quantum well laser structures using a variable energy electron beam

    Science.gov (United States)

    Trager-Cowan, C.; Bagnall, D. M.; McGow, F.; McCallum, W.; O'Donnell, K. P.; Smith, P. C.; Wright, P. J.; Cockayne, B.; Prior, K. A.; Mullins, J. T.; Horsburgh, G.; Cavenett, B. C.

    1996-02-01

    In this paper we present experimental results on electron beam pumping of MBE and MOVPE lasers with CdZnSe single quantum wells. Laser emission in the gree and blue occurs under pulsed excitation, with threshold power densities typically less than 2 kW/cm 2 at low temperatures. Threshold curves obtained at different electron beam energies show that there is an optimum electron beam energy for wells at a given depth below the surface. This suggests that it is possible to match the electron beam energy to a given structure. Results are broadly consistent with Monte Carlo calculations of the depth dependence of the energy deposition of the electron beam.

  14. Crossed-beam energy transfer in direct-drive implosions

    Energy Technology Data Exchange (ETDEWEB)

    Seka, W; Edgell, D H; Michel, D T; Froula, D H; Goncharov, V N; Craxton, R S; Divol, L; Epstein, R; Follett, R; Kelly, J H; Kosc, T Z; Maximov, A V; McCrory, R L; Meyerhofer, D D; Michel, P; Myatt, J F; Sangster, T C; Shvydky, A; Skupsky, S

    2012-05-22

    Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of the scattered (non-absorbed) light levels and measured ones that indicate the presence of a mechanism that reduces laser coupling efficiency by 10%-20%. This appears to be due to crossed-beam energy transfer (CBET) that involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters energy from the central portion of the incoming light beam to outgoing light, reducing the laser absorption and hydrodynamic efficiency of implosions. One-dimensional hydrodynamic simulations including CBET show good agreement with all observables in implosion experiments on OMEGA. Three strategies to mitigate CBET and improve laser coupling are considered: the use of narrow beams, multicolor lasers, and higher-Z ablators. Experiments on OMEGA using narrow beams have demonstrated improvements in implosion performance.

  15. Measuring the electron beam energy in a magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten

    2010-09-15

    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 {mu}m precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  16. Low energy, high power hydrogen neutral beam for plasma heating

    Science.gov (United States)

    Deichuli, P.; Davydenko, V.; Ivanov, A.; Korepanov, S.; Mishagin, V.; Smirnov, A.; Sorokin, A.; Stupishin, N.

    2015-11-01

    A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction.

  17. Low energy, high power hydrogen neutral beam for plasma heating.

    Science.gov (United States)

    Deichuli, P; Davydenko, V; Ivanov, A; Korepanov, S; Mishagin, V; Smirnov, A; Sorokin, A; Stupishin, N

    2015-11-01

    A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction. PMID:26628137

  18. Radiation degradation of marine polysaccharides by low energy electron beam

    International Nuclear Information System (INIS)

    The radiation degradations of marine polysaccharides by both gamma Co-60 and electron beam irradiations are investigated. Polysaccharides and oligosaccharides can be produced by degradation of corresponding polysaccharides including marine polysaccharides such as alginates, chitin chitosan and carrageenan. The viscosity of alginate, chitosan and carrageenan solution decreases markedly with increase of the low energy electron beam irradiation time and the beam current. Furthermore, the viscosity is reduced sharply in short time for polysaccharide solution with low concentration, for instance carrageenan solution of 1%. (author)

  19. Beam Intensity and Energy Control for the SPIRAL2 Facility

    OpenAIRE

    Jamet, C.; André, T.; Ducoudret, B.; Doutressoulles, C.; Le Coz, W.; Ledu, G.; Leloir, S.; Loret, S.

    2012-01-01

    TUPB029 - ISBN 878-3-95450-122-9 International audience The first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, consists of an ion source, a deuteron and a proton source, a RFQ and a superconducting linear accelerator delivering high intensities, up to 5 mA and 40 MeV for the deuteron beams. Diagnostic developments have been done to control both beam intensity and energy by non-interceptive methods at the linac exit. The beam current...

  20. Beam monitor system for high-energy beam transportation at HIMAC

    International Nuclear Information System (INIS)

    Heavy-Ion Medical Accelerator in Chiba (HIMAC) provides ion beams for radiotherapy of cancers and for other basic researches. High-energy beam transport lines deliver the beams to three treatment rooms and two experiment rooms with the aid of 41 beam monitor units. Each monitor unit consists of a wire grid as a profile monitor, or a combined unit in which the wire grid and a parallel plate ionization chamber are united for an additional measurement of a beam intensity. They are operated in a mixed gas of 80% Ar and 20% CO2. The gas gain of the wire grid achieves about 8000 at an applied voltage of -2700 V. Dynamic ranges of the wire gird and the parallel plate ionization chamber were measured to be 8x105 and 1x106 in test using ion beams, respectively. A control system of these monitor units offers easy operation, so that operators are almost free from miss-operations. The monitor units are interlocked with a system which protects patients from the undesired irradiation. Five wire grids are used for continuously monitoring the beam during treatments, which play a role in keeping qualities of the treatments. The monitor system has been designed to meet requirements for medical uses, and works in a stable and reliable manner and satisfies the requirements. (author)

  1. Energy gain and spectral tailoring of ion beams using ultra-high intensity laser beams

    Science.gov (United States)

    Prasad, Rajendra; Swantusch, Marco; Cerchez, Mirela; Spickermann, Sven; Auorand, Bastian; Wowra, Thomas; Boeker, Juergen; Willi, Oswald

    2015-11-01

    The field of laser driven ion acceleration over the past decade has produced a huge amount of research. Nowadays, several multi-beam facilities with high rep rate system, e.g. ELI, are being developed across the world for different kinds of experiments. The study of interaction dynamics of multiple beams possessing ultra-high intensity and ultra-short pulse duration is of vital importance. Here, we present the first experimental results on ion acceleration using two ultra-high intensity beams. Thanks to the unique capability of Arcturus laser at HHU Düsseldorf, two almost identical, independent beams in laser parameters such as intensity (>1020 W/cm2), pulse duration (30 fs) and contrast (>1010), could be accessed. Both beams are focused onto a 5 μm thin Ti target. While ensuring spatial overlap of the two beams, at relative temporal delay of ~ 50 ps (optimum delay), the proton and carbon ion energies were enhanced by factor of 1.5. Moreover, strong modulation in C4+ions near the high energy cut-off is observed later than the optimum delay for the proton enhancement. This offers controlled tailoring of the spectral content of heavy ions.

  2. Negative ions as a source of low energy neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems.

  3. Pin diode calibration - beam overlap monitoring for low energy cooling

    Energy Technology Data Exchange (ETDEWEB)

    Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    We were trying to address the question whether or not the Pin Diodes, currently installed approximately 1 meter downstream of the RHIC primary collimators, are suitable to monitor a recombination signal from the future RHIC low energy cooling section. A maximized recombination signal, with the Au+78 ions being lost on the collimator, will indicate optimal Au-electron beam overlap as well as velocity matching of the electron beam in the cooling section.

  4. High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-Up

    CERN Document Server

    Bertarelli, A; Carra, F; Cerutti, F; Dallocchio, A; Mariani, N; Timmins, M; Peroni, L; Scapin, M

    2011-01-01

    Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behaviour of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC tungsten collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from the onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedica...

  5. High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-up

    CERN Document Server

    Bertarelli, A; Carra, F; Cerutti, F; Dallocchio, A; Mariani, N; Timmins, M; Peroni, L; Scapin, M

    2011-01-01

    Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behaviour of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC tungsten collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from the onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedica...

  6. Beamed-Energy Propulsion (BEP): Considerations for Beaming High Energy-Density Electromagnetic Waves Through the Atmosphere

    Science.gov (United States)

    Manning, Robert M.

    2015-01-01

    A study to determine the feasibility of employing beamed electromagnetic energy for vehicle propulsion within and outside the Earth's atmosphere was co-funded by NASA and the Defense Advanced Research Projects Agency that began in June 2010 and culminated in a Summary Presentation in April 2011. A detailed report entitled "Beamed-Energy Propulsion (BEP) Study" appeared in February 2012 as NASA/TM-2012-217014. Of the very many nuances of this subject that were addressed in this report, the effects of transferring the required high energy-density electromagnetic fields through the atmosphere were discussed. However, due to the limitations of the length of the report, only a summary of the results of the detailed analyses were able to be included. It is the intent of the present work to make available the complete analytical modeling work that was done for the BEP project with regard to electromagnetic wave propagation issues. In particular, the present technical memorandum contains two documents that were prepared in 2011. The first one, entitled "Effects of Beaming Energy Through the Atmosphere" contains an overview of the analysis of the nonlinear problem inherent with the transfer of large amounts of energy through the atmosphere that gives rise to thermally-induced changes in the refractive index; application is then made to specific beamed propulsion scenarios. A brief portion of this report appeared as Appendix G of the 2012 Technical Memorandum. The second report, entitled "An Analytical Assessment of the Thermal Blooming Effects on the Propagation of Optical and Millimeter- Wave Focused Beam Waves For Power Beaming Applications" was written in October 2010 (not previously published), provides a more detailed treatment of the propagation problem and its effect on the overall characteristics of the beam such as its deflection as well as its radius. Comparisons are then made for power beaming using the disparate electromagnetic wavelengths of 1.06 microns and 2

  7. ILC beam energy measurement by means of laser Compton backscattering

    International Nuclear Information System (INIS)

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered γ-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10-4 or better on a bunch-to-bunch basis while the electron and positron beams are in collision. (orig.)

  8. ILC beam energy measurement by means of laser Compton backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Muchnoi, N. [Budker Inst. for Nuclear Physics, Novosibirsk (Russian Federation); Schreiber, H.J.; Viti, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2008-10-15

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered {gamma}-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10{sup -4} or better on a bunch-to-bunch basis while the electron and positron beams are in collision. (orig.)

  9. Evaluation, Energy Optimization, and Spectrum Analysis of an Artificial Noise Technique to Improve CWSN Security

    OpenAIRE

    Javier Blesa; Alvaro Araujo; Elena Romero; Octavio Nieto-Taladriz

    2013-01-01

    This paper presents the security evaluation, energy consumption optimization, and spectrum scarcity analysis of artificial noise techniques to increase physical-layer security in Cognitive Wireless Sensor Networks (CWSNs). These techniques introduce noise into the spectrum in order to hide real information. Nevertheless, they directly affect two important parameters in Cognitive Wireless Sensor Networks (CWSNs), energy consumption and spectrum utilization. Both are affected because the number...

  10. A measurement of the energy loss spectrum of 150 GeV muons in iron

    CERN Document Server

    Berger, E; Dawson, J; Fuess, T A; Guarino, V; Hill, N; Magill, S; May, E; Nodulman, L; Price, L E; Proudfoot, J; Stanek, R; Underwood, D G; Wagner, R; Wicklund, B; Blanchot, G; Bosman, M; Casado, M P; Cavalli-Sforza, M; Efthymiopoulos, I; Ivanyushenkov, Yu M; Juste, A; Miralles, L; Orteu, S; Padilla, C; Perlas, J A; Riu, I; Ronceux, B; Teubert, F; Anderson, K J; Blucher, E; Evans, H; Merritt, F S; Pilcher, J E; Sanders, H; Shochet, M J; Tang, F; Turcot, A S; Wagner, D; Arsenescu, R; Constantinescu, S; Blaj, C; Boldea, V; Dita, S; Ajaltouni, Ziad J; Badaud, F; Bouhemaid, N; Brette, P; Brossard, M; Chadelas, R; Chevaleyre, J C; Crouau, M; Daudon, F; Dugne, J J; Michel, B; Montarou, G; Muanza, G S; Pallin, D; Plothow-Besch, Hartmute; Poirot, S; Reinmuth, G; Says, L P; Vazeille, F; Cobal, M; Gildemeister, O; Nessi, Marzio; Henriques, A; Poggioli, Luc; Sonderegger, P; Karapetian, G V; Astvatsaturov, A R; Borisov, O N; Budagov, Yu A; Chirikov-Zorin, I E; Chlachidze, G; Glagolev, V V; Kakurin, S; Kolomoets, V; Kovtun, V E; Kukhtin, V V; Lebedev, A; Liba, I; Lomakina, O V; Lomakin, Yu F; Malyukov, S N; Minashvili, I A; Pantea, D; Pukhov, O; Romanov, V; Rusakovitch, N A; Senchyshyn, V G; Semenov, V; Sissakian, A N; Shchelchkov, V; Shevtsov, A; Studenov, S; Tokár, S; Topilin, N D; Vinogradov, V; Vorozhtsov, S B; Yarygin, G; Cogswell, F; Downing, R; Errede, D; Errede, S; Haney, M; Simaitis, V J; Thaler, J J; Amaral, P; Amorim, A; Carvalho, J; David, M; Gómez, A; Maio, A; Martins, J P; Onofre, A; Wolters, H; Bromberg, C; Huston, J; Miller, R; Richards, R; Yosef, C; Alifanov, A; Bogush, A A; Golubev, V B; Rumyantsev, V; Kulchitskii, Yu A; Angelini, C; Autiero, D; Cavasinni, V; Costanzo, D; De Santo, A; Del Prete, T; Di Girolamo, B; Flaminio, Vincenzo; Lami, S; Lazzeroni, C; Mazzoni, E; Renzoni, G; Davidek, T; Dolejsi, J; Dolezal, Z; Leitner, R; Soustruznik, K; Suk, M; Tas, P; Trka, Z; Valkár, S; Zdrazil, M; Lokajícek, M; Némécek, S; Karyukhin, A N; Klioukhine, V I; Khokhlov, Yu A; Kopikov, S V; Kostrikov, M E; Kulagin, M; Lapin, V; Protopopov, Yu; Sidorov, V; Solodkov, A A; Starchenko, E A; Surkov, A; Zaitsev, A; Calôba, L P; Gaspar, M; Marroquin, F; Pereira, A; Seixas, J M; Berglund, S R; Bohm, C; Johansson, E K; Hellman, S; Holmgren, S O; Jon-And, K; Selldén, B; Tardell, S; Yamdagni, N; Ferrer, A; Honoré, P F; Albiol, F; De, K; Gallas, E J; Li, J; Sawyer, L; Stephens, R; Turcotte, M; White, A; Hakopian, H H; Grabskii, V; Mnatzakanian, E A; Vartapetian, A H

    1997-01-01

    The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS.\\\\ The differential probability $dP/dv$ per radiation length of a fractional energy loss $v = \\Delta E_{\\mu} / E_{\\mu}$ has been measured in the range $v = 0.01 \\div 0.95 $; it is then compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons.\\\\ The integrated probability $\\int_{0.01}^{0.95} (dP/dv) dv$ is $(1.610\\pm0.015_{stat.}\\pm0.105_{syst.})\\cdot10^{-3}$ in agreement with the theoretical predictions of $1.556\\cdot10^{-3}$ and $1.619\\cdot10^{-3}$. %7.8.96 - start Agreement with theory is also found in two intervals of $v$ where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance ($v = 0.12\\div0.95$) the measured integrated probability $(1.160\\pm0.040_{stat}\\pm0.075_{syst})\\cdot 10^{-4}$ is in agreement with ...

  11. Measurement of the Energy Spectrum of Ultra-High Energy Cosmic Rays using Hybrid Data of the Pierre Auger Observatory

    OpenAIRE

    Schüssler, Fabian

    2009-01-01

    The subject of this thesis is the measurement of the energy spectrum of ultra-high energy cosmic rays from simultaneous observation of fluorescence and surface detectors of the Pierre Auger Observatory. Extending the nominal energy range of the Pierre Auger Observatory to lower energy, the hybrid energy spectrum above 10^{18} eV is measured. It shows a significant break of the power-law behavior at 10^{18.7} eV.

  12. Energy recuperation of intense proton beam compensated by slow electrons

    International Nuclear Information System (INIS)

    Experimental studies of direct transformation (recuperation) of intense ion beam energy are described. In a recuperator low-energy electrons of a beam are separated by a grid unit and ions are detected by one of the three types of collectors: plane, ''Faraday cylinder'' with a grid in the input hole and without it. The transformation of proton beam energy with current density up to 150 mA/cm2 at current pulse duration of 300 μ and power of ∼ 0.5 kW is realized with the efficiency of 70%, at power up to 30 kW - with the efficiency of about 50%. The investigation results can be used for the development of recuperation systems in thermonuclear facilities

  13. Staging laser plasma accelerators for increased beam energy

    International Nuclear Information System (INIS)

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  14. American Institute of Beamed Energy Propulsion: An Introduction

    Science.gov (United States)

    Pakhomov, Andrew V.

    2008-04-01

    To date ISBEP remains the main forum addressing the science and engineering of beamed energy propulsion. Hopefully, it will continue to serve BEP community in this capacity for years to come. The need for organization acting beyond ISBEP was discussed since the second symposium. This paper will address the following question: if our community is ready for having its own organization, a BEP institute, what new it should bring comparing to already existing conference. Such organization, an American Institute on Beamed Energy Propulsion (AIBEP) was recently established. The institute is designed as a nonprofit corporation serving the purpose "to promote the ideas, concepts and benefits of beamed-energy propulsion to research community, industry and society at large". The goals of the institute, expected outcomes and benefits of the organization and its membership will be discussed.

  15. American Institute of Beamed Energy Propulsion: An Introduction

    International Nuclear Information System (INIS)

    To date ISBEP remains the main forum addressing the science and engineering of beamed energy propulsion. Hopefully, it will continue to serve BEP community in this capacity for years to come. The need for organization acting beyond ISBEP was discussed since the second symposium. This paper will address the following question: if our community is ready for having its own organization, a BEP institute, what new it should bring comparing to already existing conference. Such organization, an American Institute on Beamed Energy Propulsion (AIBEP) was recently established. The institute is designed as a nonprofit corporation serving the purpose 'to promote the ideas, concepts and benefits of beamed-energy propulsion to research community, industry and society at large'. The goals of the institute, expected outcomes and benefits of the organization and its membership will be discussed

  16. Staging laser plasma accelerators for increased beam energy

    Energy Technology Data Exchange (ETDEWEB)

    Panasenko, Dmitriy; Shu, Anthony; Schroeder, Carl; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Cormier-Michel, Estelle; Plateau, Guillaume; Lin, Chen; Toth, Csaba; Geddes, Cameron; Esarey, Eric; Leemans, Wim

    2008-09-29

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  17. Modeling crossed-beam energy transfer for inertial confinement fusion

    Science.gov (United States)

    Marion, D. J. Y.; Debayle, A.; Masson-Laborde, P.-E.; Loiseau, P.; Casanova, M.

    2016-05-01

    We developed a numerical code that describes both the energy transfer occurring when two or more laser beams overlap in a weakly non-homogeneous plasma, and the beam energy losses associated with the electron-ion collisions. The numerical solutions are validated with both the exact analytical solutions in homogeneous plasmas, and with new approximate analytical solutions in non-homogeneous plasmas that include the aforementioned inverse bremsstrahlung effect. Comparisons with kinetic particle-in-cell simulations are satisfactory, provided the acoustic wave-breaking limit and the self-focusing regime are not reached. An application of the Cross-Beam Energy Transfer model is shown for a typical case of indirect-drive implosion in a gold hohlraum.

  18. Staging laser plasma accelerators for increased beam energy

    OpenAIRE

    Panasenko, Dmitriy

    2010-01-01

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, ...

  19. Crossed Beam Energy Transfer in the NIF ICF Target Design

    International Nuclear Information System (INIS)

    In the National Ignition Facility (NIF) ICF point design, the cylindrical hohlraum target is illuminated by multiple laser beams through two laser entrance holes on the ends. According to simulations by LASNEX and HYDRA plasma created inside the hohlraum will stream out of the LEH, accelerate to supersonic speeds and then fan out radially. Inside the hohlraum, flows are subsonic. Forward Brillouin scattering can transfer energy between pairs of laser beams (0 and 1) if the following frequency matching condition is satisfied: ω0 - ω1 = (k0 - k1) · V + |k0 - k1| cs (1) where ω0.1 and k0.1 are the frequencies and wave-numbers of the two laser beams, V is the plasma flow velocity and cs is the local ion sound speed. In the nominal case of equal frequency beams, this requires the component of the plasma flow velocity transverse to the bisector of the beam directions to be sonic, with the resulting transfer being to the downstream beam. In the NIF beam geometry, this is from the outer to inner cones of beams. The physics of this transfer is the same as in beam bending; the difference being that in the case of beam bending the effect is to redistribute power to the downstream side of the single beam. Were significant power transfer to occur in the point design, the delicately tuned implosion symmetry would be spoiled. To directly compensate for the transfer, the incident beam powers would have to be adjusted. The greatest vulnerability in the point design thus occurs at 15.2ns, when the inner beams are at their peak power and are at their nominal design power limit. In this situation, some other means of symmetry control would be required, such as re-pointing. At 15.2ns, the envelope focal intensities of the outer and inner beams are approximately 1015 and 6.7 1014 W/cm2 respectively. There is little absorption or diffractive spreading of the beams in the crossing region, so these intensities are also representative there. The outer beams are at higher intensity

  20. SU-E-T-557: Monte Carlo Modeling of Philips RT-250 Orthovoltage Unit for Beam Spectrum Modulation

    International Nuclear Information System (INIS)

    Purpose: To develop and validate a Monte Carlo (MC) model of a Phillips RT-250 orthovoltage unit to test various beam spectrum modulation strategies for in vitro/vivo studies. A model of this type would enable the production of unconventional beams from a typical orthovoltage unit for novel therapeutic applications such as gold nanoparticle-aided radiotherapy. Methods: The MCNP5 code system was used to create a MC model of the head of RT-250 and a 30 × 30 × 30 cm3 water phantom. For the x-ray machine head, the current model includes the vacuum region, beryllium window, collimators, inherent filters and exterior steel housing. For increased computational efficiency, the primary x-ray spectrum from the target was calculated from a well-validated analytical software package. Calculated percentage-depth-dose (PDD) values and photon spectra were validated against experimental data from film and Compton-scatter spectrum measurements. Results: The model was validated for three common settings of the machine namely, 250 kVp (0.25 mm Cu), 125 kVp (2 mm Al), and 75 kVp (2 mm Al). The MC results for the PDD curves were compared with film measurements and showed good agreement for all depths with a maximum difference of 4 % around dmax and under 2.5 % for all other depths. The primary photon spectra were also measured and compared with the MC results showing reasonable agreement between the two, validating the input spectra and the final spectra as predicted by the current MC model. Conclusion: The current MC model accurately predicted the dosimetric and spectral characteristics of each beam from the RT-250 orthovoltage unit, demonstrating its applicability and reliability for beam spectrum modulation tasks. It accomplished this without the need to model the bremsstrahlung xray production from the target, while significantly improved on computational efficiency by at least two orders of magnitude. Supported by DOD/PCRP grant W81XWH-12-1-0198

  1. Segmentation-free x-ray energy spectrum estimation for computed tomography

    CERN Document Server

    Zhao, Wei; Niu, Tianye

    2016-01-01

    X-ray energy spectrum plays an essential role in imaging and related tasks. Due to the high photon flux of clinical CT scanners, most of the spectrum estimation methods are indirect and are usually suffered from various limitations. The recently proposed indirect transmission measurement-based method requires at least the segmentation of one material, which is insufficient for CT images of highly noisy and with artifacts. To combat for the bottleneck of spectrum estimation using segmented CT images, in this study, we develop a segmentation-free indirect transmission measurement based energy spectrum estimation method using dual-energy material decomposition. The general principle of the method is to compare polychromatic forward projection with raw projection to calibrate a set of unknown weights which are used to express the unknown spectrum together with a set of model spectra. After applying dual-energy material decomposition using high- and low-energy raw projection data, polychromatic forward projection ...

  2. Rising inelastic cross section and its contribution to steepening of the cosmic ray energy spectrum

    International Nuclear Information System (INIS)

    Calculations have been carried out to investigate the contribution of an increasing total cross section to steepening of the cosmic ray energy spectrum at very high energies (E>approximately1012eV). Our results suggest that increasing total cross section contributes only a part to the steepening of primary energy spectrum at very high energies even if the composition is pure primary iron flux. (author)

  3. Narrow beam dosimetry for high-energy hadrons and electrons

    CERN Document Server

    Pelliccioni, M; Ulrici, Luisa

    2001-01-01

    Organ doses and effective dose were calculated with the latest version of the Monte Carlo transport code FLUKA in the case of an anthropomorphic mathematical model exposed to monoenergetic narrow beams of protons, pions and electrons in the energy range 10°— 400 GeV. The target organs considered were right eye, thyroid, thymus, lung and breast. Simple scaling laws to the calculated values are given. The present data and formula should prove useful for dosimetric estimations in case of accidental exposures to high-energy beams.

  4. Proton therapy monitoring by Compton imaging: influence of the large energy spectrum of the prompt-γ radiation

    Science.gov (United States)

    Hilaire, Estelle; Sarrut, David; Peyrin, Françoise; Maxim, Voichiţa

    2016-04-01

    In proton therapy, the prompt-γ (PG) radiation produced by the interactions between protons and matter is related to the range of the beam in the patient. Tomographic Compton imaging is currently studied to establish a PG image and verify the treatment. However the quality of the reconstructed images depends on a number of factors such as the volume attenuation, the spatial and energy resolutions of the detectors, incomplete absorptions of high energy photons and noise from other particles reaching the camera. The impact of all these factors was not assessed in details. In this paper we investigate the influence of the PG energy spectrum on the reconstructed images. To this aim, we describe the process from the Monte Carlo simulation of the proton irradiation, through the Compton imaging of the PG distribution, up to the image reconstruction with a statistical MLEM method. We identify specific PG energy windows that are more relevant to detect discrepancies with the treatment plan. We find that for the simulated Compton device, the incomplete absorption of the photons with energy above about 2 MeV prevents the observation of the PG distributions at specific energies. It also leads to blurred images and smooths the distal slope of the 1D PG profiles obtained as projections on the central beam axis. We show that a selection of the events produced by γ photons having deposited almost all their energy in the camera allows to largely improve the images, a result that emphasizes the importance of the choice of the detector. However, this initial-energy-based selection is not accessible in practice. We then propose a method to estimate the range of the PG profile both for specific deposited-energy windows and for the full spectrum emission. The method relies on two parameters. We use a learning approach for their estimation and we show that it allows to detect few millimeter shifts of the PG profiles.

  5. Beam monitor system for high-energy beam transportation at HIMAC

    CERN Document Server

    Torikoshi, M; Takada, E; Kanai, T; Yamada, S; Ogawa, H; Okumura, K; Narita, K; Ueda, K; Mizobata, M

    1999-01-01

    Heavy-Ion Medical Accelerator in Chiba (HIMAC) provides ion beams for radiotherapy of cancers and for other basic researches. High-energy beam transport lines deliver the beams to three treatment rooms and two experiment rooms with the aid of 41 beam monitor units. Each monitor unit consists of a wire grid as a profile monitor, or a combined unit in which the wire grid and a parallel plate ionization chamber are united for an additional measurement of a beam intensity. They are operated in a mixed gas of 80% Ar and 20% CO sub 2. The gas gain of the wire grid achieves about 8000 at an applied voltage of -2700 V. Dynamic ranges of the wire gird and the parallel plate ionization chamber were measured to be 8x10 sup 5 and 1x10 sup 6 in test using ion beams, respectively. A control system of these monitor units offers easy operation, so that operators are almost free from miss-operations. The monitor units are interlocked with a system which protects patients from the undesired irradiation. Five wire grids are use...

  6. Production of high energy photon beam at TAC

    International Nuclear Information System (INIS)

    When an electron pass through an electric field, the electron loose its part of energy and photon is generated. This process is known as Bremsstrahlung (means 'radiation breaking' in German) and this photon can be used in a variety of different application. The TAC will be first Turkish Accelerator Center (TAC) where a IR-FEL and Beamstrahlung photon beam facilities will be established in first stage. The electrons will be accelerated up to 40 MeV by two LINAC and these beam will be used to generate Bremsstrahlung photon. In this study, the main parameters for Bremsstrahlung photon beam facility will be established at TAC will be detailed and fields to be used Bremsstrahlung beam will also be presented.

  7. The high-energy dual-beam facility

    International Nuclear Information System (INIS)

    This proposal presents a new experimental facility at the Kernforschungszentrum Karlsruhe (KfK) to study the effects of irradiation on the first wall and blanket materials of a fusion reactor. A special effort is made to demonstrate the advantages of the Dual Beam Technique (DBT) as a future research tool for materials development within the European Fusion Technology Programme. The Dual-Beam-Technique allows the production both of helium and of damage in thick metal and ceramic specimens by simultaneous irradiation with high energy alpha particles and protons produced by the two KfK cyclotrons. The proposal describes the Dual Beam Technique the planned experimental activities and the design features of the Dual Beam Facility presently under construction. (orig.)

  8. High-energy accelerator for beams of heavy ions

    Science.gov (United States)

    Martin, Ronald L.; Arnold, Richard C.

    1978-01-01

    An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

  9. Focused high energy proton beam micromachining: A perspective view

    International Nuclear Information System (INIS)

    Micromachining techniques utilising optical, UV and X-ray photons, as well as electrons, low energy heavy ions and high energy light ions (protons), are briefly reviewed. The advantages and disadvantages of each process are discussed. High energy ion beam micromachining (proton micromachining) is a new process which exhibits a unique feature; direct-write 3-dimensional micromachining at submicron resolutions. Although this technique may not compete with conventional mask processes for producing high volume batch production of microcomponents, high energy ion beam micromachining may have a significant role in rapid prototyping, research into the characteristics of microstructures, and the manufacture of molds, stamps and thick masks. Several examples of high energy proton micromachining are presented to illustrate the potential of the technique

  10. High-precision absolute measurement of CEBAF beam mean energy

    International Nuclear Information System (INIS)

    The absolute measurement of the beam mean energy with an accuracy of one part in 104 or higher is an important demand of the CEBAF Hall A physics program. This accuracy may reduce the uncertainty in the d(e, e'p)p cross section δσ/σ to 1%. The need for such an accurately calibrated beam is not particular to CEBAF; at other electron facilities uncertainty in the incident energy has proven to be among the dominant sources of systematic error. The following methods for solving the problem were considered at both CEBAF and the Yerevan Physics Institute during 1990--1991: Backscattering of a plane electromagnetic wave by the relativistic electron beam. Calculations show that the intensity of the backscattered radiation in a bandwidth of 10-4 near the maximum frequency is about 1 photon per second at 4 GeV and 0.3 mA. Magnetic spectrometers performing as three- and four-magnet chicanes with appropriate detector systems. Such a system was used at SLAC for absolute measurement of the SLC beams energy, where a maximum accuracy of 5 x 10-4 was achieved. Calculations show that a similar accuracy can be achieved for the CEBAF beam in both proposed systems. Measurement of the vertical distribution of synchrotron radiation. Calculations indicate that precision of about 2.5 x 10-5 is achievable for CEBAF

  11. Beamed Energy Propulsion: Research Status And Needs--Part 1

    International Nuclear Information System (INIS)

    One promising solution to the operationally responsive space is the application of remote electromagnetic energy to propel a launch vehicle into orbit. With beamed energy propulsion, one can leave the power source stationary on the ground or space, and direct heat propellant on the spacecraft with a beam from a fixed station. This permits the spacecraft to leave its power source at home, saving significant amounts of mass, greatly improving performance. This concept, which removes the mass penalty of carrying the propulsion energy source on board the vehicle, was first proposed by Arthur Kantrowitz in 1972; he invoked an extremely powerful ground based laser. The same year Michael Minovich suggested a conceptually similar 'in-space' laser rocket system utilizing a remote laser power station. In the late 1980's, Air Force Office of Scientific Research (AFOSR) funded continuous, double pulse laser and microwave propulsion while Strategic Defense Initiative Office (SDIO) funded ablative laser rocket propulsion. Currently AFOSR has been funding the concept initiated by Leik Myrabo, repetitively pulsed laser propulsion, which has been universally perceived, arguably, to be the closest for mid-term applications. This 2-part paper examines the investment strategies in beamed energy propulsion and technical challenges to be overcome. Part 1 presents a world-wide review of beamed energy propulsion research, including both laser and microwave arenas

  12. Energy spread of ion beams generated in multicusp ion sources

    International Nuclear Information System (INIS)

    For the production of future microelectronics devices, various alternate methods are currently being considered to replace the presently used method of lithography with ion beam lithography. One of these methods is the Ion Projection Lithography (IPL), which aims at the possibility of projecting sub-0.25 μm patterns of a stencil mask onto a wafer substrate. In order to keep the chromatic aberrations below 25 nm, an ion source which delivers a beam with energy spread of less than 3 eV is desired. For this application, multicusp ion sources are being considered. We measure the longitudinal energy spread of the plasma ions by using a two-grid electrostatic energy analyzer. The energy spread of the extracted beam is measured by a high-voltage retarding-field energy analyzer. In order to obtain the transverse ion temperature, a parallel-plate scanner is being set up to study the beam emittance. In this paper, comparisons are made for different ion source configurations

  13. Characterization of low energy X-rays beams with an extrapolation chamber

    International Nuclear Information System (INIS)

    In laboratories involving Radiological Protection practices, it is usual to use reference radiations for calibrating dosimeters and to study their response in terms of energy dependence. The International Organization for Standardization (ISO) established four series of reference X-rays beams in the ISO- 4037 standard: the L and H series, as low and high air Kerma rates, respectively, the N series of narrow spectrum and W series of wide spectrum. The X-rays beams with tube potential below 30 kV, called 'low energy beams' are, in most cases, critical as far as the determination of their parameters for characterization purpose, such as half-value layer. Extrapolation chambers are parallel plate ionization chambers that have one mobile electrode that allows variation of the air volume in its interior. These detectors are commonly used to measure the quantity Absorbed Dose, mostly in the medium surface, based on the extrapolation of the linear ionization current as a function of the distance between the electrodes. In this work, a characterization of a model 23392 PTW extrapolation chamber was done in low energy X-rays beams of the ISO- 4037 standard, by determining the polarization voltage range through the saturation curves and the value of the true null electrode spacing. In addition, the metrological reliability of the extrapolation chamber was studied with measurements of the value of leakage current and repeatability tests; limit values were established for the proper use of the chamber. The PTW23392 extrapolation chamber was calibrated in terms of air Kerma in some of the ISO radiation series of low energy; the traceability of the chamber to the National Standard Dosimeter was established. The study of energy dependency of the extrapolation chamber and the assessment of the uncertainties related to the calibration coefficient were also done; it was shown that the energy dependence was reduced to 4% when the extrapolation technique was used. Finally, the first

  14. Energy Spread Reduction of Electron Beams Produced via Laser Wake

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Bradley Bolt [Univ. of California, San Diego, CA (United States)

    2012-01-01

    Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 1018 cm-3 in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a

  15. High energy beams of radioactive nuclei and their biomedical applications

    International Nuclear Information System (INIS)

    The availability of high-energy beams of radioactive species is the most recent advancement in the field of accelerator physics. One of the primary interactions experienced by relativistic heavy ions is the peripheral nuclear collision. Thus, radioactive nuclei are produced as secondary particles from peripheral nuclear fragmentation reactions. These nuclei have trajectories and energies differing little from that of the parent particle. Various radioactive beams produced as a result of these reactions, now available on a regular basis from the Bevalac, are: 11C, 13N, 15O, and 19Ne with sufficient intensity. Besides the interest in such beams for nuclear physics, important applications in therapeutic and diagnostic radiology and in nuclear medicine are discussed

  16. Optimization studies of photo-neutron production in high- metallic targets using high energy electron beam for ADS and transmutation

    Indian Academy of Sciences (India)

    V C Petwal; V K Senecha; K V Subbaiah; H C Soni; S Kotaiah

    2007-02-01

    Monte Carlo calculations have been performed using MCNP code to study the optimization of photo-neutron yield for different electron beam energies impinging on Pb, W and Ta cylindrical targets of varying thickness. It is noticed that photo-neutron yield can be increased for electron beam energies ≥ 100 MeV for appropriate thickness of the target. It is also noticed that it can be maximized by further increasing the thickness of the target. Further, at higher electron beam energy heat gradient in the target decreases, which facilitates easier heat removal from the target. This can help in developing a photo-neutron source based on electron LINAC by choosing appropriate electron beam energy and target thickness to optimize the neutron flux for ADS, transmutation studies and as high energy neutron source etc. Photo-neutron yield for different targets, optimum target thickness and photo-neutron energy spectrum and heat deposition by electron beam for different incident energy is presented.

  17. High-speed screen beam-profile-monitor system for high-energy beam-transport line at the HIMAC

    International Nuclear Information System (INIS)

    A screen monitor system was developed for beam profile monitors at the new High-Energy Beam-Transport (HEBT) section out the HIMAC. This monitor consists of the very thin fluorescent screen and the high-speed CCD camera. In addition to perform high-speed and high-resolution, this monitor does not almost destroy the beam. (author)

  18. Solar Power Satellites: Creating the Market for Beamed Energy Propulsion

    Science.gov (United States)

    Coopersmith, Jonathan

    2010-05-01

    Beamed energy advocates must investigate the potential of major markets like space based solar satellites and space-based nuclear waste disposal. For BEP to succeed, its proponents must work with these possible users to generate interest and resources needed to develop BEP.

  19. Solar Power Satellites: Creating the Market for Beamed Energy Propulsion

    International Nuclear Information System (INIS)

    Beamed energy advocates must investigate the potential of major markets like space based solar satellites and space-based nuclear waste disposal. For BEP to succeed, its proponents must work with these possible users to generate interest and resources needed to develop BEP.

  20. MEIC Proton Beam Formation with a Low Energy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  1. High energy physics with polarized beams and targets. [65 papers

    Energy Technology Data Exchange (ETDEWEB)

    Marshak, M L [ed.

    1976-01-01

    Sixty-six papers are presented as a report on conference sessions held from August 23-27, 1976, at Argonne National Laboratory. Topics covered include: (1) strong interactions; (2) weak and electromagnetic interactions; (3) polarized beams; and (4) polarized targets. A separate abstract was prepared for each paper for ERDA Energy Research Abstracts (ERA) and for the INIS Atomindex. (PMA)

  2. Recent applications of low energy electron beam processing

    International Nuclear Information System (INIS)

    It is obvious that radiation processing reduces energy consumption and avoids pollution because the coatings are solventless; but as important these factors may be, they alone do not justify the investment of an electron beam accelerator. With a few examples from the industry, motivations of users to choose electron processing is explained. (author)

  3. LOW ENERGY BEAM-GAS SPECTROSCOPY OF HIGHLY IONISED ATOMS

    OpenAIRE

    Desesquelles, J.; Denis, A.; Druetta, M.; Martin, S.

    1989-01-01

    Features of low energy beam-gas spectroscopic source are reviewed and compared to those of other light sources. Measurement techniques are surveyed. They include the study of wavelength of heavy multiply charged ions in visible and u.v. ranges from normal excited states, doubly excited states, high n levels and doubly excited Rydberg levels.

  4. Dynamic Response of Inextensible Beams by Improved Energy Balance Method

    DEFF Research Database (Denmark)

    Sfahani, M. G.; Barari, Amin; Omidvar, M.;

    2011-01-01

    An improved He's energy balance method (EBM) for solving non-linear oscillatory differential equation using a new trial function is presented. The problem considered represents the governing equations of the non-linear, large-amplitude free vibrations of a slender cantilever beam with a...

  5. Spiral design and beam dynamics for a variable energy cyclotron

    International Nuclear Information System (INIS)

    Beam-orbit studies were performed for the conversion of the SREL synchrocyclotron magnet for use as a room temperature, multiparticle, isochronous cyclotron. Based on model magnet measurements of field profiles for 8 to 230K gauss hill fields, a four sector spiral pole tip design has been realized which allows all isotope species of heavy ion beams to be accelerated to required final energies. The total spiral angle of 380 allows injection of the beams from the MP tandem into the cyclotron through a valley. The two valey RF system of 140 kV peak accelerates beams on harmonic numbers 2, 3, 4, 6 and 10 at 14 to 21 MHz. Computer calculations indicated acceptable ν/sub z/, ν/sub r/ and phase space beam characteristics and passing of resonances for typical beams considered: 16O at 8 and 150 MeV/amu, 60Ni at 100 MeV/amu and 238U at 2.5 and 16 MeV/amu. Single turn extraction is achieved with electrostatic deflection

  6. Segmentation-free x-ray energy spectrum estimation for computed tomography

    OpenAIRE

    Zhao, Wei; Zhang, Qiude; Niu, Tianye

    2016-01-01

    X-ray energy spectrum plays an essential role in imaging and related tasks. Due to the high photon flux of clinical CT scanners, most of the spectrum estimation methods are indirect and are usually suffered from various limitations. The recently proposed indirect transmission measurement-based method requires at least the segmentation of one material, which is insufficient for CT images of highly noisy and with artifacts. To combat for the bottleneck of spectrum estimation using segmented CT ...

  7. High energy photon production in strong colliding laser beams

    OpenAIRE

    Kuchiev, Michael; Ingham, Julian

    2015-01-01

    The collision of two intense, low-frequency laser beams is considered. The $e^-e^+$ pairs created in this field are shown to exhibit recollisions, which take place at high energy accumulated due to the wiggling of fermions. The resulting $e^-e^+$ annihilation produces high energy photons, or heavy particles. The coherent nature of the laser field provides strong enhancement of the probability of these events. Analytical and numerical results are outlined.

  8. Laser focusing of high-energy charged-particle beams

    International Nuclear Information System (INIS)

    It is shown that laser focusing of high-energy charged-particle beams using the inverse Cherenkov effect is well suited for applications with large linear colliders. Very high gradient (>0.5 MG/cm) lenses result that can be added sequentially without AG cancellation. These lenses are swell understood, have small geometric aberrations, and offer the possibility of correlating phase and energy aberrations to produce an achromatic final focus

  9. Constraining sterile neutrinos with a low energy beta-beam

    OpenAIRE

    Agarwalla, Sanjib K.; Huber, Patrick; Link, Jonathan M.

    2009-01-01

    We show that a low energy beta-beam facility can be used to search for sterile neutrinos by measuring the disappearance of electron anti-neutrinos. This channel is particularly sensitive since it allows to use inverse beta decay as detection reaction; thus it is free from hadronic uncertainties, provided the neutrino energy is below the pion production threshold. This corresponds to a choice of the Lorentz gamma=30 for the 6He parent ion. Moreover, a disappearance measurement allows the const...

  10. Constraining sterile neutrinos with a low energy beta-beam

    OpenAIRE

    Agarwalla, Sanjib Kumar

    2010-01-01

    We study the possibility to use a low energy beta-beam facility to search for sterile neutrinos by measuring the disappearance of electron anti-neutrinos. This channel is particularly sensitive since it allows to use inverse beta decay as detection reaction; thus it is free from hadronic uncertainties, provided the neutrino energy is below the pion production threshold. This corresponds to a choice of the Lorentz gamma=30 for the 6He parent ion. Moreover, a disappearance measurement allows th...

  11. Effects of tidal forces on the beam energy in LEP

    International Nuclear Information System (INIS)

    The e+e- collider LEP is used to investigate the Z particle and to measure its energy and width. This requires energy calibrations with ∼20 ppm precision achieved by measuring the frequency of a resonance which destroys the transverse beam polarization established by synchrotron radiation. To make this calibration valid over a longer period all effects causing an energy change have to be corrected for. Among those are the terrestrial tides due to the Moon and Sun. They move the Earth surface up and down by as much as ∼0.25 m which represents a relative local change of the Earth radius of 0.04 ppm. This motion has also lateral components resulting in a change of the LEP circumference (Cc=26.7 km) by a similar relative amount. Since the length of the beam orbit is fixed by the constant RF-frequency the change of the machine circumference will force the beam to go off-center through the quadrupoles and receive an extra deflection leading to an energy change given by ΔCc/Cc ∼ -αc ΔE/E. With the momentum compaction αc = 1.85 · 10-4 for the present LEP optics this gives tide-driven p.t.p. energy excursion up to about 220 ppm, corresponding to ∼18.5 MeV for the Z energy. A beam energy measurement carried out over a 24 hour period perfectly confirmed the effects expected from a more detailed calculation of the tides. A corresponding correction can be applied to energy calibrations

  12. Refractive analysis of interfaces with neutron beam optimised for a white spectrum: RAINBOWS

    International Nuclear Information System (INIS)

    A new technique of refractive encoding for specular reflectometry is described that uses the full white beam without the need for choppers. Depending on the resolution, gains of many orders of flux are possible opening a new area of sub-second kinetics in interface research or allowing very small sample areas to be studied. (author)

  13. Vibration piezoelectric energy harvester with multi-beam

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Yan, E-mail: yanc@dlut.edu.cn; Zhang, Qunying, E-mail: zhangqunying89@126.com; Yao, Minglei, E-mail: yaomingleiok@126.com [Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, Dalian University of Technology, 116024, Dalian, Liaoning Province (China); Dong, Weijie, E-mail: dongwj@dlut.edu.cn [School of Electronic and Information Engineering, Dalian University of Technology, 116024, Dalian, Liaoning Province (China); Gao, Shiqiao, E-mail: gaoshq@bit.edu.cn [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, 100081, Beijing Province (China)

    2015-04-15

    This work presents a novel vibration piezoelectric energy harvester, which is a micro piezoelectric cantilever with multi-beam. The characteristics of the PZT (Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}) thin film were measured; XRD (X-ray diffraction) pattern and AFM (Atomic Force Microscope) image of the PZT thin film were measured, and show that the PZT (Pb(Zr{sub 0.53}Ti{sub 0.47})O{sub 3}) thin film is highly (110) crystal oriented; the leakage current is maintained in nA magnitude, the residual polarisation Pr is 37.037 μC/cm{sup 2}, the coercive field voltage Ec is 27.083 kV/cm, and the piezoelectric constant d{sub 33} is 28 pC/N. In order to test the dynamic performance of the energy harvester, a new measuring system was set up. The maximum output voltage of the single beam of the multi-beam can achieve 80.78 mV under an acceleration of 1 g at 260 Hz of frequency; the maximum output voltage of the single beam of the multi-beam is almost 20 mV at 1400 Hz frequency. .

  14. Preliminary investigations on high energy electron beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Baertling, Yves; Hoppe, Dietrich; Hampel, Uwe

    2010-12-15

    In computed tomography (CT) cross-sectional images of the attenuation distribution within a slice are created by scanning radiographic projections of an object with a rotating X-ray source detector compound and subsequent reconstruction of the images from these projection data on a computer. CT can be made very fast by employing a scanned electron beam instead of a mechanically moving X-ray source. Now this principle was extended towards high-energy electron beam tomography with an electrostatic accelerator. Therefore a dedicated experimental campaign was planned and carried out at the Budker Institute of Nuclear Physics (BINP), Novosibirsk. There we investigated the capabilities of BINP's accelerators as an electron beam generating and scanning unit of a potential high-energy electron beam tomography device. The setup based on a 1 MeV ELV-6 (BINP) electron accelerator and a single detector. Besides tomographic measurements with different phantoms, further experiments were carried out concerning the focal spot size and repeat accuracy of the electron beam as well as the detector's response time and signal to noise ratio. (orig.)

  15. Vibrational Energy Flow Analysis of Corrected Flexural Waves in Timoshenko Beam – Part II: Application to Coupled Timoshenko Beams

    Directory of Open Access Journals (Sweden)

    Young-Ho Park

    2006-01-01

    Full Text Available This paper presents the methodology for the energy flow analysis of coupled Timoshenko beam structures and various numerical applications to verify the developed methodology. To extend the application of the energy flow model for corrected flexural waves in the Timoshenko beam, which is developed in the other companion paper, to coupled structures, the wave transmission analyses of general coupled Timoshenko beam systems are performed. First, power transmission and reflection coefficients for all kinds of propagating waves in the general, coupled Timoshenko beam structures are derived by the wave transmission approach. In numerical applications, the energy flow solutions using the derived coefficients agree well with the classical solutions for various exciting frequencies, damping loss factors, and coupled Timoshenko beam structures. Additionally, the numerical results for the Timoshenko beam are compared with those for the Euler-Bernoulli beam.

  16. High-Energy Electron Beam Application to Air Pollutants Removal

    International Nuclear Information System (INIS)

    The advantage of electron beam (EB) process in pollutants removal is connected to its high efficiency to transfer high amount of energy directly into the matter under treatment. Disadvantage which is mostly related to high investment cost of accelerator may be effectively overcome in future as the result of use accelerator new developments. The potential use of medium to high-energy high power EB accelerators for air pollutants removal is demonstrated in [1]. The lower electrical efficiencies of accelerators with higher energies are partially compensated by the lower electron energy losses in the beam windows. In addition, accelerators with higher electron energies can provide higher beam powers with lower beam currents [1]. The total EB energy losses (backscattering, windows and in the intervening air space) are substantially lower with higher EB incident energy. The useful EB energy is under 50% for 0.5 MeV and about 95% above 3 MeV. In view of these arguments we decided to study the application of high energy EB for air pollutants removal. Two electron beam accelerators are available for our studies: electron linear accelerators ALIN-10 and ALID-7, built in the Electron Accelerator Laboratory, INFLPR, Bucharest, Romania. Both accelerators are of traveling-wave type, operating at a wavelength of 10 cm. They utilize tunable S-band magnetrons, EEV M 5125 type, delivering 2 MW of power in 4 μ pulses. The accelerating structure is a disk-loaded tube operating in the 2 mode. The optimum values of the EB peak current IEB and EB energy EEB to produce maximum output power PEB for a fixed pulse duration EB and repetition frequency fEB are as follows: for ALIN-10: EEB = 6.23 MeV; IEB =75 mA; PEB 164 W (fEB = 100 Hz, EB = 3.5 s) and for ALID-7: EEB 5.5 MeV; IEB = 130 mA; PEB = 670 W (fEB = 250 Hz, EB = 3.75 s). This paper presents a special designed installation, named SDI-1, and several representative results obtained by high energy EB application to SO2, NOx and VOCs

  17. High energy density in matter produced by heavy ion beams

    International Nuclear Information System (INIS)

    This Annual Report summarizes research activities carried out in 1988 in the framework of the government-funded program 'High Energy Density in Matter produced by Heavy Ion Beams'. It addresses fundamental problems of the generation of heavy ion beams and the investigation of hot dense plasmas produced by these beams. Its initial motivation and its long-term goal is the feasibility of inertial confinement fusion by intense heavy ion beams. Two outstanding events deserve to be mentioned explicity, the Heavy Ion Inertial Fusion Conference held in Darmstadt and organized by GSI end of June and the first heavy ion beam injected into the new SIS facility in November. The former event attracted more than hundred scientists for three days to the 4th Conference in this field. This symposium showed the impressive progress since the last conference in Washington two years ago. In particular the first beams in MBE-4 at LBL and results of beam plasma interaction experiments at GSI open new directions for future investigations. The ideas for non-Lionvillean injection into storage rings presented by Carlo Rubbia will bring the discussion of driver scenarios into a new stage. The latter event is a milestone for both machine and target experiments. It characterizes the beginning of the commissioning phase for the new SIS/ESR facility which will be ready for experiments at the end of this year. The commissioning of SIS is on schedule and first experiments can start at the beginning of 1990. A status report of the accelerator project is included. Theoretical activities were continued as in previous years, many of them providing guide lines for future experiments, in particular for the radiation transport aspects and for beam-plasma interaction. (orig.)

  18. In-beam PET at high-energy photon beams: a feasibility study

    International Nuclear Information System (INIS)

    For radiation therapy with carbon ion beams, either for the stable isotope 12C or for the radioactive one 11C, it has been demonstrated that the β+-activity distribution created or deposited, respectively, within the irradiated volume can be visualized by means of positron emission tomography (PET). The PET images provide valuable information for quality assurance and precision improvement of ion therapy. Dedicated PET scanners have been integrated into treatment sites at the Heavy Ion Medical Accelerator at Chiba (HIMAC), Japan, and the Gesellschaft fuer Schwerionenforschung (GSI), Germany, to make PET imaging feasible during therapeutic irradiation (in-beam PET). A similar technique may be worthwhile for radiotherapy with high-energy bremsstrahlung. In addition to monitoring the dose delivery process which in-beam PET has been primarily developed for, it may be expected that radiation response of tissue can be detected by means of in-beam PET. We investigate the applicability of PET for treatment control in the case of using bremsstrahlung spectra produced by 15-50 MeV electrons. Target volume activation due to (γ, n) reactions at energies above 20 MeV yields moderate β+-activity levels, which can be employed for imaging. The radiation from positrons produced by pair production is not presently usable because the detectors are overloaded due to the low duty factor of medical electron linear accelerators. However, the degradation of images caused by positron motion between creation and annihilation seems to be tolerable

  19. Algorithm for removing the noise from γ energy spectrum by analyzing the evolution of the wavelet transform maxima across scales

    International Nuclear Information System (INIS)

    The γ energy spectrum is expanded in allied energy-frequency space. By the different characterization of the evolution of wavelet transform modulus maxima across scales between energy spectrum and noise, the algorithm for removing the noise from γ energy spectrum by analyzing the evolution of the wavelet transform maxima across scales is presented. The results show, in contrast to the methods in energy space or in frequency space, the method has the advantages that the peak of energy spectrum can be indicated accurately and the energy spectrum can be reconstructed with a good approximation

  20. Phase rotation of muon beams for producing intense low-energy muon beams

    CERN Document Server

    Neuffer, D; Hansen, G

    2016-01-01

    Low-energy muon beams are useful for rare decay searches, which provide access to new physics that cannot be addressed at high-energy colliders. However, muons are produced within a broad energy spread unmatched to the low-energy required. In this paper we outline a phase rotation method to significantly increase the intensity of low-energy muons. The muons are produced from a short pulsed proton driver, and develop a time-momentum correlation in a drift space following production. A series of rf cavities is used to bunch the muons and phase-energy rotate the bunches to a momentum of around 100 MeV/c. Then another group of rf cavities is used to decelerate the muon bunches to low-energy. This obtains ~0.1 muon per 8 GeV proton, which is significantly higher than currently planned Mu2e experiments, and would enable a next generation of rare decay searches, and other intense muon beam applications.

  1. Some probe experiments on a high energy cesium ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Hubach, R. A.; Peppin, G. B.

    1963-03-31

    A probe has been developed which is, in effect, a directional Langmuir probe. The directional quality is necessary for use in a beam of high energy ions to eliminate the effects of the streaming ions on the probe operation. This probe has been utilized to measure the back-streaming (albedo) electron component to verify the bottle model of space-charge neutralization. It has also been possible to infer the density of slow ions in the beam created by gas ionization and to infer a value of the cross section for such gas ionization which .agrees with the anticipated value. (auth)

  2. The production and use of ultralow energy ion beams

    Science.gov (United States)

    Goldberg, R. D.; Armour, D. G.; van den Berg, J. A.; Cook, C. E. A.; Whelan, S.; Zhang, S.; Knorr, N.; Foad, M. A.; Ohno, H.

    2000-02-01

    An ion accelerator, purpose built to produce beams at energies down to 10 eV with current densities in the 10-100 μA cm-2 range, is described. Fitted with dual ion source assemblies, the machine enables ultralow energy ion implantation and the growth of films and multilayers to be carried out under highly controlled conditions. The accelerator delivers ion beams into an ultrahigh vacuum chamber, containing a temperature controlled target stage (range -120 to +1350 °C), where they are used to study the fundamental physics relating to the interaction of ultralow energy ions with surfaces. This knowledge underlies a wide range of ion-beam and plasma-based technologies and, to illustrate its importance, results are presented from investigations designed to determine the optimum conditions for the growth of diamond-like and aluminum films by ion-beam deposition and the formation of ultrashallow junctions in semiconductors by 2.5 keV As+ implantation. The later investigation shows how transient arsenic diffusion, which occurs during post-implant thermal processing, can be controlled by manipulating the substrate temperature during implantation.

  3. Spacecraft Power Beaming Using High-Energy Lasers, Experimental Validation

    International Nuclear Information System (INIS)

    The lifetime of many spacecrafts are often limited by degradation of their electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites using high energy lasers, could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, extensive research at the Naval Postgraduate School (NPS) has shown the potential for annealing damaged solar cells using lasers. This paper describes that research and a proposed experiment to demonstrate the relevant concepts of high energy laser power beaming to an NPS-built and operated satellite. Preliminary results of ground experiment of laser illuminations of some of the solar panels of one of the spacecrafts are also presented

  4. Intermediate-energy neutron beam for NCT at MURR

    International Nuclear Information System (INIS)

    The University of Missouri Research Reactor (MURR) is one of the high-flux reactors in the USA and it can be used to produce an intense beam of intermediate-energy neutrons for neutron capture therapy. Two methods are being evaluated at MURR to produce such a beam. The first uses a moderator of Al2O3 replacing part of the graphite and water on one side of the core of the reactor to produce a source of predominantly intermediate-energy neutrons. The second method is a filter of 238U between the core and the patient position to pass only intermediate-energy neutrons. The results of these evaluations are presented in this paper along with an outline of the other resources at the University of Missouri-Columbia that are available to support an NCT program. 4 references, 7 figures, 1 table

  5. Highly Compressed Ion Beam for High Energy Density Science

    International Nuclear Information System (INIS)

    The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments

  6. A Beam Interlock System for CERN High Energy Accelerators

    CERN Document Server

    Todd, Benjamin; Schmidt, R

    2006-01-01

    The Large Hadron Collider (LHC) at CERN (The European Organisation for Nuclear Research) is one of the largest and most complicated machines envisaged to date. The LHC has been conceived and designed over the course of the last 25 years and represents the cutting edge of accelerator technology with a collision energy of 14TeV, having a stored beam energy over 100 times more powerful than the nearest competitor. Commissioning of the machine is already nderway and operation with beam is intended for Autumn 2007, with 7TeV operation expected in 2008. The LHC is set to answer some of the fundemental questions in theoretical physics, colliding particles with such high energy that the inner workings of the quantum world can be revealed. Colliding particles together at such high energy makes very high demands on machine operation and protection. The specified beam energy requires strong magnetic fields that are made in superconducting dipole magnets, these magnets are kept only around two degrees above absolute zero...

  7. Coping with spectrum and energy scarcity in Wireless Networks: a Stochastic Optimization approach to Cognitive Radio and Energy Harvesting

    OpenAIRE

    Michelusi, Nicolò

    2013-01-01

    In the last decades, we have witnessed an explosion of wireless communications and networking, spurring a great interest in the research community. The design of wireless networks is challenged by the scarcity of resources, especially spectrum and energy. In this thesis, we explore the potential offered by two novel technologies to cope with spectrum and energy scarcity: Cognitive Radio (CR) and Energy Harvesting (EH). CR is a novel paradigm for improving the spectral efficiency in wireless n...

  8. A high energy neutral beam system for reactors

    International Nuclear Information System (INIS)

    High energy neutral beams provide a promising method of heating and driving current in steady-stage tokamak fusion reactors. As an example, we have made a conceptual design of a neutral beam system for current drive on the International Thermonuclear Experimental Reactor (ITER). The system, based on electrostatic acceleration of Dions, can deliver up to 100 MW of 1.6 MeV Do neutrals through three ports. Radiation protection is provided by locating sensitive beamlime components 35 to 50 m from the reactor. In an application to a 3300 MW power reactor, a system delivering 120 MW of 2-2.4 MeV deuterium beams assisted by 21 MW of lower hybrid wave power drives 25 MA provides an adequate plasma power again (Q = 24) for a commercial fusion power plant. (author). 8 refs.; 1 fig.; 2 tabs

  9. Spheromak Energy Transport Studies via Neutral Beam Injection

    Energy Technology Data Exchange (ETDEWEB)

    McLean, H S; Hill, D N; Wood, R D; Jayakumar, J; Pearlstein, L D

    2008-02-11

    Results from the SSPX spheromak experiment provide strong motivation to add neutral beam injection (NBI) heating. Such auxiliary heating would significantly advance the capability to study the physics of energy transport and pressure limits for the spheromak. This LDRD project develops the physics basis for using NBI to heat spheromak plasmas in SSPX. The work encompasses three activities: (1) numerical simulation to make quantitative predictions of the effect of adding beams to SSPX, (2) using the SSPX spheromak and theory/modeling to develop potential target plasmas suitable for future application of neutral beam heating, and (3) developing diagnostics to provide the measurements needed for transport calculations. These activities are reported in several publications.

  10. Dual energy scanning beam laminographic x-radiography

    Energy Technology Data Exchange (ETDEWEB)

    Majewski, S.; Wojcik, R.F.

    1998-04-21

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible. 6 figs.

  11. Dual energy scanning beam laminographic x-radiography

    Science.gov (United States)

    Majewski, Stanislaw; Wojcik, Randolph F.

    1998-01-01

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible.

  12. Dual energy scanning beam laminographic x-radiography

    International Nuclear Information System (INIS)

    A multiple x-ray energy level imaging system includes a scanning x-ray beam and two detector design having a first low x-ray energy sensitive detector and a second high x-ray energy sensitive detector. The low x-ray energy detector is placed next to or in front of the high x-ray energy detector. The low energy sensitive detector has small stopping power for x-rays. The lower energy x-rays are absorbed and converted into electrical signals while the majority of the higher energy x-rays pass through undetected. The high energy sensitive detector has a large stopping power for x-rays as well as it having a filter placed between it and the object to absorb the lower energy x-rays. In a second embodiment; a single energy sensitive detector is provided which provides an output signal proportional to the amount of energy in each individual x-ray it absorbed. It can then have an electronic threshold or thresholds set to select two or more energy ranges for the images. By having multiple detectors located at different positions, a dual energy laminography system is possible. 6 figs

  13. Prediction of neutron energy spectrum in a typical MTR type research reactor using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Highlights: ► The core of a typical MTR type research reactor was modelled, in three dimensions, using the Monte Carlo code, MCNP5. ► The neutron energy spectrum at the central irradiation site was determined. ► Results are compared with earlier calculations performed by the deterministic code CITATION. - Abstract: In previous work, determination of the neutron energy spectrum in a typical pool type Material Test research Reactor (MTR) was discussed. Solution of the neutron spectrum adjustment problem, which adjusts a theoretically calculated spectrum to a set of experimentally measured reaction rates, was also analyzed. The calculated spectrum was obtained through modelling the reactor core and the surroundings in three dimensions using the deterministic code CITATION. In this work, the same core configuration was modelled in three dimensions using the Monte Carlo code, MCNP5. The calculated spectrum by MCNP is compared to that calculated by CITATION. Both calculated spectra by CITATION and MCNP were also compared as input information in the experimental determination of the neutron spectrum through the use of experimentally measured reaction rates and the adjustment code MSITER. The good agreement between the calculated and adjusted spectra indicates that the MCNP approach can be used as pre-information in the experimental determination of the neutron spectrum as well as for the prediction of neutron spectrum at other locations

  14. A Modified Energy Detection Based Spectrum Sensing Algorithm for Green Cognitive Radio Communication

    Directory of Open Access Journals (Sweden)

    Sidra Rajput

    2015-10-01

    Full Text Available Spectrum Sensing is the first and fundamental function of Cognitive Cycle which plays a vital role in the success of CRs (Cognitive Radios. Spectrum Sensing indicate the presence and absence of PUs (Primary Users in RF (Radio Frequency spectrum occupancy measurements. In order to correctly determine the presence and absence of Primary Users, the algorithms in practice include complex mathematics which increases the computational complexity of the algorithm, thus shifted the CRs to operate as ?green? communication systems. In this paper, an energy efficient and computationally less complex, energy detection based Spectrum Sensing algorithm have been proposed. The design goals of the proposed algorithm are to save the processing and sensing energies. At first, by using less MAC (Multiply and Accumulate operation, it saves the processing energy needed to determine the presence and absence of PUs. Secondly, it saves the sensing energy by providing a way to find lowest possible sensing time at which spectrum is to be sensed. Two scenarios have been defined for testing the proposed algorithm i.e. simulate detection capability of Primary Users in ideal and noisy scenarios. Detection of PUs in both of these scenarios have been compared to obtain the probability of detection. Energy Efficiency of the proposed algorithm has been proved by making performance comparison between the proposed (less complex algorithm and the legacy energy detection algorithm. With reduced complexity, the proposed spectrum sensing algorithm can be considered under the paradigm of Green Cognitive Radio Communication

  15. A modified energy detection based spectrum sensing algorithm for green cognitive radio communication

    International Nuclear Information System (INIS)

    Spectrum Sensing is the first and fundamental function of Cognitive Cycle which plays a vital role in the success of CRs (Cognitive Radios). Spectrum Sensing indicate the presence and absence of PUs (Primary Users) in RF (Radio Frequency) spectrum occupancy measurements. In order to correctly determine the presence and absence of Primary Users, the algorithms in practice include complex mathematics which increases the computational complexity of the algorithm, thus shifted the CRs to operate as ?green? communication systems. In this paper, an energy efficient and computationally less complex, energy detection based Spectrum Sensing algorithm have been proposed. The design goals of the proposed algorithm are to save the processing and sensing energies. At first, by using less MAC (Multiply and Accumulate) operation, it saves the processing energy needed to determine the presence and absence of PUs. Secondly, it saves the sensing energy by providing a way to find lowest possible sensing time at which spectrum is to be sensed. Two scenarios have been defined for testing the proposed algorithm i.e. simulate detection capability of Primary Users in ideal and noisy scenarios. Detection of PUs in both of these scenarios have been compared to obtain the probability of detection. Energy Efficiency of the proposed algorithm has been proved by making performance comparison between the proposed (less complex) algorithm and the legacy energy detection algorithm. With reduced complexity, the proposed spectrum sensing algorithm can be considered under the paradigm of Green Cognitive Radio Communication. (author)

  16. Design study of a beam energy recovery system for a negative-ion-based neutral beam injector

    International Nuclear Information System (INIS)

    A beam energy recovery system for future neutral beam injectors based on negative ions has been designed. Residual negative ions are recovered electrically, while residual positive ions are decelerated on a soft-landing beam dump. This design simplifies the beam energy recovery power supply system an reduces the heat flux on the beam dump. Residual ions are separated into negative and positive ions by the stray magnetic field from the Fusion Engineering Reactor (FER). The next Japanese tokamak reactor. Each ion beam is also guided to the collector electrode and the soft-landing beam dump by the stray magnetic field. In the 500-keV/20-MW injector designed for FER, the total power efficiency can be improved from 46 to 59% by recovering the negative ions

  17. LHC Beam Stability and Feedback Control - Orbit and Energy -

    CERN Document Server

    Steinhagen, R J

    2007-01-01

    This report presents the stability and control of the Large Hadron Collider's (LHC) two beam orbits and their particle momenta using beam-based feedback systems. The LHC, presently being built at CERN, will store, accelerate and provide particle collisions with a maximum particle momentum of 7TeV/c and a nominal luminosity of L = 10^34 cm^−2s^−1. The presence of two beams, with both high intensity as well as high particle energies, requires excellent control of particle losses inside a superconducting environment, which will be provided by the LHC Cleaning and Machine Protection System. The performance and function of this and other systems depends critically on the stability of the beam and may eventually limit the LHC performance. Environmental and accelerator-inherent sources as well as failure of magnets and their power converters may perturb and reduce beam stability and may consequently lead to an increase of particle loss inside the cryogenic mass. In order to counteract these disturbances, c...

  18. Feasibility of ceramic joining with high energy electron beams

    International Nuclear Information System (INIS)

    Joining structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for producing joints with high temperature capability. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the adjacent ceramic. The authors have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 NTa have been measured for Si3N4-Mo-Si3N4. These modest strengths are due to beam non-uniformity and the limited area of bonding. The bonding mechanism appears to be a thin silicide reaction layer. Si3N4-Si3N4 joints with no metal layer were also produced, apparently bonded an yttrium apatite grain boundary phase

  19. The energy spectrum of primary cosmic rays at 1014-1016 eV

    International Nuclear Information System (INIS)

    The new data on electron and muon size spectra are obtained at Tien Shan complex array. The shape of the primary energy spectrum at 1014-1016 eV is analysed on the base of these characteristics. (orig.)

  20. The Cosmic Ray Energy Spectrum Observed with the Surface Detector of the Telescope Array Experiment

    OpenAIRE

    Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; B.G. Cheon; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.

    2012-01-01

    The Telescope Array (TA) collaboration has measured the energy spectrum of ultra-high energy cosmic rays with primary energies above 1.6 x 10^(18) eV. This measurement is based upon four years of observation by the surface detector component of TA. The spectrum shows a dip at an energy of 4.6 x 10^(18) eV and a steepening at 5.4 x 10^(19) eV which is consistent with the expectation from the GZK cutoff. We present the results of a technique, new to the analysis of ultra-high energy cosmic ray ...

  1. Revisiting the hardening of the cosmic-ray energy spectrum at TeV energies

    CERN Document Server

    Thoudam, Satyendra

    2013-01-01

    Measurements of cosmic rays by experiments such as ATIC, CREAM, and PAMELA indicate a hardening of the cosmic-ray energy spectrum at TeV energies. In our recent work (Thoudam & H\\"orandel 2012a), we showed that the hardening can be due to the effect of nearby supernova remnants. We showed it for the case of proton and helium. In this paper, we present an improved and detailed version of our previous work, and extend our study to heavier cosmic-ray species such as boron, carbon, oxygen, and iron nuclei. Unlike our previous study, the present work involves a detailed calculation of the background cosmic rays and follows a consistent treatment of cosmic-ray source parameters between the background and the nearby components. Moreover, we also present a detailed comparison of our results on the secondary-to-primary ratios, secondary spectra, and the diffuse gamma-ray spectrum with the results expected from other existing models, which can be checked by future measurements at high energies.

  2. Energy spectrum of ultra high energy γ-rays from supernova

    International Nuclear Information System (INIS)

    If a newly born neutron star in SN1987A is a powerful injector of ultra high energy (UHE) protons, UHE γ-rays will be emitted by bombardment of supernova ejecta with these UHE particles. We compute energy spectrum of the UHE γ-rays generated by monoenergetic protons using Monte Carlo simulations at the period of high flux when the column density is 30∼100 g/cm2. If the column density of the ejecta is less than ∼100 g/cm2, low energy γ-rays do not increase as E-2, like the case for Cyg X-3, but they have much harder spectrum close to E-1. The expected numbers of PeV and TeV region γ-rays per hour are at least 0.16 counts (Lp/1041 ergs)(S/(50 m)2)(d/56 kpc)-2 and 132 counts (Lp/1041 ergs)(S/30000 m2)(d/56 kpc)-2 where Lp, S and d are the proton luminosity, the area of detectors, and the distance to LMC, respectively. (author)

  3. Comparatative Analysis of Energy Detection Spectrum Sensing of Cognitive Radio Under Wireless Environment Using SEAMCAT

    Directory of Open Access Journals (Sweden)

    A.S. Kang

    2016-01-01

    Full Text Available In the recent years, the Cognitive Radio technology imposed itself as a good solution to enhance the utilization of unused spectrum and globalized the radio environment for different band users that utilize or require different techniques for transmission. In this paper, the energy detection spectrum sensing technique that is used to detect the presence of unknown deterministic signal is studied under the non-time dispersive fading environment using the Hata propagation model for picocell communication systems. The different aspects of non-time dispersive fading regions over energy detection spectrum sensing and impact of changing a detection threshold of the secondary user Cognitive Radio on interference at primary user for non-cooperative spectrum access have been studied in the terms of probability of interference. The entire Comparatative Analysis of Spectrum Sensing in Cognitive radio has been carried out with the aid of SEAMCAT software platform.

  4. Beamed Energy Propulsion: Research Status And Needs--Part 2

    International Nuclear Information System (INIS)

    One promising solution to the operationally responsive space is the application of remote electromagnetic energy to propel a launch vehicle into orbit. With beamed energy propulsion, one can leave the power source stationary on the ground or space, and direct heat propellant on the spacecraft with a beam from a fixed station. This permits the spacecraft to leave its power source at home, saving significant amounts of mass, greatly improving performance. This concept, which removes the mass penalty of carrying the propulsion energy source on board the vehicle, was first proposed by Arthur Kantrowitz in 1972; he invoked an extremely powerful ground based laser. The same year Michael Minovich suggested a conceptually similar ''in-space'' laser rocket system utilizing a remote laser power station. In the late 1980's, Air Force Office of Scientific Research (AFOSR) funded continuous, double pulse laser and microwave propulsion while Strategic Defense Initiative Office (SDIO) funded ablative laser rocket propulsion. Currently AFOSR has been funding the concept initiated by Leik Myrabo, repetitively pulsed laser propulsion, which has been universally perceived, arguably, to be the closest for mid-term applications. This 2-part paper examines the investment strategies in beamed energy propulsion and technical challenges to be covers Part 2 covers the present research status and needs

  5. Biomaterial imaging with MeV-energy heavy ion beams

    International Nuclear Information System (INIS)

    The spatial distribution of several chemical compounds in biological tissues and cells can be obtained with mass spectrometry imaging (MSI). In conventional secondary ion mass spectrometry (SIMS) with keV-energy ion beams, elastic collisions occur between projectiles and atoms of constituent molecules. The collisions produce fragments, making the acquisition of molecular information difficult. In contrast, ion beams with MeV-energy excite near-surface electrons and enhance the ionization of high-mass molecules; hence, SIMS spectra of fragment-suppressed ionized molecules can be obtained with MeV-SIMS. To compare between MeV and conventional SIMS, we used the two methods based on MeV and Bi3-keV ions, respectively, to obtain molecular images of rat cerebellum. Conventional SIMS images of m/z 184 were clearly observed, but with the Bi3 ion, the distribution of the molecule with m/z 772.5 could be observed with much difficulty. This effect was attributed to the low secondary ion yields and we could not get many signal counts with keV-energy beam. On the other hand, intact molecular ion distributions of lipids were clearly observed with MeV-SIMS, although the mass of all lipid molecules was higher than 500 Da. The peaks of intact molecular ions in MeV-SIMS spectra allowed us to assign the mass. The high secondary ion sensitivity with MeV-energy heavy ions is very useful in biomaterial analysis

  6. Development of gamma-ray energy spectrum remote-measurement system based on LabVIEW

    International Nuclear Information System (INIS)

    Design techniques of a gamma-ray energy spectrum remote-measurement system based on Lab VIEW are described, including data acquicition and client control program, and network communication by DataSocket. The gamma-ray energy spectrum of 137Cs was measured by the system, indicating that performance of our remote-measurement system based on LabVIEW is better than that based on Java Applet. (authors)

  7. Phenomenological Rashba model for calculating the electron energy spectrum on a cylinder

    Science.gov (United States)

    Savinskiĭ, S. S.; Belosludtsev, A. V.

    2007-05-01

    The energy spectrum of an electron on the surface of a cylinder is calculated using the Pauli equation with an additional term that takes into account the spin-orbit interaction. This term is taken in the approximation of a phenomenological Rashba model, which provides exact expressions for the wave functions and the electron energy spectrum on the cylinder surface in a static magnetic field.

  8. Development and application of HFC-1 γ energy spectrum logging instrument

    International Nuclear Information System (INIS)

    The development and application of HFC-1 γ energy spectrum logging instrument has been introduced. The instrument is an exclusive use equipment of measuring underground nuclear test radionuclide. The instrument system is made up of main instrument system, γ energy spectrum detector system, logging winch control system, data acquisition and processing system. Through application in nuclear test field, the instrument performance is stability, reliable and has attained anticipatory design purpose

  9. Low-energy radioactive ion beam production of 22Mg

    International Nuclear Information System (INIS)

    The 22Mg nucleus plays an important role in nuclear astrophysics, specially in the 22Mg(α,p)25Al and proton capture 22Mg(p,γ)23Al reactions. It is believed that 22Mg is a waiting point in the αp-process of nucleosynthesis in novae. We proposed a direct measurement of the 22Mg+α resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22Mg beam used for the direct measurement of the scattering reaction 22Mg(α,α)22Mg, and the stellar reaction 22Mg(α,p)25Al in the energy region concerning an astrophysical temperature of T9=1–3 GK

  10. Research on influence of energy spectrum response of ICT detector arrays

    International Nuclear Information System (INIS)

    The energy spectrum response is important characteristic for X-ray ICT detector. But there exist many difficulties to measure these parameters by experiments. The energy spectrum response of CdWO4 detector was simulated by using the EGSnrc code. Meanwhile the effect of detection efficiency was analyzed by the distribution of accelerator bremsstrahlung spectra and the X-ray spectrum hardening, and some theoretic parameters were offered for the consistent and no-linearity correction of detector arrays. It was applied to ICT image correction, and a satisfying result was obtained. (authors)

  11. Definition of X-ray equivalent energy spectrum by the subtraction method

    International Nuclear Information System (INIS)

    Technique to reconstruct energy spectrum of X-ray radiation (initiating apparatus signal coinciding within the limits of measurement error with experimental one) at measurement conducted by filter technique, is described. The considered technique enables to determine minimal value of parameters necessary to describe energy spectrum. It may be useful when analyzing information contained in the experimental curve attenuation, especially in case of unadequacy or absence of a priori information on true spectrum. Criterion of choice of quantity and thickness of filters is suggested, as well

  12. Measurement of the high energy component of the neutron spectrum from a moderated source

    International Nuclear Information System (INIS)

    The high energy component of the neutron spectrum from a moderated source has been measured by an improved method at the LNS synchrotron. The detector size of 7 cm diam. by 30 cm long NE-213 liquid scintillator was used and a FERDOR unfolding code was adopted for the spectrum data analysis. This result is compared with a previous measurement employing a smaller detector and a rectangular unfolding technique. The accuracy of the new method was tested by measuring the same high energy neutron spectrum which was measured and analyzed both by time-of-flight and by the FERDOR unfolding method. (orig.)

  13. Etching and damage action on microbes' cells by low energy N+ beam

    International Nuclear Information System (INIS)

    The action of etching and damage by 20 keV N+ beam on the cells of Deinococcus radiodurans and Escherichia coli was investigated by scanning electron microscope (SEM) and the electron spin resonance (ESR) spectrum of free radicals. The results showed that N+ implantation exerted the direct action of etching and damage of momentum transferring and the indirect action of the free radicals of energy deposition on their cells, many microholes were found on the surface of cells' wall and/or membrane by SEM, the damaged DNA was determined using DNA unwinding technique, and the signal of free radicals was measured by ESR. The degree of damage to cells by ion beam gradually increased with the increasing implantation dose. With the post-treatment of 2 mmol/l caffeine and 0.5 mmol/l Na2-EDTA, the survival rate of D. radiodurans and E. coli further decreased in the order of caffeine > Na2-EDTA > control, and this suggested that low energy ion beam could be implanted into nucleus, doing a damage to DNA and resulting in the mutation of organisms

  14. PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

    International Nuclear Information System (INIS)

    In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates μ- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k ∼4 Mpc–1. Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of μ and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

  15. Application of a model based on a pair of Laplace transforms for standard low-energy X-ray beams spectral reconstruction

    International Nuclear Information System (INIS)

    The direct measurement of the spectrum of an X-ray beam by some spectroscopic method is relatively difficult and expensive. Spectra can be alternatively derived by an indirect method from measurements of transmission curve of the X-ray beam and the use of Laplace transforms. The objective of this work was the application of an indirect method that use a spectral model based on a pair of Laplace transforms to reconstruct experimental published spectra of standard low energy X-ray beams at radiation protection level and determine the mean photon energy from the reconstructed spectra for radiation quality specification. The spectral model was applied using calculated transmission curves and the reconstructed spectra provided a coarse approximation to experimental data. Even though, the mean photon energy of the X-ray beams determined from these reconstructed spectra present a satisfactory result showing the value of the analysis of transmission curves for the X-ray beam quality specification. (author)

  16. Si etching with reactive neutral beams of very low energy

    International Nuclear Information System (INIS)

    A Si etching process has been investigated with reactive neutral beams (NBs) extracted using a low acceleration voltage of less than 100 V from CF4 and Ar mixed plasmas. The etched Si profile shows that the etching process is predominantly anisotropic. The reactive NB has a constant Si etching rate in the acceleration voltage range from 20 V to 80 V. It is considered that low-energy NBs can trigger Si etching because F radicals adsorb onto the Si surface and weaken Si–Si bonds. The etching rate per unit beam flux is 33 times higher than that with Ar NB. These results show that the low-energy reactive NB is useful for damage-free high speed Si etching

  17. Development of an energy spectrum measurement system using screen monitor and its application to study on the longitudinal wakefield in an electron linac

    International Nuclear Information System (INIS)

    We are developing a measurement system of energy spectra for the high intensity electron beam for L-band linac of the Institute of Scientific and Industrial Research, Osaka University. It consists of a thin fluorescence screen, a 12-bit CCD camera with the gate and an image control system in a PCI board. It is possible to measure the energy spectrum of a single electron pulse at a time with this device. To demonstrate performance of the system, energy spectra of the single bunch beam have been measure at different accelerating phases. As an application of the energy spectra measurement, the bunch induced voltage and the longitudinal bunch shape have been derived using energy spectra measured at two different linac rf phases. (author)

  18. Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae

    OpenAIRE

    Liu, Ruo-Yu; Wang, Xiang-Yu

    2011-01-01

    It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or...

  19. Measuring the energy parameters of the nanosecond electron beam extracted in air through a foil

    International Nuclear Information System (INIS)

    Comparison of the measurement results of energy densities and absorbed dose during the passage of electron beam with the energy of 300 keV, duration of 10 ns, current density of > 10 A/cm2 behind the acceleration foil in the air is conducted using different methods. The measurements have been carried out using compact nanosecond accelerator comprising a generator assembled according to the Marx scheme and vacuum diode with cold cathode operating in the regime of electron explosion emission. The current in the diode constituted approximately 3 kA, accelerating voltage - 350 kV. It is shown that during oscillographic measurements and the measurements according to the voltage upon the measurement capacitance considerable mistakes are possible which are conditioned by the electron wide spectrum. Results obtained using the calorimetric method which is especially convenient when determining absorbed doses in thin targets are the most objective ones

  20. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    P Kumar; G Rodrigues; U K Rao; C P Safvan; D Kanjilal; A Roy

    2002-11-01

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion beams ranging from a few keV to a few MeV for research in materials sciences, atomic and molecular physics is described. One of the important features of this facility is the availability of relatively large currents of multiply charged positive ions from an electron cyclotron resonance (ECR) source placed entirely on a high voltage platform. All the electronic and vacuum systems related to the ECR source including 10 GHz ultra high frequency (UHF) transmitter, high voltage power supplies for extractor and Einzel lens are placed on a high voltage platform. All the equipments are controlled using a personal computer at ground potential through optical fibers for high voltage isolation. Some of the experimental facilities available are also described.

  1. Comment on study of material irradiation damage. PKA energy spectrum effect

    International Nuclear Information System (INIS)

    For the study of damage correlation, experimental data on the Stage I recovery, defect production cross sections and radiation annealing cross sections in FCC metals irradiated with electrons, various ions and neutrons are analyzed as a function of PKA (i.e. Primary Knock-on Atom) median energy. It is shown that the PKA median energy is a good parameter to characterize the PKA energy spectrum. The defect accumulation as a function of dpa is predicted in Cu and Ni for two PKA median energies, 0.6 keV and 35 keV, and the PKA spectrum effect is discussed. (author)

  2. Characterization and MCNP simulation of neutron energy spectrum shift after transmission through strong absorbing materials and its impact on tomography reconstructed image

    International Nuclear Information System (INIS)

    An ideal neutron radiograph, for quantification and 3D tomographic image reconstruction, should be a transmission image which exactly obeys to the exponential attenuation law of a monochromatic neutron beam. There are many reasons for which this assumption does not hold for high neutron absorbing materials. The main deviations from the ideal are due essentially to neutron beam hardening effect. The main challenges of this work are the characterization of neutron transmission through boron enriched steel materials and the observation of beam hardening. Then, in our work, the influence of beam hardening effect on neutron tomographic image, for samples based on these materials, is studied. MCNP and FBP simulation are performed to adjust linear attenuation coefficients data and to perform 2D tomographic image reconstruction with and without beam hardening corrections. A beam hardening correction procedure is developed and applied based on qualitative and quantitative analyses of the projections data. Results from original and corrected 2D reconstructed images obtained shows the efficiency of the proposed correction procedure. - Highlights: ► Characterization of neutron transmission through strong absorbing material. ► Neutron energy spectrum shift study. ► Beam hardening observation and characterization. ► Beam hardening effect on neutron tomography image appearance. ► MCNP and FBP simulation to adjust attenuation coefficients for a correct tomographic reconstruction.

  3. A study of the spectrum of natural dysprosium with the laser-atomic-beam technique

    International Nuclear Information System (INIS)

    A high resolution study of 31 transitions in dysprosium in the wavelength regions 435-470 nm and 560-670 nm has been performed using CW dye lasers and a collimated atomic beam. Transitions from the 5I8 ground state as well as from the metastable states at 4134 cm-15I7 of the 4f106s25I multiplet were studied. In this paper the results of isotope shift measurements on transitions to the excited-state configurations 4f106s6p, 4f96s25d, 4f96s5d2 are presented and values for the specific mass shift and atomic factor of the field shift for the various configurations are evaluated. (author)

  4. Low energy Fe+ beam irradiation to C60 thin film

    International Nuclear Information System (INIS)

    We have developed an electron cyclotron resonance ion source apparatus, which is designed for the production of endohedral fullerene. In this study, we irradiated the Fe+ beam to the C60 thin film. We changed the experimental condition of the dose and the ion energy. We could observe the Fe + C60 peak by analysis of the time-of-flight mass spectrometry. The highest intensity of the Fe + C60 peak was observed at the ion energy of 200 eV. The Fe + C60 peak intensity tended to become high in the case of long irradiation time and large dose.

  5. Influence of the Richtmyer-Meshkov instability on the kinetic energy spectrum.

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Christopher R. (University of Wisconsin-Madison, Madison, WI)

    2010-09-01

    The fluctuating kinetic energy spectrum in the region near the Richtmyer-Meshkov instability (RMI) is experimentally investigated using particle image velocimetry (PIV). The velocity field is measured at a high spatial resolution in the light gas to observe the effects of turbulence production and dissipation. It is found that the RMI acts as a source of turbulence production near the unstable interface, where energy is transferred from the scales of the perturbation to smaller scales until dissipation. The interface also has an effect on the kinetic energy spectrum farther away by means of the distorted reflected shock wave. The energy spectrum far from the interface initially has a higher energy content than that of similar experiments with a flat interface. These differences are quick to disappear as dissipation dominates the flow far from the interface.

  6. Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae

    CERN Document Server

    Liu, Ruo-Yu

    2011-01-01

    It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.

  7. Energy spectrum of cosmic-ray photons observed at the ground level in Japan

    International Nuclear Information System (INIS)

    The energy spectrum of cosmic-ray photons was estimated from the pulse-height spectra of cosmic-rays observed by a spherical NaI(Tl) scintillation detector. The pulse-height spectrum of cosmic-ray photons could be successfully separated on the basis of the difference between the pulse-height spectrum by a spherical NaI(Tl) scintillation detector and that by coincidence counting method. It seemed that the pulse-height spectra of cosmic-ray muons by the each measuring system resemble each other in shape, while the pulse-height spectra of cosmic-ray electrons by the each system different each other. So the pulse-height distribution of cosmic-ray muons was determined from the pulse-height spectrum observed by the detector covered with lead. The pulse-height distribution of cosmic-ray electrons was determined as follows: The shape of pulse-height spectrum was calculated on the basis of the energy spectra of cosmic-ray electrons in the lower atmosphere. The pulse-height distributions of cosmic-ray electrons by the single detector system and by the coincidence detector system were calculated by using the EGS4 Monte Carlo Code. The intensity of cosmic-ray electrons was determined by subtracting the pulse-height spectrum observed by the detector covered with lead from that observed by the coincidence detector system. The pulse-height distribution of cosmic-ray photons could be determined from the pulse-height spectrum by the coincidence detector system subtracted from that by the single detector system. The energy spectrum of cosmic-ray photons could be calculated from the pulse-height distribution of cosmic-ray photons by using an unfolding method. It became clear that the energy spectrum of cosmic-ray photons was identified above scores of MeV. (author)

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

    Science.gov (United States)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.

    2015-12-01

    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.

  9. Studies on biological effects of ion beams on lethality, molecular nature of mutation, mutation rate, and spectrum of mutation phenotype for mutation breeding in higher plants

    International Nuclear Information System (INIS)

    Recently, heavy ions or ion beams have been used to generate new mutants or varieties, especially in higher plants. It has been found that ion beams show high relative biological effectiveness (RBE) of growth inhibition, lethality, and so on, but the characteristics of ion beams on mutation have not been clearly elucidated. To understand the effect of ion beams on mutation induction, mutation rates were investigated using visible known Arabidopsis mutant phenotypes, indicating that mutation frequencies induced by carbon ions were 20-fold higher than by electrons. In chrysanthemum and carnation, flower-color and flower-form mutants, which are hardly produced by gamma rays or X rays, were induced by ion beams. Novel mutants and their responsible genes, such as UV-B resistant, serrated petals and sepals, anthocyaninless, etc. were induced by ion beams. These results indicated that the characteristics of ion beams for mutation induction are high mutation frequency and broad mutation spectrum and therefore, efficient induction of novel mutants. On the other hand, PCR and sequencing analyses showed that half of all mutants induced by ion beams possessed large DNA alterations, while the rest had point-like mutations. Both mutations induced by ion beams had a common feature that deletion of several bases were predominantly induced. It is plausible that ion beams induce a limited amount of large and irreparable DNA damage, resulting in production of a null mutation that shows a new mutant phenotype. (author)

  10. Time-energy relation of the nTOF neutron beam: energy standards revisited

    International Nuclear Information System (INIS)

    The accurate determination of neutron cross-sections as a function of the neutron energy at a time-of-flight facility requires a precise knowledge of the time-energy relation for the neutron beam. For the nTOF neutron beam at CERN, produced by spallation of high-energy protons on a Pb target, the time-energy relation is connected to the production mechanism and to the subsequent moderation process. A calibration of the neutron energy scale is proposed based on detailed Monte Carlo simulations of the facility. This time-energy relation has been experimentally validated by means of dedicated measurements of standard energy resonances, from 1 eV to approximately 1 MeV. On the basis of the present measurements, it is proposed to correct the energy of the 1.3 eV resonance of 193Ir, which is commonly considered as an energy standard

  11. Upgrade of beam energy measurement system at BEPC-II

    Science.gov (United States)

    Zhang, Jian-Yong; Cai, Xiao; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M. N.; Krasnov, A. A.; Muchnoi, N. Yu.; Pyata, E. E.; Mamoshkina, E. V.; Harris, F. A.

    2016-07-01

    The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III. Supported in part by National Natural Science Foundation of China (NSFC)(11375206, 10775142, 10825524, 11125525, 11235011), the Ministry of Science and Technology of China (2015CB856700, 2015CB856705), State key laboratory of particle and detection and electronics; and the CAS Center for Excellence in Particle Physics (CCEPP); the RFBR grant(14-02-00129-a), U.S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, part of this work related to the design of ZnSe viewports is supported by the Russian Science Foundation (14-50-00080)

  12. Highly Compressed Ion Beams for High Energy Density Science

    CERN Document Server

    Friedman, Alex; Briggs, Richard J; Callahan, Debra; Caporaso, George; Celata, C M; Davidson, Ronald C; Faltens, Andy; Grant-Logan, B; Grisham, Larry; Grote, D P; Henestroza, Enrique; Kaganovich, Igor D; Lee, Edward; Lee, Richard; Leitner, Matthaeus; Nelson, Scott D; Olson, Craig; Penn, Gregory; Reginato, Lou; Renk, Tim; Rose, David; Sessler, Andrew M; Staples, John W; Tabak, Max; Thoma, Carsten H; Waldron, William; Welch, Dale; Wurtele, Jonathan; Yu, Simon

    2005-01-01

    The Heavy Ion Fusion Virtual National Laboratory (HIF-VNL) is developing the intense ion beams needed to drive matter to the High Energy Density (HED) regimes required for Inertial Fusion Energy (IFE) and other applications. An interim goal is a facility for Warm Dense Matter (WDM) studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target "foils," which may in fact be foams or "steel wool" with mean densities 1% to 100% of solid. This approach complements that being pursued at GSI, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrical target. We present the requirements for warm dense matter experiments, and describe suitable accelerator concepts, including novel broadband traveling wave pulse-line, drift-tube linac, RF, and single-gap approa...

  13. SPECTRUM - a computer algorithm to derive the flux-energy spectrum of precipitating particles from EISCAT electron density profiles

    International Nuclear Information System (INIS)

    Three major improvements are included. First the new algorithm includes the time rate of change of ionisation. This can be measured on a time scale of a few seconds with the EISCAT radar during auroral precipitation. Second, the fixed energies of the incident electron beams assumed in the UNTANGLE program are replaced by energies which are calculated according to the altitudes at which measurements are made. Thus the energy resolution and energy interval included in the derived spectra are determined in a physically reasonable way by the altitude resolution and the altitude interval of the electron density measurements. Third, the equations relating the incident fluxes at each energy to the electron density at each altitude are written in matrix form which allows them to be solved using standard numerical algorithms. A possibility to fit proton fluxes rather than electron fluxes is also included. A companion program (PROFILE) which calculates ionisation rate or equilibrium electron density profiles for user-defined monoenergetic or Maxwellian particle precipitation has also been developed. (author)

  14. A fluor and wire-shadow diagnostic for low-energy ion beams

    International Nuclear Information System (INIS)

    A video diagnostic technique utilizing a fluorescent screen and a video camera has been developed to monitor the two-dimensional beam-intensity profile and angular divergence of low-energy (25-35 keV) ion beams. Detailed off-line analysis is used to compare and augment standard beam emittance data. Experimental results on 2-D beam profiles are presented

  15. Low energy hydrogen ion beams in silicon processing

    International Nuclear Information System (INIS)

    Effects of low energy hydrogen ion beams in silicon processing were studied. It was found that exposing Si to a beam of low energy ions induced extensive lattice damage at the Si surface. H passivation studies were extended to include point defects in the semiconductor bulk. These studies indicate that the role of H ions in altering the concentration of active traps in the semiconductor could be explained in a unifying manner, by taking into account the interaction of Si interstitials with point defects in the Si bulk. These interstitials are created at the Si surface when it is bombarded by energetic ions. Shallow acceptor neutralization was seen in the bulk of boron-doped, Ar+ or H+ bombarded Si, when the sample temperature during the ion-beam exposure was kept below 600C. Although these results strongly suggest that the compensation effect is not H related, the possibility of H contamination of Si from water vapor in the vacuum chamber prevented the author from completely ruling out H induced compensation as the cause of acceptor compensation. Finally, using H as a passivating agent, a novel process to fabricate ion-implanted junctions using low-temperature (T 0C), was demonstrated for both majority- and minority-carrier devices. The implications of this research have also been discussed

  16. In-phantom spectra and dose distributions from a high-energy neutron therapy beam

    CERN Document Server

    Benck, S; Denis, J M; Meulders, J P; Nath, R; Pitcher, E J

    2002-01-01

    In radiotherapy with external beams, healthy tissues surrounding the target volumes are inevitably irradiated. In the case of neutron therapy, the estimation of dose to the organs surrounding the target volume is particularly challenging, because of the varying contributions from primary and secondary neutrons and photons of different energies. The neutron doses to tissues surrounding the target volume at the Louvain-la-Neuve (LLN) facility were investigated in this work. At LLN, primary neutrons have a broad spectrum with a mean energy of about 30 MeV. The transport of a 10x10 cm sup 2 beam through a water phantom was simulated by means of the Monte Carlo code MCNPX. Distributions of energy-differential values of neutron fluence, kerma and kerma equivalent were estimated at different locations in a water phantom. The evolution of neutron dose and dose equivalent inside the phantom was deduced. Measurements of absorbed dose and of dose equivalent were then carried out in a water phantom using an ionization ch...

  17. The spectrum of high-energy cosmic rays measured with KASCADE-Grande

    CERN Document Server

    Apel, W D; Bekk, K; Bertaina, M; Bluemer, J; Bozdog, H; Brancus, I M; Buchholz, P; Cantoni, E; Chiavassa, A; Cossavella, F; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Finger, M; Fuhrmann, D; Ghia, P L; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Kickelbick, D; Klages, H O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Navarra, G; Oehlschlaeger, J; Ostapchenko, S; Over, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schroeder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, J; Wommer, M; Zabierowski, J

    2012-01-01

    The energy spectrum of cosmic rays between 10**16 eV and 10**18 eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is described. The resulting all-particle energy spectrum exhibits strong hints for a hardening of the spectrum at approximately 2x10**16 eV and a significant steepening at c. 8x10**16 eV. These observations challenge the view that the spectrum is a single power law between knee and ankle. Possible scenarios generating such features are discussed in terms of astrophysical processes that may explain the transition region from galactic to extragalactic origin of cosmic rays.

  18. Energy calibration of energy-resolved photon-counting pixel detectors using laboratory polychromatic x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Hanbean; Han, Jong Chul; Kam, Soohwa; Yun, Seungman [School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Kim, Ho Kyung, E-mail: hokyung@pusan.ac.kr [School of Mechanical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Center for Advanced Medical Engineering Research, Pusan National University, Busan 609-735 (Korea, Republic of)

    2014-10-01

    Recently, photon-counting detectors capable of resolving incident x-ray photon energies have been considered for use in spectral x-ray imaging applications. For reliable use of energy-resolved photon-counting detectors (ERPCDs), energy calibration is an essential procedure prior to their use because variations in responses from each pixel of the ERPCD for incident photons, even at the same energy, are inevitable. Energy calibration can be performed using a variety of methods. In all of these methods, the photon spectra with well-defined peak energies are recorded. Every pixel should be calibrated on its own. In this study, we suggest the use of a conventional polychromatic x-ray source (that is typically used in laboratories) for energy calibration. The energy calibration procedure mainly includes the determination of the peak energies in the spectra, flood-field irradiation, determination of peak channels, and determination of calibration curves (i.e., the slopes and intercepts of linear polynomials). We applied a calibration algorithm to a CdTe ERPCD comprised of 128×128 pixels with a pitch of 0.35 mm using highly attenuated polychromatic x-ray beams to reduce the pulse pile-up effect, and to obtain a narrow-shaped spectrum due to beam hardening. The averaged relative error in calibration curves obtained from 16,384 pixels was about 0.56% for 59.6 keV photons from an Americium radioisotope. This pixel-by-pixel energy calibration enhanced the signal- and contrast-to-noise ratios in images, respectively, by a factor of ∼5 and 3 due to improvement in image homogeneity, compared to those obtained without energy calibration. One secondary finding of this study was that the x-ray photon spectra obtained using a common algorithm for computing x-ray spectra reasonably described the peaks in the measured spectra, which implies easier peak detection without the direct measurement of spectra using a separate spectrometer. The proposed method will be a useful alternative

  19. Energy calibration of energy-resolved photon-counting pixel detectors using laboratory polychromatic x-ray beams

    International Nuclear Information System (INIS)

    Recently, photon-counting detectors capable of resolving incident x-ray photon energies have been considered for use in spectral x-ray imaging applications. For reliable use of energy-resolved photon-counting detectors (ERPCDs), energy calibration is an essential procedure prior to their use because variations in responses from each pixel of the ERPCD for incident photons, even at the same energy, are inevitable. Energy calibration can be performed using a variety of methods. In all of these methods, the photon spectra with well-defined peak energies are recorded. Every pixel should be calibrated on its own. In this study, we suggest the use of a conventional polychromatic x-ray source (that is typically used in laboratories) for energy calibration. The energy calibration procedure mainly includes the determination of the peak energies in the spectra, flood-field irradiation, determination of peak channels, and determination of calibration curves (i.e., the slopes and intercepts of linear polynomials). We applied a calibration algorithm to a CdTe ERPCD comprised of 128×128 pixels with a pitch of 0.35 mm using highly attenuated polychromatic x-ray beams to reduce the pulse pile-up effect, and to obtain a narrow-shaped spectrum due to beam hardening. The averaged relative error in calibration curves obtained from 16,384 pixels was about 0.56% for 59.6 keV photons from an Americium radioisotope. This pixel-by-pixel energy calibration enhanced the signal- and contrast-to-noise ratios in images, respectively, by a factor of ∼5 and 3 due to improvement in image homogeneity, compared to those obtained without energy calibration. One secondary finding of this study was that the x-ray photon spectra obtained using a common algorithm for computing x-ray spectra reasonably described the peaks in the measured spectra, which implies easier peak detection without the direct measurement of spectra using a separate spectrometer. The proposed method will be a useful alternative

  20. Two-beam type IH-RFQ linear accelerator for low-energy and high intensity heavy ion beam

    International Nuclear Information System (INIS)

    We developed a two-beam type IH-RFQ (Interdigital H type Radio Frequency Quadrupole) linac system to proof the principle of a multi-beam type IH-RFQ linac in Research Laboratory for Nuclear Reactors of Tokyo Institute of Technology. The multi-beam type RFQ linac has several beam channels in a cavity for accelerating high intensity and low energy heavy ion beams. The developed system consists of a two-beam type IH-RFQ cavity as a prototype of the multi-beam type cavity, a two-beam type laser ion source with DPIS (Direct Plasma Injection Scheme) and beam analyzers mainly. A a result of the beam acceleration test, the linac system accelerates carbon ions from 5 keV/u to 60 keV/u and generates about 108 mA (2x54 mA/channel) in the total output current. In this paper, we describe the development of the linac system and some results of the beam acceleration test. (author)

  1. Producing titanium-niobium alloy by high energy beam

    Energy Technology Data Exchange (ETDEWEB)

    Sharkeev, Yu. P., E-mail: sharkeev@ispms.tsc.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Golkovski, M. G., E-mail: golkoski@mail.ru [Budker Institute of Nuclear Physics, 11 Akademika Lavrentiev Prosp., Novosibirsk, 630090 (Russian Federation); Glukhov, I. A., E-mail: gia@ispms.tsc.ru; Eroshenko, A. Yu., E-mail: eroshenko@ispms.tsc.ru; Fortuna, S. V., E-mail: s-fortuna@mail.ru [Institute of Strength Physics and Materials Science, SB RAS, 2/4 Akademicheski Prosp., Tomsk, 634055 (Russian Federation); Bataev, V. A., E-mail: bataev@vadm.ustu.ru [Novosibirsk State Technical University, 20 K. Marx Prosp., Novosibirsk, 630073 (Russian Federation)

    2016-01-15

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  2. Producing titanium-niobium alloy by high energy beam

    International Nuclear Information System (INIS)

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element

  3. Producing titanium-niobium alloy by high energy beam

    Science.gov (United States)

    Sharkeev, Yu. P.; Golkovski, M. G.; Glukhov, I. A.; Eroshenko, A. Yu.; Bataev, V. A.; Fortuna, S. V.

    2016-01-01

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  4. Crystals channel high-energy beams in the LHC

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    Bent crystals can be used to deflect particle beams, as suggested by E. Tsyganov in 1976. Experimental demonstrations have been carried out for four decades in various laboratories worldwide. In recent tests, a bent crystal inserted into the LHC beam halo successfully channelled and deflected 6.5 TeV protons into an absorber, with reduced secondary irradiation.    Quasimosaic crystal for the LHC (developed by PNPI). Bent crystal technology was introduced at CERN and further developed for the LHC by the UA9 Collaboration. For about ten years, experts from CERN, INFN (Italy), Imperial College (UK), LAL (France), and PNPI, IHEP and JINR (Russia) have been investigating the advantages of using bent crystals in the collimation systems of high-energy hadron colliders. A bent crystal replacing the primary collimator can deflect the incoming halo deeply inside the secondary collimators, improving their absorption efficiency. “The bent crystals we have just tested at the world-record en...

  5. Neutron energy flux spectrum measurements for leu core of PARR-1

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.; Ayazudin, S.K.; Pervez, S.

    1995-01-01

    The Pakistan Research Reactor-1 has been converted and upgraded from highly enriched uranium (HEU) to low enriched uranium (LEU) fuel from 5 to 9MW. An experimental programme was undertaken to measure the neutron energy spectra in the core and at the irradiated and activity of the foils was measured using high efficiency HPGe gamma ray spectroscopy system. The measured saturation activities were used in the spectrum adjustment computer code SANDBP. A sample energy spectrum for the material test reactor supplied by the International Atomic Energy Agency (IAEA) was used as the input to the SANDBP code, and the final spectra were obtained by iterative adjustment.

  6. Study of Effect of Ion Source Energy Spread on RFQ Beam Dynamics at REX-ISOLDE

    CERN Document Server

    Fraser, M A

    2013-01-01

    With an upgrade to the Electron Beam Ion Source (EBIS) at REX under consideration a study was launched in order to understand the effect of an increased energy spread from the ion source on the beam dynamics of the RFQ. Due to the increased electron beam potential needed to achieve the upgrade’s charge breeding specification it is expected that the energy spread of the beam will increase from today’s estimated value of approximately +-0.1%. It is shown through beam dynamics simulations that the energy spread can be increased to +-1% without significant degradation of the beam quality output by the RFQ.

  7. An Energy Saving System for a Beam Pumping Unit.

    Science.gov (United States)

    Lv, Hongqiang; Liu, Jun; Han, Jiuqiang; Jiang, An

    2016-01-01

    Beam pumping units are widely used in the oil production industry, but the energy efficiency of this artificial lift machinery is generally low, especially for the low-production well and high-production well in the later stage. There are a number of ways for energy savings in pumping units, with the periodic adjustment of stroke speed and rectification of balance deviation being two important methods. In the paper, an energy saving system for a beam pumping unit (ESS-BPU) based on the Internet of Things (IoT) was proposed. A total of four types of sensors, including load sensor, angle sensor, voltage sensor, and current sensor, were used to detect the operating conditions of the pumping unit. Data from these sensors was fed into a controller installed in an oilfield to adjust the stroke speed automatically and estimate the degree of balance in real-time. Additionally, remote supervision could be fulfilled using a browser on a computer or smartphone. Furthermore, the data from a practical application was recorded and analyzed, and it can be seen that ESS-BPU is helpful in reducing energy loss caused by unnecessarily high stroke speed and a poor degree of balance. PMID:27187402

  8. An Energy Saving System for a Beam Pumping Unit

    Science.gov (United States)

    Lv, Hongqiang; Liu, Jun; Han, Jiuqiang; Jiang, An

    2016-01-01

    Beam pumping units are widely used in the oil production industry, but the energy efficiency of this artificial lift machinery is generally low, especially for the low-production well and high-production well in the later stage. There are a number of ways for energy savings in pumping units, with the periodic adjustment of stroke speed and rectification of balance deviation being two important methods. In the paper, an energy saving system for a beam pumping unit (ESS-BPU) based on the Internet of Things (IoT) was proposed. A total of four types of sensors, including load sensor, angle sensor, voltage sensor, and current sensor, were used to detect the operating conditions of the pumping unit. Data from these sensors was fed into a controller installed in an oilfield to adjust the stroke speed automatically and estimate the degree of balance in real-time. Additionally, remote supervision could be fulfilled using a browser on a computer or smartphone. Furthermore, the data from a practical application was recorded and analyzed, and it can be seen that ESS-BPU is helpful in reducing energy loss caused by unnecessarily high stroke speed and a poor degree of balance. PMID:27187402

  9. Energy Spectrum of the Fe4 molecular magnet

    International Nuclear Information System (INIS)

    Full text: The subject of molecular magnetism is a relatively new but very active area of research. A number of different molecular clusters containing paramagnetic metal ions have been synthesised and studied, among them 'Mn12' [Mn12O12(CH2COO)16(H2O)4] and 'Fe8' [Fe8O2(OH)12(tacn)6], both of which have an S=10 ground state. These systems are of interest, not only because of potential applications in nanotechnology, but also because they may exhibit interesting fundamental quantum phenomena such as quantum spin tunnelling, topological interference effects, and exact degeneracies at so-called 'diabolical points' in magnetic field space. These have been observed in Fe8. A more recently discovered cluster is 'Fe4' [Fe4(OCH3)6(dpm)6], which has a ground state with s=5. We present a theoretical analysis of the Fe4 cluster, using a spin-exchange model to describe the overall spectrum and a crystal field Hamiltonian to describe the splitting in zero field, and demonstrate the existence of diabolical points in nonzero field. The possible observation of these phenomena in Fe4 is discussed

  10. A depression before a bump in the highest energy cosmic ray spectrum

    OpenAIRE

    Anchordoqui, L. A.; Dova, M. T.; Epele, L. N.; Swain, J. D.

    1997-01-01

    We re-examine the interaction of ultra high energy nuclei with the microwave background radiation. We find that the giant dipole resonance leaves a new signature in the differential energy spectrum of iron sources located around 3 Mpc: A depression before the bump which is followed by the expected cutoff.

  11. The 4p6 electron energy-loss spectrum of Rb atoms

    International Nuclear Information System (INIS)

    The scattered electron energy-loss spectrum due to the excitation of the 4p5n1l1n2l2 states in rubidium atoms was measured at 25.6 eV impact energy. New optically forbidden non-autoionizing states located between 16.5 and 16.8 eV were observed.

  12. The energy-momentum spectrum in local field theories with broken Lorentz-symmetry

    International Nuclear Information System (INIS)

    Assuming locality of the observables and positivity of the energy it is shown that the joint spectrum of the energy-momentum operators has a Lorentz-invariant lower boundary in all superselection sectors. This result is of interest if the Lorentz-symmetry is (spontaneously) broken, such as in the charged sectors of quantum electrodynamics. (orig.)

  13. Beam energy considerations for gold nano-particle enhanced radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, F; Nuyts, S [Department of Experimental Radiotherapy, University of Leuven, Leuven (Belgium); Locquet, Jean-Pierre, E-mail: frank.vandenheuvel@med.kuleuven.b [Solid State Physics and Magnetism Section, University of Leuven, Leuven (Belgium)

    2010-08-21

    A novel approach using nano-technology enhanced radiation modalities is investigated. The proposed methodology uses antibodies labeled with organically inert metals with a high atomic number. Irradiation using photons with energies in the kilo-electron volt (keV) range shows an increase in dose due to a combination of an increase in photo-electric interactions and a pronounced generation of Auger and/or Coster-Kroenig (A-CK) electrons. The dependence of the dose deposition on various factors is investigated using Monte Carlo simulation models. The factors investigated include agent concentration, spectral dependence looking at mono-energetic sources as well as classical bremsstrahlung sources. The optimization of the energy spectrum is performed in terms of physical dose enhancement as well as the dose deposited by Auger and/or Coster-Kroenig electrons and their biological effectiveness. A quasi-linear dependence on concentration and an exponential decrease within the target medium is observed. The maximal dose enhancement is dependent on the position of the target in the beam. Apart from irradiation with low-photon energies (10-20 keV) there is no added benefit from the increase in generation of Auger electrons. Interestingly, a regular 110 kVp bremsstrahlung spectrum shows a comparable enhancement in comparison with the optimized mono-energetic sources. In conclusion we find that the use of enhanced nano-particles shows promise to be implemented quite easily in regular clinics on a physical level due to the advantageous properties in classical beams.

  14. Beam energy considerations for gold nano-particle enhanced radiation treatment

    Science.gov (United States)

    Van den Heuvel, F.; Locquet, Jean-Pierre; Nuyts, S.

    2010-08-01

    A novel approach using nano-technology enhanced radiation modalities is investigated. The proposed methodology uses antibodies labeled with organically inert metals with a high atomic number. Irradiation using photons with energies in the kilo-electron volt (keV) range shows an increase in dose due to a combination of an increase in photo-electric interactions and a pronounced generation of Auger and/or Coster-Krönig (A-CK) electrons. The dependence of the dose deposition on various factors is investigated using Monte Carlo simulation models. The factors investigated include agent concentration, spectral dependence looking at mono-energetic sources as well as classical bremsstrahlung sources. The optimization of the energy spectrum is performed in terms of physical dose enhancement as well as the dose deposited by Auger and/or Coster-Krönig electrons and their biological effectiveness. A quasi-linear dependence on concentration and an exponential decrease within the target medium is observed. The maximal dose enhancement is dependent on the position of the target in the beam. Apart from irradiation with low-photon energies (10-20 keV) there is no added benefit from the increase in generation of Auger electrons. Interestingly, a regular 110 kVp bremsstrahlung spectrum shows a comparable enhancement in comparison with the optimized mono-energetic sources. In conclusion we find that the use of enhanced nano-particles shows promise to be implemented quite easily in regular clinics on a physical level due to the advantageous properties in classical beams.

  15. Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

    OpenAIRE

    Shu-Quan, Liu; Thomas, Bücherl; Hang, Li; Yu-Bin, Zou; Yuan-Rong, Lu; Zhi-Yu, Guo

    2013-01-01

    Neutron spectrum and scattered neutrons caused distortions are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-II in Technische Universit\\"at M\\"unchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by neutron spectru...

  16. Search for radiative decays of cosmic background neutrino using cosmic infrared background energy spectrum

    International Nuclear Information System (INIS)

    We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obtained a lifetime lower limit of 3.1x1012 to 3.8x1012 years at 95% confidence level for the third generation neutrino v3 in the v3 mass range between 50 and 150 meV/c2 under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of v3 is predicted to be 1.5x1017 years for m3 of 50 meV/c2. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of 1.5x1017 years, by measuring a continuous energy spectrum of the cosmic infrared background. (author)

  17. Energy characteristics of beam-plasma interaction in a closed volume

    Energy Technology Data Exchange (ETDEWEB)

    Klykov, I. L. [Russian Academy of Sciences, Kotel' nikov Institute of Radio Engineering and Electronics (Fryazino Branch) (Russian Federation); Tarakanov, V. P. [Russian Academy of Sciences, Institute for High Energy Densities, Joint Institute for High Temperatures (Russian Federation); Shustin, E. G. [Russian Academy of Sciences, Kotel' nikov Institute of Radio Engineering and Electronics (Fryazino Branch) (Russian Federation)

    2012-03-15

    Energy exchange between an electron beam and plasma during a beam-plasma discharge in a closed cavity excited by the electron beam is analyzed using computer simulations by the KARAT code. A method allowing one to analyze the beam-plasma interaction in the quasi-steady stage of the discharge is proposed. Qualitative characteristics of energy exchange (such as beam energy losses and the energy distributions of beam electrons and plasma particles leaving the discharge) both during spontaneous discharge excitation and in the presence of initial beam modulation by regular or noiselike signals are determined. The results obtained enable one to estimate the energy characteristics of a plasma processing reactor based on a beam-plasma discharge.

  18. Energy characteristics of beam-plasma interaction in a closed volume

    Science.gov (United States)

    Klykov, I. L.; Tarakanov, V. P.; Shustin, E. G.

    2012-03-01

    Energy exchange between an electron beam and plasma during a beam-plasma discharge in a closed cavity excited by the electron beam is analyzed using computer simulations by the KARAT code. A method allowing one to analyze the beam-plasma interaction in the quasi-steady stage of the discharge is proposed. Qualitative characteristics of energy exchange (such as beam energy losses and the energy distributions of beam electrons and plasma particles leaving the discharge) both during spontaneous discharge excitation and in the presence of initial beam modulation by regular or noiselike signals are determined. The results obtained enable one to estimate the energy characteristics of a plasma processing reactor based on a beam-plasma discharge.

  19. Fundamental physics research using a low energy muon beam

    International Nuclear Information System (INIS)

    A process is proposed for the production of true muonium, in which the simultaneous generation of positive and negative muons is utilized in the discovery of new and more compact leptonic atoms. The proposed method, which is based on the use of a low energy muon apparatus, has certain advantages and could lead to the long-awaited appearance of positive and negative muons in the bound state, a goal that has been pursued for a half century. In this apparatus, the formation of true muonium is obtained by frictional cooling with an electron cyclotron resonance plasma,followed by the detection of high energy gamma rays. Simulation studies using the GEANT4 code were applied to the development of this low energy beam apparatus in order to provide evidence for the validity of the frictional cooling principle. (author)

  20. Emittance measurements of low-energy beam line at KVI

    NARCIS (Netherlands)

    Toprek, D; Formanoy, [No Value

    2006-01-01

    In this paper is represented the results of beam profile measurements of He-3(+) beam delivered from ECR ion source at KVI. The beam emittance is estimated by varying quadrupole method. The estimated values for the beam emittance at the different profile grid locations along the transport beam line

  1. Low-energy High-current Electron Beam Generation in Plasma System and Beam-Plasma Interaction

    International Nuclear Information System (INIS)

    The review of results of experimental investigations and computer simulations of low-energy high-current electron beam generation in a low-impedance system and dynamics of beam-plasma system are given. The system includes a long plasma-filled diode, an auxiliary thermionic cathode and an explosive emission cathode. The auxiliary cathode is used to generate the a low-current, low-voltage electron beam to form long plasma anode by means of a residual gas ionisation in an external longitudinal magnetic field. The high-current low-energy electron beam is generated from the explosive emission cathode embedded in preliminary prepared plasma. Peculiarities of the system are due to: 1) the generation of electron beams with currents exceeding Alfven's limit; 2) the charge density of the beam close to the plasma density. These peculiarities complicate beam-plasma interaction significantly due to sharp non-uniform distribution of the beam current density, dominant transverse motion of the beam electrons and redistribution of ion-plasma density under the influence of fields. Computer simulation was performed using electromagnetic PIC code KARAT for different geometry's of the system

  2. Leptoquark models and the energy spectrum of cosmic rays

    OpenAIRE

    Alikhanov, I.

    2011-01-01

    The IceCube Neutrino Observatory has recently placed a new limit on the extremely-high energy (EHE) neutrino flux lower than the Greisen--Zatsepin--Kuzmin (GZK) cosmogenic neutrino intensities expected in the case of proton-dominated primary composition. This result favors the mixed chemical composition models and excludes scenarios with strongly interacting neutrinos proposed so far. Nevertheless we argue that it is possible to construct such models consistently with the IceCube data if to e...

  3. Energy spectrum of localization statas in vanadium-phosphate glasses

    International Nuclear Information System (INIS)

    The capacitance-voltage characteristics of the Pt-vnadium-phosphate glass-Pt structures have been studied. A technique is proposed to determine the distribution of the density of loclized states versus energy, p(E). This distribution is shown to be exponential. For the 80% V2O5 - 20% P2O5 glass in the vicinity of the Fermi level p(Esub(F)) is determined to be approximately 6x1020 cm-3 eV-μ1

  4. Single particle spectrum and binding energy of nuclear matter

    OpenAIRE

    Baldo, M; Fiasconaro, A.

    2000-01-01

    In non-relativistic Brueckner calculations of nuclear matter, the self-consistent single particle potential is strongly momentum dependent. To simplify the calculations, a parabolic approximation is often used in the literature. The variation in the binding energy value introduced by the parabolic approximation is quantitatively analyzed in detail. It is found that the approximation can introduce an uncertainty of 1-2 MeV near the saturation density.

  5. A New Method of Prompt Fission Neutron Energy Spectrum Unfolding

    Science.gov (United States)

    Zeynalova, O. V.; Zeynalov, Sh.; Hambsch, F.-J.; Oberstedt, S.

    2010-11-01

    The prompt neutron emission in spontaneous fission of 252Cf has been investigated applying digital signal electronics along with associated digital signal processing algorithms. The goal was to find out the reasons of a long time existing discrepancy between theoretical calculations and the measurements of prompt fission neutron (PFN) emission dependence on the total kinetic energy (TKE) of fission fragments (FF). On the one hand the 252Cf (sf) reaction is one of the main references for nuclear data, on the other hand the understanding of PFN emission mechanism is very important for nuclear fission theory. Using a twin Frisch-grid ionization chamber for fission fragment (FF) detection and a NE213-equivalent neutron detector in total about 107 fission fragment-neutron coincidences have been registered. Fission fragment kinetic energy, mass and angular distribution, neutron time-of-flight and pulse shape have been investigated using a 12 bit waveform digitizer. The signal waveforms have been analyzed using digital signal processing algorithms. For the first time the dependence of the number of emitted neutrons as a function of total kinetic energy (TKE) of the fragments is in very good agreement with theoretical calculations in the range of TKE from 140-220 MeV.

  6. On the groundstate energy spectrum of magnetic knots and links

    International Nuclear Information System (INIS)

    By using analytical results for the constrained minimum energy of magnetic knots we determine the influence of internal twist on the minimum magnetic energy levels of knots and links, and by using ropelength data from the RIDGERUNNER tightening algorithm (Ashton et al 2011 Exp. Math. 20 57–90) we obtain the groundstate energy spectra of the first 250 prime knots and 130 prime links. The two spectra are found to follow an almost identical logarithmic law. By assuming that the number of knot types grows exponentially with the topological crossing number, we show that this generic behavior can be justified by a general relationship between ropelength and crossing number, which is in good agreement with former analytical estimates (Buck and Simon 1999 Topol. Appl. 91 245–57, Diao 2003 J. Knot Theory Ramifications 12 1–16). Moreover, by considering the ropelength averaged over a given knot family, we establish a new connection between the averaged ropelength and the topological crossing number of magnetic knots. (paper)

  7. Emittance growth in displaced, space-charge-dominated beams with energy spread

    International Nuclear Information System (INIS)

    Conversion of transverse energy associated with the coherent motion of displaced beams into thermal energy, and thus emittance growth, has been predicted theoretically by a number of authors. Here, the authors show, using 2-D particle-in-cell simulations, that emittance growth is inhibited for tune depressed beams, if the energy spread of the beam is not too large. Further, using a uniform density model to calculate the space charge field of the beam, they numerically determine the criteria for emittance growth as a function of tune depression, energy spread, and beam displacement over a wide range of parameters. A theoretical interpretation of their results is presented

  8. A device for a proton beam energy control for radiotherapy

    International Nuclear Information System (INIS)

    A Medical-Technical Facility for hadron radiotherapy based on the JINR DLNP phasotron has been constructed and put into operation. Upgrading of methods, hardware and software for radiotherapy is one of the main tasks for further development of the Facility. This article concerns one of the fields of this work, that is the development of equipment for dynamic irradiation of a deep lying target - the construction of a device for the proton beam energy control and measurement of its depth-dose curve in a treatment room. (author)

  9. Vacuum Chamber for the Measurement System of the Beam Energy

    Science.gov (United States)

    Abakumova, E.; Achasov, M.; Dong, HaiYi; Qu, HuaMin; Krasnov, A.; Kosarev, A.; Muchnoi, N.; Pyata, E.; Xiao, Qiong; Mo, XiaoHu; Wang, YiFang; Zhukov, A.

    Vacuum chamber for the beam energy measurement system based on the Compton backscattering method is presented. The main elements of the chamber are GaAs entrance viewport and a copper mirror. The viewport design provides baking out of the vacuum chamber up to 250 °C. To produce the viewport, an original technology based on brazing GaAs plate by lead has been developed. The vacuum chambers were installed at the BEPC-II and VEPP-4 M colliders. After installation the residual gas pressure is about 10-10 Torr.

  10. Beamed Energy Propulsion by Means of Target Ablation

    International Nuclear Information System (INIS)

    This paper describes hundreds of pendulum tests examining the beamed energy conversion efficiency of different metal targets coated with multiple liquid enhancers. Preliminary testing used a local laser with photographic paper targets, with no liquid, water, canola oil, or methanol additives. Laboratory experimentation was completed at Wright-Patterson AFB using a high-powered laser, and ballistic pendulums of aluminum, titanium, or copper. Dry targets, and those coated with water, methanol and oil were repeatedly tested in laboratory conditions. Results were recorded on several high-speed digital video cameras, and the conversion efficiency was calculated. Paper airplanes successfully launched using BEP were likewise recorded

  11. Measuring pion beta decay with high-energy pion beams

    International Nuclear Information System (INIS)

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay π+ → π0e+vε is predicted by the Standard Model (SM) to be R(π+ → π0e+vε) = 0.3999±0.0005 s-1. The best experimental number, obtained using in-flight decays, is R(π+ → π0e+vε) = 0.394 ± 0.015 s-1. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required

  12. Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the Telescope Array Using a Hybrid Technique

    OpenAIRE

    Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; B.G. Cheon; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.

    2013-01-01

    We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$ eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27 2008 to September 7 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is ...

  13. Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the Telescope Array Using a Hybrid Technique

    CERN Document Server

    Abu-Zayyad, T; Allen, M; Anderson, R; Azuma, R; Barcikowski, E; Belz, J W; Bergman, D R; Blake, S A; Cady, R; Cheon, B G; Chiba, J; Chikawa, M; Cho, E J; Cho, W R; Fujii, H; Fujii, T; Fukuda, T; Fukushima, M; Hanlon, W; Hayashi, K; Hayashi, Y; Hayashida, N; Hibino, K; Hiyama, K; Honda, K; Iguchi, T; Ikeda, D; Ikuta, K; Inoue, N; Ishii, T; Ishimori, R; Ito, H; Ivanov, D; Iwamoto, S; Jui, C C H; Kadota, K; Kakimoto, F; Kalashev, O; Kanbe, T; Kasahara, K; Kawai, H; Kawakami, S; Kawana, S; Kido, E; Kim, H B; Kim, H K; Kim, J H; Kitamoto, K; Kitamura, S; Kitamura, Y; Kobayashi, K; Kobayashi, Y; Kondo, Y; Kuramoto, K; Kuzmin, V; Kwon, Y J; Lan, J; Lim, S I; Lundquist, J P; Machida, S; Martens, K; Matsuda, T; Matsuura, T; Matsuyama, T; Matthews, J N; Minamino, M; Miyata, K; Murano, Y; Myers, I; Nagasawa, K; Nagataki, S; Nakamura, T; Nam, S W; Nonaka, T; Ogio, S; Ohnishi, M; Ohoka, H; Oki, K; Oku, D; Okuda, T; Ono, M; Oshima, A; Ozawa, S; Park, I H; Pshirkov, M S; Rodriguez, D C; Roh, S Y; Rubtsov, G; Ryu, D; Sagawa, H; Sakurai, N; Sampson, A L; Scott, L M; Shah, P D; Shibata, F; Shibata, T; Shimodaira, H; Shin, B K; Shin, J I; Shirahama, T; Smith, J D; Sokolsky, P; Springer, R W; Stokes, B T; Stratton, S R; Stroman, T; Suzuki, S; Takahashi, Y; Takeda, M; Taketa, A; Takita, M; Tameda, Y; Tanaka, H; Tanaka, K; Tanaka, M; Thomas, S B; Thomson, G B; Tinyakov, P; Tkachev, I; Tokuno, H; Tomida, T; Troitsky, S; Tsunesada, Y; Tsutsumi, K; Tsuyuguchi, Y; Uchihori, Y; Udo, S; Ukai, H; Urban, F; Vasiloff, G; Wada, Y; Wong, T; Yamakawa, Y; Yamane, R; Yamaoka, H; Yamazaki, K; Yang, J; Yoneda, Y; Yoshida, S; Yoshii, H; Zhou, X; Zollinger, R; Zundel, Z

    2013-01-01

    We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$ eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27 2008 to September 7 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.

  14. Correlation of D-D neutron yield and D/sup +/ energy spectrum in focused discharges

    International Nuclear Information System (INIS)

    The energy spectrum N(E) of the D/sup +/ ion emission from ≅ 0.6 MA focused discharges is determined with Thomson spectrometers for different conditions (D/sub 2/ filling pressure, capacitor bank voltage, and geometry of field distortion elements in the interelectrode gap). Linear correlation coefficients c/sub i/ for a characteristic element of the spectrum (e.g. the spectrum amplitude within a selected energy interval E, E+ΔE) and the neutron yield n is determined for a large number of discharges. The interplay of two leading processes in the neutron production, ion acceleration and ion trapping in the self magnetic field of the pinch, is analyzed in terms of correlation coefficients c/sub i/ and peak neutron energy

  15. Neutron energy spectrum adjustment using deposited metal films on Teflon in the miniature neutron source reactor.

    Science.gov (United States)

    Nassan, L; Abdallah, B; Omar, H; Sarheel, A; Alsomel, N; Ghazi, N

    2016-01-01

    The focus of this article was on the experimental estimation of the neutron energy spectrum in the inner irradiation site of the miniature neutron source reactor (MNSR), using, for the first time, a selected set of deposited metal films on Teflon (DMFTs) neutron detectors. Gold, copper, zinc, titanium, aluminum, nickel, silver, and chromium were selected because of the dependence of their neutron cross-sections on neutron energy. Emphasis was placed on the usability of this new type of neutron detectors in the total neutron energy spectrum adjustment. The measured saturation activities per target nucleus values of the DMFTs, and the calculated neutron spectrum in the inner irradiation site using the MCNP-4C code were used as an input for the STAY'SL computer code during the adjustment procedure. The agreement between the numerically calculated and experimentally adjusted spectra results was discussed. PMID:26562448

  16. Energy spectrum of UHECRs measured by newly constructed fluorescence detectors in Telescope Array experiment

    Directory of Open Access Journals (Sweden)

    Fujii Toshihiro

    2013-06-01

    Full Text Available Telescope Array (TA experiment is the largest hybrid detector to observe ultra-high energy cosmic rays (UHECRs in the northern hemisphere. In the TA experiment, we newly designed and constructed 24 fluorescence detectors (FDs located at two stations. We report the energy spectrum of UHECRs with energies above 1017.5 eV from analyzing data collected by the new FDs during the first 3.7 years in monocular mode.

  17. Interference Energy Spectrum of the Infinite Square Well

    OpenAIRE

    Waegell, Mordecai; Aharonov, Yakir; Patti, Taylor Lee

    2016-01-01

    Certain superposition states of the 1-D infinite square well have transient zeros at locations other than the nodes of the eigenstates that comprise them. It is shown that if an infinite potential barrier is suddenly raised at some or all of these zeros, the well can be split into multiple adjacent infinite square wells without affecting the wavefunction. This effects a change of the energy eigenbasis of the state to a basis that does not commute with the original, and a subsequent measuremen...

  18. The high-energy spectrum of 3C 273

    OpenAIRE

    Esposito, Valentino; Walter, Roland; Jean, Pierre; Tramacere, Andrea

    2013-01-01

    The high energy spectral shape of 3C 273 is usually understood in terms of Inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays which could be tested if simultaneous observations are available from the infrared to the GeV range. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE and LAT on board Fermi have enough sensitivity to follow the spectral variability from the keV to the GeV and to compare them with model predi...

  19. Power Laws and the Cosmic Ray Energy Spectrum

    OpenAIRE

    Hague, J. D.; Becker, B. R.; Gold, M.S.; Matthews, J. A. J.

    2006-01-01

    Two separate statistical tests are applied to the AGASA and preliminary Auger Cosmic Ray Energy spectra in an attempt to find deviation from a pure power-law. The first test is constructed from the probability distribution for the maximum event of a sample drawn from a power-law. The second employs the TP-statistic, a function defined to deviate from zero when the sample deviates from the power-law form, regardless of the value of the power index. The AGASA data show no significant deviation ...

  20. Irradiation effect on PET surface using low energy argon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, Barakat A. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy, P.O. Box 13759, Inchas, Atomic Energy (Egypt); Abdelrahman, Moustafa M., E-mail: moustafa82003@yahoo.com [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy, P.O. Box 13759, Inchas, Atomic Energy (Egypt); Abdelsalam, Fatama W. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy, P.O. Box 13759, Inchas, Atomic Energy (Egypt); Aly, Kamal A. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy, P.O. Box 13759, Inchas, Atomic Energy (Egypt); Physics Department, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut (Egypt); Physics Department, Faculty of Science and Arts, Khulais, King Abdulaziz University (KAU) (Saudi Arabia)

    2013-01-15

    A study of various physical properties of a PET film irradiated with an Ar beam is reported. SEM images and UV-VIS and FTIR spectra were obtained for a number of ionic fluxes and three irradiation times. Small changes in the energy gap of degradated samples were found, and the SEM images indicate that the optimum homogeneity and roughness are reached after 30 min of irradiation. These results may well be of practical interest. A modified saddle field ion source was used as a preparation tool of the surface of polyethylene terephthalate PET polymer substrate to be ready for coating or thin film deposition. Argon ion beam was used for this purpose, where the scanning electron microscope (SEM) shows that, the best sample is the one which was irradiated to 30 min, where this sample is more homogenous and roughness than other irradiated samples. Also the (UV-VIS) spectrum tells us that, there is small change on energy gap and this is meaning that, the change on electric properties is small also. In this case the sample is more homogenous and of higher roughness than other irradiated samples.

  1. Review of Recent Results from the RHIC Beam Energy Scan

    CERN Document Server

    Kumar, Lokesh

    2013-01-01

    We review recent results from the RHIC beam energy scan (BES) program, aimed to study the Quantum Chromodynamics (QCD) phase diagram. The main goals are to search for the possible phase boundary, softening of equation of state or first order phase transition, and possible critical point. Phase-I of the BES program has recently concluded with data collection for Au+Au collisions at center-of-mass energies ($\\sqrt{s_{NN}}$) of 7.7, 11.5, 19.6, 27, and 39 GeV. Several interesting results are observed for these lower energies where the net-baryon density is high at the mid-rapidity. These results indicate that the matter formed at lower energies (7.7 and 11.5 GeV) is hadron dominated and might not have undergone a phase transition. In addition, the centrality dependence of freeze-out parameters is observed for the first time at lower energies, slope of directed flow for (net)-protons measured versus rapidity shows an interesting behavior at lower energies, and higher moments of net-proton show deviation from Skel...

  2. Energy spectrum and phase diagrams of two-sublattice hard-core boson model

    Directory of Open Access Journals (Sweden)

    I.V. Stasyuk

    2013-06-01

    Full Text Available The energy spectrum, spectral density and phase diagrams have been obtained for two-sublattice hard-core boson model in frames of random phase approximation approach. Reconstruction of boson spectrum at the change of temperature, chemical potential and energy difference between local positions in sublattices is studied. The phase diagrams illustrating the regions of existence of a normal phase which can be close to Mott-insulator (MI or charge-density (CDW phase diagrams as well as the phase with the Bose-Einstein condensate (SF phase are built.

  3. Improved Energy Detector for Wideband Spectrum Sensing in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Y. Eghbali

    2014-04-01

    Full Text Available In this paper, an improved energy detector for a wideband spectrum sensing is proposed. For a better detection of the spectrum holes the overall band is divided into equal non-overlapping sub-bands. The main objective is to determine the detection thresholds for each of these subbands jointly. By defining the problem as an optimization problem, we aim to find the maximum aggregated opportunistic throughput of cognitive radio networks. Introducing practical constraints to this optimization problem will change the problem into a convex and solvable one. The results of this paper show that the proposed improved energy detector will increase the aggregated throughput considerably.

  4. All-particle cosmic ray energy spectrum measured with 26 IceTop stations

    OpenAIRE

    IceCube Collaboration; Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Ackermann, M; Adams, J.; Aguilar, J.A.; Ahlers, M.; Altmann, D; Andeen, K; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.

    2012-01-01

    We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 surface stations operational at that time, corresponding to about one third of the final array. The fiducial area used in this analysis was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV measured for three differen...

  5. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    International Nuclear Information System (INIS)

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Qext with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam energy

  6. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guimei [Peking Univ., Beijing (China)

    2011-12-31

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam

  7. Feasibility of a 90° electric sector energy analyzer for low energy ion beam characterization

    Energy Technology Data Exchange (ETDEWEB)

    Mahinay, C. L. S., E-mail: cmahinay@nip.upd.edu.ph; Ramos, H. J. [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101, Metro Manila (Philippines); Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2015-02-15

    A simple formula to calculate refocusing by locating the output slit at a specific distance away from the exit of 90° ion deflecting electric sector is given. Numerical analysis is also performed to calculate the ion beam trajectories for different values of the initial angular deviation of the beam. To validate the theory, a compact (90 mm × 5.5 mm × 32 mm) 90° sector ESA is fabricated which can fit through the inner diameter of a conflat 70 vacuum flange. Experimental results show that the dependence of resolution upon the distance between the sector exit and the Faraday cup agrees with the theory. The fabricated 90° sector electrostatic energy analyzer was then used to measure the space resolved ion energy distribution functions of an ion beam with the energy as low as 600 eV.

  8. An ion beam deceleration lens for ultra-low-energy ion bombardment of naked DNA

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [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); Suwannakachorn, D. [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: yuldyuld@gmail.com [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)

    2013-07-15

    Highlights: ► An ion beam deceleration lens was designed and constructed. ► The deceleration lens was installed and tested. ► The decelerated ion beam energy was measured using an electrical field. ► Decelerated ultra-low-energy ion beam bombarded naked DNA. ► Ion beam with energy of a few tens of eV could break DNA strands. -- Abstract: Study of low-energy ion bombardment effect on biological living materials is of significance. High-energy ion beam irradiation of biological materials such as organs and cells has no doubt biological effects. However, ion energy deposition in the ion-bombarded materials dominantly occurs in the low-energy range. To investigate effects from very-low-energy ion bombardment on biological materials, an ion beam deceleration lens is necessary for uniform ion energy lower than keV. A deceleration lens was designed and constructed based on study of the beam optics using the SIMION program. The lens consisted of six electrodes, able to focus and decelerate primary ion beam, with the last one being a long tube to obtain a parallel uniform exiting beam. The deceleration lens was installed to our 30-kV bioengineering-specialized ion beam line. The final decelerated-ion energy was measured using a simple electrostatic field to bend the beam to range from 10 eV to 1 keV controlled by the lens parameters and the primary beam condition. In a preliminary test, nitrogen ion beam at 60 eV decelerated from a primary 20-keV beam bombarded naked plasmid DNA. The original DNA supercoiled form was found to change to relaxed and linear forms, indicating single or double strand breaks. The study demonstrated that the ion bombardment with energy as low as several-tens eV was possible to break DNA strands and thus potential to cause genetic modification of biological cells.

  9. Enhanced creation of high energy particles in colliding laser beams

    CERN Document Server

    Kuchiev, Michael

    2015-01-01

    The creation of particles by two colliding strong laser beams is considered. It is found that the electron-positron pairs created in the laser field via the Schwinger mechanism may recollide after one or several oscillations in the field. Their collision can take place at high energy, which the pair gains from the field. As a result, high energy gamma quanta can be created by inelastic scattering or annihilation of the pair. Moreover, heavy particles such as muon pairs may also be created via the annihilation $e^+ + e^-\\rightarrow \\mu^+ + \\mu^- $. The probability of $e^-e^+$ collision is greatly enhanced due to a strong alignment of the electron and positron momenta with the electric field. The found muon creation rate exponentially exceeds the rate predicted by the direct Schwinger mechanism for muons, while the photon creation rate exponentially exceeds photon emission due to the fermion oscillation.

  10. Beam energy absolute measurement using K-edge absorption spectrometers

    International Nuclear Information System (INIS)

    A method is presented of absolute energy measurement with an accuracy of triangle Ε ∼ 10-4Εo by direct measurement of the bend angle in a high-precision magnetic dipole using two opposite-direction short (about 2 mm long) high-field-intensity magnets (bar Β dipole much-lt Βshortmag) installed at each end and two K-edge absorption spectrometers. Using these spectrometers and the hard x-ray synchrotron radiation created by the short magnets, a bend angle of 4.5 arc deg for the CEBAF energy bandwidth can be measured with an accuracy of a few units of 10-6 rad, and the main sources of systematic errors are the absolute measurement of the field integral and the determination of the centroid of the synchrotron beam at a wavelength equal to the K-edge absorption of the chosen substance

  11. High energy electron beam processing experiments with induction accelerators

    International Nuclear Information System (INIS)

    Induction accelerators are capable of producing very high electron beam power for processing at energies of 1-10 MeV. A high energy electron beam (HEEB) material processing system based on all-solid-state induction accelerator technology is in operation at Science Research Laboratory. The system delivers 50 ns 500 A current pulses at 1.5 MeV and is capable of operating at high power (500 kW) and high ( similar 5 kHz) repetition rate. HEEB processing with induction accelerators is useful for a wide variety of applications including the joining of high temperature materials, powder metallurgical fabrication, treatment of organic-contaminated wastewater and the curing of polymer matrix composites. High temperature HEEB experiments at SRL have demonstrated the brazing of carbon-carbon composites to metallic substrates and the melting and sintering of powders for graded-alloy fabrication. Other experiments have demonstrated efficient destruction of low-concentration organic contaminants in water and low temperature free-radical cross-linking of fiber-reinforced composites with acrylated resin matrices. (orig.)

  12. Holographic lens spectrum splitting photovoltaic system for increased diffuse collection and annual energy yield

    Science.gov (United States)

    Vorndran, Shelby D.; Wu, Yuechen; Ayala, Silvana; Kostuk, Raymond K.

    2015-09-01

    Concentrating and spectrum splitting photovoltaic (PV) modules have a limited acceptance angle and thus suffer from optical loss under off-axis illumination. This loss manifests itself as a substantial reduction in energy yield in locations where a significant portion of insulation is diffuse. In this work, a spectrum splitting PV system is designed to efficiently collect and convert light in a range of illumination conditions. The system uses a holographic lens to concentrate shortwavelength light onto a smaller, more expensive indium gallium phosphide (InGaP) PV cell. The high efficiency PV cell near the axis is surrounded with silicon (Si), a less expensive material that collects a broader portion of the solar spectrum. Under direct illumination, the device achieves increased conversion efficiency from spectrum splitting. Under diffuse illumination, the device collects light with efficiency comparable to a flat-panel Si module. Design of the holographic lens is discussed. Optical efficiency and power output of the module under a range of illumination conditions from direct to diffuse are simulated with non-sequential raytracing software. Using direct and diffuse Typical Metrological Year (TMY3) irradiance measurements, annual energy yield of the module is calculated for several installation sites. Energy yield of the spectrum splitting module is compared to that of a full flat-panel Si reference module.

  13. Simulation of Head-on Beam-Beam Limitations in Future High Energy Colliders

    CERN Document Server

    Buffat, Xavier; Florio, Adrien; Pieloni, Tatiana; Tambasco, Claudia

    2016-01-01

    The Future Circular Hadron Collider (FCC-hh) project calls for studies in a new regime of beam-beam interactions. While the emittance damping due to synchrotron radiation is still slower than in past or existing lepton colliders, it is significantly larger than in other hadron colliders. The slow reduction of the emittance is profitable for higher luminosity in term of transverse beam size at the interaction points and also to mitigate long-range beam-beam effects, potentially allowing for a reduction of the crossing angle between the beams during the operation. In such conditions, the strength of head-on beam-beam interactions increases, potentially limiting the beam brightness. 4D weak-strong and strong-strong simulations are performed in order to assess these limitations.

  14. Dependence of the Energy Spectrum of UHE Cosmic Rays on the Latitude of an Extensive Air Shower Array

    CERN Document Server

    Glushkov, A V

    2012-01-01

    Several energy spectra of cosmic rays with energies E_0 \\geq 10^17 eV measured at the Yakutsk EAS, AGASA, Haverah Park, HiRes, Auger, and SUGAR arrays are considered. It is shown that the fairly good mutual agreement of the spectrum shapes can be achieved if the energy of each spectrum is multiplied by a factor K specific for each spectrum. These factors exhibit a pronounced dependence on the latitude of the above-mentioned arrays.

  15. Radiation processing of natural polymers using low energy electron beam

    International Nuclear Information System (INIS)

    Radiation processing is widely used in Japan and the economic scale of radiation application amounted to about 71 b$ (ratio relative to GDP: 1.7%) in total. It consisted of 60 b$ (85%) in industry, 10 b$ (14%) in medicine and 1 b$ (1%) in agriculture. Irradiation using gamma-ray from 60Co and electron beam is commercially used for the sterilization and modification of materials. Utilization of natural polymers by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin were easily degraded by irradiation and induced various kinds of biological activities, i.e. anti-bacterial activity, elicitor activity, plant growth promotion, suppression of environmental stress on plants. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. Low energy electron beam (EB) irradiation has a variety of applications and good safety. A self-shielded low energy electron accelerator system needs an initial investment much lower than a 60Co facility. It was demonstrated that the liquid sample irradiation system using low energy EB was effective not only for the preparation of degraded polysaccharides but also for radiation vulcanization of natural rubber latex (RVNRL). Some carbohydrate derivatives, carboxymethylcellulose (CMC), carboxymethyl-starch and carboxymethyl-chitin/chitosan, can be crosslinked under certain radiation condition and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  16. Beam Energy Scan at RHIC and z-Scaling

    International Nuclear Information System (INIS)

    Beam Energy Scan (BES) data obtained at RHIC are briefly reviewed. Method of data analysis (z-scaling approach) based on self-similarity and locality of constituent interactions in hadron and nucleus collisions at high energy is described. The method is applied for analysis of BES data to search for signatures of phase transition and Critical Point (CP). Some results of analysis of hadron spectra measured in heavy ion collisions (HIC) at RHIC over a wide range of the energy √(sNN)=7.7–200 GeV are presented. Microscopic scenario of constituent interactions in the framework of this approach is discussed. Dependence of the energy loss on the momentum of the produced hadron, energy and centrality of the collision is studied. Self-similarity of the constituent interactions in terms of momentum fractions is used to characterize the nuclear medium by a “specific heat” and the colliding nuclei by fractal dimensions. Kinematic regions which are assumed to be most preferable for search for signatures of phase transition of nuclear matter produced in HIC in BES are discussed

  17. Transport of intense proton beam in the presence of subdominant species in a low energy beam transport system

    Science.gov (United States)

    Babu, P. Sing; Goswami, A.; Pandit, V. S.

    2016-04-01

    The dynamics of space-charge-dominated low energy proton beam in the presence of H2+ and H3+ beams has been studied in a solenoid based transport system using particle-in-cell (PIC) simulation method. Multispecies envelope equation and random search technique have been used to transport and match the primary beam considering two options. The PIC simulation shows the formation of hollow distribution of H2+ and H3+ beams around the proton beam in the first case where the waist of the proton beam is formed in between the solenoids and it is absent in the second case where the beam size is kept large in between the solenoids. Separation of hollow distribution appears more distinct as the proton fraction is increased and is almost independent of the combination of H2+ and H3+ beams for a given proton fraction. This effect helps to reject the unwanted species more effectively. The evolution of rms size and emittance of the proton beam has been studied in the presence of a circular aperture using KV and Gaussian distributions for the species in both the cases.

  18. Online beam energy measurement of Beijing electron positron collider II linear accelerator

    Science.gov (United States)

    Wang, S.; Iqbal, M.; Liu, R.; Chi, Y.

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

  19. Effect of fluoroscopic X-ray beam spectrum on air-kerma measurement accuracy: implications for establishing correction coefficients on interventional fluoroscopes with KAP meters.

    Science.gov (United States)

    Wunderle, Kevin A; Rakowski, Joseph T; Dong, Frank F

    2016-01-01

    The first goal of this study was to investigate the accuracy of the displayed reference plane air kerma (Ka,r) or air kerma-area product (Pk,a) over a broad spectrum of X-ray beam qualities on clinically used interventional fluoroscopes incorporating air kerma-area product meters (KAP meters) to measure X-ray output. The second goal was to investigate the accuracy of a correction coefficient (CC) determined at a single beam quality and applied to the measured Ka,r over a broad spectrum of beam qualities. Eleven state-of-the-art interventional fluoroscopes were evaluated, consisting of eight Siemens Artis zee and Artis Q systems and three Philips Allura FD systems. A separate calibrated 60 cc ionization chamber (external chamber) was used to determine the accuracy of the KAP meter over a broad range of clinically used beam qualities. For typical adult beam qualities, applying a single CC deter-mined at 100 kVp with copper (Cu) in the beam resulted in a deviation of < 5% due to beam quality variation. This result indicates that applying a CC determined using The American Association of Physicists in Medicine Task Group 190 protocol or a similar protocol provides very good accuracy as compared to the allowed ± 35% deviation of the KAP meter in this limited beam quality range. For interventional fluoroscopes dedicated to or routinely used to perform pediatric interventions, using a CC established with a low kVp (~ 55-60 kVp) and large amount of Cu filtration (~ 0.6-0.9 mm) may result in greater accuracy as compared to using the 100 kVp values. KAP meter responses indicate that fluoroscope vendors are likely normalizing or otherwise influencing the KAP meter output data. Although this may provide improved accuracy in some instances, there is the potential for large discrete errors to occur, and these errors may be difficult to identify. PMID:27167287

  20. Spallation Neutron Energy Spectrum Determination with Yttrium as a Threshold Detector on U/Pb-assembly "Energy plus Transmutation"

    Czech Academy of Sciences Publication Activity Database

    Kilim, S.; Bielewicz, M.; Strugalska-Gola, E.; Szuta, M.; Wojciechowski, A.; Krivopustov, M. I.; Kovalenko, A.D.; Adam, Jindřich; Krása, Antonín; Majerle, Mitja; Wagner, Vladimír

    Dordrecht : SPRINGER, PO BOX 17, 3300 AA DORDRECHT, 2009, s. 343-352. ISBN 978-90-481-2285-1. ISSN 1871-465X. [NATO Advanced Research Workshop on Safe Nuclear Energy. Yalta (UA), 27.09.2008-02.10.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : Spallation * neutron energy spectrum * Energy plus Transmutation Subject RIV: BG - Nuclear , Atomic and Molecular Physics, Colliders

  1. An Energy-Efficient Game-Theory-Based Spectrum Decision Scheme for Cognitive Radio Sensor Networks

    Directory of Open Access Journals (Sweden)

    Shelly Salim

    2016-06-01

    Full Text Available A cognitive radio sensor network (CRSN is a wireless sensor network in which sensor nodes are equipped with cognitive radio. In this paper, we propose an energy-efficient game-theory-based spectrum decision (EGSD scheme for CRSNs to prolong the network lifetime. Note that energy efficiency is the most important design consideration in CRSNs because it determines the network lifetime. The central part of the EGSD scheme consists of two spectrum selection algorithms: random selection and game-theory-based selection. The EGSD scheme also includes a clustering algorithm, spectrum characterization with a Markov chain, and cluster member coordination. Our performance study shows that EGSD outperforms the existing popular framework in terms of network lifetime and coordination overhead.

  2. An Energy-Efficient Game-Theory-Based Spectrum Decision Scheme for Cognitive Radio Sensor Networks.

    Science.gov (United States)

    Salim, Shelly; Moh, Sangman

    2016-01-01

    A cognitive radio sensor network (CRSN) is a wireless sensor network in which sensor nodes are equipped with cognitive radio. In this paper, we propose an energy-efficient game-theory-based spectrum decision (EGSD) scheme for CRSNs to prolong the network lifetime. Note that energy efficiency is the most important design consideration in CRSNs because it determines the network lifetime. The central part of the EGSD scheme consists of two spectrum selection algorithms: random selection and game-theory-based selection. The EGSD scheme also includes a clustering algorithm, spectrum characterization with a Markov chain, and cluster member coordination. Our performance study shows that EGSD outperforms the existing popular framework in terms of network lifetime and coordination overhead. PMID:27376290

  3. A new neutron energy spectrum unfolding code using a two steps genetic algorithm

    Science.gov (United States)

    Shahabinejad, H.; Hosseini, S. A.; Sohrabpour, M.

    2016-03-01

    A new neutron spectrum unfolding code TGASU (Two-steps Genetic Algorithm Spectrum Unfolding) has been developed to unfold the neutron spectrum from a pulse height distribution which was calculated using the MCNPX-ESUT computational Monte Carlo code. To perform the unfolding process, the response matrices were generated using the MCNPX-ESUT computational code. Both one step (common GA) and two steps GAs have been implemented to unfold the neutron spectra. According to the obtained results, the new two steps GA code results has shown closer match in all energy regions and particularly in the high energy regions. The results of the TGASU code have been compared with those of the standard spectra, LSQR method and GAMCD code. The results of the TGASU code have been demonstrated to be more accurate than that of the existing computational codes for both under-determined and over-determined problems.

  4. Factorization with a logarithmic energy spectrum of a two-dimensional potential

    Energy Technology Data Exchange (ETDEWEB)

    Gleisberg, F., E-mail: ferdinand.gleisberg@uni-ulm.de [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology, IQ" S" T, Universität Ulm, D-89069 Ulm (Germany); Volpp, M. [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology, IQ" S" T, Universität Ulm, D-89069 Ulm (Germany); Schleich, W.P. [Institut für Quantenphysik and Center for Integrated Quantum Science and Technology, IQ" S" T, Universität Ulm, D-89069 Ulm (Germany); Texas A & M University Institute for Advanced Study (TIAS), Institute for Quantum Studies and Engineering (IQSE) and Department of Physics and Astronomy, Texas A & M University, College Station, TX 77843-4242 (United States)

    2015-10-23

    We propose a method to factor numbers using a single particle caught in a separable two-dimensional potential with a logarithmic energy spectrum. The particle initially prepared in the ground state is excited with high probability by a sinusoidally time-dependent perturbation into a state whose two quantum numbers represent the factors of a number encoded in the frequency of the perturbation. We discuss the limitations of our method arising from off-resonant transitions and from decoherence. - Highlights: • A new protocol for factorization of an integer into two primes is proposed. • We report an energy spectrum optimally adapted for the factorization. • A potential for our single particle spectrum was calculated numerically. • We determined a Rabi frequency for the transition into the factor state. • An explicit limit caused by decoherence for numbers to be factored is reported.

  5. Factorization with a logarithmic energy spectrum of a two-dimensional potential

    International Nuclear Information System (INIS)

    We propose a method to factor numbers using a single particle caught in a separable two-dimensional potential with a logarithmic energy spectrum. The particle initially prepared in the ground state is excited with high probability by a sinusoidally time-dependent perturbation into a state whose two quantum numbers represent the factors of a number encoded in the frequency of the perturbation. We discuss the limitations of our method arising from off-resonant transitions and from decoherence. - Highlights: • A new protocol for factorization of an integer into two primes is proposed. • We report an energy spectrum optimally adapted for the factorization. • A potential for our single particle spectrum was calculated numerically. • We determined a Rabi frequency for the transition into the factor state. • An explicit limit caused by decoherence for numbers to be factored is reported

  6. An Energy-Efficient Game-Theory-Based Spectrum Decision Scheme for Cognitive Radio Sensor Networks

    Science.gov (United States)

    Salim, Shelly; Moh, Sangman

    2016-01-01

    A cognitive radio sensor network (CRSN) is a wireless sensor network in which sensor nodes are equipped with cognitive radio. In this paper, we propose an energy-efficient game-theory-based spectrum decision (EGSD) scheme for CRSNs to prolong the network lifetime. Note that energy efficiency is the most important design consideration in CRSNs because it determines the network lifetime. The central part of the EGSD scheme consists of two spectrum selection algorithms: random selection and game-theory-based selection. The EGSD scheme also includes a clustering algorithm, spectrum characterization with a Markov chain, and cluster member coordination. Our performance study shows that EGSD outperforms the existing popular framework in terms of network lifetime and coordination overhead. PMID:27376290

  7. Use of off-axis injection as an alternative to geometrically merging beams in an energy-recovering linac

    Science.gov (United States)

    Douglas, David R.

    2012-01-10

    A method of using off-axis particle beam injection in energy-recovering linear accelerators that increases operational efficiency while eliminating the need to merge the high energy re-circulating beam with an injected low energy beam. In this arrangement, the high energy re-circulating beam and the low energy beam are manipulated such that they are within a predetermined distance from one another and then the two immerged beams are injected into the linac and propagated through the system. The configuration permits injection without geometric beam merging as well as decelerated beam extraction without the use of typical beamline elements.

  8. Hard x-ray to low energy gamma ray spectrum of the Crab Nebula

    International Nuclear Information System (INIS)

    The spectrum of the Crab Nebula has been determined in the energy range 10 keV to 5 MeV from the data of the UCSD/MIT Hard-X-ray and Low Energy Gamma Ray Experiment on the first High Energy Astronomy Observatory, HEAO-1. The x-ray to γ-ray portion of the continuous emission from the Crab is indicative of the electron spectrum, its transport through the nebula, and the physical conditions near the shocked interface between the nebular region and the wind which is the physical link between the nebula and the pulsar, NP0532. The power-law dependence of the spectrum found in the lower-energy decade of this observation (10 to 100 keV) is not continued without modification to higher energies. Evidence for this has been accumulating from previous observations in the γ-ray ranges of 1-10 MeV and above 35 MeV. The observations on which this dissertation is based further characterize the spectral change in the 100 keV to 1 MeV region. These observations provide a crucial connection between the x-ray and γ-ray spectrum of the non-pulsed emission of the Crab Nebula. The continuity of this spectrum suggests that the emission mechanism responsible for the non-pulsed γ-rays observed above 35 MeV is of the same origin as the emission at lower energies, i.e. that of synchrotron radiation in the magnetic field of the nebula

  9. Measurements of electric field intensities and of the spectrum of electric fluctuations in relativistic electron beam driven turbulent plasma

    International Nuclear Information System (INIS)

    Laser induced fluorescence is used to obtain data for determining magnitudes and fluctuation spectra of local electric fields within a turbulent plasma. A 600 keV, 15 ka, 1 μs, 50 ns risetime electron beam is injected into a 20 cm diameter, 60 cm long polycarbonate drift tube containing 10/sup 13/ cm /sup -3/ hydrogen or helium plasmas, constrained by a 2 kgauss axial magnetic field. The transfer of beam kinetic energy to resonant plasma modes is accompanied by large, local electric fields, the average magnitude and fluctuation spectra of which cannot be measured by physical probes. A small plasma gun containing alkaline earth carbonates is used to create plasma doped with appropriate ions, or a small 10 kV electron source is used to ionize 1 mtorr of helium gas in the drift tube. The doping ions or the helium atoms and ions are then excited by laser photons to levels sensitive to the Stark effect or to levels that yield electric field stimulated optical transitions in the vicinity of forbidden lines. A 20 MW, 20 ns XeCl excimer laser is used to pump various dyes to achieve the necessary wavelengths and photon fluxes for these experiments

  10. Particle-in-cell mode beam dynamics simulation of the low energy beam transport for the SSC-linac injector

    Institute of Scientific and Technical Information of China (English)

    XIAO Chen; HE Yuan; YUAN You-Jin; YAO Qing-Gao; WANG Zhi-Jun; CHANG Wei; LIU Yong; XIA Jia-Wen

    2011-01-01

    A new SSC-linac system (injector into separated sector cyclotron) is being designed in the HIRFL (heavy ion research facility of Lanzhou). As part of SSC-Linac, the LEBT (low energy beam transport) consists of seven solenoids, four quadrupoles, a bending magnet and an extra multi-harmonic buncher. The total length of this segment is about 7 meters. The beam dynamics in this LEBT has been studied using three-dimensional PIC (particle-in-cell) code BEAMPATH. The simulation results show that the continuous beam from the ion source is first well analyzed by a charge-to-mass selection system, and the beam of the selected charge-to-mass ratio is then efficiently pre-bunched by a multi-harmonic buncher and optimally matched into the RFQ (radio frequency quadrupole) for further acceleration. The principles and effects of the solenoid collimation channel are discussed, and it could limit the beam emittance by changing the aperture size.

  11. Beam structure and transverse emittance studies of high-energy ion beams

    International Nuclear Information System (INIS)

    A visual diagnostic technique has been developed to monitor and study ion-beam structure, shape, and size along a transport line. In this technique, a commercially available fluorescent screen is used in conjunction with a video camera. The visual representation of the beam structure is digitized enhanced through false-color coding, and displayed on a TV monitor for on-line viewing. The digitized information is stored for further off-line processing (e.g.,extraction of beam profiles). An optional wire grid placed upstream of the fluor screen adds the capability of measuring transverse emittance (or angular spread). This technique allows real-time observation of the beam response to parameter changes (e.g., evolution of the beam structure, shifts in the beam intensity at various spatial locations within the beam perimeter, and shifts in the beam center and position)

  12. A two-stage spectrum sensing scheme based on energy detection and a novel multitaper method

    Institute of Scientific and Technical Information of China (English)

    齐佩汉; 李赞; 司江勃; 熊天意

    2015-01-01

    Wideband spectrum sensing has drawn much attention in recent years since it provides more opportunities to the sec-ondary users. However, wideband spectrum sensing requires a long time and a complex mechanism at the sensing terminal. A two-stage wideband spectrum sensing scheme is considered to proceed spectrum sensing with low time consumption and high performance to tackle this predicament. In this scheme, a novel multitaper spectrum sensing (MSS) method is proposed to mitigate the poor performance of energy detection (ED) in the low signal-to-noise ratio (SNR) region. The closed-form expression of the decision threshold is derived based on the Neyman–Pearson criterion and the probability of detection in the Rayleigh fading channel is analyzed. An optimization problem is formulated to maximize the probability of detection of the proposed two-stage scheme and the average sensing time of the two-stage scheme is analyzed. Numerical results validate the efficiency of MSS and show that the two-stage spectrum sensing scheme enjoys higher performance in the low SNR region and lower time cost in the high SNR region than the single-stage scheme.

  13. On the infimum of the energy-momentum spectrum of a homogeneous Bose gas

    DEFF Research Database (Denmark)

    Cornean, Horia; Derezinski, J.; Zin, P.

    2009-01-01

    We consider second-quantized homogeneous Bose gas in a large cubic box with periodic boundary conditions at zero temperature. We discuss the energy-momentum spectrum of the Bose gas and its physical significance. We review various rigorous and heuristic results as well as open conjectures about its...

  14. Future of the Beam Energy Scan program at RHIC

    International Nuclear Information System (INIS)

    The first exploratory phase of a very successful Beam Energy Scan Program at RHIC was completed in 2014 with Au+Au collisions at energies ranging from 7 to 39 GeV. Data sets taken earlier extended the upper limit of energy range to the √sNN of 200 GeV. This provided an initial look into the uncharted territory of the QCD phase diagram, which is considered to be the single most important graph of our field. The main results from BES phase I, although effected by large statistical errors (steeply increasing with decreasing energy), suggest that the highest potential for discovery of the QCD Critical Point lies bellow √sNN 20 GeV. Here, we discuss the plans and the preparation for phase II of the BES program, with an order of magnitude larger statistics, which is planned for 2018-2019. The BES II will focus on Au+Au collisions at √sNN from 20 to 7 GeV in collider mode, and from √sNN 7 to 3.5 GeV in the fixed target mode, which will be run concurrently with the collider mode operation

  15. Method for measuring prompt fission neutron energy spectrum by means of threshold activation detectors

    International Nuclear Information System (INIS)

    Prompt fission neutron energy spectrum as a function of energies of neutron inducing fission has been calculated on the basis of the Madland-Nix(MN) model. The resultant spectra have been weighted to excitation functions of 27Al(n,α), 32S(n,p) and 115In(n,n) threshold reactions in order to get the average cross sections and then spectral indices which are defined as the average cross section ratio for two selective threshold reactions among the above three. It is appeared that spectral indices together with the neutron spectra are varying with energies of neutron inducing fission. This may indicate that the prompt fission neutron energy spectrum can be determined by measuring experimentally the spectral index.(Author)

  16. Influence of the beam energy on the sensitivity of the PIXE methods applied to the detection of Pb in air

    International Nuclear Information System (INIS)

    The air pollution by lead at the downtown area of Buenos Aires city was studied applying the PIXE method. The samples were collected at different seasons of the year. An appreciable reduction of the Pb content was observed on holidays and in summer when there is a lot less of cars in the streets. The influence of the beam energy on the Bremsstrahlung background was studied in order to optimize the sensitivity of the method. The C-12 beam energy was varied from 54 MeV to 30 MeV. The maximum Bremsstrahlung energy of secondary electrons decreased from 10 keV to 5.5 keV. Simultaneously the background radiation was appreciably reduced in the whole spectrum for the lowest beam energy whereas the values for the cross section of X ray production in the Pb L shell were no substantially modified. It is concluded that it is possible to analyze those elements whose characteristic X rays have an energy larger than 5.5 keV. (Author)

  17. Determination of the Spectral Index in the Fission Spectrum Energy Regime

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Amy Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-16

    Neutron reaction cross sections play a vital role in tracking the production and destruction of isotopes exposed to neutron fluence. They are central to the process of reconciling the initial and final atom inventories. Measurements of irradiated samples by radiochemical methods in tangent with an algorithm are used to evaluate the fluence a sample is exposed to over the course of the irradiation. This algorithm is the Isotope Production Code (IPC) created and used by the radiochemistry data assessment team at Los Alamos National Laboratory (LANL). An integral result is calculated by varying the total neutron fluence seen by a sample. A sample, irradiated in a critical assembly, will be exposed to a unique neutron flux defined by the neutron source and distance of the sample from the source. Neutron cross sections utilized are a function of the hardness of the neutron spectrum at the location of irradiation. A spectral index is used an indicator of the hardness of the neutron spectrum. Cross sections fit forms applied in IPC are collapsed from a LANL 30-group energy structure. Several decades of research and development have been performed to formalize the current IPC cross section library. Basis of the current fission spectrum neutron reaction cross section library is rooted in critical assembly experiments performed from the 1950’s through the early 1970’s at LANL. The focus of this report is development of the spectral index used an indicator of the hardness of the neutron spectrum in the fission spectrum energy regime.

  18. Power Versus Spectrum 2-D Sensing in Energy Harvesting Cognitive Radio Networks

    Science.gov (United States)

    Zhang, Yanyan; Han, Weijia; Li, Di; Zhang, Ping; Cui, Shuguang

    2015-12-01

    Energy harvester based cognitive radio is a promising solution to address the shortage of both spectrum and energy. Since the spectrum access and power consumption patterns are interdependent, and the power value harvested from certain environmental sources are spatially correlated, the new power dimension could provide additional information to enhance the spectrum sensing accuracy. In this paper, the Markovian behavior of the primary users is considered, based on which we adopt a hidden input Markov model to specify the primary vs. secondary dynamics in the system. Accordingly, we propose a 2-D spectrum and power (harvested) sensing scheme to improve the primary user detection performance, which is also capable of estimating the primary transmit power level. Theoretical and simulated results demonstrate the effectiveness of the proposed scheme, in term of the performance gain achieved by considering the new power dimension. To the best of our knowledge, this is the first work to jointly consider the spectrum and power dimensions for the cognitive primary user detection problem.

  19. Beam and spin dynamics of hadron beams in intermediate-energy ring accelerators

    International Nuclear Information System (INIS)

    In this thesis beam and spin dynamics of ring accelerators are described. After a general theoretical treatment methods for the beam optimization and polarization conservation are discussed. Then experiments on spin manipulation at the COSY facility are considered. Finally the beam simulation and accelerator lay-out for the HESR with regards to the FAIR experiment are described. (HSI)

  20. Spin diffusion in an inhomogeneous internal field (non equidistant energy spectrum)

    OpenAIRE

    Furman, Gregory B.; Goren, Shaul D.

    2004-01-01

    The theory of spin diffusion is extended to the case of spin lattice relaxation and spin diffusion in an inhomogeneous field in spin systems with non-equidistant energy spectrum. Two coupled equations describing the mutual relaxation and the spin diffusion of the nuclear magnetization and dipolar energy were obtained by using the method of nonequilibrium state operator. The equations were solved for short and long times approximation corresponding to the direct and diffusion relaxation regimes.

  1. The Ultra-High Energy Cosmic Ray Spectrum Measured by the Telescope Array's Middle Drum Detector

    OpenAIRE

    Rodriguez, Douglas; Collaboration, Matt Wood for the Telescope Array

    2011-01-01

    The Telescope Array's Middle Drum fluorescence detector was constructed using refurbished telescopes from the High Resolution Fly's Eye (HiRes) experiment. As such, there is a direct comparison between these two experiments' fluorescence energy spectra. An energy spectrum has been calculated based on one year of collected data by the Middle Drum site of Telescope Array and agrees well with the HiRes monocular spectra. The quality of the Middle Drum results has also been determined to show goo...

  2. A Fractal Scheme for Interaction Probabilities and the High Energy Cosmic Ray Spectrum

    International Nuclear Information System (INIS)

    The present article is an attempt to provide a parametrization of particle production for the extreme energy range combining a fractal scheme for interaction probabilities and the observed power law energy spectrum for cosmic ray particles. As a first result towards a genuine transition matrix we conclude that for a scaling factor of d ∼ 2 the matrix element vertical bar Mk vertical bar ∝ √(Y(k))Ek5

  3. Primary CR energy spectrum and mass composition by the data of Tunka-133 array

    Directory of Open Access Journals (Sweden)

    Prosin V.V.

    2015-01-01

    Full Text Available The Cherenkov light array for the registration of extensive air showers (EAS Tunka-133 collected data during 5 winter seasons from 2009 to 2014. The differential energy spectrum of all particles and the dependence of the average maximum depth on the energy in the range of 6 ⋅ 1015–1018 eV measured for 1540 hours of observation are presented.

  4. Design of energy spectrum device for radon measuring with electrostatic collection method

    International Nuclear Information System (INIS)

    Background: This research is to take energy spectrum of α particle into consideration in the measurement of radon. Purpose: We aim to find the influence factors of screening particle energy. during the process of detector design. Methods: Based on the electrostatic collection radon measurement method, in order to study the influence factors of the measurement such as aluminum foil and air layer, the reasonable radiation source and geometric model are abstracted and calculated with Geant4 software. Results: The best ranges of aluminum foil thickness and air layer thickness are obtained by analyzing their relationship with a energy, the Full Width at Half Maximum (FWHM), the energy resolution, the distance of peaks and the peaks screening power. Conclusion: With the results adopted above, the energy spectrum device is fabricated. Based on the α energy spectrum sampled in a radon chamber, the validity of this design has been proved. It provides a set of reliable data for the design of radon measuring device with electrostatic collection method. (authors)

  5. TIBER II [Tokamak Ignition/Burn Experimental Reactor] parameters with neutral beams at high energies

    International Nuclear Information System (INIS)

    The baseline neutral beam energy for TIBER II was chosen to be 500 keV consistent with the use of near term dc acceleration technology. Adequate penetration to the axis for core current drive in larger ETR devices requires higher beam energies. However, beam instabilities may limit the current drive efficiency at high energy to lower values than predicted classically. The characteristics of TIBER II and a device with 4.5 m major radius as functions of beam energy are presented. 11 refs

  6. Scheme for Low Energy Beam Transport with a Non-Neutralized Section

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Prost, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-04-23

    A typical Low Energy Beam Transport (LEBT) design relies on dynamics with nearly complete beam space charge neutralization over the entire length of the LEBT. This paper argues that, for a beam with modest perveance and uniform current density distribution when generated at the source, a downstream portion of the LEBT can be un-neutralized without significant emittance growth.

  7. The KASCADE-Grande experiment: measurements of the all-particle energy spectrum of cosmic rays

    CERN Document Server

    Arteaga-Velázquez, J C; Bekk, K; Bertaina, M; Blümer, J; Bozdog, H; Brancus, I M; Buchholz, P; Cantoni, E; Chiavassa, A; Cossavella, F; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Finger, M; Fuhrmann, D; Ghia, P L; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Huege, T; Isar, P G; Kampert, K -H; Kickelbick, D; Klages, H O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Navarra, G; Nehls, S; Oehlschläger, J; Ostapchenko, S; Over, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schröder, F; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, J; Wommer, M; Zabierowski, J

    2010-01-01

    The all-particle energy spectrum as measured by the KASCADE-Grande experiment for E = 10^{16} - 10^{18} eV is presented within the framework of the QGSJET II/FLUKA hadronic interaction models. Three different methods were applied based on the muon size and the total number of charged particles individually and in combination. From the study it is found that the spectrum cannot be completely described by a smooth power law due to the presence of characteristic features.

  8. Measurement of the Solar Neutrino Energy Spectrum Using Neutrino-Electron Scattering

    International Nuclear Information System (INIS)

    A measurement of the energy spectrum of recoil electrons from solar neutrino scattering in the Super-Kamiokande detector is presented. The results shown here were obtained from 504 days of data taken between 31 May 1996 and 25 March 1998. The shape of the measured spectrum is compared with the expectation for solar 8B neutrinos. The comparison takes into account both kinematic and detector related effects in the measurement process. The spectral shape comparison between the observation and the expectation gives a χ2 of 25.3 with 15 degrees of freedom, corresponding to a 4.6% confidence level. copyright 1999 The American Physical Society

  9. Beam energy loss to parasitic modes in SPEAR II

    International Nuclear Information System (INIS)

    The energy loss due to the excitation of parasitic modes in the SPEAR II rf cavities and vacuum chamber components has been measured by observing the shift in synchronous phase angle as a function of circulating beam current and accelerating cavity voltage. The resulting parasitic mode loss resistance is 5 Mω at a bunch length of 6.5 cm. The loss resistance varies with bunch length σ/sub z/ approximately as exp(/minus/0.3 σ/sub z/). If the measured result is compared with reasonable theoretical predictions, we infer that the major portion of the parasitic loss takes place in ring vacuum components rather than in the rf cavities. 7 refs., 5 figs., 2 tabs

  10. Energy deposition studies for the LBNE beam absorber

    Energy Technology Data Exchange (ETDEWEB)

    Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

    2015-01-29

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  11. Energy deposition studies for the LBNE beam absorber

    CERN Document Server

    Rakhno, Igor L; Tropin, Igor S

    2015-01-01

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system -- all with corresponding radiation shielding -- was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  12. Realistic modeling of microwave instability effects on the evolution of the beam energy-phase distribution in proton synchrotrons

    International Nuclear Information System (INIS)

    Either bunched or coasting beam in a synchrotron may exhibit microwave instability of the momentum spread is small. A useful physical picture is that beam particles are captured in buckets generated by the beam image current flowing in the longitudinal coupling impedance. Qualitatively, trapping and auto-deceleration occur when the height of the buckets exceed the FWHM energy spread of the beam. Microwave instability implies in addition that the coupling impedance is largest at several times the rf frequency and that the decay of the wakefield is fast enough that bunches do not affect each other. The parameters used in this paper are influenced by the Fermilab Main Ring and design of the Main Injector. The numerical modeling uses standard features of the code ESME. In most of the reported simulations 2 · 104 macroparticles and 32 values of n separated by 1113 provide the current spectrum. Microwave instability may be an intensity limitation during parts of the acceleration cycle where the beam is debunched or loosely bunched, perhaps at injection or high duty factor extraction. Probably of more general importance is the time near transition when the spread in circulation frequency is sharply reduced, i.e., when η ∼ 0. Concrete examples are given in this report

  13. Precise beam energy measurement using resonant spin depolarization in the SOLEIL storage ring

    International Nuclear Information System (INIS)

    The average electron beam energy for the operational mode of 400 mA in 416 bunches in the SOLEIL storage ring was measured to be 2.73724±0.00016 GeV with an accuracy of 5.9×10−5 using the method of resonant spin depolarization (RSD). A Touschek-dominated electron beam was excited using a shaker magnet, and the beam polarization and depolarization were monitored using the change in beam lifetime and beam loss rate. To establish the primary condition that is required to perform energy measurement using the RSD method, the radiative beam polarization was first simulated using the SLIM beam dynamics code and then measured using the relative increase of beam lifetime for a Touschek-dominated electron beam. With a fast frequency sweep rate, the main depolarization resonance to be used to extract the beam energy, along with sidebands within the range of frequency sweep, was identified during our first trials. Sweeping the frequency of the excitation field around the main resonance with a slower frequency sweep rate, the beam energy measurement accuracy was increased from 1.7×10−4 to 5.9×10−5. Finally, the effects of closed orbit distortions on the radiative polarization and measured energy accuracy are discussed.

  14. Results from the STAR Beam Energy Scan Program

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Lokesh [Department of Physics, Kent State University (United States)

    2011-07-15

    The main aim of the beam energy scan (BES) program at the Relativistic Heavy-Ion Collider (RHIC) is to explore the quantum chromodynamics (QCD) phase diagram. The specific physics goal is to search for the phase boundary and the QCD critical point. We present results from Au+Au collisions at various energies collected in the BES program by the Solenoidal Tracker At RHIC (STAR) experiment. First results on transverse momentum (p{sub T}) spectra, dN/dy, and average transverse mass () for identified hadrons produced at mid-rapidity for {radical}(s{sub NN})=7.7 GeV are presented. Centrality dependence of dN/dy and are also discussed and compared to corresponding data from other energies. In addition, first results on charged hadron directed (v{sub 1}) and elliptic flow (v{sub 2}) for {radical}(s{sub NN})=7.7, 11.5 and 39 GeV are presented. New results on event-by-event fluctuations (particle ratio, net-proton and net-charge higher moments) are presented for {radical}(s{sub NN})=39 GeV.

  15. Beam energy scan using a viscous hydro+cascade model

    CERN Document Server

    Karpenko, Iu A; Huovinen, P; Petersen, H

    2013-01-01

    Following the experimental program at BNL RHIC, we perform a similar "energy scan" using 3+1D viscous hydrodynamics coupled to the UrQMD hadron cascade, and study the collision energy dependence of pion and kaon rapidity distributions and $m_T$-spectra, as well as charged hadron elliptic flow. To this aim the equation of state for finite baryon density from a Chiral model coupled to the Polyakov loop is employed for hydrodynamic stage. 3D initial conditions from UrQMD are used to study gradual deviation from boost-invariant scaling flow. We find that the inclusion of shear viscosity in the hydrodynamic stage of evolution consistently improves the description of the data for Pb-Pb collisions at CERN SPS, as well as of the elliptic flow measurements for Au-Au collisions in the Beam Energy Scan (BES) program at BNL RHIC. The suggested value of shear viscosity is $\\eta/s\\ge0.2$ for $\\sqrt{s_{NN}}=6.3\\dots39$ GeV.

  16. STAR Results from the RHIC Beam Energy Scan-I

    CERN Document Server

    ,

    2012-01-01

    The Beam Energy Scan (BES) program is being pursued at RHIC to study the QCD phase diagram, and search for the possible QCD phase boundary and possible QCD critical point. The data for Phase-I of the BES program have been collected for Au+Au collisions at center-of-mass energies ($\\sqrt{s_{NN}}$) of 7.7, 11.5, 19.6, 27, and 39 GeV. These collision energies allowed the STAR experiment to cover a wide range of baryon chemical potential $\\mu_{B}$ (100--400 MeV) in the QCD phase diagram. We report on several interesting results from the BES Phase-I covering the high net-baryon density region. These results shed light on particle production mechanism and freeze-out conditions, first-order phase transition and "turn-off" of QGP signatures, and existence of a critical point in the phase diagram. Finally, we give an outlook for the future BES Phase-II program and a possible fixed target program at STAR.

  17. Results from the STAR Beam Energy Scan Program

    CERN Document Server

    Kumar, Lokesh

    2011-01-01

    The main aim of the beam energy scan (BES) program at the Relativistic Heavy-Ion Collider (RHIC) is to explore the quantum chromodynamics (QCD) phase diagram. The specific physics goal is to search for the phase boundary and the QCD critical point. We present results from Au+Au collisions at various energies collected in the BES program by the Solenoidal Tracker At RHIC (STAR) experiment. First results on transverse momentum ($p_{T}$) spectra, $dN/dy$, and average transverse mass ($$) for identified hadrons produced at mid-rapidity for $\\sqrt{s_{NN}}$ = 7.7 GeV are presented. Centrality dependence of $dN/dy$ and $$ are also discussed and compared to corresponding data from other energies. In addition, first results on charged hadron directed ($v_{1}$) and elliptic flow ($v_{2}$) for $\\sqrt{s_{NN}}=$ 7.7, 11.5, and 39 GeV are presented. New results on event-by-event fluctuations (particle ratio, net-proton and net-charge higher moments) are presented for $\\sqrt{s_{NN}}=$ 39 GeV.

  18. Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF

    International Nuclear Information System (INIS)

    Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe (Δx ∼ 10μm), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10-3 beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 μA to 100 μA

  19. Low-energy run of Fermilab Electron Cooler's beam generation system

    Energy Technology Data Exchange (ETDEWEB)

    Prost, Lionel; Shemyakin, Alexander; /Fermilab; Fedotov, Alexei; Kewisch, Jorg; /Brookhaven

    2010-08-01

    As a part of a feasibility study of using the Fermilab Electron Cooler for a low-energy Relativistic Heavy Ion Collider (RHIC) run at Brookhaven National Laboratory (BNL), the cooler operation at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main result of the study is that the cooler beam generation system is suitable for BNL needs. In a striking difference with running 4.3 MeV beam, no unprovoked beam recirculation interruptions were observed.

  20. Development of Ultra Small Shock Tube for High Energy Molecular Beam Source

    Science.gov (United States)

    Miyoshi, Nobuya; Nagata, Shuhei; Kinefuchi, Ikuya; Shimizu, Kazuya; Takagi, Shu; Matsumoto, Yoichiro

    2008-12-01

    A molecular beam source exploiting a small shock tube is described for potential generation of high energy beam in a range of 1-5 eV without any undesirable impurities. The performance of a non-diaphragm type shock tube with an inner diameter of 2 mm was evaluated by measuring the acceleration and attenuation process of shock waves. With this shock tube installed in a molecular beam source, we measured the time-of-flight distributions of shock-heated beams, which demonstrated the ability of controlling the beam energy with the initial pressure ratio of the shock tube.

  1. High-Energy Beam Transport in the Hanford FMIT Linear Accelerator

    International Nuclear Information System (INIS)

    The High-Energy Beam Transport (HEBT) for the Hanford Fusion Materials Irradiation Test (FMIT) Facility's Linear Accelerator must transport a large emittance, high-current, high-power continuous duty deuteron beam with a large energy spread. Both periodic and nonperiodic systems have been designed to transport and shape the beam as required by the liquid lithium target. An energy spreader system distributes the Bragg Peak within the lithium. A beam spreader and a beam stop have been provided for tune-up purposes. Characterizing the beam will require extensions of beam diagnostics techniques and non-interceptive sensors. Provisions are being made in the facility for suspending the transport system from overhead supports

  2. Energy spectrum of cosmic rays as derived from GPS-synchronized EAS array experiments

    International Nuclear Information System (INIS)

    Using data from 2.5 years of observations with the Large Area Air Shower (LAAS) experiments in Okayama area, we report the cosmic ray energy spectrum obtained by applying cuts on the number of coincidences of 4 extensive air shower (EAS) arrays, which are synchronized by GPS time stamp system with an accuracy of 1 μs. The spectral indices in the energy ranges of 1015 - 1016eV and 1016 - 1018eV are obtained and are consistent with assumed ones within statistical errors. The methods to determine the energy spectrum without evaluating the parameters for each individual EAS in each LAAS array, are reported in this paper. The performances of each single array are simulated as well as those of multiple arrays coincident within a several μs time interval

  3. Neutron energy flux spectrum measurements for LEU core of PARR-1

    International Nuclear Information System (INIS)

    The Pakistan Research Reactor-1 has been converted and upgraded from highly enriched uranium (HEU) to low enriched uranium (LEU) fuel from 5 to 9 MW. An experimental programme was undertaken to measure the neutron energy spectra in the core and at the irradiation facilities of the new core. several threshold activation detectors were irradiated and activity of the foils was measured using high efficiency HPGe gamma ray spectroscopy system. The measured saturation activities were used in the spectrum adjustment computer code SANDBP. A sample energy spectrum for the material test reactor supplied by the International Atomic Energy Agency (IAEA) was used as the input to the SANDBP code, and the final spectra were obtained by iterative adjustment. (author) 7 figs

  4. Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

    Science.gov (United States)

    Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

    2016-05-23

    The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. PMID:27062543

  5. Spectrum and energy levels of five-times ionized zirconium (Zr VI)

    Science.gov (United States)

    Reader, Joseph; Lindsay, Mark D.

    2016-02-01

    We carried out a new analysis of the spectrum of five-times-ionized zirconium Zr VI. For this we used sliding-spark discharges together with normal- and grazing-incidence spectrographs to observe the spectrum from 160 to 2000 Å. These observations showed that the analysis of this spectrum by Khan et al (1985 Phys. Scr. 31 837) contained a significant number of incorrect energy levels. We have now classified ˜420 lines as transitions between 23 even-parity levels 73 odd-parity levels. The 4s24p5, 4s4p6, 4s24p44d, 5s, 5d, 6s configurations are now complete, although a few levels of 4s24p45d are tentative. We determined Ritz-type wavelengths for ˜135 lines from the optimized energy levels. The uncertainties range from 0.0003 to 0.0020 Å. Hartree-Fock calculations and least-squares fits of the energy parameters to the observed levels were used to interpret the observed configurations. Oscillator strengths for all classified lines were calculated with the fitted parameters. The results are compared with values for the level energies, percentage compositions, and transition probabilities from recent ab initio theoretical calculations. The ionization energy was revised to 777 380 ± 300 cm-1 (96.38 ± 0.04 eV).

  6. High-energy spectrum and zenith-angle distribution of atmospheric neutrinos

    CERN Document Server

    Sinegovsky, S I; Sinegovskaya, T S

    2011-01-01

    High-energy neutrinos, arising from decays of mesons produced through the collisions of cosmic ray particles with air nuclei, form the background in the astrophysical neutrino detection problem. An ambiguity in high-energy behavior of pion and especially kaon production cross sections for nucleon-nucleus collisions may affect essentially the calculated neutrino flux. We present results of the calculation of the energy spectrum and zenith-angle distribution of the muon and electron atmospheric neutrinos in the energy range 10 GeV to 10 PeV. The calculation was performed with usage of known hadronic models (QGSJET-II-03, SIBYLL 2.1, Kimel & Mokhov) for two of the primary spectrum parametrizations, by Gaisser & Honda and by Zatsepin & Sokolskaya. The comparison of the calculated muon neutrino spectrum with the IceCube40 experiment data make it clear that even at energies above 100 TeV the prompt neutrino contribution is not so apparent because of tangled uncertainties of the strange (kaons) and charm...

  7. Corrections on energy spectrum and scatterings for fast neutron radiography at NECTAR facility

    CERN Document Server

    Shu-Quan, Liu; Hang, Li; Yu-Bin, Zou; Yuan-Rong, Lu; Zhi-Yu, Guo

    2013-01-01

    Neutron spectrum and scattered neutrons caused distortions are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-II in Technische Universit\\"at M\\"unchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by neutron spectrum, as well as the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve images qualities. Good analysis results prove the sounded effects of above two corrections.

  8. Corrections on energy spectrum and scattering for fast neutron radiography at NECTAR facility

    International Nuclear Information System (INIS)

    Distortions caused by the neutron spectrum and scattered neutrons are major problems in fast neutron radiography and should be considered for improving the image quality. This paper puts emphasis on the removal of these image distortions and deviations for fast neutron radiography performed at the NECTAR facility of the research reactor FRM-Ⅱ in Technische Universitaet Mounchen (TUM), Germany. The NECTAR energy spectrum is analyzed and established to modify the influence caused by the neutron spectrum, and the Point Scattered Function (PScF) simulated by the Monte-Carlo program MCNPX is used to evaluate scattering effects from the object and improve image quality. Good analysis results prove the sound effects of the above two corrections. (authors)

  9. A novel method to shape a neutron energy distribution: application to a maxwell-Boltzmann neutron spectrum at kt = 30 keV

    International Nuclear Information System (INIS)

    A novel method to obtain a shaped neutron energy spectrum for accelerator-based neutron source is presented in this paper. The proposed method modify the monoenergetic proton beam coming from an accelerator to a proton energy distribution, so the produced neutron spectra has the desired energy distribution. The application to a 5 MeV, 50 mA proton beam of the superconductive RFQ of the SPES project at Laboratori Nazionali di Legnaro is investigated for the production of a Maxwell-Boltzmann neutron spectrum at kT=30keV via the 7Li(p, n)7Be reaction. Concept, solutions, and calculations for a setup consisting of a proton energy shaper and a lithium target are presented. Calculations show that a power density of 3 kW/cm2 can be sustained by the lithium target and a forward-directed neutron flux higher than 1010 n/s at the sample position could be obtained

  10. A new beam loss detector for low-energy proton and heavy-ion accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhengzheng, E-mail: liuz@frib.msu.edu; Crisp, Jenna; Russo, Tom; Webber, Robert; Zhang, Yan

    2014-12-11

    The Facility for Rare Isotope Beams (FRIB) to be constructed at Michigan State University shall deliver a continuous, 400 kW heavy ion beam to the isotope production target. This beam is capable of inflicting serious damage on accelerator components, e.g. superconducting RF accelerating cavities. A Beam Loss Monitoring (BLM) System is essential for detecting beam loss with sufficient sensitivity and promptness to inform the machine protection system (MPS) and operations personnel of impending dangerous losses. Radiation transport simulations reveal shortcomings in the use of ionization chambers for the detection of beam losses in low-energy, heavy-ion accelerators. Radiation cross-talk effects due to the folded geometry of the FRIB LINAC pose further complications to locating specific points of beam loss. We propose a newly developed device, named the Loss Monitor Ring (LMR), to be implemented upstream of each FRIB cryomodule, as part of the direct loss monitoring system to fulfill the needs of machine protection. - Highlights: • Traditional BLM is not effective for beam loss monitoring at FRIB low energy linac segments. • We developed LMR to intercept a small portion of beam loss and output voltage signals. • We made a prototype LMR and demonstrated its functionality to monitor small beam losses. • The LMR is very sensitive for small beam losses and is independent of beam current. • The LMR is especially useful for loss monitoring at low energy ion/proton accelerators.

  11. A new beam loss detector for low-energy proton and heavy-ion accelerators

    International Nuclear Information System (INIS)

    The Facility for Rare Isotope Beams (FRIB) to be constructed at Michigan State University shall deliver a continuous, 400 kW heavy ion beam to the isotope production target. This beam is capable of inflicting serious damage on accelerator components, e.g. superconducting RF accelerating cavities. A Beam Loss Monitoring (BLM) System is essential for detecting beam loss with sufficient sensitivity and promptness to inform the machine protection system (MPS) and operations personnel of impending dangerous losses. Radiation transport simulations reveal shortcomings in the use of ionization chambers for the detection of beam losses in low-energy, heavy-ion accelerators. Radiation cross-talk effects due to the folded geometry of the FRIB LINAC pose further complications to locating specific points of beam loss. We propose a newly developed device, named the Loss Monitor Ring (LMR), to be implemented upstream of each FRIB cryomodule, as part of the direct loss monitoring system to fulfill the needs of machine protection. - Highlights: • Traditional BLM is not effective for beam loss monitoring at FRIB low energy linac segments. • We developed LMR to intercept a small portion of beam loss and output voltage signals. • We made a prototype LMR and demonstrated its functionality to monitor small beam losses. • The LMR is very sensitive for small beam losses and is independent of beam current. • The LMR is especially useful for loss monitoring at low energy ion/proton accelerators

  12. Simulation of wire-compensation of long range beam beam interaction in high energy accelerators

    International Nuclear Information System (INIS)

    Full text: We present weak-strong simulation results for the effect of long-range beam-beam (LRBB) interaction in LHC as well as for proposed wire compensation schemes or wire experiments, respectively. In particular, we discuss details of the simulation model, instability indicators, the effectiveness of compensation, the difference between nominal and PACMAN bunches for the LHC, beam experiments, and wire tolerances. The simulations are performed with the new code BBTrack. (author)

  13. Improved Measurement of the Branching Fraction and Energy Spectrum of eta' from Upsilon(1S) Decays

    CERN Document Server

    Aquines, O; Adams, G S; Alexander, J P; Anderson, M; Aquines, O; Artuso, M; Asner, D M; Athar, S B; Berkelman, K; Besson, D; Blusk, S; Bonvicini, G; Briere, R A; Brock, I; Butt, J; Cassel, D G; Cawlfield, C; Chen, J; Cinabro, D; Coan, T E; Cronin-Hennessy, D; Csorna, S E; Cummings, J P; Danko, I; Dobbs, S; Duboscq, J E; Dubrovin, M; Dytman, S A; Ecklund, K M; Edwards, K W; Ehrlich, R; Eisenstein, B I; Ernst, J; Ferguson, T; Fields, L; Galik, R S; Gao, K Y; Gao, Y S; Gibbons, L; Gong, D T; Gray, R; Gray, S W; Hartill, D L; He, Q; Heltsley, B K; Hertz, D; Hietala, J; Huang, G S; Insler, J; Jones, C D; Kandaswamy, J; Karliner, I; Kim, D; Klein, T; Kreinick, D L; Kubota, Y; Kuznetsov, V E; Lang, B W; Li, J; Li, Z; Lincoln, A; Liu, F; Love, W; Lowrey, N; López, A; Mahlke-Krüger, H; Mehrabyan, S S; Menaa, N; Metreveli, Z V; Miller, D H; Mountain, R; Muramatsu, H; Méndez, H; Naik, P; Napolitano, J; Nisar, S; Onyisi, P U E; Park, C S; Patel, R; Patterson, J R; Pavlunin, V; Pedlar, T K; Peterson, D; Pivarski, J; Poling, R; Potlia, V; Ramírez, J; Randrianarivony, K; Redjimi, R; Riley, D; Rosner, J L; Rubin, P; Ryd, A; Sadoff, A J; Sanghi, B; Savinov, V; Schwarthoff, H; Scott, A W; Sedlack, C; Selen, M; Seth, K K; Severini, H; Shepherd, M R; Shi, X; Shipsey, I P J; Sia, R; Skwarnicki, T; Smith, A; Stone, S; Stroiney, S; Sun, W M; Tatishvili, G T; Thorndike, E H; Tomaradze, A G; Vogel, H; Wang, J C; Watkins, M E; Weinberger, M; White, E J; Wilksen, T; Wiss, J; Xin, B; Yang, F; Yelton, J; Zhang, K; Zweber, P; al, et

    2006-01-01

    We present an improved measurement of the eta' meson energy spectrum in Upsilon(1S) decays, using 1.2 fb^{-1} of data taken at the Upsilon(1S) center-of-mass energy with the CLEO III detector. We compare our results with models of the eta' gluonic form factor that have been suggested to explain the unexpectedly large B to eta' X_s rate. Models based on perturbative QCD fail to fit the data for large eta' energies, and thus an explanation outside the realm of the Standard Model or an improved understanding of non-perturbative QCD effects may be needed to account for this large rate.

  14. Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

    International Nuclear Information System (INIS)

    The DL-Alanine (C3H7NO2) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm2; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1σ), and the energy dependence response, to the same doses, is better 3% (1σ) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

  15. Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber F. [Faculdade Metodo de Sao Paulo (FAMESP), SP (Brazil). Radiologia; Campos, Leticia L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm{sup 2}; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1{sigma}), and the energy dependence response, to the same doses, is better 3% (1{sigma}) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

  16. The knee in the cosmic ray energy spectrum from the simultaneous EAS charged particles and muon density spectra

    CERN Document Server

    Bijay, Biplab; Bhadra, Arunava

    2015-01-01

    In this work we examine with the help of Monte Carlo simulation whether a consistent primary energy spectrum of cosmic rays emerges from both the experimentally observed total charged particles and muon size spectra of cosmic ray extensive air showers considering primary composition may or may not change beyond the knee of the energy spectrum. It is found that EAS-TOP observations consistently infer a knee in the primary energy spectrum provided the primary is pure unchanging iron whereas no consistent primary spectrum emerges from simultaneous use of the KASCADE observed total charged particle and muon spectra. However, it is also found that when primary composition changes across the knee the estimation of spectral index of total charged particle spectrum is quite tricky, depends on the choice of selection of points near the knee in the size spectrum.

  17. Allotropic conversion of carbon-related films by using energy beams

    International Nuclear Information System (INIS)

    Energy beams such as ion and laser beams are employed to convert of C60 molecules into another carbon allotropes. The ion beam deposition (IBD) technique is effective to study the nucleation process by changing several growth parameters (beam energy, substrate temperature and ion species). The 12CHx+ (x = 0-4) ions with different energies (50-200 eV) are incident on two kinds of substrates (Si(111) and Ir(100)/MgO(100)) at room temperature and 700 deg C. Immersed nanosize diamonds are found in amorphous films in all cases. The topological features obtained in IBD are compared with laser processing experiments

  18. Diffuse gamma radiation. [intensity, energy spectrum and spatial distribution from SAS 2 observations

    Science.gov (United States)

    Fichtel, C. E.; Simpson, G. A.; Thompson, D. J.

    1978-01-01

    Results are reported for an investigation of the intensity, energy spectrum, and spatial distribution of the diffuse gamma radiation detected by SAS 2 away from the galactic plane in the energy range above 35 MeV. The gamma-ray data are compared with relevant data obtained at other wavelengths, including 21-cm emission, radio continuum radiation, and the limited UV and radio information on local molecular hydrogen. It is found that there are two quite distinct components to the diffuse radiation, one of which shows a good correlation with the galactic matter distribution and continuum radiation, while the other has a much steeper energy spectrum and appears to be isotropic at least on a coarse scale. The galactic component is interpreted in terms of its implications for both local and more distant regions of the Galaxy. The apparently isotropic radiation is discussed partly with regard to the constraints placed on possible models by the steep energy spectrum, the observed intensity, and an upper limit on the anisotropy.

  19. All-particle cosmic ray energy spectrum measured with 26 IceTop stations

    CERN Document Server

    Abbasi, R; Abu-Zayyad, T; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Alba, J L Bazo; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K -H; Bell, M; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Brayeur, L; Brown, A M; Buitink, S; Caballero-Mora, K S; Carson, M; Casier, M; Chirkin, D; Christy, B; Clevermann, F; Cohen, S; Cowen, D F; Silva, A H Cruz; D'Agostino, M V; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; Degner, T; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dreyer, J; Dumm, J P; Dunkman, M; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Goodman, J A; Góra, D; Grant, D; Groß, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Han, K; Hanson, K; Heimann, P; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, B; Homeier, A; Hoshina, K; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Johansson, H; Kappes, A; Karg, T; Karle, A; Kiryluk, J; Kislat, F; Klein, S R; Klepser, S; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Laihem, K; Landsman, H; Larson, M J; Lauer, R; Lünemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; Meagher, K; Merck, M; Mészáros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Naumann, U; Nowicki, S C; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Heros, C Pérez de los; Pieloth, D; Posselt, J; Price, P B; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rothmaier, F; Rott, C; Ruhe, T; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Scheel, M; Schmidt, T; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Schultes, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Smith, M W E; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Stüer, M; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Tosi, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wasserman, R; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wischnewski, R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Zoll, M

    2012-01-01

    We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 surface stations operational at that time, corresponding to about one third of the final array. The fiducial area used in this analysis was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV measured for three different zenith angle ranges between 0{\\deg} and 46{\\deg}. Because of the isotropy of cosmic rays in this energy range the spectra from all zenith angle intervals have to agree. The cosmic-ray energy spectrum was determined under different assumptions on the primary mass composition. Good agreement of spectra in the three zenith angle ranges was found for the assumption of pure proton and a simple two-component model. For zenith angles {\\theta} < 30{\\deg}, where the mass dependence is smallest, the knee in the cosmic ray ener...

  20. On the absorbed dose determination method in high energy electrons beams

    International Nuclear Information System (INIS)

    The absorbed dose determination method in water for electron beams with energies in the range from 1 MeV to 50 MeV is presented herein. The dosimetry equipment for measurements is composed of an UNIDOS.PTW electrometer and different ionization chambers calibrated in air kerma in a Co60 beam. Starting from the code of practice for high energy electron beams, this paper describes the method adopted by the secondary standard dosimetry laboratory (SSDL) in NILPRP - Bucharest

  1. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    Energy Technology Data Exchange (ETDEWEB)

    Garnica-Garza, H M, E-mail: hgarnica@cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Monterrey, Via del Conocimiento 201 Parque de Investigacion e Innovacion Tecnologica, Apodaca NL CP 66600 (Mexico)

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5{sup 0} around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  2. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    International Nuclear Information System (INIS)

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 50 around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  3. Ion acceleration with a narrow energy spectrum by nanosecond laser-irradiation of solid target

    Energy Technology Data Exchange (ETDEWEB)

    Altana, C., E-mail: altana@lns.infn.it [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S. Sofia 64, 95123 Catania (Italy); Lanzalone, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Enna “Kore,” Via delle Olimpiadi, 94100 Enna (Italy); Mascali, D.; Cirrone, G. A. P.; Schillaci, F.; Tudisco, S. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Muoio, A. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F. D’Alcontres 31, 98166 Messina (Italy)

    2016-02-15

    In laser-driven plasma, ion acceleration of aluminum with the production of a quasi-monoenergetic beam has occurred. A useful device to analyze the ions is the Thomson parabolas spectrometer, a well-known diagnostic that is able to obtain information on charge-to-mass ratio and energy distribution of the charged particles. At the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS in Catania, experimental measures were carried out; the features of LENS are: Q-switched Nd:YAG laser with 2 J laser energy, 1064 nm fundamental wavelengths, and 6 ns pulse duration.

  4. Ion acceleration with a narrow energy spectrum by nanosecond laser-irradiation of solid target

    International Nuclear Information System (INIS)

    In laser-driven plasma, ion acceleration of aluminum with the production of a quasi-monoenergetic beam has occurred. A useful device to analyze the ions is the Thomson parabolas spectrometer, a well-known diagnostic that is able to obtain information on charge-to-mass ratio and energy distribution of the charged particles. At the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS in Catania, experimental measures were carried out; the features of LENS are: Q-switched Nd:YAG laser with 2 J laser energy, 1064 nm fundamental wavelengths, and 6 ns pulse duration

  5. Theoretical study of cylindrical energy analyzers for MeV range heavy ion beam probes

    International Nuclear Information System (INIS)

    A cylindrical energy analyzer with drift spaces is shown to have a second order focusing for beam incident angle when the deflection angle is properly chosen. The analyzer has a possibility to be applied to MeV range heavy ion beam probes, and will be also available for accurate particle energy measurements in many other fields. (author)

  6. Studies for the determination of the beam energy with Compton backscattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Cheng; Judin, Vitali; Huttel, Erhard; Schuh, Marcel; Streichert, Max; Papash, Alexander; Nasse, Michael J.; Hertle, Edmund; Mueller, Anke-Susanne [Karlsruhe Institute of Technology (Germany)

    2013-07-01

    The method of resonant depolarization which is now used for determination of beam energy (2.5 GeV) at ANKA becomes cumbersome for lower beam energies. As an alternative method, a compact Compton backscattering setup with a storage cavity of laser and appropriate detection system is proposed. In the presentation, the preliminary design of the setup and simulation results are present.

  7. Space charge compensation in the Linac4 low energy beam transport line with negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Valerio-Lizarraga, Cristhian A., E-mail: cristhian.alfonso.valerio.lizarraga@cern.ch [CERN, Geneva (Switzerland); Departamento de Investigación en Física, Universidad de Sonora, Hermosillo (Mexico); Lallement, Jean-Baptiste; Lettry, Jacques; Scrivens, Richard [CERN, Geneva (Switzerland); Leon-Monzon, Ildefonso [Facultad de Ciencias Fisico-Matematicas, Universidad Autónoma de Sinaloa, Culiacan (Mexico); Midttun, Øystein [CERN, Geneva (Switzerland); University of Oslo, Oslo (Norway)

    2014-02-15

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Transport using the package IBSimu [T. Kalvas et al., Rev. Sci. Instrum. 81, 02B703 (2010)], which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H{sup −} beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  8. Beam-induced energy deposition issues in the Very Large Hadron Collider

    CERN Document Server

    Mokhov, N V; Foster, G W

    2001-01-01

    Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage and quench stability. The beam abort and beam collimation systems are designed to protect accelerator from accidental and operational beam losses, IP region quadrupoles from irradiation by the products of beam-beam collisions, and to reduce the accelerator-induced backgrounds in the detectors. (7 refs).

  9. Role of staircase potential in the energy spectrum of a periodic system

    International Nuclear Information System (INIS)

    An exhaustive study on the energy spectrum and the wave functions of semiconductor superlattices (SLs) in the presence of saw-tooth potential, step potential and the combined potential has been carried out. The study uses a realistic model for the SL based on the periodic crystal potential of the host crystals. The application of the staircase potential results in the formation of discrete Wannier-Stark ladder (WSL) which is experimentally exploited to achieve quantum cascade laser. The conditions for the WSL in SL has been pointed out. For the purpose of comparison, the effect of these potentials on the energy spectrum and the wave functions has also been reported for a single crystal

  10. Shape variation of the two-electron photoionization spectrum with photon energy growth

    International Nuclear Information System (INIS)

    We trace the evolution of the shape of the two-electron photoionization spectrum with photon energy growth using quite a precise two-electron wave function, obtained by the correlation function hyperspherical harmonic method. We obtain the values of ω1 and ω2 at which the spectrum curve changes its shape. At ω=ω1 the U shape changes to a W shape. At ω=ω2 the central W peak splits into two. We consider ground states of the helium atom and of heliumlike ions with the nuclear charge Z, the negative ion of hydrogen H-, and the excited n1S state of helium. The limiting laws for Z>>1 and n>>1 are obtained. The analysis is carried out without calculations of the particular energy distributions themselves

  11. Minimax determination of the energy spectrum of the Dirac equation in a Schwarzschild background

    CERN Document Server

    Caceres, A; Caceres, Alejandro; Doran, Chris

    2005-01-01

    We calculate the bound-state energy spectrum of the Dirac Equation in a Schwarzschild black hole background using a minimax variational method. Our method extends that of Talman to the case of non-Hermitian interactions, such as a black hole. The trial function is expressed in terms of a basis set that takes into account both the Hermitian limit of the interaction in the non-relativistic approximation, and the general behaviour of the solutions at the origin, the horizon and infinity. Using this trial function an approximation to the full complex energy bound-state spectrum is computed. We study the behaviour of the method as the coupling constant of the interaction is increased, which increases both the relativistic effects and the size of the non-Hermitian part of the interaction. Finally we confirm that the method follows the expected Hylleraas-Undheim behaviour.

  12. High energy Coulomb-scattered electrons for relativistic particle beam diagnostics

    CERN Document Server

    Thieberger, P; Carlson, C; Chasman, C; Costanzo, M; Degen, C; Drees, K A; Fischer, W; Gassner, D; Gu, X; Hamdi, K; Hock, J; Marusic, A; Miller, T; Minty, M; Montag, C; Luo, Y; Pikin, A I; White, S M

    2016-01-01

    A new system used for monitoring energetic coulomb-scattered electrons as the main diagnostic for accurately aligning the electron and ion beams in the new Relativistic Heavy Ion Collider electron lenses is described in detail. Other possible applications of such energetic electrons are also discussed, such as similar systems for aligning electron beams for long-range beam-beam compensation and hollow electron beams for halo collimation and halo monitoring. A new type of "electron wire" beam profile monitor is described as well. Use of atomic electrons from the residual gas accelerated to high energies by the relativistic ions could lead to yet another type of non-destructive beam diagnostics, in this case not requiring an electron beam.

  13. Energy-Based Cooperative Spectrum Sensing of SC-FDMA Systems

    Directory of Open Access Journals (Sweden)

    Fucheng Yang

    2014-07-01

    Full Text Available In this paper, we propose a frequency-hopping M-ary frequency-shift keying spectrum sensing network (FH/MFSK SSN for identifying the on/off states of the users supported by a single-carrier frequency-division multiple assess (SC-FDMA primary radio (PR system. Specifically, the spectrums of an uplink interleaved frequency-division multiple access (IFDMA PR system are monitored by a number of cognitive radio sensing nodes (CRSNs. These CRSNs distributedly detect the on/off states of users based on one of the three energy detection schemes. After the local spectrum sensing, the CRSNs transmit their detected states to a fusion centre (FC with the aid of FH/MFSK techniques. At the FC, the on/off states of the users supported the IFDMA PR system are finally classified according to either the conventional equal-gain combining (EGC scheme or the novel erasure-supported EGC (ES-EGC scheme. In this way, the on/off information about the spectrums occupied by an IFDMA PR systemcan be obtained, so that they can be exploited by a cognitive radio (CR system. For local spectrum sensing, in this paper, we consider four synchronisation scenarios concerning the synchronisation between the received IFDMA signals and the CRSNs. The performance of the FH/MFSK SSN associated with various schemes is investigated by simulations. Our studies show that the FH/MFSK SSN constitutes one of the highly reliable spectrum sensing schemes, which are capable of exploiting both the space diversity provided by local CRSNs and the frequency diversity provided by the subcarriers of IFDMA system.

  14. Uncertainty of the beam energy measurement in the e+e- collision using Compton backscattering

    Science.gov (United States)

    Mo, Xiao-Hu

    2014-10-01

    The beam energy is measured in the e+e- collision by using Compton backscattering. The uncertainty of this measurement process is studied by virtue of analytical formulas, and the special effects of variant energy spread and energy drift on the systematic uncertainty estimation are also studied with the Monte Carlo sampling technique. These quantitative conclusions are especially important for understanding the uncertainty of the beam energy measurement system.

  15. Energy spectrum of an electron confined in the hexagon-shaped quantum well

    Institute of Scientific and Technical Information of China (English)

    Yu.; V.; VOROBIEV; V.; R.; VIEIRA; P.; P.; HORLEY; P.; N.; GORLEY; J.; GONZLEZ-HERNNDEZ

    2009-01-01

    Considering the hexagonal-shaped quantum-scale formations on the surface of thin semiconductor films, a methodology was developed to obtain the analytical solution of the Schrdinger equation when impenetrable walls of a quantum well are treated as mirrors. The results obtained allowed the calculation of the space probability distributions and the energy spectrum of the particle confined in a hex-agonal-shaped well.

  16. Energy spectrum of an electron confined in the hexagon-shaped quantum well

    Institute of Scientific and Technical Information of China (English)

    Yu.V.VOROBIEV; V.R.VlEIRA; P.P.HORLEY; P.N.GORLEY; J.GONZ(A)LEZ-HERN(A)NDEZ

    2009-01-01

    Considering the hexagonal-shaped quantum-scale formations on the surface of thin semiconductor films, a methodology was developed to obtain the analytical solution of the Schr(o)dinger equation when impenetrable walls of a quantum well are treated as mirrors. The results obtained allowed the calcula-tion of the space probability distributions and the energy spectrum of the particle confined in a hex-agonal-shaped well.

  17. Is the primary energy spectrum around the knee a statistical game?

    International Nuclear Information System (INIS)

    The present state of research of the shape of the energy spectrum of primary cosmic ray nuclei and the chemical composition in the region of the so-called, knee, and beyond is highly unsatisfactory. It was not very successful when using extensive air showers. In the present paper an attempt is made to explain what is the cause of such a situation. The experimental results as to which there is no doubt that they were wrongly interpreted, will be indicated

  18. Study of natural γ-energy spectrum measurement system based on the microcomputer

    International Nuclear Information System (INIS)

    A microcomputer-based measurement system for the natural γ-energy spectrum is developed, which delivers a high quality automatic acquisition and analysis capability. By means of designing a simple interface, 2048-channel ADC can be connected with a microcomputer. The measuring results of soil-samples and rock-samples show that system improves reliability, measurement accuracy and automatic level. It can be applied to environmental and geological investigations

  19. Energy Spectrum of Helium Confined to a Two-Dimensional Space

    Institute of Scientific and Technical Information of China (English)

    XIEWen-Fang

    2005-01-01

    Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of a two-dimensional helium in a magnetic field. The results show that the ground and low-excited states of helium in low-dimensional space are more stable than those in three-dimensional space and there may exist more bound states.

  20. Measurememnt of the linear energy losses spectrum of cosmic radiation aboard the Kosmos-1129 satellite

    International Nuclear Information System (INIS)

    Results are presented of measuring the linear energy losses spectrum (LEL) of cosmic radiation (CR) aboard the ''Kosmos-1129'' satellite. Experiments were carried out using a detector of normal nuclear emulsion with a detection threshold controlled in a wide range of LEL. As a result of comparison with experimental data obtained aboard the ''Kosmos-782'' and ''Kosmos-936'' satellites it is concluded that the technique in use allows to increase the range of particle detection

  1. Multi-detector setup for nuclear astrophysical reaction studies on the low energy ion beam

    International Nuclear Information System (INIS)

    The multi-detector setup assembled on the basis of the ion beam from 'SOKOL' electrostatic accelerator is described. The setup allows one to measure three various spectra in a single experiment: prompt gamma-quanta from nuclear reactions, positrons from the decays of radioactive nuclei formed in the reactions and coincidence spectrum of annihilation gamma-quanta. (authors)

  2. Influence of initial energy modulation on premodulated electron beam propagating through a drift tube

    International Nuclear Information System (INIS)

    Influence of the initial energy modulation caused by the self-potential depression on the premodulated electron-beam propagation through a drift tube is investigated. The potential depression κ can significantly vary because of the initial current modulation. Thus, beam close-quote s kinetic energy at the injection varies accordingly. A self-consistent nonlinear theory of current modulation of the premodulated electron beam is developed. It is shown that the initial energy modulation caused by the self-potential depression at injection plays a significant role in the current modulation for long range propagation. It is also found from a small signal theory that reduction of the beam close-quote s kinetic energy due to its potential depression accelerates debunching process of the initial current modulation. Although the initial current modulation is debunched quickly for high current beam, amplitude of the current modulation never becomes zero because of the initial energy modulation. copyright 1997 American Institute of Physics

  3. Monte Carlo dosimetric evaluation of high energy vs low energy photon beams in low density tissues

    International Nuclear Information System (INIS)

    Background and purpose: Low megavoltage photon beams are often the treatment choice in radiotherapy when low density heterogeneities are involved, because higher energies show some undesirable dosimetric effects. This work is aimed at investigating the effects of different energy selection for low density tissues. Patients and methods: BEAMnrc was used to simulate simple treatment set-ups in a simple and a CT reconstructed lung phantom and an air-channel phantom. The dose distribution of 6, 15 and 20 MV photon beams was studied using single, AP/PA and three-field arrangements. Results: Our results showed no significant changes in the penumbra width in lung when a pair of opposed fields were used. The underdosage at the anterior/posterior tumor edge caused by the dose build-up at the lung-tumor interface reached 7% for a 5x5 cm AP/PA set-up. Shrinkage of the 90% isodose volume was noticed for the same set-up, which could be rectified by adding a lateral field. For the CT reconstructed phantom, the AP/PA set-up offered better tumor coverage when lower energies were used but for the three field set-up, higher energies resulted to better sparing of the lung tissue. For the air-channel set-up, adding an opposed field reduced the penumbra width. Using higher energies resulted in a 7% cold spot around the air-tissue interface for a 5x5 cm field. Conclusions: The choice of energy for treatment in the low density areas is not a straightforward decision but depends on a number of parameters such as the beam set-up and the dosimetric criteria. Updated calculation algorithms should be used in order to be confident for the choice of energy of treatment

  4. Kolmogorov argument for the scaling of the energy spectrum in a stratified fluid

    International Nuclear Information System (INIS)

    In this work we show that the global energy balance part of the Kolmogorov argument for the kinetic energy spectrum in a homogeneous fluid repeated for the stratified fluid will inevitably exhibit a small deviation from perfect scaling. It is shown that an unambiguous scaling with an exponent of 11/5 can be observed only if the fluid is stably stratified in agreement with the original suggestion of Bolgiano. We find that even if the kinetic energy flux shows the predicted fall-off with wave-vector and the thermal energy (entropy) flux is constant, the kinetic energy spectrum will show a small deviation from perfect scaling. - Highlights: • A Kolmogorov argument for global energy balance for turbulence in a stratified fluid is presented. • It is seen that for unstable stratification an unambiguous argument cannot be set up. • For stable stratification there is clear Kolmogorov scenario but the flux is a combination of kinetic and thermal fluxes. • A pure Bolgiano–Obukhov scaling is seen only for wave-numbers greater than a critical wave-number. • The critical wave-number decreases as the Richardson number increases

  5. Investigations of the Turbulent Energy Spectrum in an Oscillating Grid Experiment

    Science.gov (United States)

    Hall, Stephen C.; Honey, Rose E.; Donnelly, Russell J.

    1998-03-01

    We report a novel technique to investigate the turbulent energy spectrum generated by an oscillating grid in water. We suspend tubes of a variety of diameters below the oscillating grid and measure the steady state position in the tube of the turbulent front. This position decreases (becomes closer to the grid) as the tube diameter is decreased. We present a model, in which the tubes act as low-pass filters that exclude eddies larger than the tube diameter, to explain the observations and discuss the implications for the turbulent energy spectrum. We estimate the effect of boundary layers formed on the tubes. due to viscosity before the larger ones. The energy spectrum in cross-sections further and further from the grid is contained in an increasingly narrow range of eddy sizes towards the larger eddies. The tubes, acting as low-pass filters, exclude eddies of size larger than the tube diameter and are only filled with eddies smaller than the tube. Therefore, the turbulence in a smaller tube is expected to decay away before turbulence in a larger tube which contains more larger, longer lived eddies.

  6. Low-Energy Plasma Focus Device as an Electron Beam Source

    Science.gov (United States)

    Seong Ling, Yap; Naresh Kumar, Nitturi; Lian Kuang, Lim; Chiow San, Wong

    2014-01-01

    A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line radiations were registered upon usage as targets. The maximum electron beam charge and density were estimated to be 0.31 μC and 13.5 × 1016/m3, respectively. The average energy of the electron beam was 500 keV. The high flux of the electron beam can be potentially applicable in material sciences. PMID:25544952

  7. Low-Energy Plasma Focus Device as an Electron Beam Source

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Khan

    2014-01-01

    Full Text Available A low-energy plasma focus device was used as an electron beam source. A technique was developed to simultaneously measure the electron beam intensity and energy. The system was operated in Argon filling at an optimum pressure of 1.7 mbar. A Faraday cup was used together with an array of filtered PIN diodes. The beam-target X-rays were registered through X-ray spectrometry. Copper and lead line radiations were registered upon usage as targets. The maximum electron beam charge and density were estimated to be 0.31 μC and 13.5×1016/m3, respectively. The average energy of the electron beam was 500 keV. The high flux of the electron beam can be potentially applicable in material sciences.

  8. Beam life time studies and design optimization of the Ultra-low energy Storage Ring

    Science.gov (United States)

    Welsch, C. P.; Papash, A. I.; Harasimowicz, J.; Karamyshev, O.; Karamysheva, G. A.; Newton, D.; Panniello, M.; Putignano, M.; Siggel-King, M. R. F.; Smirnov, A.

    2014-04-01

    The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV. Based on the original design concept developed in 2005, the USR has been completely redesigned over the past few years by the QUASAR Group. The ring structure is now based on a 'split achromat' lattice. This ensures compact ring dimensions of 10 m × 10 m, whilst allowing both, in-ring experiments with gas jet targets and studies with extracted beams. In the USR, a wide range of beam parameters shall be provided, ranging from very short pulses in the nanosecond regime to a coasting beam. In addition, a combined fast and slow extraction scheme will be featured that allows for providing external experiments with cooled beams of different time structure. Detailed investigations into the dynamics of low energy beams, including studies into the long term beam dynamics and ion kinetics, beam life time, equilibrium momentum spread and equilibrium lateral spread during collisions with an internal target were carried out. This required the development of new simulation tools to further the understanding of beam storage with electrostatic fields. In addition, studies into beam diagnostics methods for the monitoring of ultra-low energy ions at beam intensities less than 10 6 were carried out. This includes instrumentation for the early commissioning of the machine, as well as for later operation with antiprotons. In this paper, on overview of the technical design of the USR is given with emphasis on two of the most important operating modes, long term beam dynamics and the design of the beam diagnostics system.

  9. Investigation of hyperfine structures of spectral lines of singly ionized praseodymium using fourier transform spectrum, saturation spectroscopy and collinear laser ion beam spectroscopy

    International Nuclear Information System (INIS)

    The hyperfine (hf) structure splitting of a fine structure energy level is caused by the interaction of the electromagnetic nuclear moments with the electromagnetic moments of the electron shell. The splitting of the hf structure is determined by the magnetic dipole interaction constant A and an additional small shift in the hf levels is determined by the quadrupole interaction constant B. Praseodymium (Pr) has five electrons in the outermost shells. The coupling of five (Pr I) or four (Pr II) electrons produces a large number of fine structure levels resulting in a dense and complicated optical spectrum. For the classification of spectral lines, precise values of hf constants and energy values of the levels involved in the transitions are required. This work is divided into three parts: In the first part, the spectral lines of Pr II are analyzed using a high resolution Fourier transform spectrum in the spectral range from 3260 to 11700 Å. Transition wavelengths of Pr II spectral lines are re-determined and then, using these accurate transition wavelengths, the energy values of the levels involved in the transitions are improved. Wavelengths for 477 spectral lines and energy values for 227 known levels of Pr II are improved. Investigation of narrow hf structures needs a reduction of the Doppler broadening of the investigated lines. The hf structures are experimentally investigated using two methods of Doppler reduced spectroscopy. In the second part of this work, the hf structures of the Pr II spectral lines are investigated in a hollow cathode discharge lamp using inter-modulated laser induced fluorescence spectroscopy. Using this method 6 Pr II transitions are investigated and a spectral width of about ca. 200 MHz was achieved. The main research work is carried out in the third part. The Pr II spectral lines are investigated using the high resolution method of Collinear Laser Ion Beam Spectroscopy (CLIBS). The CLIBS measurements are performed using the Marburg

  10. A beam source model for scanned proton beams

    International Nuclear Information System (INIS)

    A beam source model, i.e. a model for the initial phase space of the beam, for scanned proton beams has been developed. The beam source model is based on parameterized particle sources with characteristics found by fitting towards measured data per individual beam line. A specific aim for this beam source model is to make it applicable to the majority of the various proton beam systems currently available or under development, with the overall purpose to drive dose calculations in proton beam treatment planning. The proton beam phase space is characterized by an energy spectrum, radial and angular distributions and deflections for the non-modulated elementary pencil beam. The beam propagation through the scanning magnets is modelled by applying experimentally determined focal points for each scanning dimension. The radial and angular distribution parameters are deduced from measured two-dimensional fluence distributions of the elementary beam in air. The energy spectrum is extracted from a depth dose distribution for a fixed broad beam scan pattern measured in water. The impact of a multi-slab range shifter for energy modulation is calculated with an own Monte Carlo code taking multiple scattering, energy loss and straggling, non-elastic and elastic nuclear interactions in the slab assembly into account. Measurements for characterization and verification have been performed with the scanning proton beam system at The Svedberg Laboratory in Uppsala. Both in-air fluence patterns and dose points located in a water phantom were used. For verification, dose-in-water was calculated with the Monte Carlo code GEANT 3.21 instead of using a clinical dose engine with approximations of its own. For a set of four individual pencil beams, both with the full energy and range shifted, 96.5% (99.8%) of the tested dose points satisfied the 1%/1 mm (2%/2 mm) gamma criterion

  11. 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.

  12. Beam optics of a dipole magnet for energy measurement in an RF linac

    International Nuclear Information System (INIS)

    This paper presents the analytical calculation and simulation for the beam optics study of a 30° sector magnet. This sector magnet will be used to measure the energy of a 1.5 MeV electron beam being injected from an RF linac. From initial beam parameters, arc length of the magnet and number of ampere-turns have been optimised. To find out beam size, Transfer matrix method is used for different initial beam conditions. A program is written in MATHEMATICA to solve the envelope equation in both dispersive and non-dispersive plane . To validate this program, simulation is carried out in the software CST PARTICLE STUDIO. (author)

  13. Executive summary of the workshop on polarisation and beam energy measurement at the ILC

    International Nuclear Information System (INIS)

    This note summarizes the results of the ''Workshop on Polarisation and Beam Energy Measurements at the ILC'', held at DESY (Zeuthen) April 9-11 2008. The topics for the workshop included (i) physics requirements, (ii) polarised sources and low energy polarimetry, (iii) BDS polarimeters, (iv) BDS energy spectrometers, and (v) physics-based measurements of beam polarisation and beam energy from collider data. Discussions focused on the current ILC baseline programme as described in the Reference Design Report (RDR), which includes physics runs at beam energies between 100 and 250 GeV, as well as calibration runs on the Z-pole. Electron polarisation of Pe- >or similar 80% and positron polarisation of Pe+ >or similar 30% are part of the baseline configuration of the machine. Energy and polarisation measurements for ILC options beyond the baseline, including Z-pole running and the 1 TeV energy upgrade, were also discussed. (orig.)

  14. Analysis of the hadronic energy spectrum in high-energy cosmic-ray families detected by emulsion chambers

    International Nuclear Information System (INIS)

    We analyze the hadronic energy spectrum for cosmic-ray families detected by emulsion chambers in the high-energy region, by means of the solution of diffusion equations for the hadronic cascade induced by one single nucleon in the atmosphere, assuming three different models for the energy distribution function in multiple pion production. We describe the experimental data for the energy of three high-energy families detected in emulsion chamber of Brazil-Japan Colloboration (BJC) at Mt. Chacaltaya and of two families detected by Pamir Collaboration (PC). We look also for consistency of the rapidity-density distribution, obtained for the different hypotheses for multiple pion production above, with accelerator data in the ISR and Collider regions. Finally, the Models are analysed with respect to the energy dependence of the mean inelasticity

  15. Lowering the limit of detection in high spatial resolution electron beam microanalysis with the microcalorimeter energy dispersive X-ray spectrometer

    International Nuclear Information System (INIS)

    Low-beam-energy X-ray microanalysis with the field-emission-gun scanning electron microscope suffers limitations due to physical factors of X-ray generation. Instrumental limitations are imposed by the poor resolution of the conventional semiconductor energy dispersive X-ray spectrometry. Wavelength dispersive X-ray spectrometry provides sufficient resolution to solve spectroscopic problems, but the poor geometric efficiency and the single channel nature of spectrum measurement restrict its practical use for low-beam-energy microanalysis. The microcalorimeter energy dispersive X-ray spectrometer combines high resolution (<10 eV) with energy dispersive operation. The utility of this new spectrometer is examined in four categories: (1) qualitative analysis; (2) quantitative analysis; (3) chemical speciation studies, and (4) measurement of trace constituents. For the low-beam-energy regime, the microcalorimeter energy dispersive X-ray spectrometer provides important new performance capabilities for qualitative analysis and chemical speciation studies. However, there are limitations for quantitative studies imposed by detector geometrical characteristics. In addition, trace element detection is impractical below 0.001 mass fraction with low-beam energy (<5 keV) because of count rate limitations. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Thermodynamic properties of a solid exhibiting the energy spectrum given by the logistic map

    International Nuclear Information System (INIS)

    We show that the infinite-dimensional representation of the recently introduced Logistic algebra can be interpreted as a non-trivial generalization of the Heisenberg or oscillator algebra. This allows to construct a quantum Hamiltonian having the energy energy spectrum given by the logistic map. We analyze the Hamiltonian of a solid whose collective modes of vibrations are described by this generalized oscillator and compute the thermodynamic properties of the model in the two-cycle and γ3.6785 chaotic region of the logistic map. (author)

  17. Post acceleration of a pseudospark-produced high-brightness electron beam

    International Nuclear Information System (INIS)

    Preliminary results are presented of post-acceleration experiment of a pseudospark-produced high-brightness electron beam. The electron beam that is propagating in a low pressure gas is accelerated by a simple induction linac system. Time-resolved energy spectrum is constructed for the electron beam. The resultant spectrum reveals that the instantaneous beam energy is approximately equal to the sum of the cathode voltage and the induction-linac accelerating voltage

  18. Preservation effect of high energy electron beam on kyoho grape

    International Nuclear Information System (INIS)

    The Kyoho grapes were kept in cold storage of-0.5 degree C ∼ 0.5 degree C, RH 85% ∼ 95% after irradiation of 400, 700, 1000, 1500, 2500 Gy and SO2 treatment, and the antiseptic effect and storage quality were studied. The result showed that high energy electron beam could control the growth of bacteria, mould, yeast, coliform, alleviate the deterioration of grapes during storage. Irradiation below the dose 1000 Gy can decrease the respiration intensity, prevent the decreasing of titratable acid, ascorbic acid content, and keep higher activity of SOD enzyme. The Vc content was 3.79 mg /100 g after 700 Gy irradiation 90 days, the titratable acid and total soluble sugar content were 0.348%, 11.44%, and the activity of SOD was 14.89 U /g, which was higher than the control significantly (P 2 bleaching spot. Integrate the effects on microorganism control and grape quality, treatment of 700 Gy had the best preservation effect in this study. After preserved for 98 d, the good fruit rate of 700 Gy treatment was 93.33% , significantly higher than other treatments (P < 0.05). (authors)

  19. Global energy confinement scaling for neutral-beam-heated tokamaks

    International Nuclear Information System (INIS)

    A total of 677 representative discharges from seven neutral-beam-heated tokamaks has been used to study the parametric scaling of global energy confinement time. Contributions to this data base were from ASDEX, DITE, D-III, ISX-B, PDX, PLT, and TFR, and were taken from results of gettered, L-mode type discharges. Assuming a power law dependence of tau/sub E/ on discharge parameters kappa, I/sub p/, B/sub t/, anti n/sub e/ P/sub tot/, a, and R/a, standard multiple linear regression techniques were used in two steps to determine the scaling. The results indicate that the discharges used in the study are well described by the scaling tau/sub E/ α kappa/sup 0.28/ B/sub T//sup -0.09/ I/sub p//sup 1.24/anti n/sub e//sup -0.26/ P/sub tot//sup -0.58/ a/sup 1.16/ (R/a)/sup 1.65/

  20. Global energy confinement scaling for neural-beam-heated tokamaks

    International Nuclear Information System (INIS)

    A total of 677 representative discharges from seven neutral-beam-heated tokamaks have been used to study the parametric scaling of global energy confinement time. Contributions to this data base were from Asdex, DITE, D-III, ISX-B, PDX, PLT and TFR, and were taken from results of gettered, L-mode type discharges. Assuming a power law dependence of tausub(E) on the discharge parameters kappa, Isub(p), Bsub(t), n-barsub(e)Psub(tot), a and R, standard multiple linear regression techniques were used in two steps to determine the scaling. The results indicate that the discharges used in the study are well described by the scaling tausub(E) is proportional to kappasup(0.28)Bsub(T)sup(-0.09)Isub(p)sup(1.24)n-barsub(e)sup(0.26) Psub(tot)sup(-0.58)asup(-0.49)Rsup(1.65). (author)