NSLS 3: Conceptual design report: 750 MeV e+ or e- injector

International Nuclear Information System (INIS)

1986-05-01

The 750 MeV positron or electron injector is comprised of an electron linear accelerator which accelerates an intense beam of electrons to an energy of about 250 MeV, a positron converter, a second linear accelerator that boosts the final positron energy to 750 MeV, and a damping ring in which radiation damping is used to reduce the emittance of the positron beam for injection into the storage rings. The reasons for the need of a new injector are enumerated. The conceptual design of the system and its component systems are described, as well as project cost, schedule, and manpower requirements

Optimisation of 12 MeV electron beam simulation using variance reduction technique

International Nuclear Information System (INIS)

Jayamani, J; Aziz, M Z Abdul; Termizi, N A S Mohd; Kamarulzaman, F N Mohd

2017-01-01

Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 10 7 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 10 7 to 20 × 10 7 . In this study, 5 MeV electron cut-off with 10 × 10 7 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy. (paper)

Number transmission of 0.6 and 0.8MeV electrons in elemental materials

International Nuclear Information System (INIS)

Harami, Taikan; Takagaki, Torao; Matsuda, Koji; Nakai, Yohta.

1975-01-01

The number transmissions of electrons in Be, Al, Cu and Ag were obtained experimentally for well collimated electron beams of 0.6 and 0.8 MeV. Experimental results of the present work join smoothly to the previous ones of 1.0 MeV to 2.0 MeV electrons. The ratios of extrapolated range Rsub(ex) to true range R 0 give generally minimum values near 1 MeV (approximately 2mc 2 ) as well as the stopping power. An investigation was done for empirical equation of the form eta=exp(-xP/CEsup(m)), where E is the incident electron energy, x, penetration depth, and p, C and m are the parameters determined from experimental data. (author)

Crosslinking of commercial polyethylenes by 10 MeV electrons

International Nuclear Information System (INIS)

Singh, A.; Lopata, V.J.; Kremers, W.; Sze, Yu-keung

1995-08-01

Commercial polyethylenes were irradiated with 10 MeV electrons to induce crosslinking. The gel fraction data measured as a function of total dose suggests that crosslinking proceeds on irradiation, as expected. A number of the properties of the irradiated polyethylenes, such as the degree of oxidation, crystallinity and thermal degradation, were studied by Fourier transform infrared/photo acoustic spectroscopy, X-ray diffraction, and a pyrolysis technique coupled with gas chromatography and mass spectrometry. The results of this study suggest that commercial polyethylenes can be crosslinked to a gel fraction of ∼70%, required for wire and cable applications, by 10 MeV electrons. (author). 35 refs., 6 figs

The KAERI 10 MeV Electron Linac - Description and Operational Manual

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-15

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

The KAERI 10 MeV Electron Linac - Description and Operational Manual

International Nuclear Information System (INIS)

Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

2005-06-01

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting

A sub-picosecond pulsed 5 MeV electron beam system

International Nuclear Information System (INIS)

Farrell, J. Paul; Batchelor, K.; Meshkovsky, I.; Pavlishin, I.; Lekomtsev, V.; Dyublov, A.; Inochkin, M.; Srinivasan-Rao, T.

2001-01-01

Laser excited pulsed, electron beam systems that operate at energies from 1 MeV up to 5 MeV and pulse width from 0.1 to 100 ps are described. The systems consist of a high voltage pulser and a coaxial laser triggered gas or liquid spark gap. The spark gap discharges into a pulse forming line designed to produce and maintain a flat voltage pulse for 1 ns duration on the cathode of a photodiode. A synchronized laser is used to illuminate the photocathode with a laser pulse to produce an electron beam with very high brightness, short duration, and current at or near the space charge limit. Operation of the system is described and preliminary test measurements of voltages, synchronization, and jitter are presented for a 5 MeV system. Applications in chemistry, and accelerator research are briefly discussed

High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

Science.gov (United States)

Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

2018-03-01

The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

Calorimetry for absorbed dose measurement at 1-4 MeV electron accelerators

International Nuclear Information System (INIS)

Miller, A.

2000-01-01

Calorimeters are used for dose measurement, calibration and intercomparisons at industrial electron accelerators, and their use at 10 MeV electron accelerators is well documented. The work under this research agreement concerns development of calorimeters for use at electron accelerators with energies in the range of 2-4 MeV. The dose range of the calorimeters is 3-40 kGy, and their temperature stability after irradiation was found to be sufficient for practical use in an industrial environment. Measurement uncertainties were determined to be 5% at k = 2. (author)

50 MeV Run of the IOTA / FAST Electron Accelerator

Energy Technology Data Exchange (ETDEWEB)

Edstrom Jr., D.; et al.

2017-02-02

The low-energy section of the photoinjector-based electron linear accelerator at the Fermilab Accelerator Science & Technology (FAST) facility was recently commissioned to an energy of 50 MeV. This linear accelerator relies primarily upon pulsed SRF acceleration and an optional bunch compressor to produce a stable beam within a large operational regime in terms of bunch charge, total average charge, bunch length, and beam energy. Various instrumentation was used to characterize fundamental properties of the electron beam including the intensity, stability, emittance, and bunch length. While much of this instrumentation was commissioned in a 20 MeV running period prior, some (including a new Martin- Puplett interferometer) was in development or pending installation at that time. All instrumentation has since been recommissioned over the wide operational range of beam energies up to 50 MeV, intensities up to 4 nC/pulse, and bunch structures from ~1 ps to more than 50 ps in length.

A technique for determining electron losses for a 20 MeV microtron

International Nuclear Information System (INIS)

Harisha, P.; Nayak, A.R.; Mehta, S.K.; Soni, H.C.; Siddappa, K.

1999-01-01

A 22 orbit, 20 MeV electron microtron is used as a preaccelerator for the 700 MeV booster synchrotron at INDUS-1, CAT, Indore. Estimation of electron losses at the RF cavity from each orbit is important in obtaining the radiation doses from the body of the microtron. Radiation mapping of the microtron can be used to estimate these loss terms as an alternate to actual measurement by using a measuring probe. (author)

The 600 MeV Saclay electron linac: 40000 hour operation

International Nuclear Information System (INIS)

Netter, F.

1977-01-01

After 40000 hours of operation, the 600 MeV Saclay's electron linac (ALS) does appear as an efficient and versatile tool, for high resolution work (20 μA in ΔE = 40 keV at E = 200MeV), for high power pion production (300 μA in 20 μs pulses at 1000 Hz and 400 MeV or 240 μA in 4 μs pulses at 3000 Hz and 390 MeV), for highly reliable positron beams acceleration, a.s.o. Main improvements made in the recent years are described in particular the automatic beam switching between any two ways among the beam handling system; and the computer newly installed in the control room with a powerful visual display allowing an easy and flexible dialogue of the operators with the computer [fr

Thermoluminescence response of Ge-, Al- and Nd- doped optical fibers by 6 MeV - electron and 6 MeV - photon irradiations

International Nuclear Information System (INIS)

Hossain, I.; Moburak, A. A.; Saeed, M.A.; Wagiran, H.; Hida, N.; Yaakob, H.N.

2015-01-01

In this paper, we report the prediction of thermoluminescence responses of Neodymium-doped SiO 2 optical fibre with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MeV - electron irradiations without requirement for experimental measurements. A technique has been developed to calculate prediction of 6 MeV - electron response of Neodymium-doped SiO 2 optical fibre by observing the measured TL response of 6 MV - photon and the ratio of known measured photon/electron yield ratio distribution for Ge-doped, Al-doped optical fibre and standard TLD 100 dosimeter. The samples were kept in gelatin capsule an irradiated with 6 MV - photon at the dose range from 0.5 Gy to 4.0 Gy. Siemens model Primus 3368 linear accelerator located at Hospital Sultan Ismail, Johor Bahru has been used to deliver the photon beam to the samples. We found the average response ratio of 6 MV - photon and 6 MeV - electron in Ge-doped, Al-doped optical fibre and standard TLD-100 dosimeter are 0.83(3). Observing the measured value of 6 MV - photon irradiation this average ratio is useful to find the prediction of thermoluminescence responses by 6 MeV - electron irradiation of Neodymium-doped SiO 2 optical fibre by the requirement for experimental measurements with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MV - photon irradiations.

Energy monitoring device for 1.5-2.4 MeV electron beams

Energy Technology Data Exchange (ETDEWEB)

Fuochi, P.G., E-mail: fuochi@isof.cnr.i [CNR-ISOF, Via P. Gobetti 101, I-40129 Bologna (Italy); Lavalle, M.; Martelli, A. [CNR-ISOF, Via P. Gobetti 101, I-40129 Bologna (Italy); Kovacs, A. [Institute of Isotopes, HAS, P.O.Box 77, H-1525 Budapest (Hungary); Mehta, K. [Arbeiterstrandbad Strasse 72, Vienna, A-1210 (Austria); Kuntz, F.; Plumeri, S. [Aerial, Parc d' Innovation Rue Laurent Fries F-67400 Illkirch (France)

2010-03-11

An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.

Energy monitoring device for 1.5-2.4 MeV electron beams

Science.gov (United States)

Fuochi, P. G.; Lavalle, M.; Martelli, A.; Kovács, A.; Mehta, K.; Kuntz, F.; Plumeri, S.

2010-03-01

An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.

Results and analysis of free-electron-laser oscillation in a high-energy storage ring

International Nuclear Information System (INIS)

Couprie, M.E.; Velghe, M.; Prazeres, R.; Jaroszynski, D.; Billardon, M.

1991-01-01

A storage-ring free-electron laser at Orsay has been operating since 1989 in the visible wavelength range. In contrast with previous experiments, it operates with positrons and at higher energies (600--800 MeV), with the storage ring Super-ACO (ACO denotes Anneau de Collisions d'Orsay). The optical gain, the laser power, the transverse profile, and the macrotemporal structure of the laser are analyzed. In particular, we show that the gain matrix possesses many off-diagonal elements, which results in lasing on a combination of noncylindrical Gaussian modes. The eigenmode of the laser oscillation is a combination of one or two main Gaussian modes and several higher-order modes, which results in most of the power being extracted in these modes

The drive system of 100 MeV electron linear accelerator

International Nuclear Information System (INIS)

Sun Yuzhen; Su Guoping; Wang Xiulong; Tianlu

1988-06-01

The principle, structure, measurement results and technical performances of microwave drive system for 100MeV electron linear accelerator are presented. In this system the peak power of 15 kW is produced by the S bank middle power klystron. The output power of the klystron is divided into six subdrive lines that drive six high power klystrons respectively. The results show the system with simple structure and good characteristics completely meets the requirements of 100 MeV Linac

Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

International Nuclear Information System (INIS)

Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R.; Hong-Nian Jow

1996-07-01

The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm 3 thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm 3 active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response

RBE comparison between rapid electrons of 20 MeV and 45 MeV with survival rate, DNA synthesis, DNA reparation and nucleoid sedimentation

International Nuclear Information System (INIS)

Alth, G.; Weniger, P.; Turtzer, K.; Klein, W.; Kocsis, F.; Krankenhaus der Stadt Wien-Lainz; Oesterreichisches Forschungszentrum Seibersdorf G.m.b.H. Inst. fuer Biologie)

1982-01-01

In order to find out possible differences of the biologic efficacy of rapid electrons of different energies, the authors examined the influence of rapid electrons of 20 MeV and 45 MeV upon the survival rate of Hela cells S3, their cell growth, DNA synthesis, DNA reparation, and sedimentation of nucleoids. The results show a difference only for the nucleoid sedimentation, i.e. there are more fractured DNA cords after 45 MeV irradiation. No significant differences could be demonstrated for the parameters of the survival curve, DNA synthesis and DNA reparation. Four double tests were carried out corresponding to the indicated types of examination. (orig.) [de

Production and aging of paramagnetic point defects in P-doped floating zone silicon irradiated with high fluence 27 MeV electrons

Science.gov (United States)

Joita, A. C.; Nistor, S. V.

2018-04-01

Enhancing the long term stable performance of silicon detectors used for monitoring the position and flux of the particle beams in high energy physics experiments requires a better knowledge of the nature, stability, and transformation properties of the radiation defects created over the operation time. We report the results of an electron spin resonance investigation in the nature, transformation, and long term stability of the irradiation paramagnetic point defects (IPPDs) produced by high fluence (2 × 1016 cm-2), high energy (27 MeV) electrons in n-type, P-doped standard floating zone silicon. We found out that both freshly irradiated and aged (i.e., stored after irradiation for 3.5 years at 250 K) samples mainly contain negatively charged tetravacancy and pentavacancy defects in the first case and tetravacancy defects in the second one. The fact that such small cluster vacancy defects have not been observed by irradiation with low energy (below 5 MeV) electrons, but were abundantly produced by irradiation with neutrons, strongly suggests the presence of the same mechanism of direct formation of small vacancy clusters by irradiation with neutrons and high energy, high fluence electrons, in agreement with theoretical predictions. Differences in the nature and annealing properties of the IPPDs observed between the 27 MeV electrons freshly irradiated, and irradiated and aged samples were attributed to the presence of a high concentration of divacancies in the freshly irradiated samples, defects which transform during storage at 250 K through diffusion and recombination processes.

Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

Energy Technology Data Exchange (ETDEWEB)

Furuta, Masakazu; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Katayama, Tadashi; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

1993-10-01

In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

Observation of the UPSILON''' at the Cornell electron-storage ring

International Nuclear Information System (INIS)

Finocchiaro, G.; Giannini, G.; Lee-Franzini, J.; Schamberger, R.D. Jr.; Sivertz, M.; Spencer, L.J.; Tuts, P.M.; Boehringer, T.; Costantini, F.; Dobbins, J.; Franzini, P.; Han, K.; Herb, S.W.; Kaplan, D.M.; Lederman, L.M.; Mageras, G.; Peterson, D.; Rice, E.; Yoh, J.K.; Levman, G.

1980-01-01

During an energy scan at the Cornell Electron Storage Ring, with use of the Columbia University-Stony Brook NaI detector, an enhancement in sigma(e + e - →hadrons) is observed at center-of-mass energy approx.10.55 GeV. The mass and leptonic width of this state (UPSILON''') suggest that it is the 4 3 S 1 bound state of the b quark and its anitquark. After applying to the data a cut in a (pseudo) thrust variable, the natural width is measured to be GAMMA=12.6 +- 6.0 MeV, indicating that the UPSILON''' is above the threshold for BB-bar production

Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code

Science.gov (United States)

Peri, Eyal; Orion, Itzhak

2017-09-01

High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.

Out-of-ecliptic quiet time MeV electron increases: Ulysses COSPIN/KET observations

International Nuclear Information System (INIS)

Heber, B.; Ferreira, S.E.S.; Potgieter, M.S.; Henize, V.K.; Moeketsi, D.M.; Fichtner, H.; Kissmann, R.

2004-01-01

The propagation of cosmic rays in turbulent magnetic fields can be studied in detail by way of in-situ measurements of energetic particles in the three-dimensional heliosphere. Measurements of 3-20 MeV electrons from 1990 to 2003 have been made by the Kiel Electron Telescope (KET) onboard the Ulysses spacecraft during varying solar conditions. In order to interpret these measurements, it is necessary to distinguish between solar, galactic and Jovian electrons and to investigate their propagation, by using sophisticated particle propagation models. The solar contribution to the MeV electron intensities can be excluded by analyzing the electron energy spectra and the nuclei time histories. The residual electron intensities can be reasonably described by modulation models taking into account galactic cosmic rays as well as Jovian electrons using different diffusion coefficients for solar minimum and maximum. The way in which the relative contribution of Jovian (point source in the ecliptic) and galactic electrons (isotropic source) varies along the Ulysses orbit is strongly dependent on the choice of these coefficients. Since the 1970's quiet time electron increases have been observed in the ecliptic and interpreted as Jovian electron increases. Therefore, the occurrence of such quiet time electron increases is an indicator for a dominant Jovian contribution to the measured MeV electron intensities. At solar minimum and maximum such events have been observed up to ∼30 deg. and ∼45 deg. These observations are crucial for a determination of the diffusion parameters. At solar maximum a more efficient latitude transport is needed to account for the electron intensity variations

Beam dynamics study of a 30 MeV electron linear accelerator to drive a neutron source

Science.gov (United States)

Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik

2014-02-01

An experimental neutron facility based on 32 MeV/18.47 kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E = 30 MeV, P = 18 kW, dE/E E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2π/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32 MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5 × 1011 n/cm2/s/mA. Future development will be the real design of a 30 MeV electron linac based on S band traveling wave.

Ultrafast electron diffraction with megahertz MeV electron pulses from a superconducting radio-frequency photoinjector

Energy Technology Data Exchange (ETDEWEB)

Feng, L. W.; Lin, L.; Huang, S. L.; Quan, S. W.; Hao, J. K.; Zhu, F.; Wang, F.; Liu, K. X., E-mail: kxliu@pku.edu.cn [Institute of Heavy Ion Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Jiang, T.; Zhu, P. F.; Fu, F.; Wang, R.; Zhao, L.; Xiang, D., E-mail: dxiang@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

2015-11-30

We report ultrafast relativistic electron diffraction operating at the megahertz repetition rate where the electron beam is produced in a superconducting radio-frequency (rf) photoinjector. We show that the beam quality is sufficiently high to provide clear diffraction patterns from gold and aluminium samples. With the number of electrons, several orders of magnitude higher than that from a normal conducting photocathode rf gun, such high repetition rate ultrafast MeV electron diffraction may open up many new opportunities in ultrafast science.

Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

Science.gov (United States)

Du, Jishi; Wu, Jiehua; Zhao, Lili; Song, Lixin

2013-05-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass.

10 MeV RF electron linac for industrial applications

International Nuclear Information System (INIS)

2017-01-01

Electron linacs have found numerous applications in the field of radiation processing on an industrial scale. High power RF electron linacs are commonly used for food irradiation, medical sterilization, cross-linking of polymers, etc. For this purpose, the 10 MeV RF linac has been indigenously designed, developed, commissioned and is being used regularly at 3 kW beam power. This paper gives a brief description of the linac and its utilization for various applications. Safety considerations and regulatory aspects of the linac are also discussed

Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV

Science.gov (United States)

Krauss, A.; Kapsch, R.-P.

2018-02-01

For the ionometric determination of the absorbed dose to water, D w, in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q, are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV.

Science.gov (United States)

Krauss, A; Kapsch, R-P

2018-02-06

For the ionometric determination of the absorbed dose to water, D w , in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q , are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

Electron-positron collision physics: 1 MeV to 2 TeV

International Nuclear Information System (INIS)

Perl, M.L.

1988-07-01

An overview of electron-positron collision physics is presented. It begins at 1 MeV, the energy region of positronium formation, and extends to 2 TeV, the energy region which requires an electron- positron linear collider. In addition, the concept of searching for a lepton-specific forces is discussed. 18 refs., 15 figs., 1 tab

National synchrotron light source VUV storage ring

International Nuclear Information System (INIS)

Blumberg, L.; Bittner, J.; Galayda, J.; Heese, R.; Krinsky, S.; Schuchman, J.; van Steenbergen, A.

1979-01-01

A 700 MeV electron storage ring designed for synchrotron radiation applications is described. Lattice and stability calculations are presented and the vacuum, correction and injection systems are discussed

Neutrino Signals in Electron-Capture Storage-Ring Experiments

Directory of Open Access Journals (Sweden)

Avraham Gal

2016-06-01

Full Text Available Neutrino signals in electron-capture decays of hydrogen-like parent ions P in storage-ring experiments at GSI are reconsidered, with special emphasis placed on the storage-ring quasi-circular motion of the daughter ions D in two-body decays P → D + ν e . It is argued that, to the extent that daughter ions are detected, these detection rates might exhibit modulations with periods of order seconds, similar to those reported in the GSI storage-ring experiments for two-body decay rates. New dedicated experiments in storage rings, or using traps, could explore these modulations.

Monte-Carlo calculations of forward directed bremsstrahlung produced by 20 and 45 MeV electrons on tungsten

International Nuclear Information System (INIS)

Goosman, D.R.

1983-01-01

The SANDYL Monte-Carlo code has been used to calculate the Bremsstrahlung photon production from beams of parallel electrons incident upon three target geometries. These are 20 MeV electrons onto 1 mm of tungsten + 59 mm of Be, which simulates the operating parameters of the FXR electron accelerator at LLNL Bldg. 801, 45 MeV electrons onto 1 mm of tungsten, and finally 45 MeV electrons onto 1 mm of tungsten and 147 mm of Be. The latter two situations simulate possible future modifications to the FXR accelerator. Graphs of the spectral shape of the Bremsstrahlung photons emitted with angles between 0 0 and 1 0 to the electron direction, the angular distribution of photon-MeV, and the dose reduction curves for each of the three geometries are given. The latter dose reduction curves allow one to calculate forward-directed photon fluxes in real-life situations where the electron beam has non-zero angular divergence

Physical design of 9 MeV travelling wave electron linac accelerating tube

International Nuclear Information System (INIS)

Chen Huaibi; Ding Xiaodong; Lin Yuzheng

2000-01-01

An accelerating tube is described. It is a part of an accelerator used for inspection of vehicle cargoes in rail cars, trucks, shipping containers, or airplanes in customs. A klystron with power of 4 MW and frequency of 2856 MHz will be applied to supply microwave power. The electrons can be accelerated by a travelling wave in the accelerating tube about 220 cm long, with a buncher whose capture efficiency is more than 80%. Energy of electrons after travelling through the tube can reach 9 MeV (pulse current intensity 170 mA) or 6 MeV (pulse current intensity 300 mA). Physical design of the accelerating tube, including the calculations of longitudinal particle dynamics, structure parameter and working character is carried out

Compact electron storage rings

International Nuclear Information System (INIS)

Williams, G.P.

1987-01-01

There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

Design and development of 3 MeV, 30 kW DC industrial electron accelerator at Electron Beam Centre, Kharghar

International Nuclear Information System (INIS)

Mittal, K.C.; Nanu, K.; Jain, A.

2006-01-01

High power electron beam accelerators are becoming an important tool for industrial radiation process applications. Keeping this in mind, a 3 MeV, 10 mA, 30 kW DC industrial electron accelerator has been designed and is in advanced stage of development at Electron Beam Center, Kharghar, Navi Mumbai. The operating range of this accelerator is 1 MeV to 3 MeV with maximum beam current of 10 mA. Electron beam at 5 keV is generated in electron gun with LaB 6 cathode and is injected into accelerating column at a vacuum of 10 -7 torr. After acceleration the beam is scanned and taken out in air through a 100 cm X 7 cm titanium window for radiation processing applications. The high voltage accelerating power supply is based on a capacitive coupled parallel fed voltage multiplier scheme operating at 120 kHz. A 50 kW oscillator feeds power to high voltage multiplier column. The electron gun, accelerating column and high voltage multiplier column are housed in accelerator tank filled with SF 6 gas insulation at 6 kg/cm 2 . The accelerator is located in a RCC building with product conveyor for handling products. A central computerized control system is adopted for operation of the accelerator. Accelerator is in the advance stage of commissioning. Many of the subsystems have been commissioned and tested. This paper describes the design details and current status of the accelerator and various subsystems. (author)

Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

Energy Technology Data Exchange (ETDEWEB)

Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brossard, Tom [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Roussin, Ethan [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krebs, John [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

2016-10-31

Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.

Imaging nanoscale spatial modulation of a relativistic electron beam with a MeV ultrafast electron microscope

Science.gov (United States)

Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Liu, Yaqi; Xu, Jun; Yu, Dapeng; Wan, Weishi; Zhu, Yimei; Xiang, Dao; Zhang, Jie

2018-03-01

An accelerator-based MeV ultrafast electron microscope (MUEM) has been proposed as a promising tool to the study structural dynamics at the nanometer spatial scale and the picosecond temporal scale. Here, we report experimental tests of a prototype MUEM where high quality images with nanoscale fine structures were recorded with a pulsed ˜3 MeV picosecond electron beam. The temporal and spatial resolutions of the MUEM operating in the single-shot mode are about 4 ps (FWHM) and 100 nm (FWHM), corresponding to a temporal-spatial resolution of 4 × 10-19 s m, about 2 orders of magnitude higher than that achieved with state-of-the-art single-shot keV UEM. Using this instrument, we offer the demonstration of visualizing the nanoscale periodic spatial modulation of an electron beam, which may be converted into longitudinal density modulation through emittance exchange to enable production of high-power coherent radiation at short wavelengths. Our results mark a great step towards single-shot nanometer-resolution MUEMs and compact intense x-ray sources that may have widespread applications in many areas of science.

Construction of a 1 MeV Electron Accelerator for High Precision Beta Decay Studies

Science.gov (United States)

Longfellow, Brenden

2014-09-01

Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles. Beta decay energy calibration for detectors is typically established using conversion sources. However, the calibration points from conversion sources are not evenly distributed over the beta energy spectrum and the foil backing of the conversion sources produces perturbations in the calibration spectrum. To improve this, an external, tunable electron beam coupled by a magnetic field can be used to calibrate the detector. The 1 MeV electron accelerator in development at Triangle Universities Nuclear Laboratory (TUNL) utilizes a pelletron charging system. The electron gun shoots 104 electrons per second with an energy range of 50 keV to 1 MeV and is pulsed at a 10 kHz rate with a few ns width. The magnetic field in the spectrometer is 1 T and guiding fields of 0.01 to 0.05 T for the electron gun are used to produce a range of pitch angles. This accelerator can be used to calibrate detectors evenly over its energy range and determine the detector response over a range of pitch angles

Development of polystyrene calorimeter for application at electron energies down to 1.5 MeV

DEFF Research Database (Denmark)

Miller, A.; Kovacs, A.; Kuntz, F.

2002-01-01

Polystyrene (PS) calorimeters developed at Riso National Laboratory for use below 4 MeV have been modified due to irradiation technology requirements concerning both design principles and dimensions. The temperature-time relationship after irradiation was measured, and two ways of dose measurement...... the average and the surface dose and to prove the applicability of the new low energy calorimeter for calibration purposes at 1.5 and 2 MeV electron energy. Alanine dosimeters of 2 mm thickness were used to calibrate the calorimeters and their use for nominal dose measurements was demonstrated in a series...... of intercomparisons. The use as routine dosimeters at electron accelerators operating in the energy range of 1.5-4 MeV was also demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved....

POSITRON-ELECTRON DECAY OF SI-28, AT AN EXCITATION-ENERGY OF 50-MEV

NARCIS (Netherlands)

BUDA, A; BACELAR, JC; BALANDA, A; VANDERPLOEG, H; SUJKOWSKI, Z; VANDERWOUDE, A

1993-01-01

The electron-positron pair decay of Si-28 at 50 MeV excitation produced by the isospin T=0 (alpha + Mg-24) and the mixed isospin T=0,1 (He-3 + Mg-25) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI.

Secondary electron emission from 0.5--2.5-MeV protons and deuterons

International Nuclear Information System (INIS)

Thornton, T.A.; Anno, J.N.

1977-01-01

Measurement of the secondary electron currents leaving Al, V, Fe, 316 stainless steel, Nb, and Mo foils undergoing 0.5--2.5-MeV proton and deuteron bombardment were made to determine the secondary electron emission ratios for these ions. The measured secondary electron yields were of the order of 1.0, with the deuterons producing generally higher yields than the protons

Long-term preservation of bacon by high energy electrons

International Nuclear Information System (INIS)

Hannah, K.W.; Simic, M.G.

1985-01-01

Extra long-term storage of frozen, vacuum packed, cured bacon can be achieved by electronation, using 3 MeV electrons generated by an electron accelerator. A combination process consisting of low nitrite curing (40 ppm), smoking, vacuum packaging in Saran plastic, electronation (1 to 3 Mrad), and freezing (-10 C) allows storage for at least 2 1/2 years without any noticeable loss in quality, e.g. color, appearance, smell, or taste. This process also eliminates microbiological hazards associated with Salmonella and C. botulinum. Six Mrad tons/hour throughput of a 3 MeV 50 kw electron beam accelerator for standard sliced bacon packaging indicates a practical and economic commercial use for this combination process. (author)

Planning and Prototyping for a Storage Ring Measurement of the Proton Electric Dipole Moment

Energy Technology Data Exchange (ETDEWEB)

Talman, Richard [Cornell Univ., Ithaca, NY (United States)

2015-07-01

Electron and proton EDM's can be measured in "frozen spin" (with the beam polarization always parallel to the orbit, for example) storage rings. For electrons the "magic" kinetic energy at which the beam can be frozen is 14.5 MeV. For protons the magic kinetic energy is 230 MeV. The currently measured upper limit for the electron EDM is much smaller than the proton EDM upper limit, which is very poorly known. Nevertheless, because the storage ring will be an order of magnitude cheaper, a sensible plan is to first build an all-electric electron storage ring as a prototype. Such an electron ring was successfully built at Brookhaven, in 1954, as a prototype for their AGS ring. This leaves little uncertainty concerning the cost and performance of such a ring. (This is documentedin one of the Physical Review papers mentioned above.)

Interpretation of recent positron-electron measurements between 20 and 800 MeV

International Nuclear Information System (INIS)

Pellerin, C.J.; Hartman, R.C.

1975-01-01

The recent positron and negatron spectra measured by Hartman and Pellerin (see pages 402-407) are discussed with regard to the problem of solar modulation. At energies above 180 MeV, the spherically symmetric Fokker-Planck equation with a diffusion coefficient proportional to particle rigidity provides reasonable fits to both the positron and total electron data. At energies below 180 MeV the data are consistent with a continuation of the same diffusion coefficient and local source of negatrons, or a change in the diffusion coefficient to a constant value. (orig.) [de

Intensity maps of MeV electrons and protons below the radiation belt

International Nuclear Information System (INIS)

Kohno, T.; Munakata, K.; Murakami, H.; Nakamoto, A.; Hasebe, N.; Kikuchi, J.; Doke, T.

1988-01-01

The global distributions of energetic electrons (0.19 - 3.2 MeV) and protons (0.64 - 35 MeV) are shown in the form of contour maps. The data were obtained by two sets of energetic particle telescopes on board the satellite OHZORA. The observed altitude range is 350 - 850 Km. Ten degress meshes in longitude and latitude were used to obtain the intensity contours. A pitch angle distribution of J(α) = J(90). sin n α with n = 5 A is assumed to get the average intensity in each mesh. (author) [pt

Measurement of photon showers in lead produced by electrons of 150 MeV

International Nuclear Information System (INIS)

Goeringer, H.; Eyss, H.J. von; Schoch, B.

1976-01-01

The photon energy spectra induced by 150 MeV electrons in lead were measured in the energy range from 40 MeV up to the primary electron energy. The target thickness was varied between 0.1 and 2.5 radiation lengths X 0 . The photons were analyzed by use of a technique based on deuteron photodisintegration. Differential and integral shower spectra are presented and compared with Monte Carlo calculations of Nagel and Messel et al., both interpolated to our primary energy of 150 MeV. The measured spectra show good agreement with these Monte Carlo calculations for the thickest target of 2.5X 0 and with calculated bremsstrahlung spectra for the thinnest target of 0.1X 0 . Considerable discrepancies, however, are found for medium target thicknesses in the range 0 . Around the shower maxima, the shower spectra are narrower and the maxima are shifted about 0.3-0.4X 0 to lower target thicknesses, furthermore the number of photons at the shower maxima are up to 50% higher than calculated. (Auth.)

Technology on the storage of laser power

International Nuclear Information System (INIS)

Urakawa, Junji

2001-01-01

I report the technology on the storage of laser power using Fabry-Perot Optical Cavity. This technology is applicable for the generation of high brightness X-ray with the combination of compact electron linac or small storage ring in which about 100 MeV electron beam with normalized emittance of 10 -5 m is controlled. The distance of two concave mirrors with high reflectivity is controlled within sub-nm is essential to keep the resonance condition for the storage of laser power. I also report the possibility on several kind of applications and the status of this technology. (author)

Chiral recognition in electron scattering by S- and R-2-butanol

DEFF Research Database (Denmark)

Jones, Nykola C.; Hoffmann, Søren Vrønning; Field, David

2015-01-01

Experiments are described involving the low energy scattering of electrons from the two optical enantiomers S- and R- 2-butanol. Using a synchrotron radiation photoionization source on the ASTRID storage ring, scattering spectra are reported between a few meV and 140 meV at an electron energy...

Evaluation of BPW-34 photodiode answer for 10 MeV electron dosimetry

International Nuclear Information System (INIS)

Khoury, H.J.; Melo, F.A.; Hazin, C.A.

1992-01-01

The viability of commercial photodiodes used for dosimetry of high energy electron beams was studied. The measures were made in a linear accelerators of 10 MeV, using the BPW-34 photodiode. The average energy of electrons on phantom surface and their average range were determined with the photodiode, and the results were compared with the obtained with a ionization chamber of parallel plate. (C.G.C.)

Microwave system of the 7-10 MeV electron linear accelerator ALIN for medical applications

International Nuclear Information System (INIS)

Martin, D.; Iliescu, E.; Stirbet, M.; Oproiu, C.; Vintan, I.

1978-01-01

A detailed description of the Central Institute of Physics 10 MeV linear microwave system and its associated subsystems are presented. Methods of impedance matching to obtain maximum power transfer are described along with broadband design methods for transmission-line impedance transformers. Experimental results for such microwave devices are included. With respect to microwave device performances, simultaneous high efficiency and high power capability with reliability and long life at relatively low unit cost have only recently been achieved as typical device characteristics. Industrial, medical and scientific application of microwave electron accelerators have markedly influenced microwave research progress. Radiographic linear accelerators have grown substantially mainly during the past few years. Following this, the improvements of microwave device performances solicit our attention. The first electron therapy Linear Accelerator ALIN 10 marks a new stage in the development of such instrumentation. Its subsequent ALIN 15 is designed to produce a maximum energy of 18 MeV to widen its applicability in radiotherapy. In addition, a new electron linear accelerator of 8 MeV for nondestructive testing has been started. (author)

Bias dependent charge trapping in MOSFETs during 1 and 6 MeV electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Shinde, N.S. [Department of Chemical Engineering, Mie University, 5148507 (Japan); Kulkarni, V.R.; Mathakari, N.L.; Bhoraskar, V.N. [Department of Physics, Univeristy of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, Univeristy of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

2008-06-15

To study irradiation-induced charge trapping in SiO{sub 2} and around the SiO{sub 2}-Si interface, depletion n-MOSFETs (metal-oxide-semiconductor field effect transistor) were used. The devices were gate biased during 1 and 6 MeV pulsed electron irradiation. The I{sub D}-V{sub DS} (drain current versus drain voltage) and I{sub D}-V{sub GS} (drain current versus gate voltage) characteristics were measured before and after irradiation. The shift in threshold voltage {delta}V{sub T} (difference in threshold voltage V{sub T} before and after irradiation) exhibited trends depending on the applied gate bias during 1 MeV electron irradiation. This behavior can be associated to the contribution of irradiation-induced negative charge {delta}N{sub IT} buildup around the SiO{sub 2}-Si interface to {delta}V{sub T}, which is sensitive to the electron tunneling from the substrates. However, only weak gate bias dependence was observed in 6 MeV electron irradiated devices. Independent of the energy loss and applied bias, the positive oxide trapped charge {delta}N{sub OT} is marginal and can be associated to thin and good quality of SiO{sub 2}. These results are explained using screening of free and acceptor states by the applied bias during irradiation, thereby reducing the total irradiation-induced charges.

Accuracy evaluation of a Compton X-ray spectrometer with bremsstrahlung X-rays generated by a 6 MeV electron bunch

Energy Technology Data Exchange (ETDEWEB)

Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp; Arikawa, Yasunobu; Zhang, Zhe; Ikenouchi, Takahito; Morace, Alessio; Nagai, Takahiro; Abe, Yuki; Sakata, Shouhei; Inoue, Hiroaki; Utsugi, Masaru; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishimura, Yasuhiko; Togawa, Hiromi [Toyota Technical Development Corporation, 1-21 Imae, Hanamoto-cho, Toyota, Aichi 470-0334 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshicho, Toki, Gifu 509-5292 (Japan); Kato, Ryukou [The Institute of Science and Industrial Research, Osaka University, 2-6 Yamada-oka, Suita, Osaka (Japan)

2014-11-15

A Compton-scattering-based X-ray spectrometer is developed to obtain the energy distribution of fast electrons produced by intense laser and matter interactions. Bremsstrahlung X-rays generated by fast electrons in a material are used to measure fast electrons’ energy distribution in matter. In the Compton X-ray spectrometer, X-rays are converted into recoil electrons by Compton scattering in a converter made from fused silica glass, and a magnet-based electron energy analyzer is used to measure the energy distribution of the electrons that recoil in the direction of the incident X-rays. The spectrum of the incident X-rays is reconstructed from the energy distribution of the recoil electrons. The accuracy of this spectrometer is evaluated using a quasi-monoenergetic 6 MeV electron bunch that emanates from a linear accelerator. An electron bunch is injected into a 1.5 mm thick tungsten plate to produce bremsstrahlung X-rays. The spectrum of these bremsstrahlung X-rays is obtained in the range from 1 to 9 MeV. The energy of the electrons in the bunch is estimated using a Monte Carlo simulation of particle-matter interactions. The result shows that the spectrometer's energy accuracy is ±0.5 MeV for 6.0 MeV electrons.

Production of iodine-123 radiobiological specimen on 25 MeV electron beam

International Nuclear Information System (INIS)

Oganesyan, Yu.Ts.; Starodub, G.Ya.; Buklanov, G.V.; Korotkin, Yu.S.; Belov, A.G.

1988-01-01

The technique is described and experimental results are presented for production of radioactive specimen-iodine-123 for medical biological investigations. It is shown that in ten hour irradiation of 124 Xe enriched target of 10 g weight by the 25 MeV electron beam at MT-25 microtron short lived 123 I with activity of about 200 mCl can be accumulated. The procedure was developed for extraction of radioactive atoms and preparing the solution that permits to obtain during 1-1.5 h after the end of irradiation the specimen which satisfies all pharmacopeia requirements. It follows from the results that using small-size electron accelerators with the beam energy up to 25 MeV permits to organize economical and large-scale production of high quality radioactive specimen of 123 I for servicing a large region of this country. 14 refs.; 4 figs.; 1 tab

Positron-electron decay of 28Si at an excitation energy of 50 MeV

International Nuclear Information System (INIS)

Buda, A.; Bacelar, J.C.; Balanda, A.; Ploeg, H. van der; Sujkowski, Z.; Woude, A. van der

1993-01-01

The electron-positron pair decay of 28 Si at 50 MeV excitation produced by the isospin T=0 (α+ 24 Mg) and the mixed isospin T=0, 1 ( 3 He+ 25 Mg) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI. (orig.)

Microdosimetry of 0.5 to 2.0 MeV electron beams

International Nuclear Information System (INIS)

Braby, L.A.; Roesch, W.C.

1980-08-01

The energy imparted in microscopic volumes by electron beams with initial energies from 0.5 to 2.0 MeV has been measured at various depths in plastic. The problems associated with measuring energy deposition spectra of low LET radiations are serious, but the potential importance of these measurements in radiation biophysics justifies the effort required to obtain them. Recent results obtained by Goodhead et al. indicate an RBE greater than 2 for 0.3 keV x-rays compared to 250 kV x-rays, and our results with Chlamydomonas reinhardi indicate an RBE of 1.6 for a 1.5 MeV electron beam at a depth of 400 gm/cm 2 in lucite compared to the same beam at the surface. Development of a theory which appears to explain these results in terms of the microscopic distribution of energy deposition has motivated a detailed study of energy deposition spectra for an electron beam attenuated by various thicknesses of lucite. Simulated sites from 0.5 to 1.9 μm in diameter were studied. The values of anti y determined in these single event measurements compare favorably with those calculated from direct measurements of z reported previously. As expected, the means of the distributions increase significantly with increasing depth in an absorber

5 MeV 300 kW electron accelerator project

International Nuclear Information System (INIS)

Auslender, V.L.; Cheskidov, V.G.; Gornakov, I.V.

2004-01-01

The paper presents a project of a high power linear accelerator for industrial applications. The accelerator has a modular structure and consists of the chain of accelerating cavities connected by the axis-located coupling cavities with coupling slots in the common walls. Main parameters of the accelerator are: operating frequency of 176 MHz, electron energy of up to 5 MeV, average beam power of 300 kW. The required RF pulse power can be supplied by the TH628 diacrode

Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

International Nuclear Information System (INIS)

Du, Jishi; Wu, Jiehua; Zhao, Lili; Song, Lixin

2013-01-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60 Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60 Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass. - Highlights: ► All the three types of irradiation induce the same types of color centers. ► Calculated change of the band gap introduced a paradox. ► Mott and Davis's theory on band gap cannot be adopted in the irradiated glass

Application of clear polymethylmethacrylate dosimeter Radix W to a few MeV electron in radiation processing

International Nuclear Information System (INIS)

Seito, Hajime; Ichikawa, Tatsuya; Hanaya, Hiroaki; Sato, Yoshishige; Kaneko, Hirohisa; Haruyama, Yasuyuki; Watanabe, Hiroshi; Kojima, Takuji

2009-01-01

Characteristics of clear PMMA dosimeter (Radix W) were studied for electron irradiation and compared with the response for gamma irradiation. The dose-response curves were nearly linear up to 30 kGy and become sublinear at higher doses. The radiation-induced absorbance was reduced with 6% within 4 h after irradiation. Dose comparisons were performed for 2, 3, 4 and 5 MeV electron irradiation using cellulose triacetate dosimeter (CTA) (FTR-125) and Radix W dosimeters which were independently calibrated for 2 MeV electrons and 60 Co gamma-rays using calorimeter and ionizing chamber, respectively. The doses estimated by CTA and Radix W were different by about 20%. The magnitude of this difference was, however, independent of electron energy.

MeV energy electron beam induced damage in isotactic polypropylene

Energy Technology Data Exchange (ETDEWEB)

Mathakari, N.L.; Bhoraskar, V.N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

2008-06-15

A few thin films of isotactic polypropylene were irradiated with 6 MeV energy electrons, in the fluence range from 5 x 10{sup 14} to 2 x 10{sup 15} electrons/cm{sup 2}. The structural, optical and mechanical properties were characterized by techniques such as FTIR, UV-vis, XRD, SEM, hardness and contact angle measurements. The FTIR spectra indicate that C-H and C-C bonds are scissioned and an isotactic arrangement of chains is partially destroyed. Moreover, the new carbonyl groups (C=O) are observed, which signifies oxidation. The UV-vis spectra shows a red shift in the absorption edge from pristine value of 240 to 380 nm, which corresponds to decrease in the optical band gap from 5.17 to 3.27 eV. This is because of the formation of conjugated double bonds as well as carbonization. The crystalline properties were analysed using XRD and it shows no profound change. This result may attribute that the radiation-induced changes have probably occurred to a large extent in amorphous regions. However, surface morphology by SEM and contact angle measurements showed considerable surface roughening, which indicates an uneven evolution of gases from the surface. Interestingly, the surface hardness of the films was found to increase with fluence and it may be due to crosslinking and carbonization on the surface. Overall, in conclusion this study shows considerable modifications in the physicochemical properties of isotactic polypropylene irradiated by 6 MeV energy pulsed electrons.

7-MeV electron LINAC based pulse radiolysis facility at RPCD, BARC

International Nuclear Information System (INIS)

Naik, C.B.; Nadkarni, S.A.; Toley, M.A.; Shinde, S.J.; Naik, P.D.

2017-01-01

7-MeV electron LINAC based pulse radiolysis facility is operational in Chemistry Group of BARC since 1986. The Accelerator is housed in B-132 room in basement of Modular Labs. BARC Accelerator was procured from Radiation Dynamics Inc. UK and its detection system was indigenously developed

Temperature and 8 MeV electron irradiation effects on GaAs solar cells

Indian Academy of Sciences (India)

1Department of Physics, Mangalore Institute of Technology and Engineering, ... strate were irradiated with 1 MeV electrons, they showed high radiation tolerance ... under both forward and reverse bias in the temperature range of 270–315 K ...

Dislocation Climb Sources Activated by 1 MeV Electron Irradiation of Copper-Nickel Alloys

DEFF Research Database (Denmark)

Barlow, P.; Leffers, Torben

1977-01-01

Climb sources emitting dislocation loops are observed in Cu-Ni alloys during irradiation with 1 MeV electrons in a high voltage electron microscope. High source densities are found in alloys containing 5, 10 and 20% Ni, but sources are also observed in alloys containing 1 and 2% Ni. The range of ...

Electron Charged Graphite-based Hydrogen Storage Material

Energy Technology Data Exchange (ETDEWEB)

Dr. Chinbay Q. Fan; D Manager

2012-03-14

The electron-charge effects have been demonstrated to enhance hydrogen storage capacity using materials which have inherent hydrogen storage capacities. A charge control agent (CCA) or a charge transfer agent (CTA) was applied to the hydrogen storage material to reduce internal discharge between particles in a Sievert volumetric test device. GTI has tested the device under (1) electrostatic charge mode; (2) ultra-capacitor mode; and (3) metal-hydride mode. GTI has also analyzed the charge distribution on storage materials. The charge control agent and charge transfer agent are needed to prevent internal charge leaks so that the hydrogen atoms can stay on the storage material. GTI has analyzed the hydrogen fueling tank structure, which contains an air or liquid heat exchange framework. The cooling structure is needed for hydrogen fueling/releasing. We found that the cooling structure could be used as electron-charged electrodes, which will exhibit a very uniform charge distribution (because the cooling system needs to remove heat uniformly). Therefore, the electron-charge concept does not have any burden of cost and weight for the hydrogen storage tank system. The energy consumption for the electron-charge enhancement method is quite low or omitted for electrostatic mode and ultra-capacitor mode in comparison of other hydrogen storage methods; however, it could be high for the battery mode.

12 MeV, 4.3 kW electron linear accelerator irradiation application

International Nuclear Information System (INIS)

Hang Desheng; Lai Qiji

2000-01-01

Characteristics of an electron linear accelerator, which has 6-12 MeV energy, 4.2 kW average beam power is introduced. Results show that it has advantages on improving the characteristics of semiconductor devices such as diodes, triodes, SCR, preventing garlic from sprout, preservation of food, and so on

Web based electronic log book for Indus-2

International Nuclear Information System (INIS)

Srivastava, B.S.K.; Fatnani, P.

2011-01-01

Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, India has a 20 MeV Microtron injector, a 450/700 MeV Booster Synchrotron, a 450 MeV Storage Ring Indus-1 and another 2.5 GeV Storage Ring Indus-2. Both the machines are national facilities and are run round the clock to provide synchrotron radiation to users as well as carrying out machine related studies. In a multi accelerator complex like this, an effective system for electronically recording experimental data, machine status, events etc is considered essential. Considering the advantages of Internet technologies, a first version of web based Electronic Logbook (Elogbook) has been developed using HTML, JavaScript, java servlets and SQL database. This Elogbook will provide convenient way to review machine performance, help in problem diagnosis and improve communications among working teams. (author)

Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring

International Nuclear Information System (INIS)

Tanabe, Tetsumi

2006-01-01

At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)

High-resolution inelastic electron scattering on 208Pb at 50 and 63.5 MeV and fragmentation of the magnetic quadrupole strength

International Nuclear Information System (INIS)

Knuepfer, W.; Frey, R.; Richter, A.; Schwierczinski, A.; Spamer, E.; Titze, O.

1977-12-01

High-resolution inelastic electron scattering (FWHM approximately equal to 33 keV) with 50 MeV and 63.5 MeV electrons on 208 Pb has been used to study magnetic excitations between Esub(x) = 6 MeV and 8 MeV. Angular distributions were analyzed in terms of the DWBA with RPA wave functions. Eight Isup(π) = 2- states carrying a total strength ΣB(M2) = 8500 μ 2 sub(K) fm 2 have been found. The strong fragmentation is in qualitative agreement with theoretical predictions. (orig.) [de

Estimation of the measurement effective point in cylindrical ionization chamber used in electron beams with energies between 6 and 20 MeV

International Nuclear Information System (INIS)

Araujo, M.M. de.

1984-01-01

The radial displacement was determined in a water phantom for electrons beams at energies from 6 to 20 MeV for three commercial cylindrical ionization chambers of internal diameters varying from 3.5 to 9.0 mm. The chambers were irradiated with the main axis perpendicular to the direction of the beam. A 300 V bias voltage was applied and readings were taken with both polarities. It was observed that, with increasing depth in the water phantom, the radial displacement remains constant for the 8.9 MeV beam, it increases for the 12.6 MeV electrons and decreases for those of 16.8 and 19.7 MeV. A theoretical model was built in order to calculate the displacement of the effective point of measurement. The Fermi-Eyges multiple scattering theory and a retangular beam normalism developed by Jette (1983) for therapeutic electron beam are used. It was found that the radial displacement stays constant with increasing depth and it decreases with increasing average energy of the incident beam. The model also predicts that the displacement is dependent on the chamber radius. The experimental and theoretical results are compared. They show good agreement for 8.9 and 12.6 MeV electrons, while for 16.8 and 19.7 MeV electrons they indicate that modifications in the theoretical model are necessary. (Author) [pt

Design of scan-horn and beam extraction window for a 3 MeV electron accelerator

International Nuclear Information System (INIS)

Ghodke, S.R.; Acharya, S.; Puthran, G.P.; Majumder, R.; Mittal, K.C.; Mahendra Kumar; Sethi, R.C.

2003-01-01

A 3 MeV, 30 kW D.C. electron accelerator is being developed for installation at the Electron Beam Center at Khargar, Navi Mumbai to cater to industrial uses like cable irradiation. This paper describes the design of the scan horn and beam extraction window of this accelerator. (author)

Project of the compact superconducting storage ring Siberia-SM

Energy Technology Data Exchange (ETDEWEB)

Anashin, V V; Arbuzov, V S; Blinov, G A; Veshcherevich, V G; Vobly, P D; Gorniker, E I; Zinevich, N I; Zinin, E I; Zubkov, N I; Kiselev, V A; Kollerov, E P; Kulipanov, G N; Matveev, Yu G; Medvedko, A S; Mezentsev, N A; Morgunov, L G; Petrov, V M; Petrov, S P; Repkov, V V; Roenko, V A; Skrinsky, A N; Sukhanov, S V; Tokarev, Yu I; Trakhtenberg, E M [AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki

1989-10-10

In the last decade researches dealing with the creation of technology for X-ray lithography and for appropriate production equipment have been performed in many countries. The basic aim of these works is to provide a mass production of inexpensive devices with submicron structures (0.7-0.1 {mu}m). Bringing X-ray lithographic technology into commercial practice necessitates to design and build a dedicated SR source for the electronic industry. The use of superconducting bending magnets with 40-70 kG field strength enables the storage ring circumference to be reduced by a factor of 2-5 and the injection energy by a factor of 3-4 as compared to the conventional designs of storage rings. In the present paper we consider a storage ring which was designed for a maximum energy of 600 MeV, with 60 kG field strength in its bending magnets and 10 m circumference. The critical SR wavelength is 8.6 A. The electrons are injected into the storage ring at 50-60 MeV and the maximum stored current is assumed to be equal to 0.3 A. (orig.).

Effect of 1.5 MeV electron irradiation on β-Ga2O3 carrier lifetime and diffusion length

Science.gov (United States)

Lee, Jonathan; Flitsiyan, Elena; Chernyak, Leonid; Yang, Jiancheng; Ren, Fan; Pearton, Stephen J.; Meyler, Boris; Salzman, Y. Joseph

2018-02-01

The influence of 1.5 MeV electron irradiation on minority transport properties of Si doped β-Ga2O3 vertical Schottky rectifiers was observed for fluences up to 1.43 × 1016 cm-2. The Electron Beam-Induced Current technique was used to determine the minority hole diffusion length as a function of temperature for each irradiation dose. This revealed activation energies related to shallow donors at 40.9 meV and radiation-induced defects with energies at 18.1 and 13.6 meV. Time-resolved cathodoluminescence measurements showed an ultrafast 210 ps decay lifetime and reduction in carrier lifetime with increased irradiation.

Calibration of a silicon semiconductor detecter using a 2 MeV electron accelerator beam

International Nuclear Information System (INIS)

Fleurot, N.; Gouard, P.; Mazataud, E.; Nail, M.; Savy, C.; Bayer, C.; Cauchois, Y.; Kherouf, R.; Mathieu, D.

1981-01-01

This paper describes the current mode calibration, carried out on a 2 MeV electron accelerator, of PIN detectors involved in electron spectrum measurements for laser-matter interaction experiments. A theoretical analysis simulating the interaction between the incident electrons and the irradiated medium has been carried out using the FOTELEC code. It accounts well for the experimental results giving a reasonable value for the mean electron-hole pair formation energy when back-scattering corrections are included. This work provides the transfer function data required for a plasma diagnostic spectrometer. (orig.)

Photoreactivity in Saccharomyces cerevisiae cells after irradiation with 25 MeV electrons

International Nuclear Information System (INIS)

Tsyb, T.S.; Seleva, N.G.; Myasnik, M.N.; Kabakova, N.M.

1986-01-01

Significant photoreactivation was noted in radio- and UV-sensitive rad-mutants of Saccharomyces cerevisiae cells exposed to 25 MeV electrons. In order to make the photoreactivable damage be manifest anoxic conditions of irradiation should be chosen as optimal ones. It was shown that the low oxygen effect was partially associated with the photoreactivable damage involved in the lethal effect of ionizing radiation

6 MeV pulsed electron beam induced surface and structural changes in polyimide

Energy Technology Data Exchange (ETDEWEB)

Mathakari, Narendra L.; Bhoraskar, Vasant N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Ganeshkhind, Pune 411007, Maharashtra (India); Dhole, Sanjay D., E-mail: sanjay@physics.unipune.ernet.i [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Ganeshkhind, Pune 411007, Maharashtra (India)

2010-04-15

Thin films of polyimide (PMDA-ODA, Kapton) having 50 mum thickness were irradiated with 6 MeV pulsed electron beam. The bulk and surface properties of pristine and irradiated samples were characterized by several techniques such as stress-strain measurements, Fourier Transform Infrared (FTIR), UV-vis spectroscopy, contact angle, atomic force microscopy (AFM) and profilometry. The tensile strength, percentage elongation and strain energy show an enhancement from pristine value of 73-89 MPa, 10-22% and 4.75-14.2 MJ/m{sup 3} respectively at the maximum fluence of 4 x 10{sup 15} electrons/cm{sup 2}. This signifies that polyimide being an excessively aromatic polymer is crosslinked due to high-energy electron irradiation. In surface properties, the contact angle shows a significant decrease from 59 deg. to 32 deg. indicating enhancement in hydrophilicity. This mainly attributes to surface roughening, which is due to the electron beam induced sputtering. The surface roughening is confirmed in AFM and profilometry measurements. The AFM images clearly show that surface roughness increases after electron irradiation. Moreover, the roughness average (R{sub a}) as measured from surface profilograms is found to increase from 0.06 to 0.1. The FTIR and UV-vis spectra do not show noticeable changes as regards to scissioning of bonds and the oxidation. This work leads to a definite conclusion that 6 MeV pulsed electron beam can be used to bring about desired changes in surface as well as bulk properties of polyimide, which is considered to be a high performance space quality polymer.

Revealing by secondary electronic emission of internal electric fields in the yttriated zirconia, irradiated by electrons of 1 MeV

International Nuclear Information System (INIS)

Blaise, G.; Paris-11 Univ., 91 - Orsay

2007-01-01

The defects due to irradiation in a dielectric material present an activity which can generate macroscopic internal electric fields. A method of investigation of these fields, based on the measure of the Secondary Electronic Emission coefficient, has been developed on a scanning electric microscope. This ones contains two low noise detectors which respectively measure the influence current I IC produced by the charges trapping in the material and the current I SB due to secondary and backscattered electrons which come from the sample. The Secondary Emission coefficient is given by σ=I SB /(I SB +I IC ). The charges trapping during an electrons injection leads to a variation of σ for its intrinsic value σ 0 relative to the uncharged material, until the stationary value σ st =1 corresponding to the auto-regulated condition. This variation is due to the development of an internal electric field produced by the accumulation of the charges trapped during injection. In comparing the evolutions of σ of a fresh yttriated zirconia and of an yttriated zirconia irradiated by electrons of 1 MeV with a dose rate of 10 18 e/cm 2 , it has been revealed that an internal field (due to irradiation) of about 0.5*10 6 V/m exists at a depth of the micron order. This field, directed towards the outside of the material surface, is attributed to the F + defects and to the T centers produced by the impact of the electrons of 1 MeV. In carrying out annealings until 1000 K, a progressive disappearance of this field is observed in the temperature range of 400-600 K, directly due to the F + defects and T centers recovery, as it has been observed by ESR. An internal field three times weaker than the preceding ones has been revealed at a few nm under the surface. Its disappearance from a temperature of 1000 K suggests that it is due to the redistribution of the chemical species into the surface, during the irradiation with electrons of 1 MeV. (O.M.)

Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

CERN Document Server

Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

2005-01-01

An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

A measurement of auroral electrons in the 1–10 MeV range

NARCIS (Netherlands)

Gils, J.N. van; Beek, H.F. van; Fetter, L.D. de; Hendrickx, R.V.

Particle fluxes have been measured by means of shielded Geiger-Müller telescopes mounted m a rocket, which was launched from ESRANGE(Kiruna) into a diffuse aurora. The analysis of the dependence of the counting rates on altitude indicates that a weak flux of energetic electrons, 1–10 MeV, has been

Calculation of wake field and couple impedance of upgraded and old RF cavity in Hefei electron storage ring

International Nuclear Information System (INIS)

Xu Hongliang; Wang Lin; Sun Baogen; Li Weimin; Liu Jinying; He Duohui

2003-01-01

The phase II upgrading project of Hefei 800 MeV electron storage ring is being done, and the important component of the project, the RF cavity, will be finished soon. The old RF cavity with many disadvantages will be replaced by the new one. To estimate the effect of RF cavity coupling impedance to storing bunch intensity fully, the wake potential and the broad band couple impedance of RF cavity were calculated with MAFIA program. And the calculation results were compared between new and old cavity, it is found that the impedance of the new is bigger than that of the old

Low emittance lattices for electron storage rings revisited

International Nuclear Information System (INIS)

Trbojevic, D.; Courant, E.

1994-01-01

Conditions for the lowest possible emittance of the lattice for electron storage rings are obtained by a simplified analytical approach. Examples of electron storage lattices with minimum emittances are presented. A simple graphical presentation in the normalized dispersion space (Floquet's transformation) is used to illustrate the conditions and results

Utilization of 5 MeV electron accelerator center and perspective

International Nuclear Information System (INIS)

Tanaka, Hiromi

1990-01-01

Electron beam process gives instantaneous effect as compared with heating process, and has such merits that energy consumption is very small, objects can be treated from outside, harmful chemicals are not used and treatment can be done as packed. The spread of electron beam process is largely due to the results of the development of highly reliable accelerators and utilization technologies, but as observed from all industrial fields, it is limited to only a part. In order to contribute to the solution of problems and the spread of electron beam process, Sumitomo Heavy Industries, Ltd. installed a 5 MeV, 200 kW large power accelerator developed by RDI in USA in the Electron Irradiation Application and Development Center opened in Tsukuba City. The Center was completed in June, 1989, and has carried out the activities of the development of irradiation utilization technologies, test irradiation and entrusted irradiation service. The features of electron beam process are high dose rate, the possibility of on and off as occasion demands, the preparation of radiation sources and the disposal of wastes being unnecessary, and no environmental problem. The industrialized processes, the types, energy and use of electron accelerators, the Tsukuba irradiation facilities and others are reported. (K.I.)

Radiation damage of silicon structures with electrons of 900 MeV

CERN Document Server

Rachevskaia, I; Bosisio, L; Dittongo, S; Quai, E; Rizzo, G

2002-01-01

We present first results on the irradiation of double-sided silicon microstrip detectors and test structures performed at the Elettra synchrotron radiation facility at Trieste, Italy. The devices were irradiated with 900 MeV electrons. The test structures we used for studying bulk, surface and oxide irradiation damage were guard ring diodes, gated diodes and MOS capacitors. The test structures and the double-sided microstrip detectors were produced by Micron Semiconductor Ltd. (England) and IRST (Trento, Italy). For the first time, bulk-type inversion is observed to occur after high-energy electron irradiation. Current and inter-strip resistance measurements performed on the microstrip detectors show that the devices are still usable after type inversion.

Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

International Nuclear Information System (INIS)

Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.

2015-01-01

The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D 10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation. - Highlights: • 10 MeV eBeam energy was attenuated to 2.9±0.22 MeV using HDPE sheets. • Attenuation of eBeam energy does not affect the inactivation kinetics of Salmonella. • Microbial inactivation is independent of eBeam energy in the range of 3–10 MeV

Electron Storage Ring Development for ICS Sources

Energy Technology Data Exchange (ETDEWEB)

Loewen, Roderick [Lyncean Technologies, Inc., Palo Alto, CA (United States)

2015-09-30

There is an increasing world-wide interest in compact light sources based on Inverse Compton Scattering. Development of these types of light sources includes leveraging the investment in accelerator technology first developed at DOE National Laboratories. Although these types of light sources cannot replace the larger user-supported synchrotron facilities, they offer attractive alternatives for many x-ray science applications. Fundamental research at the SLAC National Laboratory in the 1990’s led to the idea of using laser-electron storage rings as a mechanism to generate x-rays with many properties of the larger synchrotron light facilities. This research led to a commercial spin-off of this technology. The SBIR project goal is to understand and improve the performance of the electron storage ring system of the commercially available Compact Light Source. The knowledge gained from studying a low-energy electron storage ring may also benefit other Inverse Compton Scattering (ICS) source development. Better electron storage ring performance is one of the key technologies necessary to extend the utility and breadth of applications of the CLS or related ICS sources. This grant includes a subcontract with SLAC for technical personnel and resources for modeling, feedback development, and related accelerator physics studies.

DELSY project: status and development Dubna Electron Synchrotron

CERN Document Server

Balalykin, N; Bykovsky, V

2003-01-01

The DELSY (Dubna Electron Synchrotron) project is under development at the Joint Institute for Nuclear Research. It is based on an acceleration facility donated to the Joint Institute for Nuclear Research by the Institute for Nuclear and High Energy Physics (NIKHEF, Amsterdam). The NIKHEF accelerator facility consists of the linear electron accelerator MEA, which has an electron energy of 700 MeV, and the electron storage ring AmPS, with a maximum energy of 900 MeV and a beam current of 200 mA. There are three phases to the construction of the DELSY facility. Phase I will be accomplished with the construction of a complex of free-electron lasers covering continuously the spectrum from the far infrared down to the ultraviolet (approx 150 nm). Phase II will be accomplished with the commissioning of the storage ring DELSY. Complete commissioning of the DELSY project will take place after finishing Phase III, the construction of an X-ray free-electron laser. This phase is considered as the ultimate goal of the pr...

MeV gamma-ray observation with a well-defined point spread function based on electron tracking

Science.gov (United States)

Takada, A.; Tanimori, T.; Kubo, H.; Mizumoto, T.; Mizumura, Y.; Komura, S.; Kishimoto, T.; Takemura, T.; Yoshikawa, K.; Nakamasu, Y.; Matsuoka, Y.; Oda, M.; Miyamoto, S.; Sonoda, S.; Tomono, D.; Miuchi, K.; Kurosawa, S.; Sawano, T.

2016-07-01

The field of MeV gamma-ray astronomy has not opened up until recently owing to imaging difficulties. Compton telescopes and coded-aperture imaging cameras are used as conventional MeV gamma-ray telescopes; however their observations are obstructed by huge background, leading to uncertainty of the point spread function (PSF). Conventional MeV gamma-ray telescopes imaging utilize optimizing algorithms such as the ML-EM method, making it difficult to define the correct PSF, which is the uncertainty of a gamma-ray image on the celestial sphere. Recently, we have defined and evaluated the PSF of an electron-tracking Compton camera (ETCC) and a conventional Compton telescope, and thereby obtained an important result: The PSF strongly depends on the precision of the recoil direction of electron (scatter plane deviation, SPD) and is not equal to the angular resolution measure (ARM). Now, we are constructing a 30 cm-cubic ETCC for a second balloon experiment, Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment: SMILE-II. The current ETCC has an effective area of 1 cm2 at 300 keV, a PSF of 10° at FWHM for 662 keV, and a large field of view of 3 sr. We will upgrade this ETCC to have an effective area of several cm2 and a PSF of 5° using a CF4-based gas. Using the upgraded ETCC, our observation plan for SMILE-II is to map of the electron-positron annihilation line and the 1.8 MeV line from 26Al. In this paper, we will report on the current performance of the ETCC and on our observation plan.

Detailed studies of a high-density polarized hydrogen gas target for storage rings

International Nuclear Information System (INIS)

Zapfe, K.; Brueckner, W.; Gaul, H.G.; Grieser, M.; Lin, M.T.; Moroz, Z.; Povh, B.; Rall, M.; Stechert, B.; Steffens, E.; Stenger, J.; Stock, F.; Tonhaeuser, J.; Montag, C.; Rathmann, F.; Fick, D.; Braun, B.; Graw, G.; Haeberli, W.

1996-01-01

A high-density target of polarized atomic hydrogen gas for applications in storage rings was produced by injecting atoms from an atomic beam source into a T-shaped storage cell. The influence of the internal gas target on electron-cooled beams of 27 MeV α-particles and 23 MeV protons in the Heidelberg Test Storage Ring has been studied in detail. Target polarization and target thickness were measured by means of 27 MeV α-particles. For hyperfine states 1+2 a target thickness of n=(0.96±0.04) x 10 14 H/cm 2 was achieved with the cell walls cooled to 100 K. Working with a weak magnetic holding field (∼5 G) the maximum target polarization was P T =0.84±0.02 when state 1 and P T =0.46±0.01 when states 1+2 were injected. The target polarization was found to be constant over a period of 3 months with a net charge of Q∼100 C passing the storage cell. (orig.)

Electron Cooling of RHIC

CERN Document Server

Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

2005-01-01

We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

Calibration of imaging plates to electrons between 40 and 180 MeV

International Nuclear Information System (INIS)

Rabhi, N.; Batani, D.; Boutoux, G.; Ducret, J.-E.; Bohacek, K.; Guillaume, E.; Thaury, C.; Jakubowska, K.; Thfoin, I.

2016-01-01

This paper presents the response calibration of Imaging Plates (IPs) for electrons in the 40-180 MeV range using laser-accelerated electrons at Laboratoire d’Optique Appliquée (LOA), Palaiseau, France. In the calibration process, the energy spectrum and charge of electron beams are measured by an independent system composed of a magnetic spectrometer and a Lanex scintillator screen used as a calibrated reference detector. It is possible to insert IPs of different types or stacks of IPs in this spectrometer in order to detect dispersed electrons simultaneously. The response values are inferred from the signal on the IPs, due to an appropriate charge calibration of the reference detector. The effect of thin layers of tungsten in front and/or behind IPs is studied in detail. GEANT4 simulations are used in order to analyze our measurements.

Detection of electrons in the 10 MeV range by plastic scintillators

Energy Technology Data Exchange (ETDEWEB)

Beaudoin, G; Champagne, A; Jeremie, H; Lessard, L

1986-09-10

Response functions for electrons from 1 to 12 MeV have been measured with a plastic scintillator telescope. A parametrization model for these response functions has been found to give good results at all energies. Furthermore it was established that the type of reflector used for the scintillator has a considerable influence on the response functions. A mechanism for this influence has been proposed and tested by Monte Carlo calculations.

Experience with the Alderson Rando phantom. [17-MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Somerwil, A; Kleffens, H.J. Van [Rotterdams Radio Therapeutisch Instituut (Netherlands)

1977-04-01

The dose delivered to the spinal cord is of particular interest in electron beam therapy of medulloblastoma. Lithium fluoride thermoluminescent dosimetry has been used in an assessment of the dose distributions from a 17 MeV electron beam in an Alderson Rando Phantom (Alderson, S.W., Lanzl, L.H., Rollins, M., and Spira, J., 1962, American J. of Roentgenology, Radium Therapy and Nuclear Medicine, vol. 87, 185). Measurements were also made on three autopsy specimens immersed in water. There were substantial differences between the two sets of results. The density of the bony part of the phantom seemed to be markedly lower than that of the water; radiographs of various parts of the phantom confirmed that large areas of low density existed. The manufacturers have stated that in order to simulate true in vivo conditions, an artificial skeleton would have to be introduced into the tissue-like material of the phantom, and that the real skeletons now used appear to be unsuitable for electron beam dosimetry. It is therefore doubtful whether this electron beam dosimetry justifies the expense associated with the insertion of these unsatisfactory skeletons into the soft tissue-equivalent material.

Application of FEL technique for constructing high-intensity, monochromatic, polarized gamma-sources at storage rings

Energy Technology Data Exchange (ETDEWEB)

Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

1995-12-31

A possibility to construct high-intensity tunable monochromatic{gamma}-source at high energy storage rings is discussed. It is proposed to produce {gamma}-quanta by means of Compton backscattering of laser photons on electrons circulating in the storage. The laser light wavelength is chosen in such a way that after the scattering, the electron does not leave the separatrix. So as the probability of the scattering is rather small, energy oscillations are damped prior the next scattering. As a result, the proposed source can operate in {open_quotes}parasitic{close_quote} mode not interfering with the main mode of the storage ring operation. Analysis of parameters of existent storage rings (PETRA, ESRF, Spring-8, etc) shows that the laser light wavelength should be in infrared, {lambda}{approximately} 10 - 400 {mu}m, wavelength band. Installation at storage rings of tunable free-electron lasers with the peak and average output power {approximately} 10 MW and {approximately} 1 kW, respectively, will result in the intensity of the {gamma}-source up to {approximately} 10{sup 14}s{sup -1} with tunable {gamma}-quanta energy from several MeV up to several hundreds MeV. Such a {gamma}-source will reveal unique possibilities for precision investigations in nuclear physics.

Design and modelling of a 5 MeV radio frequency electron gun

International Nuclear Information System (INIS)

Batchelor, K.; Sheehan, J.; Woodle, M.

1988-01-01

The Accelerator Test Facility (ATF) at Brookhaven National Laboratory is a linac-laser complex for research into laser acceleration and for the generation of coherent radiation from electron beams. In order to achieve the design 50 MeV output emittance (γσ/sub x/σ/sub x/') of less than 3 /times/ 10/sup /minus/5/ m rad a high brightness electron gun is required. This paper describes computations and measurements made on a full scale brass model of a 1-1/2 cell, π-mode, resonant, disc loaded, radiofrequency gun structure which has been designed for this purpose. 7 refs., 9 figs., 6 tabs

First studies of 500-nm Cherenkov radiation from 255-MeV electrons in a diamond crystal

Energy Technology Data Exchange (ETDEWEB)

Takabayashi, Y., E-mail: takabayashi@saga-ls.jp [SAGA Light Source, 8-7 Yayoigaoka, Tosu, Saga 841-0005 (Japan); Fiks, E.I. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Pivovarov, Yu.L. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); National Research Tomsk State University, 634050 Tomsk (Russian Federation)

2015-06-12

The first experiment on Cherenkov light from 255-MeV electrons passing through a 50-μm-thick diamond crystal in a special geometry allowing extraction of 500-nm Cherenkov light at a right angle with respect to the electron beam direction has been performed at the injector linac of SAGA Light Source accelerator facility. The dependence of 500-nm Cherenkov light intensity (separated by a band-pass filter) on the crystal rotation angle was measured by a CCD detector. The experimentally obtained rocking curve with an intense maximum is theoretically explained as the projector effect of Cherenkov light deflected by the exit surface of the crystal. The width of the rocking curve is explained by the convolution of the standard Tamm–Frank angular distribution of Cherenkov radiation with chromatic aberration, the multiple scattering of electrons in a crystal, and initial electron beam angular divergence. In addition, it is found that the Cherenkov light intensity did not change under the (220) planar channeling condition, which is consistent with a recent theory. - Highlights: • Cherenkov light from 255-MeV electrons in a diamond crystal has been investigated. • The Cherenkov light from channeled electrons has been observed for the first time. • The experimental results are in good agreement with theory.

Subnanosecond pulsing of an 1 MeV ELIT electron accelerator by beam deflection

International Nuclear Information System (INIS)

Vasserman, S.B.; Kuzenko, V.; Mehnert, R.; Hermann, R.

1984-01-01

Operation principle and performance of a beam deflection system developed for subnanosecond pulsing of an 1 MeV ELIT resonance transformer accelerator are described. Using this system a minimum pulse duration of 0.5 ns (FWHM) and a dose per pulse of about 20 Gy were obtained. As an example the fluorescence of cyclohexane excited by the subnanosecond electron pulse was measured. (author)

Effect of MeV Electron Radiation on Europa’s Surface Ice Analogs

Science.gov (United States)

Gudipati, Murthy; Henderson, Bryana; Bateman, Fred

2017-10-01

MeV electrons that impact Europa’s trailing hemisphere and cause both physical and chemical alteration of the surface and near-surface. The trailing hemisphere receives far lower fluxes above 25 MeV as compared with lower energy particles, but can cause significant chemical and physical modifications at these energies. With NASA's planned Europa Clipper mission and a Europa Lander Concept on the horizon, it is critical to understand and quantify the effect of Europa’s radiation environment on the surface and near surface.Electrons penetrate through ice by far the deepest at any given energy compared to protons and ions, making the role of electrons very important to understand. In addition, secondary radiation - Bremsstrahlung, in X-ray wavelengths - is generated during high-energy particle penetration through solids. Secondary X-rays are equally lethal to life and penetrate even deeper than electrons, making the cumulative effect of radiation on damaging organic matter on the near surface of Europa a complex process that could have effects several meters below Europa’s surface. Other physical properties such as coloration could be caused by radiation.In order to quantify this effect under realistic Europa trailing hemisphere conditions, we devised, built, tested, and obtained preliminary results using our ICE-HEART instrument prototype totally funded by JPL’s internal competition funding for Research and Technology Development. Our Ice Chamber for Europa High-Energy Electron And Radiation-Environment Testing (ICE-HEART) operates at ~100 K. We have also implemented a magnet that is used to remove primary electrons subsequent to passing through an ice column, in order to determine the flux of secondary X-radiation and its penetration through ice.Some of the first results from these studies will be presented and their relevance to understand physical and chemical properties of Europa’s trailing hemisphere surface.This work has been carried out at Jet

Radiation from 39 and 45 MEV electrons channeled in lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Diedrich, E.; Kufner, W.; Buschhorn, G. (Max-Planck-Institut fuer Physik und Astrophysik, Muenchen (Germany). Werner-Heisenberg-Inst. fuer Physik)

1991-12-01

Channeling radiation from 39 and 45 MeV electrons channeled along the (0001) axis, the (0110) plane and the (1210) plane of a 30 {mu}m thick LiNbO{sub 3} crystal has been measured. Calculations of the planar crystal potentials were performed by means of the many-beam formalism. Good agreement between theory and experiment is obtained for the planar channeling radiation. Associated with channeling, additional radiation lines have been observed, which may be explained by a periodic perturbation of the continuum potential. (author).

Angular distributions for the charged components in a cascade shower induced by 350 MeV electrons

International Nuclear Information System (INIS)

Kobayashi, S.; Itoh, H.; Murakami, A.; Muto, T.

1978-01-01

The angular distributions of secondary electrons contained in a cascade shower are studied by using a streamer chamber. The primary electrons with energy of about 350 MeV are incident on a lead converter of various thickness. The angular data are analyzed for the number of electrons in a shower, and for the converter thickness. The obtained distributions show a systematic agreement with the Monte Carlo calculations presented by Messel and Crawford. (Auth.)

Electron cloud dynamics in the Cornell Electron Storage Ring Test Accelerator wiggler

Directory of Open Access Journals (Sweden)

C. M. Celata

2011-04-01

Full Text Available The interference of stray electrons (also called “electron clouds” with accelerator beams is important in modern intense-beam accelerators, especially those with beams of positive charge. In magnetic wigglers, used, for instance, for transverse emittance damping, the intense synchrotron radiation produced by the beam can generate an electron cloud of relatively high density. In this paper the complicated dynamics of electron clouds in wigglers is examined using the example of a wiggler in the Cornell Electron Storage Ring Test Accelerator experiment at the Cornell Electron Storage Ring. Three-dimensional particle-in-cell simulations with the WARP-POSINST computer code show different density and dynamics for the electron cloud at locations near the maxima of the vertical wiggler field when compared to locations near the minima. Dynamics in these regions, the electron cloud distribution vs longitudinal position, and the beam coherent tune shift caused by the wiggler electron cloud will be discussed.

Coherent bremsstrahlung and channeling radiation from electrons of one to three MeV in silicon and gold

International Nuclear Information System (INIS)

Watson, J.E.

1981-01-01

The observation of sharp peaks in the x-ray spectrum from 1 to 3 MeV electrons striking thin single crystals of silicon and gold is reported. These peaks were observed in the range 1 to 25 keV. The peaks are of two different origins, both direct results of the periodic nature of the target crystals. The first kind of radiation is caused by the interference of incoming and scattered electron wave functions. Because of the periodicity of the target material there is a coherence effect for certain bremsstrahlung wave vectors. This coherent bremsstrahlung, though well known at very high electron energies, has never been adequately studied at electron energies below several hundred MeV. Detailed agreement between theoretical prediction and observation in silicon is shown. The second kind of radiation is caused by electrons channeled along major crystal axes. The electrons enter certain quantized orbits as they channel and may emit photons as a consequence of transitions between the various orbits. Observations of channeling radiation for various crystal axes in silicon are presented. Both phenomena were observed in gold, the first such observation for any metallic target

Physics design of a 10 MeV, 6 kW travelling wave electron linac

Indian Academy of Sciences (India)

We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear accelerator (linac), which has been recently built and successfully operated at Raja Ramanna Centre for Advanced Technology, Indore. The accelerating structure is a 2 π / 3 mode constant impedance travelling wave structure, which ...

Design of cavities of a standing wave accelerating tube for a 6 MeV electron linear accelerator

Directory of Open Access Journals (Sweden)

S Zarei

2017-08-01

Full Text Available Side-coupled standing wave tubes in  mode are widely used in the low-energy electron linear accelerator, due to high accelerating gradient and low sensitivity to construction tolerances. The use of various simulation software for designing these kinds of tubes is very common nowadays. In this paper, SUPERFISH code and COMSOL are used for designing the accelerating and coupling cavities for a 6 MeV electron linear accelerator. Finite difference method in SUPERFISH code and Finite element method in COMSOL are used to solve the equations. Besides, dimension of accelerating and coupling cavities and also coupling iris dimension are optimized to achieve resonance frequency of 2.9985 MHz and coupling constant of 0.0112. Considering the results of this study and designing of the RF energy injection port subsequently, the construction of 6 MeV electron tube will be provided

238U and 237Np nuclear fission by 90-270 MeV electrons

International Nuclear Information System (INIS)

Kuznetsov, V.L.; Nedorezov, V.G.; Nikitina, N.V.; Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.; Smirnov, A.N.; Ehjsmont, V.P.

1981-01-01

A technique for measuring cross sections of 238 U and 237 Np nuclei fission caused by 90-270 MeV electrons is described. Measurement results are given. The results obtained are discussed on the basis of the virtual photon method. It is shown that the difference in cross sections of 238 U and 237 Np electrofission is due to the different contribution of the giant resonance [ru

Identification of defects in GaAs induced by 1 MeV electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Lai, S.T.; Nener, B.D.; Faraone, L.; Nassibian, A.G. [Western Australia Univ., Nedlands, WA (Australia); Hotchkis, M.A.C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1993-12-31

This paper shows that 1 MeV electron irradiation on n-type vapor phase epitaxial (VPE) GaAs creates three electron traps E1, E2 and EL6, and results in the splitting of the EL2 center into two levels EL2-A and EL2-B. A 15 minutes isochronal anneal results in the annihilation of the E1 and E2 traps, a reduction in EL6 trap concentration, and the return of EL2 to a single level EL2-A. A defect model is outlined which correlates with the observed results. 4 refs., 2 tabs., 3 figs.

Identification of defects in GaAs induced by 1 MeV electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Lai, S T; Nener, B D; Faraone, L; Nassibian, A G [Western Australia Univ., Nedlands, WA (Australia); Hotchkis, M A.C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1994-12-31

This paper shows that 1 MeV electron irradiation on n-type vapor phase epitaxial (VPE) GaAs creates three electron traps E1, E2 and EL6, and results in the splitting of the EL2 center into two levels EL2-A and EL2-B. A 15 minutes isochronal anneal results in the annihilation of the E1 and E2 traps, a reduction in EL6 trap concentration, and the return of EL2 to a single level EL2-A. A defect model is outlined which correlates with the observed results. 4 refs., 2 tabs., 3 figs.

Electronic Monitoring Of Storage And Transport Temperatures Of ...

African Journals Online (AJOL)

Electronic Monitoring Of Storage And Transport Temperatures Of Thermostable Newcastle ... 22) were monitored during storage and transport from vaccine production laboratory in Temeke, Dar es ... EMAIL FULL TEXT EMAIL FULL TEXT

Optimization of beam parameters of electron gun for 2.5 MeV/100 kW high power industrial accelerator

International Nuclear Information System (INIS)

Pramod, R.; Petwal, V.C.

2009-01-01

A 2.5 MeV/100 kW transformer type industrial accelerator is being developed at RRCAT. A Pierce type electron gun consisting of 10 mm diameter LaB 6 disc (indirectly heated) is used as a source of electron beam. The cathode assembly is put on the top of the accelerating structure, which consists of many electrostatic lenses of which the first lens acts as anode of the gun. The quality of the beam injected into the accelerating structure depends on the anode voltage, shape and size of anode and its distance from the cathode. The anode is subjected to variable voltage during the operation of accelerator from energy 1 MeV to 2.5 MeV, which results in variable emittance at the exit of the electron gun. The electron beam from the gun should provide parallel or slightly convergent beam with long focal length and the emittance of the beam at the exit of electron gun should match the beam acceptance limit of the accelerating structure. The EGUN code is used to optimize the shape and size of the anode, its distance from the cathode to achieve above objectives. Our study suggests that the desired beam parameters at the exit of the anode can be obtained by reducing the aperture size of the anode and by applying suitable voltage gradient to the anode. (author)

Low emittance electron storage rings

Science.gov (United States)

Levichev, E. B.

2018-01-01

Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

Electromagnetic design and beam dynamics studies for a 10 MeV, 10 kW electron linac

International Nuclear Information System (INIS)

Dhingra, Rinky; Kulkarni, Nita S.; Kumar, Vinit

2013-01-01

Bi-periodic on-axis coupled standing wave linac is seen as an attractive choice for low energy (∼10 MeV) electron accelerators for industrial applications. In this paper, we present the physics design of an S-band bi-periodic on-axis coupled standing wave structure operating in π/2 mode. The structure operates at 2856 MHz and can accelerate electrons to 10 MeV. The 2D optimization of structure cells carried out using SUPERFISH is reported. Magnetic coupling is achieved through bean shaped coupling slots. Analytical calculations have been carried out to fix the dimensions of coupling slots. The paper discusses the complete 3D design of accelerating structure with coupling slots carried out using CST-MWS. The approach used to achieve confluence is outlined. Finally, the beam dynamics studies carried out using PARMELA are also discussed. (author)

Dislocation Loops with a Burgers Vector Produced by 1 MeV Electron Irradiation in FCC Copper-Nickel

DEFF Research Database (Denmark)

Leffers, Torben; Barlow, P.

1975-01-01

Dislocation loops with Burgers vector a are formed in Cu-Ni alloys during 1 MeV electron irradiation in a high-voltage electron microscope at 350°-400°C. The dislocation loops are of interstitial type and pure edge in character with line vectors. Some of the loops are seen to dissociate into loop...

Energy distribution of 0. 279 MeV gamma rays Compton scattered from bound electrons

Energy Technology Data Exchange (ETDEWEB)

Singh, B; Singh, P; Singh, G; Ghumman, B S

1984-11-01

Energy and intensity distribution of 0.279 MeV gamma rays Compton scattered from K-shell electrons of tantalum is measured at scattering angle of 70deg. The experimental results are compared with the available theoretical data. Spectral distribution is also obtained as a function of scatterer thickness to account for the contribution of false events. 13 refs.

Study of imaging plate detector sensitivity to 5-18 MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Boutoux, G., E-mail: boutoux@celia.u-bordeaux1.fr; Rabhi, N.; Batani, D.; Ducret, J.-E. [Univ. de Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence (France); Binet, A.; Nègre, J.-P.; Reverdin, C.; Thfoin, I. [CEA DAM DIF, F-91297 Arpajon (France); Jakubowska, K. [Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw (Poland)

2015-11-15

Imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. We calibrated at the ELSA electron beam facility (CEA DIF) the five different available types of IPs (namely, MS-SR-TR-MP-ND) to electrons from 5 to 18 MeV. In the context of diagnostic development for the PETawatt Aquitaine Laser (PETAL), we investigated the use of stacks of IP in order to increase the detection efficiency and get detection response independent from the neighboring materials such as X-ray shielding and detector supports. We also measured fading functions in the time range from a few minutes up to a few days. Finally, our results are systematically compared to GEANT4 simulations in order to provide a complete study of the IP response to electrons over the energy range relevant for PETAL experiments.

Facility for electron cooling experiments

International Nuclear Information System (INIS)

Budker, G.I.; Dikanskij, N.S.; Kudelajnen, V.I.

1982-01-01

The NAP-M proton storage ring intended for electron cooling experiments is described. The NAP-M magnetic system comprises four bending magnets and eight correction elements. located at the ends of rectilinear gaps. An electron beam facility is located in one of the rectilinear gaps. An 1.5 MeV electrostatic accelerator is used as a proton injector. The NAP-M accelerating system includes a driving generator, a power amplifier and a resonator. The proton beam lifetime (at the RF-system switched-off) up to 7 s has been obtained at the NAP-N at the injection energy, and up to 600 s at 65 MeV and the proton current of 120 μA

Effect of the energy of recoil atoms on conductivity compensation in moderately doped n-Si and n-SiC under irradiation with MeV electrons and protons

Energy Technology Data Exchange (ETDEWEB)

Kozlovski, V.V. [St. Petersburg State Polytechnic University, St. Petersburg 195251 (Russian Federation); Lebedev, A.A., E-mail: shura.lebe@mail.ioffe.ru [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); National Research University of Information Technologies, Mechanics, and Optics, St. Petersburg 197101 (Russian Federation); Emtsev, V.V.; Oganesyan, G.A. [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

2016-10-01

Processes of radiation defect formation and conductivity compensation in silicon and silicon carbide irradiated with 0.9 MeV electrons are considered in comparison with the electron irradiation at higher energies. The experimental values of the carrier removal rate at the electron energy of 0.9 MeV are nearly an order of magnitude smaller than the similar values of the parameter for higher energy electrons (6–9 MeV). At the same time, the formation cross-section of primary radiation defects (Frenkel pairs, FPs) is nearly energy-independent in this range. It is assumed that these differences are due to the influence exerted by the energy of primary knocked-on atoms (PKAs). As the PKA energy increases, the average distance between the genetically related FPs grows and, as a consequence, the fraction of FPs unrecombined under irradiation becomes larger. The FP recombination radius is estimated (∼1.1 nm), which makes it possible to ascertain the charge state of the recombining components. Second, the increase in the PKA energy enables formation of new, more complex secondary radiation defects. At electron energies exceeding 15 MeV, the average PKA energies are closer to the values obtained under irradiation with 1 MeV protons, compared with an electron irradiation at the same energy. As for the radiation-induced defect formation, the irradiation of silicon with MeV protons can be, in principle, regarded as a superposition of the irradiation with 1 MeV electrons and that with silicon ions having energy of ∼1 keV, with the “source” of silicon ions generating these ions uniformly across the sample thickness.

MeV electron acceleration at 1kHz with <10 mJ laser pulses

Science.gov (United States)

Salehi, Fatholah; Goers, Andy; Hine, George; Feder, Linus; Kuk, Donghoon; Kim, Ki-Yong; Milchberg, Howard

2016-10-01

We demonstrate laser driven acceleration of electrons at 1 kHz repetition rate with pC charge above 1MeV per shot using required for relativistic self-focusing low enough for mJ scale laser pulses to self- focus and drive strong wakefields. Experiments and particle-in-cell simulations show that optimal drive pulse duration and chirp for maximum electron bunch charge and energy depends on the target gas species. High repetition rate, high charge, and short duration electron bunches driven by very modest pulse energies constitutes an ideal portable electron source for applications such as ultrafast electron diffraction experiments and high rep. rate γ-ray production. This work is supported by the US Department of Energy, the National Science Foundation, and the Air Force Office of Scientific Research.

Diffusion of interstitial atoms in FCC metals after irradiation with 2 MeV electrons

International Nuclear Information System (INIS)

Kornmann, H.

1980-01-01

Selfdiffusion in nickel after electron irradiation has been restudied. The diffusion velocity near the surface and the diffusion constant in the interior of the crystal have been determined as a function of radiation flux and temperature. A special method for the measurement of diffusion has been improved, which is based on radioactive tracer atoms for indication and on ion etching for the removal of thin films. To improve additionally the accuracy of the technique tracer atoms are induced into the crystal by thermal diffusion and then irradiated with 2 MeV electrons. (orig./GSCH) [de

Lateral propagation of MeV electrons generated by femtosecond laser irradiation

International Nuclear Information System (INIS)

Seely, J. F.; Szabo, C. I.; Audebert, P.; Brambrink, E.; Tabakhoff, E.; Hudson, L. T.

2010-01-01

The propagation of MeV electrons generated by intense (≅10 20 W/cm 2 ) femtosecond laser irradiation, in the lateral direction perpendicular to the incident laser beam, was studied using targets consisting of irradiated metal wires and neighboring spectator wires embedded in electrically conductive (aluminum) or resistive (Teflon) substrates. The K shell spectra in the energy range 40-60 keV from wires of Gd, Dy, Hf, and W were recorded by a transmission crystal spectrometer. The spectra were produced by 1s electron ionization in the irradiated wire and by energetic electron propagation through the substrate material to the spectator wire of a different metal. The electron range and energy were determined from the relative K shell emissions from the irradiated and spectator wires separated by varying substrate lateral distances of up to 1 mm. It was found that electron propagation through Teflon was inhibited, compared to aluminum, implying a relatively weak return current and incomplete space-charge neutralization. The energetic electron propagation in the direction parallel to the electric field of the laser beam was larger than perpendicular to the electric field. Energetic electron production was lower when directly irradiating aluminum or Teflon compared to irradiating the heavy metal wires. These experiments are important for the determination of the energetic electron production mechanism and for understanding lateral electron propagation that can be detrimental to fast-ignition fusion and hard x-ray backlighter radiography.

Simulation of equivalent dose due to accidental electron beam loss in Indus-1 and Indus-2 synchrotron radiation sources using FLUKA code

International Nuclear Information System (INIS)

Sahani, P.K.; Dev, Vipin; Singh, Gurnam; Haridas, G.; Thakkar, K.K.; Sarkar, P.K.; Sharma, D.N.

2008-01-01

Indus-1 and Indus-2 are two Synchrotron radiation sources at Raja Ramanna Centre for Advanced Technology (RRCAT), India. Stored electron energy in Indus-1 and Indus-2 are 450MeV and 2.5GeV respectively. During operation of storage ring, accidental electron beam loss may occur in addition to normal beam losses. The Bremsstrahlung radiation produced due to the beam losses creates a major radiation hazard in these high energy electron accelerators. FLUKA, the Monte Carlo radiation transport code is used to simulate the accidental beam loss. The simulation was carried out to estimate the equivalent dose likely to be received by a trapped person closer to the storage ring. Depth dose profile in water phantom for 450MeV and 2.5GeV electron beam is generated, from which percentage energy absorbed in 30cm water phantom (analogous to human body) is calculated. The simulation showed the percentage energy deposition in the phantom is about 19% for 450MeV electron and 4.3% for 2.5GeV electron. The dose build up factor in 30cm water phantom for 450MeV and 2.5GeV electron beam are found to be 1.85 and 2.94 respectively. Based on the depth dose profile, dose equivalent index of 0.026Sv and 1.08Sv are likely to be received by the trapped person near the storage ring in Indus-1 and Indus-2 respectively. (author)

A Complete Reporting of MCNP6 Validation Results for Electron Energy Deposition in Single-Layer Extended Media for Source Energies <= 1-MeV

Energy Technology Data Exchange (ETDEWEB)

Dixon, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hughes, Henry Grady [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-04

In this paper, we expand on previous validation work by Dixon and Hughes. That is, we present a more complete suite of validation results with respect to to the well-known Lockwood energy deposition experiment. Lockwood et al. measured energy deposition in materials including beryllium, carbon, aluminum, iron, copper, molybdenum, tantalum, and uranium, for both single- and multi-layer 1-D geometries. Source configurations included mono-energetic, mono-directional electron beams with energies of 0.05-MeV, 0.1-MeV, 0.3- MeV, 0.5-MeV, and 1-MeV, in both normal and off-normal angles of incidence. These experiments are particularly valuable for validating electron transport codes, because they are closely represented by simulating pencil beams incident on 1-D semi-infinite slabs with and without material interfaces. Herein, we include total energy deposition and energy deposition profiles for the single-layer experiments reported by Lockwood et al. (a more complete multi-layer validation will follow in another report).

Dosimetric evaluation of multi-sided irradiation on HDPE pipes under 2 MeV electron beam

Energy Technology Data Exchange (ETDEWEB)

Benny, P.G., E-mail: bennypg@yahoo.com; Khader, S.A.; Sarma, K.S.S.

2014-03-01

The use of electron beam technology has enabled the production of heat resistant pipe for hot water circulation. One of the difficulties in the irradiation of pipe products is the uneven penetration of electrons. Quality of the radiation process depends on radiation dose and homogeneity of the dose distribution, which becomes a major concern when treatments of circular objects like pipes are performed. One method to achieve uniformity in the absorbed dose in the product is to use multi-sided irradiation. The paper discusses the importance of dosimetry mapping in industrial electron beam radiation processing and outlines the challenges in delivering a uniform dose to cylindrical objects. In this study, HDPE pipe of 5 mm thickness of homogeneous material (40 mm outer diameter and 30 mm inner diameter) has been chosen for multi-sided irradiation under 2 MeV scanned electron beam from the ILU-6 accelerator. - Highlights: • The paper outlines the challenges in delivering uniform dose to cylindrical objects at 2 MeV industrial electron beam facility. • HDPE pipe of 40 mm outer diameter and 30 mm inner diameter has been chosen for the study. • The circumferential dose distribution inside and outside of the pipes were evaluated by using calibrated CTA dosimeter strips. • Using stack of dosimeter strips, changes in circumferential dose distribution in the annular region of the pipe was evaluated. • Optimization of multi-sided irradiation on the HDPE pipes for better dose homogeneity is reported in the paper.

Dosimetric evaluation of multi-sided irradiation on HDPE pipes under 2 MeV electron beam

International Nuclear Information System (INIS)

Benny, P.G.; Khader, S.A.; Sarma, K.S.S.

2014-01-01

The use of electron beam technology has enabled the production of heat resistant pipe for hot water circulation. One of the difficulties in the irradiation of pipe products is the uneven penetration of electrons. Quality of the radiation process depends on radiation dose and homogeneity of the dose distribution, which becomes a major concern when treatments of circular objects like pipes are performed. One method to achieve uniformity in the absorbed dose in the product is to use multi-sided irradiation. The paper discusses the importance of dosimetry mapping in industrial electron beam radiation processing and outlines the challenges in delivering a uniform dose to cylindrical objects. In this study, HDPE pipe of 5 mm thickness of homogeneous material (40 mm outer diameter and 30 mm inner diameter) has been chosen for multi-sided irradiation under 2 MeV scanned electron beam from the ILU-6 accelerator. - Highlights: • The paper outlines the challenges in delivering uniform dose to cylindrical objects at 2 MeV industrial electron beam facility. • HDPE pipe of 40 mm outer diameter and 30 mm inner diameter has been chosen for the study. • The circumferential dose distribution inside and outside of the pipes were evaluated by using calibrated CTA dosimeter strips. • Using stack of dosimeter strips, changes in circumferential dose distribution in the annular region of the pipe was evaluated. • Optimization of multi-sided irradiation on the HDPE pipes for better dose homogeneity is reported in the paper

The electron beam characteristics of energies up to 20 MeV and comparison of electron parameters of linear accelerators

International Nuclear Information System (INIS)

Awada, M.; Elleithy, M.A.; ElWihady, G.F.; Mostafa, K.A.

2005-01-01

The electron beams characteristics studded for the energies 4-20 MeV of Varian 23 EX ,experimental results are presented and compared with the published data. The CADD curves are measured for all energies and carried out the PDD of different applicator sizes ,that compared with the PDD of in the BJR. The quality beam parameters are determined from the CADD curves and calculated the yielded parameters of the corresponding electron energies which compared with the published data of other accelerators and theoretical Monte-Carlo calculation. The beam profiles are measured at different depths to construct the isodose distribution

Polarized electrons from GaAs for parity nonconservation studies and Moeller scattering at 250 MeV

International Nuclear Information System (INIS)

Cates, G.D. Jr.

1987-01-01

A description is given of a polarized electron source based on photoemission from GaAs with circularly polarized light, which was developed for use in the study of parity nonconservation (PNC) in e- 12 C scattering at 250 MeV at the MIT Bates Linear Accelerator Center. A multi-chamber vacuum system houses up to four GaAs crystals simultaneously, and is contained in a Faraday cage to provide 365 KeV in electrostatic acceleration. Stable operation is achieved through the use of a modulated cw laser. The PNC experiment is discussed, particularly with regards to its requirements on the source. The peak current from the source is 20 mA, resulting in a current in excess of 6 mA at high energy. The electron beam polarization has been measured to be 0.36 ± 0.004 using Moeller scattering at 250 MeV

Superconducting snake with the field of 75 kGs for the VEPP-2M electron-positron storage ring

International Nuclear Information System (INIS)

Anashin, V.V.; Vasserman, I.B.; Vlasov, A.M.

1985-01-01

Superconducting ''snake'' with the field of 75 kG is established in the VEPP-2M electron-positron storage ring for increase of colliding beam luminosity up to 2x10 31 cmsup(-2)sdup(-1) in the energy range from 2x200 to 2x700 MeV. The ''snake'' comprises three central magnets with the field of 75 kG and two side ones with the field of 45 kG and it is placed in one of rectilinear experimental gaps. Description of design peculiarities of the ''snake'' and its parameters are given. Parameters of beams with switched on and switched off ''snake'' as well as parameters of coils and superconducting wire are presented

Analysis of thermionic DC electron gun for 125 MeV linac

International Nuclear Information System (INIS)

Kanno, K.; Sato, Isamu; Sato, K.

2000-01-01

The beam trace calculation for the 100 kV thermionic DC electron gun with EIMAC 646E cathode, which is currently used for the 125 MeV linac at Nihon University, has been performed using EGUN code. The result showed a strong focus of the beam at the exit of the anode. A better geometry of the gun has been investigated by varying the shape of the wehnelt electrode. Also the trace calculation has been performed for the case of EIMAC 646B, which showed a considerably small emittance compared with that estimated for the present gun. (author)

Analysis of thermionic DC electron gun for 125 MeV linac

Energy Technology Data Exchange (ETDEWEB)

Kanno, K. [Graduate School of Science and Technology, Nihon Univ., Funabashi, Chiba (Japan); Sato, Isamu; Sato, K. [Nihon Univ., Funabashi, Chiba (Japan). Atomic Energy Research Inst] [and others

2000-07-01

The beam trace calculation for the 100 kV thermionic DC electron gun with EIMAC 646E cathode, which is currently used for the 125 MeV linac at Nihon University, has been performed using EGUN code. The result showed a strong focus of the beam at the exit of the anode. A better geometry of the gun has been investigated by varying the shape of the wehnelt electrode. Also the trace calculation has been performed for the case of EIMAC 646B, which showed a considerably small emittance compared with that estimated for the present gun. (author)

Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations

Energy Technology Data Exchange (ETDEWEB)

Goosman, D.R.

1984-08-14

The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table.

Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations

International Nuclear Information System (INIS)

Goosman, D.R.

1984-01-01

The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table

A compact electron storage ring design

International Nuclear Information System (INIS)

Swenson, C.A.

1992-01-01

Electron storage rings are sources of synchrotron radiation in the soft and hard parts of the x-ray spectrum. X-ray lithography is an ideal candidate technology for the production of microelectronic devices with sizes between 0.3-0.5 microns. Industrial x-ray lithography requires the x-ray source, which is the electron storage ring, to be as compact and reliable as possible. In this thesis the author reviews and develops the basic physical principles governing the design of compact electron synchrotrons for x-ray lithography. He explores the various aspects of lattice design for this application. He argues that the optimal storage ring design consists of a four fold symmetric cell lattice with two quadrupole families and 90 degrees zero gradient dipole magnets. It is demonstrated that radiation requirements for lithography and the use of zero gradient magnetic dipole fields constrains the lattice to four or more dipole magnets. The author develops a lattice design for x-ray lithography following this logic. He then develops a dipole magnet design for a machine using this lattice. Particle tracking data is integrated into the magnet design and used to optimize the end coil configurations of the magnets. The author then reviews the magnet's physical construction and measurement. He develops a cryogenic Hall probe mapping apparatus for this magnet and measure its excitation curves

Beam diagnostics using transition radiation produced by a 100 Mev electron beam

International Nuclear Information System (INIS)

Jablonka, M.; Leroy, J.; Hanus, X.; Derost, J.C.; Wartski, L.

1991-01-01

We report on several experiments using the optical transition radiation (OTR) produced by a 100 MeV electron beam. In using a sensitive video camera coupled with a digital image processing system an accurate and simple beam profile monitor has been devised. In measuring with a photo-multiplier the radiation emitted in a small solid angle around the direction of the OTR emission, a signal very sensitive to beam energy variations has been obtained. These experiments have been carried out on the Saclay ALS linac

Numerical simulation of electrons dynamics in a microtron on 6 - 10 MeV

Science.gov (United States)

Bashmakov, Y. A.; Dyubkov, V. S.; Lozeev, Y. Y.

2017-12-01

Electron dynamics in 6.5 MeV classic microtron of the Lebedev Physics Institute (LPI) is investigated by means of numerical methods. Particular emphasis is placed on the formation mechanism of electron bunches at the first circular orbits. An effect of microtron main parameters such as accelerating RF field amplitude, DC magnetic field, as well as a geometry and a position of a thermal emitter on characteristics of electron beam extracted from the microtron are studied. In the space of mentioned parameters a region corresponding an optimal microtron operation mode is found. It is noted that the unique geometric and energy characteristics of accelerated beam makes use of microtron attractive not only as injector into a synchrotron, but also as a driver in experiments on generation of coherent terahertz electromagnetic radiation.

Thermoluminescent response of LiF: Mg, Cu, P (GR-200) below an electron beam of 6 MeV

International Nuclear Information System (INIS)

Torijano C, E.F.S.; Azorin N, J.; Villasenor N, I.; Lujan C, P.J.; Rivera M, T.

2007-01-01

Full text: In this work the experimental results of studying the thermoluminescent response (TL) of LiF:Mg,Cu,P (GR-200) previously irradiated with 6 MeV electrons are presented. The electrons beam was generated by a Lineal Accelerator VARIAN I for medical use. The lineal accelerator is installed in the General Hospital of Mexico (HGM). A lot of 25 thermoluminescent dosemeters (DTL) was used. The mass and volume of each one of them were determined. Obtaining a variation of 14% in standard deviation (SD). The DTLs were irradiated to an energy of 6 MeV. The dose given to the DTL was of 50 c Gy. The linearity of the response of the GR-200 also was determined. (Author)

Polarization Studies for the eRHIC Electron Storage Ring

Energy Technology Data Exchange (ETDEWEB)

Gianfelice-Wendt, Eliana [Fermilab; Tepikian, S. [Brookhaven

2018-04-01

A hadron/lepton collider with polarized beams has been under consideration by the scientific community since some years, in the U.S. and Europe. Among the various proposals, those by JLAB and BNL with polarized electron and proton beams are currently under closer study in the U.S. Experimenters call for the simultaneous storage of electron bunches with both spin helicity. In the BNL based Ring-Ring design, electrons are stored at top energy in a ring to be accommodated in the existing RHIC tunnel. The transversely polarized electron beam is injected into the storage ring at variable energies, between 5 and 18 GeV. Polarization is brought into the longitudinal direction at the IP by a couple of spin rotators. In this paper results of first studies of the attainable beam polarization level and lifetime in the storage ring at 18 GeV are presented.

Characterization and optimization of laser-driven electron and photon sources in keV and MeV energy ranges

International Nuclear Information System (INIS)

Bonnet, Thomas

2013-01-01

This work takes place in the framework of the characterization and the optimization of laser-driven electron and photon sources. With the goal of using these sources for nuclear physics experiments, we focused on 2 energy ranges: one around a few MeV and the other around a few tens of keV. The first part of this work is thus dedicated to the study of detectors routinely used for the characterization of laser-driven particle sources: Imaging Plates. A model has been developed and is fitted to experimental data. Response functions to electrons, photons, protons and alpha particles are established for SR, MS and TR Fuji Imaging Plates for energies ranging from a few keV to several MeV. The second part of this work present a study of ultrashort and intense electron and photon sources produced in the interaction of a laser with a solid or liquid target. An experiment was conducted at the ELFIE facility at LULI where beams of electrons and photons were accelerated up to several MeV. Energy and angular distributions of the electron and photons beams were characterized. The sources were optimized by varying the spatial extension of the plasma at both the front and the back end of the initial target position. In the optimal configuration of the laser-plasma coupling, more than 1011 electrons were accelerated. In the case of liquid target, a photon source was produced at a high repetition rate on an energy range of tens of keV by the interaction of the AURORE Laser at CELIA (10 16 W.cm -2 ) and a melted gallium target. It was shown that both the mean energy and the photon number can be increased by creating gallium jets at the surface of the liquid target with a pre-pulse. A physical interpretation supported by numerical simulations is proposed. (author)

Preliminary conceptual design for a 510 MeV electron/positron injector for a UCLA φ factory

International Nuclear Information System (INIS)

Dahlbacka, G.; Hartline, R.; Barletta, W.; Pellegrini, C.

1991-01-01

UCLA is proposing a compact suer conducting high luminosity (10 32-33 cm -2 sec -1 ) e + e - collider for a φ factory. To achieve the required e + e - currents, full energy injections from a linac with intermediate storage in a Positron Accumulator Ring (PAR) is used. The elements of the linac are outlined with cost and future flexibility in mind. The preliminary conceptual design starts with a high current gun similar in design to those developed at SLAC and at ANL (for the APS). Four 4-section linac modules follow, each driven by a 60 MW klystron with a 1 μsec macropulse and an average current of 8.6 A. The first 4-section model is used to create positrons in a tungsten target at 186 MeV. The three remaining three modules are used to accelerate the e + e - beam to 558 MeV (no load limit) for injection into the PAR

The study of 1 MeV electron irradiation induced defects in N-type and P-type monocrystalline silicon

Science.gov (United States)

Babaee, S.; Ghozati, S. B.

2017-12-01

Despite extensive use of GaAs cells in space, silicon cells are still being used. The reason is that not only they provide a good compromise between efficiency and cost, but also some countries do not have the required technology for manufacturing GaAs. Behavior of a silicon cell under any levels of charged particle irradiation could be deducted from the results of a damage equivalent 1 MeV electron irradiation using the NASA EQflux open source software package. In this paper for the first time, we have studied the behavior of a silicon cell before and after 1 MeV electron irradiation with 1014, 1015 and 1016 electrons-cm-2 fluences, using SILVACO TCAD simulation software package. Simulation was carried out at room temperature under AM0 condition. Results reveal that open circuit voltage and efficiency decrease after irradiation while short circuit current shows a slight increase in the trend around 5 × 1016 electrons-cm-2, and short circuit current loss plays an important role on efficiency changes rather than open circuit voltage.

Decoupling electron and ion storage and the path from interfacial storage to artificial electrodes

Science.gov (United States)

Chen, Chia-Chin; Maier, Joachim

2018-02-01

The requirements for rechargeable batteries place high demands on the electrodes. Efficient storage means accommodating both ions and electrons, not only in substantial amounts, but also with substantial velocities. The materials' space could be largely extended by decoupling the roles of ions and electrons such that transport and accommodation of ions take place in one phase of a composite, and transport and accommodation of electrons in the other phase. Here we discuss this synergistic concept being equally applicable for positive and negative electrodes along with examples from the literature for Li-based and Ag-based cells. Not only does the concept have the potential to mitigate the trade-off between power density and energy density, it also enables a generalized view of bulk and interfacial storage as necessary for nanocrystals. It furthermore allows for testable predictions of heterogeneous storage in passivation layers, dependence of transfer resistance on the state of charge, or heterogeneous storage of hydrogen at appropriate contacts. We also present an outlook on constructing artificial mixed-conductor electrodes that have the potential to achieve both high energy density and high power density.

Physics design of a 10 MeV, 6 kW travelling wave electron linac for ...

Indian Academy of Sciences (India)

2016-10-11

Oct 11, 2016 ... We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear ... linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Three- ... structures are preferred for relatively higher energy ... klystron in a TW linac, which results in cost reduction.

Comparative time-series analysis of MeV electron data by Ulysses and Pioneer 10/11 in the Jovian magnetosphere

International Nuclear Information System (INIS)

Dunzlaff, P.; Kiel Univ.; Heber, B.; Kopp, A.; North-West Univ., Potchefstroom; Potgieter, M.S.

2013-01-01

The dynamics of the Jovian magnetosphere is dominated by the planet's fast rotation with a period of ∝ 10 h.Within the magnetosphere, this periodicity can in particular be seen in the temporal variation of the spectral index of MeV electrons: every ∝ 10 h the counting rates show a maximum (minimum), while the spectral index shows a minimum (maximum) known as the Jovian ''clock'' mechanism. In this study we re-analyse Ulysses and Pioneer 10/11 data and show that another periodic modulation in the MeV electrons can be identified, manifested by local maxima of the spectral index and local minima of the counting rates. For Ulysses, this modulation can be observed throughout the magnetosphere near the magnetic equator, suggesting an azimuthal asymmetric distribution of MeV electrons near the current sheet. This modulation is found to trail the ''clock'' mechanism by ∝ 3.25 h. The Pioneer 10 data, however, only show occasional evidence of the presence of these local maxima while there is no evidence of this modulation in the Pioneer 11 data. A comparison of the times of observed minor peaks and Ulysses' distance from the current sheet using a simple rigid disc model as well as the model of Khurana and Schwarzl (2005) is performed.

High power pulsed/microwave technologies for electron accelerators vis a vis 10MeV, 10kW electron LINAC for food irradiation at CAT

International Nuclear Information System (INIS)

Shrivastava, Purushottam; Mulchandani, J.; Mohania, P.; Baxy, D.; Wanmode, Y.; Hannurkar, P.R.

2005-01-01

Use of electron accelerators for irradiation of food items is gathering momentum in India. The various technologies for powering the electron LINAC were needed to be developed in the country due to embargo situations as well as reservations of the developers worldwide to share the information related to this development. Centre for Advanced Technology, CAT, Indore, is engaged in the development of particle accelerators for medical industrial and scientific applications. Amongst other electron accelerators developed in CAT, a 10MeV, 10kW LINAC for irradiation of food items has been commissioned and tested for full rated 10kW beam power. The high power pulsed microwave driver for the LINAC was designed, developed and commissioned with full indigenous efforts, and is right now operational at CAT. It consists of a 6MW, 25kW S-band pulsed klystron, 15MW peak power pulse modulator system for the klystron, microwave driver amplifier chain, stabilized generator, protection and control electronics, waveguide system to handle the high peak and average power, gun modulator electronics, grid electronics etc. The present paper highlights various technologies like the pulsed power systems and components, microwave circuits and systems etc. Also the performance results of the high power microwave driver for the 10MeV LINAC at CAT are discussed. Future strategies for developing the state of art technologies are highlighted. (author)

ELECTRON COOLING FOR RHIC

International Nuclear Information System (INIS)

BEN-ZVI, I.; AHRENS, L.; BRENNAN, M.; HARRISON, M.; KEWISCH, J.; MACKAY, W.; PEGGS, S.; ROSER, T.; SATOGATA, T.; TRBOJEVIC, D.; YAKIMENKO, V.

2001-01-01

We introduce plans for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This project has a number of new features as electron coolers go: It will cool 100 GeV/nucleon ions with 50 MeV electrons; it will be the first attempt to cool a collider at storage-energy; and it will be the first cooler to use a bunched beam and a linear accelerator as the electron source. The linac will be superconducting with energy recovery. The electron source will be based on a photocathode gun. The project is carried out by the Collider-Accelerator Department at BNL in collaboration with the Budker Institute of Nuclear Physics

HOM (higher-order mode) test of the storage ring single-cell cavity with a 20-MeV e- beam for the Advanced Photon Source (APS)

International Nuclear Information System (INIS)

Song, J.; Kang, Y.W.; Kustom, R.

1993-01-01

To test the effectiveness of damping techniques of the APS storage ring single-cell cavity, a beamline has been designed and assembled to use the ANL Chemistry Division linac beam (20-MeV, FWHM of 20 ps). A single-cell cavity will be excited by the electron beam to investigate the effect on higher-order modes (HOMs) with and without coaxial dampers (H-loop damper, E-probe damper), and wideband aperture dampers. In order for the beam to propagate on- and off-center of the cavity, the beamline consists of two sections -- a beam collimating section and a cavity measurement section -- separated by two double Aluminum foil windows. RF cavity measurements were made with coupling loops and E-probes. The results are compared with both the TBCI calculations and 'cold' measurements with the bead-perturbation method. The data acquisition system and beam diagnostics will be described in a separate paper

Preliminary examination of induced radioactivity in pepper by 10 MeV electron irradiation

International Nuclear Information System (INIS)

Katayama, Tadashi; Furuta, Masakazu; Sibata, Setsuko; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu; Takeda, Atsuhiko.

1991-01-01

β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper with liquid scintillation counter in order to reconfirm the wholesomeness of irradiated foods and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. In irradiated black pepper no radioactivity other than from natural source, un-irradiated one, was detected. But in irradiated white pepper, it was suggested that induced radioactivity might be detected if the detection method was more improved. (author)

Quantum lifetime in electron storage rings

International Nuclear Information System (INIS)

Chao, A.W.

1977-02-01

One of the mechanisms which contribute to beam lifetime in electron storage rings is the quantum emission of energetic photons causing particles to be lost from the rf bucket. This quantum lifetime is among other things important in defining the required aperture in a storage ring. An approximate expression of quantum lifetime, predicted by a one-dimensional model which takes into account only the betatron motion, has been used in most storage ring designs. If the beam is aperture-limited at a position with nonzero dispersion, both the betatron and synchrotron motions have to be included and a two-dimensional model must be used. An exact expression of quantum lifetime for the one-dimensional case and an approximate expression for the two-dimensional case are given

Quantum lifetime in electron storage rings

International Nuclear Information System (INIS)

Chao, A.W.

1977-01-01

One of the mechanisms which contributes to beam lifetime in electron storage rings is the quantum emission of energetic photons causing particles to be lost from the rf bucket. This quantum lifetime is among other things important in defining the required aperture in a storage ring. An approximate expression of quantum lifetime, predicted by a one-dimensional model which takes into account only the betatron motion, has been used in most storage ring designs. If the beam is aperture-limited at a position with nonzero dispersion, both the betatron and synchrotron motions have to be included, and a two-dimensional model must be used. An exact expression of quantum lifetime for the one-dimensional case and an approximate expression for the two-dimensional case are given

High-resolution Auger spectroscopy on 79 MeV Ar5+, 89 MeV Ar6+, and 136 MeV Ar7+ ions after excitation by helium

International Nuclear Information System (INIS)

Schneider, T.

1988-01-01

In this thesis the atomic structure of highly excited Ar 6+ and Ar 7+ ions was studied. For this 79 MeV Ar 5+ , 89 MeV Ar 6+ , and 136 MeV Ar 7+ ions of a heavy ion accelerator were excited by a He gas target to autoionizing states and the Auger electrons emitted in the decay were measured in highly-resolving state. The spectra were taken under an observational angle of zero degree relative to the beam axis in order to minimize the kinematical broadening of the Auger lines. (orig./HSI) [de

Estimation of Electron Dose Delivered by a 0.4 MeV Accelerator from Bremsstrahlung Dose Measurements

DEFF Research Database (Denmark)

Karadjov, A. G.; Hansen, Jørgen-Walther

1980-01-01

Determination of a 0.4 MeV electron dose from a bremsstrahlung dose measurement using a converter-detector system is considered. The detector used is a Frickle dosimeter, and the converters are aluminum, copper and lead foils. Optimal converter thickness is ascertained experimentally for each mat...... materials within a Z-range of 13–82. A linear relation is found between bremsstrahlung dose and electron dose ranging from 2 to 20 Mrad. Finally the effect of converter area on detector response is studied....

Absolute Calibration of Image Plate for electrons at energy between 100 keV and 4 MeV

Energy Technology Data Exchange (ETDEWEB)

Chen, H; Back, N L; Eder, D C; Ping, Y; Song, P M; Throop, A

2007-12-10

The authors measured the absolute response of image plate (Fuji BAS SR2040) for electrons at energies between 100 keV to 4 MeV using an electron spectrometer. The electron source was produced from a short pulse laser irradiated on the solid density targets. This paper presents the calibration results of image plate Photon Stimulated Luminescence PSL per electrons at this energy range. The Monte Carlo radiation transport code MCNPX results are also presented for three representative incident angles onto the image plates and corresponding electron energies depositions at these angles. These provide a complete set of tools that allows extraction of the absolute calibration to other spectrometer setting at this electron energy range.

Electron and ion currents relevant to accurate current integration in MeV ion backscattering spectrometry

International Nuclear Information System (INIS)

Matteson, S.; Nicolet, M.A.

1979-01-01

The magnitude and characteristics of the currents which flow in the target and the chamber of an MeV ion backscattering spectrometer are examined. Measured energy distributions and the magnitude of high-energy secondary electron currents are reported. An empirical universal curve is shown to fit the energy distribution of secondary electrons for several combinations of ion energy, targets and ion species. The magnitude of tertiary electron currents which arise at the vacuum vessel walls is determined for various experimental situations and is shown to be non-negligible in many cases. An experimental arrangement is described which permits charge integrations to 1% arruracy without restricting access to the target as a Faraday cage does. (Auth.)

Characterization of a power bipolar transistor as high-dose dosimeter for 1.9-2.2 MeV electron beams

Energy Technology Data Exchange (ETDEWEB)

Fuochi, P.G., E-mail: fuochi@isof.cnr.i [ISOF-CNR Institute, Via P. Gobetti 101, I-40129, Bologna (Italy); Lavalle, M.; Corda, U. [ISOF-CNR Institute, Via P. Gobetti 101, I-40129, Bologna (Italy); Kuntz, F.; Plumeri, S. [Aerial, Parc d' Innovation Rue Laurent Fries F-67400 Illkirch (France); Gombia, E. [IMEM-CNR Institute, Viale delle Scienze 37 A, Loc. Fontanini, 43010 Parma (Italy)

2010-04-15

Results of the characterization studies on a power bipolar transistor investigated as a possible radiation dosimeter under laboratory condition using electron beams of energies from 2.2 to 8.6 MeV and gamma rays from a {sup 60}Co source and tested in industrial irradiation plants having high-activity {sup 60}Co gamma-source and high-energy, high-power electron beam have previously been reported. The present paper describes recent studies performed on this type of bipolar transistor irradiated with 1.9 and 2.2 MeV electron beams in the dose range 5-50 kGy. Dose response, post-irradiation heat treatment and stability, effects of temperature during irradiation in the range from -104 to +22 deg. C, dependence on temperature during reading in the range 20-50 deg. C, and the difference in response of the transistors irradiated from the plastic side and the copper side are reported. DLTS measurements performed on the irradiated devices to identify the recombination centres introduced by radiation and their dependence on dose and energy of the electron beam are also reported.

Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction.

Science.gov (United States)

Sokolowski-Tinten, K; Shen, X; Zheng, Q; Chase, T; Coffee, R; Jerman, M; Li, R K; Ligges, M; Makasyuk, I; Mo, M; Reid, A H; Rethfeld, B; Vecchione, T; Weathersby, S P; Dürr, H A; Wang, X J

2017-09-01

We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

Secondary electron emission from metals irradiated by 0.4-3 MeV gamma-quanta

International Nuclear Information System (INIS)

Grudskij, M.Ya.; Malyshenkov, A.V.; Smirnov, V.V.

1975-01-01

Experimental and calculational data were considered on the secondary electron emission outgoing from metal targets of an equilibrium thickness irradiated by gamma-quanta fluxes with the energies from 0.4 to 3 MeV. New experimental data are presented. Characteristics of emission were measured by two methods: by magnetic spectrometers with a transverse magnetic field, and by means of an electrometric device with using radioisotopic gamma-sources of 198 Au, 137 Cs, 60 Co and 24 Na. The dependence of the electron emission on the atomic number of the target material was studied. For this purpose the parameters of emissions outgoing from Al-, Cu-, Cd-, Pb- and Au-targets were measured. The advantages and shortcomings of the known methods of calculating the second electron emission were discussed. The obtained experimental and calculational results on studying electrons were compared with those known from literature, and possible sources of systematic errors were discussed

Comparative time-series analysis of MeV electron data by Ulysses and Pioneer 10/11 in the Jovian magnetosphere

Energy Technology Data Exchange (ETDEWEB)

Dunzlaff, P. [North-West Univ., Potchefstroom (South Africa). Centre for Space Research; Kiel Univ. (Germany). Inst. fuer Experimentelle und Angewandte Physik; Heber, B. [Kiel Univ. (Germany). Inst. fuer Experimentelle und Angewandte Physik; Kopp, A. [Kiel Univ. (Germany). Inst. fuer Experimentelle und Angewandte Physik; North-West Univ., Potchefstroom (South Africa). Centre for Space Research; Potgieter, M.S. [North-West Univ., Potchefstroom (South Africa). Centre for Space Research

2013-11-01

The dynamics of the Jovian magnetosphere is dominated by the planet's fast rotation with a period of {proportional_to} 10 h.Within the magnetosphere, this periodicity can in particular be seen in the temporal variation of the spectral index of MeV electrons: every {proportional_to} 10 h the counting rates show a maximum (minimum), while the spectral index shows a minimum (maximum) known as the Jovian ''clock'' mechanism. In this study we re-analyse Ulysses and Pioneer 10/11 data and show that another periodic modulation in the MeV electrons can be identified, manifested by local maxima of the spectral index and local minima of the counting rates. For Ulysses, this modulation can be observed throughout the magnetosphere near the magnetic equator, suggesting an azimuthal asymmetric distribution of MeV electrons near the current sheet. This modulation is found to trail the ''clock'' mechanism by {proportional_to} 3.25 h. The Pioneer 10 data, however, only show occasional evidence of the presence of these local maxima while there is no evidence of this modulation in the Pioneer 11 data. A comparison of the times of observed minor peaks and Ulysses' distance from the current sheet using a simple rigid disc model as well as the model of Khurana and Schwarzl (2005) is performed.

Low energy spread 100 MeV-1 GeV electron bunches from laser wakefield acceleration at LOASIS

International Nuclear Information System (INIS)

Geddes, C.G.R.; Esarey, E.; Michel, P.; Nagler, B.; Nakamura, K.; Plateau, G.R.; Schroeder, C.B.; Shadwick, B.A.; Toth, Cs.; Van Tilborg, J.; Leemans, W.P.; Hooker, S.M.; Gonsalves, A.J.; Michel, E.; Cary, J.R.; Bruhwiler, D.

2006-01-01

Experiments at the LOASIS laboratory of LBNL recently demonstrated production of 100 MeV electron beams with low energy spread and low divergence from laser wakefield acceleration. The radiation pressure of a 10 TW laser pulse guided over 10 diffraction ranges by a plasma density channel was used to drive an intense plasma wave (wakefield), producing acceleration gradients on the order of 100 GV/m in a mm-scale channel. Beam energy has now been increased from 100 to 1000 MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies. Particle simulations indicate that the low energy spread beams were produced from self trapped electrons through the interplay of trapping, loading, and dephasing. Other experiments and simulations are also underway to control injection of particles into the wake, and hence improve beam quality and stability further

Bunch evolution study in optimization of MeV ultrafast electron diffraction

International Nuclear Information System (INIS)

Lu Xianhai; Du Yingchao; Huang Wenhui; Tang Chuanxiang

2014-01-01

transverse ultrafast electron diffraction (UED) is a promising detection tool for ultrafast processes. The quality of diffraction image is determined by the transverse evolution of the probe bunch. In this paper, we study the contributing terms of the emittance and space charge effects to the bunch evolution in the MeV UED scheme, employing a mean-field model with an ellipsoidal distribution as well as particle tracking simulation. The small transverse dimension of the drive laser is found to be critical to improve the reciprocal resolution, exploiting both smaller emittance and larger transverse bunch size before the solenoid. The degradation of the reciprocal spatial resolution caused by the space charge effects should be carefully controlled. (authors)

Bunch evolution study in optimization of MeV ultrafast electron diffraction

Science.gov (United States)

Lu, Xian-Hai; Du, Ying-Chao; Huang, Wen-Hui; Tang, Chuan-Xiang

2014-12-01

Megaelectronvolt ultrafast electron diffraction (UED) is a promising detection tool for ultrafast processes. The quality of diffraction image is determined by the transverse evolution of the probe bunch. In this paper, we study the contributing terms of the emittance and space charge effects to the bunch evolution in the MeV UED scheme, employing a mean-field model with an ellipsoidal distribution as well as particle tracking simulation. The small transverse dimension of the drive laser is found to be critical to improve the reciprocal resolution, exploiting both smaller emittance and larger transverse bunch size before the solenoid. The degradation of the reciprocal spatial resolution caused by the space charge effects should be carefully controlled.

Design and simulation of a 1.2MeV electron accelerator used for desulfuration and denitrogenation

Energy Technology Data Exchange (ETDEWEB)

Zhou, J.; Zhu, D.J.; Liu, S.G.; Wang, H.B.; Xu, Z.; Liu, X.S. [University of Electrical Science & Technology of China, Chengdu (China)

2005-07-01

This paper presents the structural design and functional analysis of a new kind of 1.2MeV industrial electron accelerator. PIC (Particle-In-Cell) method is used to simulate this accelerator and to optimize the design. The results show that the optics property of this accelerator has been improved. This electron accelerator is used for desulfurisation and denitrification in environmental industry. This application purifies flue gases of the thermal power stations from sulphur oxide and nitrogen oxides in order to reduce air pollution.

Electron angular distributions in He single ionization impact by H2+ ions at 1 MeV

International Nuclear Information System (INIS)

Zhang Shaofeng; Ma Xinwen; Suske, J; Fischer, D; Kuehnel, K U; Voitkiv, A; Najjaril, B; Krauss, A; Moshammer, R; Ullrich, J; Hagmann, S

2009-01-01

For the first time we investigated in a kinematically complete experiment the ionization of helium in collisions with H 2 + -molecular ions at 1 MeV. Using two separate detectors, the orientation of the projectile H 2 + -molecular ions was determined at the instance of the collision. The electron angular distribution was measured by a R eaction Microscope . The observed structures are found in agreement with theoretical calculations, indicating that the ionized electron of He shows a slight preferential emission direction parallel to the molecular axis.

Electron cooling and recombination experiments with an adiabatically expanded electron beam

International Nuclear Information System (INIS)

Pastuszka, S.; Heidelberg Univ.; Schramm, U.; Heidelberg Univ.; Grieser, M.; Heidelberg Univ.; Broude, C.; Heidelberg Univ.; Grimm, R.; Heidelberg Univ.; Habs, D.; Heidelberg Univ.; Kenntner, J.; Heidelberg Univ.; Miesner, H.J.; Heidelberg Univ.; Schuessler, T.; Heidelberg Univ.; Schwalm, D.; Heidelberg Univ.; Wolf, A.; Heidelberg Univ.

1996-01-01

Magnetically guided electron beams with transverse temperatures reduced with respect to the cathode temperature by a factor of more than 7 were realized in the electron cooling device of the heavy-ion storage ring TSR and the effect of the reduced transverse temperature in recombination and electron cooling experiments was studied. Measured dielectronic recombination resonances at low relative energy and spectra of laser-stimulated recombination indicate that transverse electron temperatures of about 17 meV have been obtained at cathode temperatures of about 110 meV. The temperature dependence of the spontaneous electron-ion recombination rate during electron cooling was investigated and found to follow the inverse square-root law expected from the theory of radiative recombination, although the measured absolute rates are higher than predicted. A new method based on analyzing the intensity of the fluorescence light emitted during simultaneous laser and electron cooling is used to measure the longitudinal electron cooling force in a range of relative velocities extending over two orders of magnitude (10 5 -10 7 cm/s). The results confirm the occurrence of 'magnetized electron cooling' also at the reduced transverse temperature and show that, compared to earlier measurements at the high transverse temperature, the cooling force increases by about a factor of 2; a considerably larger increase by a factor of ∼5 would be expected if 'magnetized electron cooling' would not exist. (orig.)

EAST: Developing an Electronic Assessment and Storage Tool.

Science.gov (United States)

Edwards, Katherine I.; Fernandez, Eugenia; Milionis, Tracey M.; Williamson, David M.

2002-01-01

Describes the purpose, development, analysis, prototyping, and features of the Electronic Assessment and Storage Tool (EAST). The Web-based system aids curriculum assessment at Purdue School of Engineering and Technology at Indiana University Purdue University Indianapolis through the ability to easily store artifacts in electronic form, support…

Confinement of 2,4 MeV deuterons by plasmoids and focalization of electron beams in plasma focus discharges

International Nuclear Information System (INIS)

Nardi, V.; Bostick, W.; Prior, W.; Feugeas, J.; Bortolotti, A.

1982-01-01

A detailed analysis has been completed on the internal structure of ions and electron beams which are efected, along the system axis, in opposite directions (0 0 and 180 0 ). An image (contact print) of plasmoids which emit MeV deuterons is formed by the deuteron emission and it is revealed by etching deuteron tracks in a target of plastic material (CR-39). Ion-imaging with different energy filters discriminates between tracks of plasmoid ions and tracks of charged products of D-D fusion reactions. Ions-imaging can also discriminate plasmoid deuterons from MeV deuterons of a directed beam. (L.C.) [pt

Present status of the ETL electron linac and associated experimental facilities

International Nuclear Information System (INIS)

Tomimasu, T.

1983-01-01

The 500-MeV electron linac ''TELL'' is operated since Dec. 1980. The main features of TELL are high efficiency, high current - high power acceleration and economical beam sharing to four experimental rooms at the same time. The available beam current is 240 mA (--180 μA ) at 300 MeV at present. A pion channel ( QQDQ ) with solid angle larger than 0.15 sr is under construction. Research on establishing spectro-dosimetric standards of high energy - high intensity electrons, X-rays and pions are in progress. The 600-MeV storage ring ''TERAS'' is operated since Oct. 1981. The circumference is 31.45 m and lambdasub(p) is 22 A. The maximum stored current is 150 mA and 1/e lifetime is 1.5 hours at present. Studies on photometry and soft X ray standards, electronic materials and lithography technology are in progress using synchrotron radiation. (author)

From Molecular Electronics to Solar Thermal Energy Storage

DEFF Research Database (Denmark)

Olsen, Stine Tetzschner

The Sun's signicant resource potential provides a solution for the world's increasing energy demand in a sustainable and responsible manner. However, the intrinsic property of the on-o cycles of the solar irradiation, i.e. daynight, sunny-cloudy, and summer-winter, constitutes a signicant challenge...... for the utilization of solar energy. An eective technology for storing the solar energy is required. This thesis focuses on solar thermal energy storage in molecules, since it oers a very compact and eective storage method. The rst chapter after the introduction of the thesis, chapter two, introduces the fundamental...... properties of the molecule, i.e. the electronic behaviour of the molecule in dierent environments, which is a key property for investigations of solar energy storage. The main focus of the research is on the electron transport in the Coulomb blockade regime. The third chapter goes into the challenge...

New initiatives for producing high current electron accelerators

International Nuclear Information System (INIS)

Faehl, R.J.; Keinigs, R.K.; Pogue, E.W.

1996-01-01

New classes of compact electron accelerators able to deliver multi-kiloamperes of pulsed 10-50 MeV electron beams are being studied. One class is based upon rf linac technology with dielectric-filled cavities. For materials with ε/ε o >>1, the greatly increased energy storage permits high current operation. The second type is a high energy injected betatron. Circulating current limits scale as Β 2 γ 3

Shielding Calculations for Industrial 5/7.5MeV Electron Accelerators Using the MCNP Monte Carlo Code

International Nuclear Information System (INIS)

Peri, E.; Orion, I.

2014-01-01

High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, in order to extend the shelf life of products. High energy photons can cause food activation due to (D 3 ,n) reactions. Until 2004, to eliminate the possibility of food activation, the electron energy was limited to 5 MeV X-rays for food irradiation. In 2004, the FDA approved the usage of up to 7.5 MeV, but only with tantalum and gold targets (1). Higher X-ray energy results an increased flux of X-rays in the forward direction, increased penetration, and higher photon dose rate due to better electron-to-photon conversion. These improvements could decrease the irradiation time and allow irradiation of larger packages, thereby providing higher production rates with lower treatment cost. Medical accelerators usually work with 6-18 MV electron energy with tungsten target to convert the electron beam to X-rays. In order to protect the patients, the accelerator head is protected with a heavy lead shielding; therefore, the bremsstrahlung is emitted only in the forward direction. There are many publications and standards that guide how to design optimal shielding for medical accelerator rooms. The shielding data for medical accelerators is not applicable for industrial accelerators, since the data is for different conversion targets, different X-Ray energies, and only for the forward direction. Collimators are not always in use in industrial accelerators, and therefore bremsstrahlung photons can be emitted in all directions. The bremsstrahlung spectrum and dose rate change as a function of the emission angle. The dose rate decreases from maximum in the forward direction (0°) to minimum at 180° by 1-2 orders of magnitude. In order to design and calculate optimal shielding for food accelerator rooms, there is a need to have the bremsstrahlung spectrum data, dose rates and concrete attenuation data in all emission directions

75 FR 42575 - Electronic Signature and Storage of Form I-9, Employment Eligibility Verification

Science.gov (United States)

2010-07-22

... Electronic Signature and Storage of Form I-9, Employment Eligibility Verification AGENCY: U.S. Immigration... published an interim final rule to permit electronic signature and storage of the Form I-9. 71 FR 34510... because electronic signature and storage technologies are optional, DHS expects that small entities will...

Design and simulation of a 1.2 MeV electron accelerator used for desulfuration and denitrogenation

International Nuclear Information System (INIS)

Zhou Jun; Zhu Dajun; Liu Shenggang

2005-01-01

This paper presents the structural design and functional analysis of a new kind of 1.2 MeV industrial electron accelerator. PIC (Particle-In-Cell) method is used to simulate this accelerator and to optimize the design, the results show that the optics property of this accelerator has been improved. This electron accelerator is used for desulfuration and denitrogenation in environmental industry. This application purifies flue gases of the thermal power station from Sulphurous oxide and Nitrogen oxide in order to reduce the pollution in the air. (author)

Properties of the electron cloud in a high-energy positron and electron storage ring

International Nuclear Information System (INIS)

Harkay, K.C.; Rosenberg, R.A.

2003-01-01

Low-energy, background electrons are ubiquitous in high-energy particle accelerators. Under certain conditions, interactions between this electron cloud and the high-energy beam can give rise to numerous effects that can seriously degrade the accelerator performance. These effects range from vacuum degradation to collective beam instabilities and emittance blowup. Although electron-cloud effects were first observed two decades ago in a few proton storage rings, they have in recent years been widely observed and intensely studied in positron and proton rings. Electron-cloud diagnostics developed at the Advanced Photon Source enabled for the first time detailed, direct characterization of the electron-cloud properties in a positron and electron storage ring. From in situ measurements of the electron flux and energy distribution at the vacuum chamber wall, electron-cloud production mechanisms and details of the beam-cloud interaction can be inferred. A significant longitudinal variation of the electron cloud is also observed, due primarily to geometrical details of the vacuum chamber. Such experimental data can be used to provide realistic limits on key input parameters in modeling efforts, leading ultimately to greater confidence in predicting electron-cloud effects in future accelerators.

A high intensity beam line of γ-rays up to 22MeV energy based on Compton backscattering

International Nuclear Information System (INIS)

Guo, W.; Xu, W.; Chen, J.G.; Ma, Y.G.; Cai, X.Z.; Wang, H.W.; Xu, Y.; Wang, C.B.; Lu, G.C.; Tian, W.D.; Yuan, R.Y.; Xu, J.Q.; Wei, Z.Y.; Yan, Z.; Shen, W.Q.

2007-01-01

Shanghai Laser Electron Gamma Source, a high intensity beam line of γ-ray, has been proposed recently. The beam line is expected to generate γ-rays up to the maximum energy of 22MeV by Compton backscattering between a CO 2 laser and electrons in the 3.5 GeV storage ring of the Shanghai Synchrotron Radiation Facility. The flux of non-collimated γ-rays is estimated to be 10 9 -10 10 s -1 when a CO 2 laser of several hundred Watt power is employed. We will discuss physics issues in the design and optimization of the beam line

Product conveying system for 10 MeV electron beam accelerator for electron beam centre, Kharghar, Navi Mumbai

International Nuclear Information System (INIS)

Bandi, L.N.; Lavale, D.S.; Sarma, K.S.S.; Khader, S.A.; Assadullah, M.; Sabharwal, S.

2003-01-01

In industrial radiation processing applications using accelerators, product conveying system plays a vital role in exposing the product to high energy electron beam for imparting specified dose to the product and delivering required through puts. The speed of the conveyor corresponds to a definite time of exposure of the product in the radiation zone. Design of suitable conveyor system for a variety of products with differing dose requirements call for a conveyor with wide speed range. This paper discusses the design features of a suitable under beam conveyor system for 10 MeV, 10 kW accelerator for processing a range of products including medical and food products

High efficiency charge recuperation for electron beams of MeV energies

International Nuclear Information System (INIS)

MacLachlan, J.A.

1996-05-01

Electron cooling of ion beams with energies of some GeV per nucleon requires high-quality electron beams of MeV energies and currents as high as several amperes. The enormous beam power dictates that the beam current be returned to the high voltage terminal which provides the accelerating potential. The beam is returned to a carefully designed collector within the terminal and biased a few kV positive with respect to it. Thus the load on the HV supply is only the accelerating potential times the sum of the beam current loss and the current used to maintain a graded potential on the accelerating structure. If one employs an electrostatic HV supply like a Van de Graaff with maximum charging current of a few hundred microA, the permissible fractional loss is ∼ 10 -4 . During the 15 years or so the concept of medium energy electron cooling has been evolving, the need to demonstrate the practicability of such high efficiency beam recovery has been recognized. This paper will review some experimental tests and further experiments which have been proposed. The design and status are presented for a new re-circulation experiment at 2 MV being carried out by Fermilab at National Electrostatics Corp

Optimization of the transverse electron polarization of HERA at 26.7 GeV

International Nuclear Information System (INIS)

Grosshauser, C.

1994-08-01

The methods applied for the optimization of the transverse electron polarization were presented in the following and the measurements performed by this extensively described. By these measurements could be shown that in pure electron-beam operation a degree of polarization of P similar 67% can be reached. A adjustment of the electron storage ring determined by this allows also under luminosity conditions without further optimization an only fewly deminuished transverse electron polarization. The measured polarization values where thereby over several hours stable and could also after months be reproduced. An interference of the polarization by electron-proton collisions could not be stated in the framework of the measurements. In an optimization of the electron polarization performed during the luminosity operation polarization values of P similar 67% could be reached. Thereby could be stated that an optimization of the electron polarization can be perforemd parallel to the data taking of the experiments H1 and ZEUS without fearing of extensive interferences for the measurement conditions of the experiments. By means of the resonance depolarization, which was at HERA for the first time successfully applied, the electron energy was determined with a maximal error of similar 3 MeV and an energy calibration of the HERA electron storage ring performed. At this energy calibration a mean deviation of the nominal energy from the energy values, which were determined by means of the depolarization measurements, of similar 35 MeV resulted. By the different studies on the transverse electron polarization and by the production of the worldwide first longitudinally polarized electron beam in a storage ring, in which a degree of polarization of P long ≥55% was observed, could be shown that a data taking of the experiment HERMES can be pursued parallel to the experiments H1 and ZEUS in the electron storage ring HERA

Ultra high vacuum system of the 3 MeV electron beam accelerator

International Nuclear Information System (INIS)

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

2003-01-01

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

Coherent synchrotron radiation by an electron linear accelerator

International Nuclear Information System (INIS)

Nakazato, T.; Oyamada, M.; Niimura, N.

1990-01-01

Coherent effects in synchrotron radiation (SR) have been observed for the first time from 180 MeV short electron bunches of 1.7 mm using the Tohoku 300 MeV Linac. The intensity of the coherent SR was about 10 5 times as strong as that of incoherent SR at wavelengths of 0.33 to 2.0 mm. This enhancement factor roughly corresponds to the number of electrons in a bunch. The SR intensity showed a quadratic dependence on the electron beam current. The radiation was mainly polarized in the orbital plane. The possibility of induced rf in a vacuum chamber was excluded experimentally. An electron linear accelerator will be applied to a strong light source from infrared to millimeter wavelengths instead of the storage rings. The bunch length of shorter than 1 mm can be observed by the spectrum measurement of coherent SR. (author)

Physics design of a 10 MeV, 6 kW travelling wave electron linac for industrial applications

International Nuclear Information System (INIS)

Kulkarni, Nita S.; Dhingra, Rinky; Kumar, Vinit

2016-01-01

We present the physics design of a 10 MeV, 6 kW S-band (2856 MHz) electron linear accelerator (linac), which has been recently built and successfully operated at Raja Ramanna Centre for Advanced Technology, Indore. The accelerating structure is a 2π/3 mode constant impedance travelling wave structure, which comprises travelling wave buncher cells, followed by regular accelerating cells. The structure is designed to accelerate 50 keV electron beam from the electron gun to 10 MeV. This paper describes the details of electromagnetic design simulations to fix the mechanical dimensions and tolerances, as well as heat loss calculations in the structure. Results of design simulations have been compared with those obtained using approximate analytical formulae. The beam dynamics simulation with space charge is performed and the required magnetic field profile for keeping the beam focussed in the linac has been evaluated and discussed. An important feature of a travelling wave linac (in contrast with standing wave linac) is that it accepts the RF power over a band of frequencies. Three dimensional transient simulations of the accelerating structure along with the input and output couplers have been performed using the software CST-MWS to explicitly demonstrate this feature. (author)

Latest on polarization in electron storage rings

International Nuclear Information System (INIS)

Chao, A.W.

1983-01-01

The field of beam polarization in electron storage rings is making rapid progress in recent several years. This report is an attempt to summarize some of these developments concerning how to produce and maintain a high level of beam polarization. Emphasized will be the ideas and current thoughts people have on what should and could be done on electron rings being designed at present such as HERA, LEP and TRISTAN. 23 references

Test calculations of photoneutrons emission from surface of uranium sphere irradiated by 28 MeV electrons

International Nuclear Information System (INIS)

Blokhin, A.I.; Degtyarev, I.I.

2002-01-01

In this paper the results of physical verification for the BOFOD photonuclear data files are reported, available for the uranium isotopes U 235 , U 238 . These results were compared with calculated data by the parameterization driven model of photonuclear reaction and experimental data. Experimental data of photoneutron yields from surface of uranium sphere irradiated by 28 MeV electrons are used for a verification. Both calculations have been carried out with the RTS and T general purpose Monte Carlo code with detailed electron-photon-nucleon transport simulation using the ENDF/B-VI and EPDL evaluated data libraries

Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV.

Science.gov (United States)

Maigne, L; Perrot, Y; Schaart, D R; Donnarieix, D; Breton, V

2011-02-07

The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV.

MeV Mott polarimetry at Jefferson Lab

International Nuclear Information System (INIS)

Steigerwald, M.

2001-01-01

In the recent past, Mott polarimetry has been employed only at low electron beam energies (≅100 keV). Shortly after J. Sromicki demonstrated the first Mott scattering experiment on lead foils at 14 MeV (MAMI, 1994), a high energy Mott scattering polarimeter was developed at Thomas Jefferson National Accelerator Facility (5 MeV, 1995). An instrumental precision of 0.5% was achieved due to dramatic improvement in eliminating the background signal by means of collimation, shielding, time of flight and coincidence methods. Measurements for gold targets between 0.05 μm and 5 μm for electron energies between 2 and 8 MeV are presented. A model was developed to explain the depolarization effects in the target foils due to double scattering. The instrumental helicity correlated asymmetries were measured to smaller than 0.1%

Atomic and molecular physics with ion storage rings

International Nuclear Information System (INIS)

Larsson, M.

1995-01-01

Advances in ion-source, accelerator and beam-cooling technology have made it possible to produce high-quality beams of atomic ions in arbitrary charged states as well as molecular and cluster ions are internally cold. Ion beams of low emittance and narrow momentum spread are obtained in a new generation of ion storage-cooler rings dedicated to atomic and molecular physics. The long storage times (∼ 5 s ≤ τ ≤ days) allow the study of very slow processes occurring in charged (positive and negative) atoms, molecules and clusters. Interactions of ions with electrons and/or photons can be studied by merging the stored ion beam with electron and laser beams. The physics of storage rings spans particles having a charge-to-mass ratio ranging from 60 + and C 70 + ) to 0.4 - 1.0 (H + , D + , He 2+ , ..., U 92+ ) and collision processes ranging from <1 meV to ∼ 70 GeV. It incorporates, in addition to atomic and molecular physics, tests of fundamental physics theories and atomic physics bordering on nuclear and chemical physics. This exciting development concerning ion storage rings has taken place within the last five to six years. (author)

Investigation of ionization losses of shower electrons in electron-photon shower developed in liquid xenon by gamma quanta in the energy range 1600-3400 MeV

International Nuclear Information System (INIS)

Okhrymenko, L.S.; Slowinski, B.; Strugalski, Z.; Sredniawa, B.

1975-01-01

Results of the investigation of differential distributions of ionization losses and the corresponding fluctuations for shower electrons in the longitudinal development of electron-photon showers produced by gamma-quanta of energies Esub(γ)=1600-3400 MeV in liquid xenon are given. A simple and convenient from the methodical point of view two-parametric function, approximating the observed distribution has been obtained. The independence of the fluctuations of ionization losses of shower electrons on the energy of gamma-quanta in the investigated interval of Esub(γ) values has been found

Simulation of energy deposit distribution in water for 10 and 25 MeV electron beams

International Nuclear Information System (INIS)

Borrell Carbonell, Maria de los Angeles.

1977-01-01

The Monte Carlo method was applied to transport simulation of electron beams from the exit window of a linear accelerator till the absorption by a water phantom. The distribution of energy deposit is calculated for ideal apparatus and experimental conditions. Calculations are made for a distance window-water surface of one meter, for 10 and 25 MeV monoenergetic incident electrons, and for different fields (15x15 cm 2 to 4x4 cm 2 ). Comparisons with experimental measurements obtained in comparable conditions with a Sagittaire accelerator (C.G.R.-MeV), show a good agreement concerning radial distribution and depth distribution around isodose 100%. However a certain disagreement appears in the end of depth penetration [fr

8 MeV electron beam induced modifications in the thermal, structural and electrical properties of nanophase CeO2 for potential electronics applications

Science.gov (United States)

Babitha, K. K.; Sreedevi, A.; Priyanka, K. P.; Ganesh, S.; Varghese, Thomas

2018-06-01

The effect of 8 MeV electron beam irradiation on the thermal, structural and electrical properties of CeO2 nanoparticles synthesized by chemical precipitation route was investigated. The dose dependent effect of electron irradiation was studied using various characterization techniques such as, thermogravimetric and differential thermal analyses, X-ray diffraction, Fourier transformed infrared spectroscopy and impedance spectroscopy. Systematic investigation based on the results of structural studies confirm that electron beam irradiation induces defects and particle size variation on CeO2 nanoparticles, which in turn results improvements in AC conductivity, dielectric constant and loss tangent. Structural modifications and high value of dielectric constant for CeO2 nanoparticles due to electron beam irradiation make it as a promising material for the fabrication of gate dielectric in metal oxide semiconductor devices.

Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells

Energy Technology Data Exchange (ETDEWEB)

Bhat, Sathyanarayana, E-mail: asharao76@gmail.com; Rao, Asha, E-mail: asharao76@gmail.com [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore-574225 (India); Krishnan, Sheeja [Department of Physics, Sri Devi Institute of Technology, Kenjar, Mangalore-574142 (India); Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri-574199 (India); Suresh, E. P. [Solar Panel Division, ISRO Satellite Centre, Bangalore-560017 (India)

2014-04-24

The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy – 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance – Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

Optimization calculations for slow neutron production with the 136 MeV Harwell electron linac

International Nuclear Information System (INIS)

Needham, J.; Sinclair, R.N.

1978-10-01

The new 136 MeV Harwell electron linac is to be used to produce pulsed beams of slow neutrons for condensed matter research. Design details and performance of the two types of moderator which will be available have been optimised using a Monte Carlo neutronics code (TIMOC). The choice of reflector, the necessary decoupling energy to prevent pulse broadening and the influence of γ shields and moderator shape have been investigated. The predicted yield of leakage neutrons of energy 1 eV is compared to published values for comparable facilities. (author)

Evolution of defects in a multicomponent glass irradiated by 1 MeV electrons

International Nuclear Information System (INIS)

Wang Qingyan; Geng Hongbin; Sun Chengyue; Zhang Zhonghua; He Shiyu

2010-01-01

The optical properties and microstructural degradation of a multicomponent glass after exposure to 1 MeV electrons for fluences of 10 13 to 10 16 e - /cm 2 , as well as the recovery during annealing at room temperature (RT) for the fluence of 10 16 e - /cm 2 , are investigated. The non-bridging oxygen hole centers (NBOHCs), as well as trapped electrons (TEs), are mainly attributed to optical absorption bands and paramagnetic spectra. In comparison of the exponential curves, the in-growth kinetics for each type of defect with increasing fluence are separable, and a new linearly-combined exponential model is used to describe the structural responses during irradiation. Accordingly, RT bleaching curves of defects follow a linearly-combined exponential decay function. Consistent results from optical and paramagnetic signals suggest that this linearly-combined model provides a reasonable kinetic description of the growth and bleaching process of defects.

Number distribution of emitted electrons by MeV H+ impact on carbon

Science.gov (United States)

Ogawa, H.; Koyanagi, Y.; Hongo, N.; Ishii, K.; Kaneko, T.

2017-09-01

The statistical distributions of the number of the forward- and backward-emitted secondary electrons (SE's) from a thin carbon foil have been measured in coincidence with foil-transmitted H+ ions of 0.5-3.0 MeV in every 0.5 MeV step. The measured SE energy spectra were fitted by assuming a Pólya distribution for the simultaneous n-SE emission probabilities. For our previous data with a couple of the carbon foils with different thicknesses, a similar analysis has been carried out. As a result, it was found that the measured spectra could be reproduced as well as by an analysis without placing any restriction on the emission probabilities both for the forward and backward SE emission. The obtained b-parameter of the Pólya distribution, which is a measure of the deviation from a Poisson distribution due to the cascade multiplication by high energy internal SE's, increases monotonically with the incident energy of proton beams. On the other hand, a clear foil-thickness dependence is not observed for the b-parameter. A theoretical model which could reproduced the magnitude of the b-parameter for the SE energy spectra obtained with thick Au, Cu and Al targets is found to overestimates our values for thin carbon foils significantly. Another model calculation is found to reproduce our b-values very well.

Radiation Shielding Analyses of A 10 MeV, 15kW LINAC for Electron Beam and X-ray at KACST

Energy Technology Data Exchange (ETDEWEB)

Kang, W. G.; Pyo, S. H.; Han, B. S.; Kang, C. M. [EB Tech Co., Daejeon (Korea, Republic of); Alkhuraiji, T. S. [King AbdulAziz City for Science and Technology, Riyadh (Saudi Arabia)

2016-10-15

The King AbdulAziz City for Science and Technology (KACST) in the Kingdom of Saudi Arabia has a plan to build a 10 MeV, 15kW linear accelerator (LINAC) for electron beam and X-ray, which is to be supplied by EB Tech in Republic of Korea. The design and construction of the accelerator building will be carried out jointly between EB Tech and KACST. Recommendations for the design and installation of radiation shielding for x-ray and gamma-ray can be found in NCRP No. 49(1976) and for accelerators with energies over 10 MeV in NCRP No. 151 (2005). Monte Carlo calculations were conducted using the MCNP6 code to determine photon fluxes and doses at the point detectors locations around the accelerator building. The problem was run as an electron, photon and neutron transport problem to account for all reactions including the (γ,n) reaction. The detectors where the DXTRAN spheres were used are indicated in the table. The computation was continued until electrons reached a total of 1x10{sup +8} histories.

Two-section linear direct-current accelerator of 1.2 MeV electrons. Mean beam current of 50 mA

International Nuclear Information System (INIS)

Alimov, A.S.; Ermakov, D.I.; Ishkhanov, B.S.; Shvedunov, V.I.; Sakharov, V.P.; Trower, W.P.

2002-01-01

The theoretical and experimental results, obtained by simulation, creation and start-up of the two-section linear electron accelerator, are presented. The following beam parameters: beam current of 49 mA, mean energy of 1.2 MeV, of 59 kV, normalized emittance of 11 mm mrad are determined on the basis of the data on the beam dynamics simulation and the accelerating structure optimization. Special attention is paid to the choice of the version of the SHF-supply system of the two-section accelerator. The version of the SHF-supply system, based on the sections phasing, operating in the auto-oscillation model by means of the synchronizing signal from the feedback chain of the first section into the feedback chain of the second section, is considered. The electron beam parameters on the accelerator outlet (beam current - 44 mA, beam energy - 1.15 MeV, beam efficiency - 50.6 kW) proved to be close to the simulation results [ru

FEL radiation power available in electron storage rings

International Nuclear Information System (INIS)

Miyahara, Yoshikazu

1994-01-01

FEL radiation power available in electron storage rings was studied in the small signal regime in considering the increase of the energy spread of the electron beam caused by the FEL interaction and the decrease of the FEL gain with the increase of the energy spread in addition to the radiation damping and the quantum excitation. All these effects were considered separately, and combined with FEL power equations. The radiation power available was expressed explicitly with the parameters of the storage ring, the wiggler and the mirrors. The transient process of FEL lasing is simulated with the power equations. A rough estimation is made of the radiation power available by the FEL at different beam energies, and optimization of FEL parameters for a higher radiation power is discussed. ((orig.))

Application of the Ethanol-Chlorobenzene Dosimeter to Electron Beam Dosimetry: Pulsed 10 MeV Electrons

Energy Technology Data Exchange (ETDEWEB)

Dvornik, I.; Razem, D.; Baric, M. [Institute ' ' Ruder Boskovic' ' , Zagreb, Yugoslavia (Croatia)

1969-12-15

With gamma irradiation, the ethanol-chlorobenzene chemical dosimetric systems have shown valuable properties. They are simple to prepare and analyse, the G(HC1) values are not sensitive to normal impurities and are constant within the dose range of interest for processing. This paper describes the experiments performed with 10 MeV pulsed electrons from the linear accelerator of the Research Establishment Riso, Denmark (7 microsecond pulses repeated 300 times per second, 10{sup 9} rad/sec in the pulse). The irradiations were calibrated calorimetrically. The G(HC1) values independent of dose up to 40 Mrad are given as a function of chlorobenzene concentration. The comparison with gamma irradiations shows only insignificant differences in the G-values. Above 10 vol. % chlorobenzene the G-values are approximately constant up to 20 Mrad or more, and are to within 2% equal to those obtained for gamma rays with free access of air. The addition of 0.04% of acetone or benzene to the systems had within the experimental error, no influence upon the G(HC1). The results show the applicability of ethanol-chlorobenzene dosimeters to the dosimetry of electron beam irradiations at dose rates as high as 10{sup 9} rad/sec and dosages up to 6 Mrad. (author)

Electron cloud development in the Proton Storage Ring and in the Spallation Neutron Source

International Nuclear Information System (INIS)

Pivi, M.T.F.; Furman, M.A.

2002-01-01

We have applied our simulation code ''POSINST'' to evaluate the contribution to the growth rate of the electron-cloud instability in proton storage rings. Recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos are presented in this paper. A key ingredient in our model is a detailed description of the secondary emitted-electron energy spectrum. A refined model for the secondary emission process including the so-called true secondary, rediffused and backscattered electrons has recently been included in the electron-cloud code

Study of interactions of a electron beam of 10 MeV energy and matter

International Nuclear Information System (INIS)

Askri, Boubaker

2002-01-01

In this work, we tried to extend the algorithm of the Monte Carlo method to the case of relativistic electrons of energy 10 MeV through the material, after appropriate to the simple case of non-relativistic electrons of energy 20 keV. It was determined the coefficients of reflection, transmission and absorption of electrons through the middle in both cases. As the energy and angular distributions of electrons transmitted. The results show a fairly good precision on the determination of the three coefficients. For the non-relativistic case, it was in 1000 simulations of 1000 lots electrons for gold and aluminum, it has reached an accuracy of about 0.5 pour cent. For the relativistic case, it was 20 lots of simulations for 500 electrons carbon and aluminum. we reached an accuracy of about 2, 5 pour cent determining the coefficients. The energy and angular distributions of electrons transmitted, are close those derived from the program GEANT, taken as a reference and as comparison tool. It hopes to increase the accuracy by increasing the number of lots and the size of each batch of electrons. However, the process took six days to simulate ten miles electrons under normal conditions on the HP9000 machine calculation takes a greatest time of execution for a statistical sample of smaller great. Several criteria are necessary to optimize the study. About improving the theoretical model and the algorithm, and implementation the procedure on a machine more powerful computing. (Author)

Present status of storage ring free electron laser experiment at ETL

International Nuclear Information System (INIS)

Yamazaki, T.; Nakamura, T.; Tomimasu, T.; Sugiyama, S.; Noguchi, T.

1988-01-01

Outline is described of the present status of the ETL storage-ring free electron laser project. The structure and the performance of the ETL-type transverse optical klystron are given. A modification of the dispersive section has decreased the degradation of the shape of the spontaneous-emission spectrum due to energy spread of the electron beam. Relevant parameters of the stored beam are presented. Measurement of the optical-cavity loss is under way. (author)

Commissioning of Fermilab's Electron Cooling System for 8-GeV Antiprotons

CERN Document Server

Nagaitsev, Sergei; Burov, Alexey; Carlson, Kermit; Gai, Wei; Gattuso, Consolato; Hu, Martin; Kazakevich, Grigory; Kramper, Brian J; Kroc, Thomas K; Leibfritz, Jerry; Prost, Lionel; Pruss, Stanley M; Saewert, Greg W; Schmidt, Chuck; Seletsky, Sergey; Shemyakin, Alexander V; Sutherland, Mary; Tupikov, Vitali; Warner, Arden

2005-01-01

A 4.3-MeV electron cooling system has been installed at Fermilab in the Recycler antiproton storage ring and is being currently commissioned. The cooling system is designed to assist accumulation of 8.9-GeV/c antiprotons for the Tevatron collider operations. This paper will report on the progress of the electron beam commissioning effort as well as on detailed plans of demonstrating the cooling of antiprotons.

Measurements of the electron cloud in the APS storage ring

International Nuclear Information System (INIS)

Harkey, K. C.

1999-01-01

Synchrotron radiation interacting with the vacuum chamber walls in a storage ring produce photoelectrons that can be accelerated by the beam, acquiring sufficient energy to produce secondary electrons in collisions with the walls. If the secondary-electron yield (SEY) coefficient of the wall material is greater than one, as is the case with the aluminum chambers in the Advanced Photon Source (APS) storage ring, a runaway condition can develop. As the electron cloud builds up along a train of stored positron or electron bunches, the possibility exists that a transverse perturbation of the head bunch will be communicated to trailing bunches due to interaction with the cloud. In order to characterize the electron cloud, a special vacuum chamber was built and inserted into the ring. The chamber contains 10 rudimentary electron-energy analyzers, as well as three targets coated with different materials. Measurements show that the intensity and electron energy distribution are highly dependent on the temporal spacing between adjacent bunches and the amount of current contained in each bunch. Furthermore, measurements using the different targets are consistent with what would be expected based on the SEY of the coatings. Data for both positron and electron beams are presented

Investigation of longitudinal dynamic in laser electron storage ring

Energy Technology Data Exchange (ETDEWEB)

Karnaukhov, I.; Zelinsky, A. E-mail: zelinsky@kipt.kharkov.ua; Telegin, Yu

2001-09-01

Longitudinal dynamic of electron beam due to radiation damping and quantum fluctuations in the storage ring with a laser-electron interaction section (Compton scattering) is investigated. This investigation was carried out by numerical simulations using the Monte Carlo method. The dependence of the steady-state energy spread of electron beam due to the Compton back scattering of photons on the electron beam energy and photon flash density were obtained. Simulation findings are compared with the analytical estimations by Z. Huang.

Investigation of longitudinal dynamic in laser electron storage ring

CERN Document Server

Karnaukhov, I; Telegin, Yu P

2001-01-01

Longitudinal dynamic of electron beam due to radiation damping and quantum fluctuations in the storage ring with a laser-electron interaction section (Compton scattering) is investigated. This investigation was carried out by numerical simulations using the Monte Carlo method. The dependence of the steady-state energy spread of electron beam due to the Compton back scattering of photons on the electron beam energy and photon flash density were obtained. Simulation findings are compared with the analytical estimations by Z. Huang.

Irradiation effects of 6 MeV electron on electrical properties of Al/Al2O3/n-Si MOS capacitors

International Nuclear Information System (INIS)

Laha, P.; Banerjee, I.; Bajaj, A.; Chakraborty, P.; Barhai, P.K.; Dahiwale, S.S.; Das, A.K.; Bhoraskar, V.N.; Kim, D.; Mahapatra, S.K.

2012-01-01

The influence of 6 MeV electron irradiation on the electrical properties of Al/Al 2 O 3 /n-Si metal–oxide–semiconductor (MOS) capacitors has been investigated. Using rf magnetron sputtering deposition technique, Al/Al 2 O 3 /n-Si MOS capacitors were fabricated and such twelve capacitors were divided into four groups. The first group of MOS capacitors was not irradiated with 6 MeV electrons and treated as virgin. The second group, third group and fourth group of MOS capacitors were irradiated with 6 MeV electrons at 10 kGy, 20 kGy, and 30 kGy doses, respectively, keeping the dose rate ∼1 kGy/min. The variations in crystallinity of the virgin and irradiated MOS capacitors have been compared from GIXRD (Grazing Incidence X-ray Diffraction) spectra. Thickness and in-depth elemental distributions of individual layers were performed using Secondary Ion Mass Spectrometry (SIMS). The device parameters like flat band voltage (V FB ) and interface trap density (D it ) of virgin and irradiated MOS capacitors have been calculated from C vs V and G/ω vs V curve, respectively. The electrical properties of the capacitors were investigated from the tan δ vs V graph. The device parameters were estimated using C–V and G/ω–V measurements. Poole–Frenkel coefficient (β PF ) of the MOS capacitors was determined from leakage current (I)–voltage (V) measurement. The leakage current mechanism was proposed from the β PF value. - Highlights: ► The electron irradiation effects make variation in the device parameters. ► The device parameters changes due to percentage of defects and charge trapping. ► Leakage current of Al/Al 2 O 3 /n-Si changes due to interface dangling bonds. ► The leakage current mechanism of MOS structures is due to Poole-Frenkel effect.

Dose Mapping of Frozen Chickens Using 10 MeV Electrons

International Nuclear Information System (INIS)

Eichenberger, C.; Haider, S.A.; Maxim, J.; Miller, R.B.

2005-09-01

Irradiation of locally produced and imported food products was approved in the Kingdom of Saudi Arabia (KSA) in 2002. SureBeam Middle East (SME) has constructed the first food irradiation facility in Riyadh, KSA and will begin production irradiation in Q4 of 2005. In an effort to find efficient and cost effective means of irradiating frozen whole body chickens, SME has sponsored dose mapping studies using a 10 MeV dual electron beam processing system at the Electron Beam Food Research Facility at Texas A and M University (TAMU). Frozen chickens available to consumers in KSA range in size from nominal 600 grams to 1400 grams. Poultry processors typically provide retailers with equal weight birds packaged ten to a box (2 rows of 5 birds). Areal densities of the packages increase with the weight of the birds. For this study equivalent size birds were grown and processed by the Department of Poultry Science at TAMU and packaged in the same manner as in KSA. The goal of this investigation was to determine which size birds could be processed at a minimum dose of 2.5 kGy and not have the maximum dose exceed the level where negative sensory effects become noticeable. The minimum dose was chosen to reduce the population of any salmonella contamination by more than a factor of 1000. A description of the experimental set up and results of the dose mapping of frozen whole body chickens are reported herein, as are the results which indicate that electron beam processing of frozen chickens up to approximately 1000 grams can be readily accomplished and that processing of chickens up to 1400 grams may be possible Salmonella

Preliminary examination of induced radio activity in pepper by 10 MeV electron irradiation

International Nuclear Information System (INIS)

Furuta, Masakazu; Katayama, Tadashi; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu; Takeda, Atsuhiko

1989-01-01

β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper in order to reconfirm the wholesomeness of irradiated food and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. From elemental composition of the samples and investigation of photonuclear reactions, several β-emmitters were listed up. But no radioactivity other than from natural sources was detected in the irradiated sample by β-ray counting with 2 π gass flow counter, suggesting that the induced β-emmitters in the irradiated sample was below the detection limit of its induced radioactivity. (author)

Sudden Intensity Increases and Radial Gradient Changes of Cosmic Ray Mev Electrons and Protons Observed at Voyager 1 Beyond 111 AU in the Heliosheath

Science.gov (United States)

Webber, W. R.; Mcdonald, F. B.; Cummings, A. C.; Stone, E. C.; Heikkila, B.; Lal, N.

2012-01-01

Voyager 1 has entered regions of different propagation conditions for energetic cosmic rays in the outer heliosheathat a distance of about 111 AU from the Sun. The low energy 614 MeV galactic electron intensity increased by 20over a time period 10 days and the electron radial intensity gradient abruptly decreased from 19AU to 8AU at2009.7 at a radial distance of 111.2 AU. At about 2011.2 at a distance of 116.6 AU a second abrupt intensity increase of25 was observed for electrons. After the second sudden electron increase the radial intensity gradient increased to18AU. This large positive gradient and the 13 day periodic variations of 200 MeV particles observed near theend of 2011 indicate that V1 is still within the overall heliospheric modulating region. The implications of these resultsregarding the proximity of the heliopause are discussed.

Electron beam properties and impedance characterization for storage rings used for free electron lasers

International Nuclear Information System (INIS)

Dattoli, G.; Mezi, L.; Renieri, A.; Migliorati, M.; Walker, R.

2000-01-01

Good electron beam qualities and stability are the crucial features of Storage Rings dedicated to synchrotron radiation sources or to Free Electron Laser. Most of these characteristics depends on the coupling of the e-beam with the machine environment, which can be in turn modelled in terms of a characteristic impedance, whose absolute value and structure can be used to specify both the stability (longitudinal and transverse) of the beam and its qualities (energy spread, bunch length, peak current ...). In this paper are considered two specific examples of Storage Rings used for FEL operation and analyze their performances by means of semi analytical and numerical methods. The analysis is aimed at clarifying the dependence of beam energy spread and bunch length on beam current and at providing a set of parameters useful for the optimization of Free Electron Laser or synchrotron radiation sources [it

The electron beam dynamics simulation in the laser-electron storage ring involving compton and intrabeam scattering

International Nuclear Information System (INIS)

Gladkikh, P.I.; Telegin, Yu.N.; Karnaukhov, I.M.

2002-01-01

The feasibility of the development of intense X-ray sources based on Compton scattering in laser-electron storage rings is discussed. The results of the electron beam dynamics simulation involving Compton and intrabeam scattering are presented

The electron beam dynamics simulation in the laser-electron storage ring involving compton and intrabeam scattering

CERN Document Server

Gladkikh, P I; Karnaukhov, I M

2002-01-01

The feasibility of the development of intense X-ray sources based on Compton scattering in laser-electron storage rings is discussed. The results of the electron beam dynamics simulation involving Compton and intrabeam scattering are presented.

Multiple ionization of noble gases by 2.0 MeV proton impact: comparison with equi-velocity electron impact ionization

International Nuclear Information System (INIS)

Melo, W.S.; Santos, A.C.F.; Sant'Anna, M.M.; Sigaud, G.M.; Montenegro, E.C.

2002-01-01

Absolute single- and multiple-ionization cross sections of rare gases (He, Ne, Ar, Kr and Xe) have been measured for collisions with 2.0 MeV p + . A comparison is made with equi-velocity electron impact ionization cross sections as well as with the available proton impact data. For the light rare gases the single-ionization cross sections are essentially the same for both proton and electron impacts, but increasing differences appear for the heavier targets. (author). Letter-to-the-editor

Confirm calculation of 12 MeV non-destructive testing electron linear accelerator target

International Nuclear Information System (INIS)

Ma Shudong; Zhang Rutong; Guo Yanbin; Zhou Yuan; Li Xuexian; Chen Yan

2012-01-01

The confirm calculation of 12 MeV non-destructive testing (NDT) electron linear accelerator (LINAC) target was studied. Firstly, the most optimal target thickness and related photon dose yield, distributions of dose rate, and related photon conversion efficiencies were got by calculation with specific analysis of the physical mechanism of the interactions between the beam and target; Secondly, the photon dose rate distribution, converter efficiencies, and thickness of various kinds of targets, such as W, Au, Ta, etc. were verified by MCNP simulation and the most optimal target was got using the MCNP code; Lastly, the calculation results of theory and MCNP were compared to confirm the validity of target calculation. (authors)

14 MeV proton activation analysis

International Nuclear Information System (INIS)

Constantinescu, B.; Ivanov, E.; Plostinaru, D.; Popa-Nemoiu, A.; Pascovichi, G.

1985-01-01

A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14 N (p,n) 14 O, (Tsub(1/2)=71 s). The 14 O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)

1-MeV electron beam propagation experiments in neutral gas

International Nuclear Information System (INIS)

Greenspan, M.A.; Rose, E.A.

1984-01-01

Experiments were performed studying the propagation of a 1-MeV, 10-ns electron beam at currents of 2-8 kA. Propagation was studied in a 7.6-cm-diam glass guide tube, the same tube with a conducting screen inside, and in a 3.4-m-diam chamber. In the guide tube with the screen, ion-focused propagation is observed at low pressures (≤ 40 Pa) with net current equal to beam current. At higher pressures (55-130 Pa), a notch in beam current is observed for pressure time products of ≅ 100 Pa-ns. Between 270 Pa and 1070 Pa, good propagation is again observed with net currents of 50-70% of the beam current. The net current fraction of beam current increases with increasing pressure and with decreasing beam current. At pressure above 1070 Pa, hose instability occurs, and net current nearly equal to beam current is observed. The hose frequency is in reasonable accord with theory. Nose erosion is minimized at pressures for 1000-2000 Pa depending on beam current, and increases at lower and higher pressures

Scattering of 14. 0 MeV electrons. Fundamental study of the scattering foil. [Angular distribution, 14. 0 MeV, gaussian distribution

Energy Technology Data Exchange (ETDEWEB)

Takei, C [Kyushu Univ., Fukuoka (Japan). School of Health Sciences; Yoshimoto, S

1977-07-01

The angular distribution of 14.0 MeV electrons scattered by thin Al and Pb foils has been measured, since the beam flatness is important on the high energy electron therapy. These distributions measured were almost completely Gaussian. The root mean square scattering angles were obtained and were compared with the theories of Williams and Rossi. In our experiments the root mean square scattering angles obtained have the experimental errors of about 4% and 1% for 5/sup 0/ and 10/sup 0/, respectively. For Al foils of 0.5 mm to 3.0 mm the experimental values of the root mean square scattering angles are 5.49/sup 0/ and 12.43/sup 0/ and are 30% to 10% higher than those predicted by Williams. Although, these values are 4% to 9% lower than those calculated from the theory of Rossi. The root mean square scattering angles obtained with Pb foils of 0.1 mm to 0.3 mm are 9.62/sup 0/ to 18.05/sup 0/ and are 14% to 18% higher than Williams, and are 14% to 7% lower than those theoretically calculated by Rossi.

Infrared synchrotron radiation from electron storage rings

International Nuclear Information System (INIS)

Duncan, W.D.; Williams, G.P.

1983-01-01

Simple and useful approximations, valid at infrared wavelengths, to the equations for synchrotron radiation are presented and used to quantify the brightness and power advantage of current synchrotron radiation light sources over conventional infrared broadband laboratory sources. The Daresbury Synchrotron Radiation Source (SRS) and the Brookhaven National Synchrotron Light Source (vacuum ultraviolet) [NSLS(VUV)] storage rings are used as examples in the calculation of the properties of infrared synchrotron radiation. The pulsed nature of the emission is also discussed, and potential areas of application for the brightness, power, and time structure advantages are presented. The use of infrared free electron lasers and undulators on the next generation of storage ring light sources is briefly considered

The Cornell electron-positron storage ring - CESR

International Nuclear Information System (INIS)

DeWire, J.W.

1977-01-01

At the Laboratory of Nuclear Studies of Cornell University we are working on a project to convert the present 12 GeV electron synchrotron complex into the Cornell Electron-Positron Storage Ring - CESR. The design studies for this new device were begun in early 1975. During the past eighteen months the National Science Foundation has supported a program of research and development on CESR and funds to begin construction are included in the NSF budget now before the U.S. Congress. Our goal is to have CESR in operation in the fall of 1979. (orig.) [de

Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

International Nuclear Information System (INIS)

De Santis, S.; Byrd, J.M.; Billing, M.; Palmer, M.; Sikora, J.; Carlson, B.

2010-01-01

A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated (S. De Santis, J.M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M.T.F. Pivi, and K.G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008).). We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.

Preliminary microstructural characterization by transmission electron microscopy of 14 MeV neutron irradiated type 316 stainless steel

International Nuclear Information System (INIS)

Echer, C.J.

1977-01-01

Substantial changes in the mechanical properties of 316 stainless steel were observed after neutron irradiation (phi/sub t/ = 2.3 x 10 21 n/m 2 and E = 14 MeV) at 25 0 C. Comparison of microstructures of the unirradiated and neutron irradiated materials were evaluated using transmission electron microscopy. Evidence of small defect clusters in the irradiated material was found. These findings are consistent with other investigators also evaluating low dose irradiations

Evidence for a resonant behaviour in e+e- annihilation into hadrons, around 1820 MeV, at Adone

International Nuclear Information System (INIS)

Bacci, C.; Zorzi, G. de; Penso, G.; Stella, B.; Baldini-Celio, R.; Capon, G.; Fabbro, R. del; Iarocci, E.; Murtas, G.P.; Spinetti, M.

1977-01-01

Multihadron production has been measured at the Adone e + e - storage ring in the c.m. energy region 1600/1900 MeV. A resonant behaviour is observed, centered at 1819 +- 5 (+-2) MeV, with a width of 24 +-5 (+-4) MeV. This effect is observed only in the events with 3 or 4 charged particles together with photons, but not in those without photons. (Auth.)

Calculation of energy and angular distributions of the bremsstrahlung of 10 MeV electrons bombarding a thick tungsten target

International Nuclear Information System (INIS)

Tsovbun, V.I.

1977-01-01

Computer calculations have been performed to extend the data available on energy and angular distribution of the 10 MeV electron bremsrahlung into a higher angle region. The ETRAN-16D program developed by R.G.Berger for calculation of electron-photon cascades passing through matter using computers IBM-360 and UNIVAC-1108 was modified to operate with the CDC-6500 computer. A brief summary of the program is provided. An angular distribution of the bremsstrahlung dose absorbed in the air has been also calculated. The results extended into the 90-180 deg region can be used to calculate the biological shield of electron accelerators

Optimum design for 12 MeV linear induction accelerator diode

International Nuclear Information System (INIS)

Yu Haijun; Shi Jinshui; Li Qin; He Guorong; Ma Bing; Wang Jingsheng; Wang Liping

2001-01-01

A series of optimization designs of electron diode in 12 Mev linear induction accelerator are studied by using numerical simulation code MAGIC and experiment method in order to improve the electron beam quality. MAGIC code solves the Maxwell equations in the presence of charged particle, electron field distribution on cathode surface which influences electron emission is given, the optimum diode is obtained by comparing the results of experiment in 12 MeV linear induction accelerator. The author also gives SEM analysis and experiment comparison of velvet emission. Finally, emitted current I e = 8.52 kA, beam current I 8 ≥ 3.0 kA, targeted current I 0 ≥ 2.30 kA with optimum diode are obtained

Fermilab turns up the heat on electron cooling

CERN Document Server

Riesselmann, K

2002-01-01

A technique that was first proposed by Gersh Budker in 1966 is being injected with new life by a team of physicists at Fermilab in the US. Working on an ambitious electron-cooling project, the team set a new world record for DC beam power, they maintained a continuous 3.5 MeV electron beam with a current of more than 500 mA for up to 8 h with only short interruptions. They use an electron beam to cool antiprotons inside Fermilab's 3 km Recycler antiproton storage ring and boost the luminosity of the laboratory's Tevatron collider. When the electron-cooling system is complete, electrons and antiprotons will travel side by side in the Recycler.

Slow positron beam production by a 14 MeV C.W. electron accelerator

Science.gov (United States)

Begemann, M.; Gräff, G.; Herminghaus, H.; Kalinowsky, H.; Ley, R.

1982-10-01

A 14 MeV c.w. electron accelerator is used for pair production in a tungsten target of 0.7 radiation lengths thickness. A small fraction of the positrons is thermalized and diffuses out of the surface ofsurface of a well annealed tungsten foil coated with MgO which is positioned immediately behind the target. The slow positrons are extracted from the target region and magnetically guided over a distance of 10 m onto a channelplate multiplier at the end of an S-shaped solenoid. The positrons are identified by their annihilation radiation using two NaI-detectors. The intensity of the slow positrons is proportional to the accelerator electron beam current. The maximum intensity of 2.2 × 10 5 slow positrons per second reaching thedetector at an accelerator current of 15 μA was limited by the power deposited in the uncooled target. The energy of the positrons is concentrated in a small region at about 1 eV and clearly demonstrates the emission of thermal positrons.

Slow positron beam production by a 14 MeV c.w. electron accelerator

International Nuclear Information System (INIS)

Begemann, M.; Graeff, G.; Herminghaus, H.; Kalinowsky, H.; Ley, R.

1982-01-01

A 14 MeV c.w. electron accelerator is used for pair production in a tungsten target of 0.7 radiation lengths thickness. A small fraction of the positrons is thermalized and diffuses out of the surface of a well annealed tungsten foil coated with MgO which is positioned immediately behind the target. The slow positrons are extracted from the target region and magnetically guided over a distance of 10 m onto a channelplate multiplier at the end of an S-shaped solenoid. The positrons are identified by their annihilation radiation using two Nal-detectors. The intensity of the slow positrons is proportional to the accelerator electron beam current. The maximum intensity of 2.2 x 10 5 slow positrons per second reaching the detector at an accelerator current of 15 μA was limited by the power deposited in the uncooled target. The energy of the positrons is concentrated in a small region at about 1 eV and clearly demonstrates the emission of thermal positrons. (orig.)

Depth distribution of damage in copper irradiated with MeV, Ni and He ions

International Nuclear Information System (INIS)

Narayan, J.; Noggle, T.S.; Oen, O.S.

1975-01-01

Transmission electron microscopy was used to study radiation damage as a function of depth caused by 58 and 4-MeV 58 Ni and 1-MeV He ions in copper single crystals at ambient temperature. The experimental damage density vs penetration depth distributions were compared with calculations based on the atomic collision theory of Lindhard et al. (LSS). For 58-MeV Ni ions, the calculated damage profile using the theoretical LSS value of the electronic stopping parameter (k = 0.167) agrees well with experiment. However, for 4-MeV Ni ions it is necessary to use k = 0.12 to get agreement with the experimental data. In the case of 1-MeV He, the depth location of the calculated damage peak is in good agreement with experiment when the electronic stopping determined by Chu and Powers is used whereas it is about 15 percent too close to the surface using the tables of Northcliffe and Schilling. (auth)

Development of HF-systems for electron storage systems

International Nuclear Information System (INIS)

Androsov, V.P.; Karnaukhov, I.M.; Popkov, Yu.P.; Reva, S.N.; Telegin, Yu.N.

1999-01-01

Development of HF systems for electron storages is described. Its final task is construction of 100 kW HF station at 699,3 MHz frequency consisting from low-power HF system, klystron amplifier, wave line for HF power transmission and accelerating section. Functional parameters of HF station are given

Study of the yield of the Fricke dosimetry for electron energies from 2 to 90 MeV

International Nuclear Information System (INIS)

Berkvens, I.P.

1988-01-01

The chemical yield for the ferrous sulphate dosimeters was determined for 60 Co-γ radiation and for electron beams of mean energies in the points of measurements, between 2.7 and about 9 MeV. As references, absolute determinations of absorbed dose based on calorimetric measurements, were used. The irradiation geometry for the ferrous sulphate dosimeter differ always due to technical reasons somewhat from that for the absorber of the calorimeter. The investigators took this difference into account. Perturbation correction factors that correct for the difference in electron scattering in the air gaps around the absorber of the calorimeter and in the graphite, were computed with the Monte Carlo method. Also the ''reference volume method'' recently introduced by the ICRU (report No.35), was applied to correct for the introduction of a ferrous sulphate dosimeter in a graphite phantom. This correction is necessary as the electrons are stopped and scattered in a different way in graphite and water. The results indicated that there is no energy dependence of the chemical yield (G-value) of the dosimeter in the energy range 2.7 to about 9 MeV. A mean G-value of 1,584 (± 0.006) μ mol/J was obtained. For 60 Co-γ a G-value of 1.601 μ mol/J was determined. However, this difference might not be real but due to the present uncertainty in the stopping-power ratios graphite to water. These ratios are thus made use of to determine the G-value from measurements of the absorbed dose to graphite. Previous investigations, by the group from Gent, indicated a small increase of the G-value with the electron energy. These more accurate determinations thus instead indicate a constant G-value. Refs, figs, tabs

Experimental modelling of the dipole magnet for the electron storage ring DELSY

CERN Document Server

Meshkov, I N; Syresin, E M

2003-01-01

In the Joint Institute for Nuclear Research (Dubna) the project of Dubna Electron Synchrotron (DELSY) with an electron energy of 1.2 GeV is developed. The electron storage ring in the DELSY project is planned to be created on the basis of magnetic elements, which were used earlier in the storage ring AmPS (NIKHEF, Amsterdam). The optics of the ring is necessary to be changed, its perimeter to be reduced approximately in one and a half time, the energy of electrons to be increased. The paper is devoted to the development of a modified dipole magnet of the storage ring. The preliminary estimation of geometry of the magnet pole is carried out by means of computer modelling using two- and three- dimensional codes of the magnetic field calculation SUPERFISH and RADIA. The experimental stand for the measurements of the dipole magnetic field is described. As the result of calculational and experimental modelling for the dipole magnet, the geometry of its poles was estimated, providing in the horizontal aperture +- 3...

Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

Directory of Open Access Journals (Sweden)

S. De Santis

2010-07-01

Full Text Available A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated [S. De Santis, J. M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M. T. F. Pivi, and K. G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008.PRLTAO0031-900710.1103/PhysRevLett.100.094801]. We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.

Microwave matching and tuning on the 20-MeV medical electron linac with feedback of rf power

International Nuclear Information System (INIS)

Yuan-ling, Wang

1983-01-01

This article describes the 20 Mev medical electron linac at Jiangsu Tumour Hospital. In the linac, feedback of rf power is used. In the linac with feedback (or with the resonator) the reflection affects the energy gain of the electron and the performance of the accelerator. By means of the theory of the traveling wave resonator, the field multiplication factor and the reflection coefficients inside and outside the feedback ring are calculated. The bands of the linacs without and with feedback are measured. In order to achieve a desirable band in front of the load (i.e. outside the feedback ring) a matching iris is added. After the linac with feedback has been matched, the band is given

Free electron laser on the ACO storage ring

International Nuclear Information System (INIS)

Elleaume, P.

1984-06-01

This dissertation presents the design and characteristics of a Free Electron Laser built on the electron storage ring ACO at Orsay. The weak optical gain available (approximately 0.1% per pass) necessitated the use of an optical klystron instead of an undulator and the use of mirror with extremely high reflectivity. The laser characteristics: spectra, micro and macro-temporal structures, transverse structure and power are presented. They are in very good agreement with a classical theory based on the Lorentz force and Maxwell equations [fr

Operation of the APEX photoinjector accelerator at 40 MeV

International Nuclear Information System (INIS)

Feldman, D.W.; Bender, S.C.; Byrd, D.A.; Carlsten, B.E.; Early, J.W.; Feldman, R.B.; Goldstein, J.C.; Martineau, R.L.; O'Shea, P.G.; Pitcher, E.J.; Schmitt, M.J.; Stein, W.E.; Wilke, M.D.; Zaugg, T.J.

1992-01-01

We have successfully operated the photoinjector and rf linear accelerator for the Los Alamos APEX free electron laser (FEL) at design energy, average macropulse current, and emittance. The accelerator, which operates at 1.3 GHz, consists of a 6 MeV photoinjector and three standing-wave structures with a total beam energy of 40 MeV. This paper presents performance characteristics of the APEX system. The results show that this technology is capable of providing reliable, high-peak current, ultra-high brightness electron beams

Simulation of enhanced characteristic x rays from a 40-MeV electron beam laser accelerated in plasma

Directory of Open Access Journals (Sweden)

L. Nikzad

2012-02-01

Full Text Available Simulation of x-ray generation from bombardment of various solid targets by quasimonoenergetic electrons is considered. The electron bunches are accelerated in a plasma produced by interaction of 500 mJ, 30 femtosecond laser pulses with a helium gas jet. These relativistic electrons propagate in the ion channel generated in the wake of the laser pulse. A beam of MeV electrons can interact with targets to generate x-ray radiation with keV energy. The MCNP-4C code based on Monte Carlo simulation is employed to compare the production of bremsstrahlung and characteristic x rays between 10 and 100 keV by using two quasi-Maxwellian and quasimonoenergetic energy distributions of electrons. For a specific electron spectrum and a definite sample, the maximum x-ray flux varies with the target thickness. Besides, by increasing the target atomic number, the maximum x-ray flux is increased and shifted towards a higher energy level. It is shown that by using the quasimonoenergetic electron profile, a more intense x ray can be produced relative to the quasi-Maxwellian profile (with the same total energy, representing up to 77% flux enhancement at K_{α} energy.

3 MeV DC accelerator, EBC Kharghar

International Nuclear Information System (INIS)

Bakhtsingh, R.I.; Acharya, S.

2017-01-01

The Accelerator and Pulse Power Division (APPD) has designed and developed a 3 MeV, 10 mA DC electron beam accelerator at Electron Beam Centre, Kharghar, Navi Mumbai. This machine has been utilized for reduction of SO_x and NO_x in simulated flue gases and treatment of waste water to reduce COD and BOD

Lactose and sucrose aqueous solutions for high-dose dosimetry with 10-MeV electron beam irradiation

International Nuclear Information System (INIS)

Amraei, R.; Kheirkhah, M.; Raisali, G.

2012-01-01

In the present study, dosimetric characterisation of aqueous solutions of lactose and sucrose was analysed by UV spectrometry following irradiation using 10-MeV electron beam at doses between 0.5 and 10.5 kGy. As a dosimetric index, absorbance is selected at 256 and 264 nm for lactose and sucrose aqueous solutions, respectively. The intensity of absorbance for irradiated solutions depends on the pre-irradiation concentration of lactose and sucrose. The post-irradiation stability of both solutions was investigated at room temperature for a measurement period of 22 d. (authors)

Radiation-induced damage and recovery effects in GG17 glass irradiated by 1 MeV electrons

International Nuclear Information System (INIS)

Wang Qingyan; Zhang Zhonghua; Geng Hongbin; Sun Chengyue; Yang Dezhuang; He Shiyu; Hu Zhaochu

2012-01-01

The optical properties and microstructural damage of GG17 glasses, as well as their recovery during annealing at room temperature, are investigated after exposure to 1 MeV electrons with various fluences. Experimental results show that the electrons lead to severe optical degradation in the GG17 glass, and induce the formation of paramagnetic defects which can be mainly attributed to the boron–oxygen hole centers. With increasing annealing time at room temperature their decay serves as long-lived defects following first order kinetics. Except for the strong absorption bands located at 334–352 nm and 480 nm that corresponds to the boron–oxygen hole centers, weaker absorption bands appear at 780 nm or 794.6 nm after irradiation, inducing a decrease in transmittance by approximately 17% for a fluence of 1 × 10 16 cm −2 . It is shown that electron irradiation could cause a harmful effect on rubidium lamps when GG17 glass is used as the lamp envelope material.

2 MeV/20 kW industrial electron beam accelerator vis-s-vis its vacuum system

International Nuclear Information System (INIS)

Khader, S.A.; Assadullah, M.; Sarma, K.S.S.; Bandi, L.N.

2003-01-01

Full text: Electron beam accelerators in the energy range 200 keV to 10 MeV have been extensively used for many radiation processing applications that include polymerization, polymer modifications, radiation sterilization, food irradiation and gem coloration. The accelerator technology is a multidisciplinary one wherein production of stable vacuum in various accelerator systems is of utmost importance to achieve required output beam parameters like beam energy and current for processing industrial products at large through puts on continuous basis. A 2 MeV, 20 kW industrial electron beam accelerator has been in operation since 2001 at BARC-BRIT complex, Navi Mumbai for commercial and R and D applications like crosslinking of wire and cables, heat shrinkable tubes, PE O rings, PTEE degradation and color enhancement in diamonds. The machine is a ILU-6 type pulse RF accelerator consisting of a single resonator copper cavity of 1.2 m diameter and 1.2 m height (volume:∼ 1.5 m3) placed inside a stainless steel container (called cavity container) and a s.s. beam extraction window wherein vacuum needs to be maintained at a minimum 10-6 torr. Four sputter ion pumps are directly fixed on the cavity container to obtain maximum pumping efficiency. The fore vacuum is generated using a combination rotary and a roots pump. The beam extraction widow has a 50 and 956 m thick titanium foil acting as the exit window for electrons from the vacuum into air. Both the cavity and the beam extraction window are coupled through a gate valve which acts as a vacuum separator isolating the systems from each other during foil puncture, scanning system failure or any other related problems. This paper reports details of the vacuum system, measurements, vacuum leaks and detection and the operational experience related to maintenance and troubleshooting exercises that have been carried in the accelerator

Prognoz 4 observations of electrons accelerated up to energies <=2 MeV and of the cold plasma between the magnetopause and the bow shock

International Nuclear Information System (INIS)

Mineev, Yu.V.; Spir'kova, E.S.

1980-05-01

The experimental data from Prognoz 4 satellite obtained on a layer of electrons with energies <=2 MeV in the magnetosheath adjacent to magnetopause at different latitudes are given. At moderate latitudes the data are in favour of the leakage of electrons from the outer radiation belt as a source of the layer considered. At high latitudes these electrons apparently arrive along magnetosheath magnetic field lines trapping the magnetopause. (author)

Free electron laser and microwave instability interplay in a storage ring

Directory of Open Access Journals (Sweden)

G. L. Orlandi

2004-06-01

Full Text Available Collective effects, such as the microwave instability, influence the longitudinal dynamics of an electron beam in a storage ring. In a storage ring free electron laser (FEL they can compete with the induced beam heating and thus be treated as a further concomitant perturbing source of the beam dynamics. Bunch length and energy spread measurements, carried out at the Super-ACO storage ring, can be correctly interpreted according to a broad-band impedance model. Quantitative estimations of the relative role that is played by the microwave instability and the laser heating in shaping the beam longitudinal dynamics have been obtained by the analysis of the equilibrium laser power. It has been performed in terms of either a theoretical limit, implemented with the measured beam longitudinal characteristics, or the numerical results obtained by a macroparticle tracking code, which includes the laser pulse propagation. Such an analysis, carried out for different operating points of the Super-ACO storage ring FEL, indicates that the laser heating counteracts the microwave instability.

Ambient-temperature diffusion and gettering of Pt atoms in GaN with surface defect region under 60Co gamma or MeV electron irradiation

Science.gov (United States)

Hou, Ruixiang; Li, Lei; Fang, Xin; Xie, Ziang; Li, Shuti; Song, Weidong; Huang, Rong; Zhang, Jicai; Huang, Zengli; Li, Qiangjie; Xu, Wanjing; Fu, Engang; Qin, G. G.

2018-01-01

Generally, the diffusion and gettering of impurities in GaN needs high temperature. Calculated with the ambient-temperature extrapolation value of the high temperature diffusivity of Pt atoms in GaN reported in literature, the time required for Pt atoms diffusing 1 nm in GaN at ambient temperature is about 19 years. Therefore, the ambient-temperature diffusion and gettering of Pt atoms in GaN can hardly be observed. In this work, the ambient-temperature diffusion and gettering of Pt atoms in GaN is reported for the first time. It is demonstrated by use of secondary ion mass spectroscopy that in the condition of introducing a defect region on the GaN film surface by plasma, and subsequently, irradiated by 60Co gamma-ray or 3 MeV electrons, the ambient-temperature diffusion and gettering of Pt atoms in GaN can be detected. It is more obvious with larger irradiation dose and higher plasma power. With a similar surface defect region, the ambient-temperature diffusion and gettering of Pt atoms in GaN stimulated by 3 MeV electron irradiation is more marked than that stimulated by gamma irradiation. The physical mechanism of ambient-temperature diffusion and gettering of Pt atoms in a GaN film with a surface defect region stimulated by gamma or MeV electron irradiation is discussed.

Radiation control

International Nuclear Information System (INIS)

Uchida, Akira

1981-01-01

This paper describes on how the condition of radiation level in the ring (storage ring) experimentation room changes corresponding to the operating stage of SOR-ring (synchrotron radiation storage ring), and does not describe on the present radiation control in the SOR facility. The operating stage of SOR is divided into the following five: (1) 307 MeV electron injection, (2) 307 MeV electron storage (used for SOR experiments), (3) energy increase from 307 to 380 MeV, (4) 380 MeV electron storage, (5) re-injection and completion of operation. Gamma and X ray levels are shown when electron beam is injected from the electron synchrotron to the SOR-ring. Two main causes of the high level are reported. Spatial dose rate in storing 307 MeV electrons in also illustrated. This is sufficiently lower than that at electron incidence. The measurement of radiation level at the time of energy increase from 307 to 380 MeV has just started. Since the radiation level in 380 MeV storage, measured at the points about 20 cm apart from the electron orbit, showed several mR/h, the level seems to be negligible at the points where experiments are carried out, 1 m away from the measurement points. The radiation level in electron reinjection and completion of operation may be large during a short period (a few Roentgen) like the time of energy increase. Therefore, the beam shall be re-injected or decreased after confirming that all experimenters have retreated into the predetermined place. (Wakatsuki, Y.)

Electrostatic storage ring with focusing provided by the space charge of an electron plasma

International Nuclear Information System (INIS)

Pacheco, J. L.; Ordonez, C. A.; Weathers, D. L.

2013-01-01

Electrostatic storage rings are used for a variety of atomic physics studies. An advantage of electrostatic storage rings is that heavy ions can be confined. An electrostatic storage ring that employs the space charge of an electron plasma for focusing is described. An additional advantage of the present concept is that slow ions, or even a stationary ion plasma, can be confined. The concept employs an artificially structured boundary, which is defined at present as one that produces a spatially periodic static field such that the spatial period and range of the field are much smaller than the dimensions of a plasma or charged-particle beam that is confined by the field. An artificially structured boundary is used to confine a non-neutral electron plasma along the storage ring. The electron plasma would be effectively unmagnetized, except near an outer boundary where the confining electromagnetic field would reside. The electron plasma produces a radially inward electric field, which focuses the ion beam. Self-consistently computed radial beam profiles are reported.

A Monte Carlo simulation code for calculating damage and particle transport in solids: The case for electron-bombarded solids for electron energies up to 900 MeV

Energy Technology Data Exchange (ETDEWEB)

Yan, Qiang [College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001 (China); Shao, Lin, E-mail: lshao@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

2017-03-15

Current popular Monte Carlo simulation codes for simulating electron bombardment in solids focus primarily on electron trajectories, instead of electron-induced displacements. Here we report a Monte Carol simulation code, DEEPER (damage creation and particle transport in matter), developed for calculating 3-D distributions of displacements produced by electrons of incident energies up to 900 MeV. Electron elastic scattering is calculated by using full-Mott cross sections for high accuracy, and primary-knock-on-atoms (PKAs)-induced damage cascades are modeled using ZBL potential. We compare and show large differences in 3-D distributions of displacements and electrons in electron-irradiated Fe. The distributions of total displacements are similar to that of PKAs at low electron energies. But they are substantially different for higher energy electrons due to the shifting of PKA energy spectra towards higher energies. The study is important to evaluate electron-induced radiation damage, for the applications using high flux electron beams to intentionally introduce defects and using an electron analysis beam for microstructural characterization of nuclear materials.

Generation of 300 MeV Quasi-Monochromatic Electron Beams from Laser Wakefield and Initiation of Photonuclear Reactions

Science.gov (United States)

Maksimchuk, A.; Beene, J. R.

2005-10-01

In the interaction of 30 fs, 40 TW Ti:sapphire Hercules laser at the University of Michigan, which is focused to the intensity of 10^19 W/cm^2 onto a supersonic He gas jet with electron density close to the resonant density, we observed quasi-monoenergetic electron beams with energy up to 300 MeV and angular divergence of about 10 mrad. The results on characterization of relativistic electron beam in terms of energy spread, its charge, divergence and pointing stability will be presented. 2D PIC simulations performed for the parameters close to the experimental conditions show the evolution of the laser pulse in plasma, electron injection, and the specifics of electron acceleration observed in experiments. Resulted relativistic electron beams have been used to perform gamma-neutron activation of ^12C and ^63Cu and photo-fission of ^238U. We demonstrated that approximately 10^6 reaction per shot has been produced in each case. This work was supported by the NSF through the Physics Frontier Center FOCUS. JRB, DRS, DWS, and CRV acknowledge support by the DOE under contract DE-AC05-00OR22725 with UT-Battelle, LLC.

Calculation of ion storage in electron beams with account of ion-ion interactions

International Nuclear Information System (INIS)

Perel'shtejn, Eh.A.; Shirkov, G.D.

1979-01-01

Ion storage in relativistic electron beams was calculated taking account of ion-ion charge exchange and ionization. The calculations were made for nitrogen ion storage from residual gas during the compression of electron rings in the adhezator of the JINR heavy ion accelerator. The calculations were made for rings of various parameters and for various pressures of the residual gas. The results are compared with analogous calculations made without account of ion-ion processes. It is shown that at heavy loading of a ring by ions ion-ion collisions play a significant part, and they should be taken into account while calculating ion storage

Influence of 2 MeV electrons irradiation on gallium phosphide light-emitting diodes reverse currents

Directory of Open Access Journals (Sweden)

V. G. Vorobiov

2015-10-01

Full Text Available Results of reverse electrophysical characteristics study of red and green LEDs, initial and irradiated with 2 MeV electrons were given. It was found that reverse current was predominantly caused by carriers tunneling at Urev ≤ 9 V, and by the avalanche multiplication at Urev ≥ 13 V, in the range U = 9 ÷ 13 V both mechanisms are available. Current increase at high voltage areas (Urev > 19 V is limited by the base resistance of diode. In the case of significant reverse currents (I > 1 mA irradiation of diodes leads to the shift of reverse current-voltage characteristics into the high voltages direction.

Stability and electronic structure of carbon capsules with superior gas storage properties: A theoretical study

International Nuclear Information System (INIS)

Manna, Arun K.; Pati, Swapan K.

2013-01-01

Highlights: • Stability and electronic structure of various carbon capsules are studied. • Effects of capsule’s sizes on electronic and optical properties are explored. • Changes in cohesive and formation energy and electronic gap are discussed. • Capsule’s gas storage propensity is addressed using DFT and ab initio MD. • Capsule’s optical absorptions are discussed with and without stored gas molecules. - Abstract: Structures, electronic and optical properties of carbon nanocapsules of varying sizes (length and diameter) are studied using first-principles density functional theory. Based on calculated cohesive energy, formation energy, electronic gap and extent of orbital delocalization, we examine structural stability and changes in low-energy physics of these carbon capsules. We find that both cohesive and formation energy decrease with increase in capsule’s sizes, indicating their greater structural rigidity and favorable formation feasibility. The electronic gap also decreases with increase in capsule’s sizes due to the larger electronic delocalization. The simulated optical absorption spectra show lowering of low-energy peak positions with increase in the capsule’s dimensions, consistent with the reduction in electronic gap. Additionally, we also provide an estimate of gas storage capacity for the larger carbon capsule (C 460 ) considered. We find 7.69 wt.% and 28.08 wt.% storage propensity for hydrogen and carbon dioxide gases, respectively, which clearly suggests their potential use as light storage materials

Proposal to detect an emission of unusual super-high energy electrons in electron storage rings

Directory of Open Access Journals (Sweden)

Da-peng Qian

2014-01-01

Full Text Available According to an extended Lorentz–Einstein mass formula taken into the uncertainty principle, it is predicted that the electron beams passing accelerating electric field should with a small probability generate abnormal super-high energy electrons which are much higher than the beam energy. Author’s preliminary experiment result at electron storage ring has hinted these signs, so suggests to more strictly detect this unusual phenomenon, and thus to test the extended mass formula as well as a more perfect special relativity.

Effect of 1MeV electron beam on transistors and circuits

International Nuclear Information System (INIS)

Lee, Tae Hoon

1998-02-01

It has been known that semiconductor devices operating in a radiation environment exhibited significant alterations of their electrical responses. Since an electron beam bombardment produces lattice damage in Si and charged defects in SiO 2 , several electrical parameters of transistors exhibit significant changes. Those parameters are the current gain of BJT (Bipolar Junction Transistor) and the threshold voltage of MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The degradation of transistors brings about that of circuits. This paper presents the results of experiments and simulations performed to study the effects of 1MeV electron beam irradiation on selected silicon transistors and circuits. For BJTs, the current gains of npn (2N3904) and pnp (2N3906) linearly decreased as the irradiation dose increased, and from this result, the damage constants, Ks were obtained as 13.65 for 2N3904 and 22.52 for 2N3906 in MGy, indicating a more stable operation in the electron radiation environment for pnp than that for npn. The decrease of current gain was due to that of minority-carrier lifetime in the base region. For MOSFETs (CD4007s), the threshold voltages of NMOS and PMOS shifted to the lower values, which was resulted from the accumulation of charge in SiO 2 . The charges could be categorized into fixed oxide charge and interfacial trap charge. From experimental results, the amounts of the induced charges could be quantitatively estimated. These degradations of transistors brought about the decrease in the voltage gain of CE (Common Emitter) amplifier and the shifts in the inverting voltage of inverter. Additionally, PSpice simulations of these circuits were carried out by modeling of irradiated transistors. The comparison of simulation with experiment showed the relatively good agreement of simulation for the degradation of circuits after irradiation

The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

Science.gov (United States)

Shang, Jing; Li, Juexin; Xu, Bing; Li, Yuxiong

2011-10-01

Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the 60Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

Energy Technology Data Exchange (ETDEWEB)

Shang Jing [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Li Juexin, E-mail: juexin@ustc.edu.cn [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Xu Bing; Li Yuxiong [National Synchrotron Radiation Lab, University of Science and Technology of China (China)

2011-10-01

Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the {sup 60}Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

Fibre optic control for electron gun power supplies and data acquisition of 3 MeV DC accelerator

International Nuclear Information System (INIS)

Chavan, R.B.; Yadav, Vivek; Dixit, K.P.; Bakhtsingh, R.I.; Rajan, Rehim; Nanu, K.; Mittal, K.C.; Chakravarthy, D.P.; Gantayet, L.M.

2011-01-01

A 3 MeV, 10 mA DC Industrial Electron Beam Accelerator is being commissioned at Electron Beam Centre, Navi Mumbai. The electron beam is generated by a triode electron gun and injected into the accelerating column at 5 keV. The gun and its power supplies, (5 kV anode, 3 kV grid and 15V/20A filament), are floating at 3 Million volts, and are situated in a tank which is pressurized with SF6 at 6 kg/cm 2 . These power supplies are required to be controlled remotely. The various accelerator parameters like Beam Energy, Beam Current, RF Electrode Voltage, Power Oscillator Plate Voltage / Current and Vacuum are required to be monitored during beam operation. The software was developed in VB.Net for control and data acquisition. The database is provided in SQL 2005 for storing the data. For this purpose, control system using ADAM modules and Optical fibre has been designed and developed. This paper describes the design features of the control system and experience of use of control software during initial beam trials. (author)

Introductory statistical mechanics for electron storage rings

International Nuclear Information System (INIS)

Jowett, J.M.

1986-07-01

These lectures introduce the beam dynamics of electron-positron storage rings with particular emphasis on the effects due to synchrotron radiation. They differ from most other introductions in their systematic use of the physical principles and mathematical techniques of the non-equilibrium statistical mechanics of fluctuating dynamical systems. A self-contained exposition of the necessary topics from this field is included. Throughout the development, a Hamiltonian description of the effects of the externally applied fields is maintained in order to preserve the links with other lectures on beam dynamics and to show clearly the extent to which electron dynamics in non-Hamiltonian. The statistical mechanical framework is extended to a discussion of the conceptual foundations of the treatment of collective effects through the Vlasov equation

Renewal of beam position monitor electronics of the SPring-8 storage ring

International Nuclear Information System (INIS)

Sasaki, Shigeki; Fujita, Takahiro

2007-01-01

Signal processing electronics for the beam position monitors (BPM) of the SPring-8 Storage Ring were renewed during the summer shutdown period of 2006. The configurations of the electronics of before and after the alteration are described. The evaluation of the performance of the electronics is shown with the data taken by using the actual beams. (author)

200 MeV RF linac for synchrotron injection

International Nuclear Information System (INIS)

Whitham, K.; Anamkath, H.; Lyons, S.; Manca, J.; Miller, R.; Treas, P.; Zante, T.; Miller, R.

1992-01-01

Construction has been completed on an electron linear accelerator for the Brookhaven National Laboratory. This accelerator will be used for the injection of a 200 MeV electron beam into a synchrotron for lithography experiments. This paper describes the conceptual design of the linac, its e-gun pulser, and its control and timing systems. 3 figs., ref

Measures of gamma rays between 0,3 MeV and 3,0 MeV and of the 0,511 MeV annihilation line coming from Galactic Center Region

International Nuclear Information System (INIS)

Jardim, M.V.A.

1982-04-01

The detection of the flux of the electron-positron annihilation line coming from the Galactic Center direction allows one to estimate the rate of positrons production and the corresponding luminosity. The results of measurements of the annihilation line flux intensity at 0.511 MeV, obtained with a balloon borne experiment to measure gamma rays in the energy interval 0.3 to 3 MeV are presented. The detector looked at the galactic disk in the longitude interval -31 0 0 and observed a flux intensity of (6.70 +- 0.85) x 10 -3 photons cm -2 s -1 , which is in good agreement with the flux value estimated assuming that the Galactic Center is a line source emitting uniformly. Some likely sources of positrons and annhilation regions are also discussed. The results for the continuum spectrum emitted from the Galactic Center in the energy interval 0.3 to 0.67 MeV are presented and compared with measurements had already made. (Author) [pt

Calculation of equivalent dose index for electrons from 5,0 to 22,0 MeV by the Monte Carlo method

International Nuclear Information System (INIS)

Peixoto, J.E.

1979-01-01

The index of equivalent dose in depth and in a sphere surface of a soft tissue equivalent material were determined by Monte Carlo method for electron irradiations from 5,0 to 22.00 MeV. The effect of different irradiation geometries which simulate the incidence of onedirectional opposite rotational and isotropic beams was studied. It is also shown that the detector of wall thickness with 0.5g/cm 2 and isotropic response com be used to measure index of equivalent dose for fast electrons. The alternative concept of average equivalent dose for radiation protection is discussed. (M.C.K.) [pt

Dose measurements in the treatment of mycosis fungoides with total skin irradiation using a 4 MeV electron beam

Energy Technology Data Exchange (ETDEWEB)

Poli, M.E.R. [Hospital Real e Benemerita Sociedade Portuguesa de Beneficencia (Brazil); Todo, A.S.; Campos, L.L. [Instituto de Pesquisas Energeticas e Nucleares, CNEN/SP Travessa R, Sao Paulo (Brazil)

2000-05-01

The total skin irradiation (TSI) is one of the most efficient techniques in the treatment administered with curative intent of the mycosis fungoides. The cure may be obtained in 10% to 40% of cases. The original Stanford University technique, created in 1960, was applied in a 4.8 MeV linear accelerator, that provided 2.5 MeV electrons in the patient, by the use of 4 couple beams with the patient placed in front of the beam, 3 meters distant from the apparatus. In this work we describe a 4 MeV electrons beam treatment method. We intend to improve the uniformity of the dose in the patient, as well, to reduce the problems with the overlapping treatment fields, that occurs in conventional treatment that uses 1 meter of focus-skin distance, and the treatment time to the patient. Only one modification was done in the apparatus: the dose rate for this treatment was doubled. The patient is placed on a rotative base and he assumes successively 6 positions: stand up and perpendicular to the beam, distant 2.83 meters from the gantry, with 60 degrees of interval between the rotations. In each position, the patient receives a couple of beams (the beam angulation is 19.5 degrees above the transversal axis in the middle of the patient and 19.5 degrees below it). The dosimetric data obtained were compared to the international protocols (AAPM). The delivered doses in the patient were measured with thermoluminescent dosimeters placed on skin surface and with Kodak XV-2 films placed between different slabs of an anthropomorphic phantom. The dose distribution in the phantom shows a good uniformity, in all thickness of interest, so it is possible to use this technique in the treatment of the mycosis fungoides as well Kaposi's sarcoma. (author)

Monitoring storage time and quality attribute of egg based on electronic nose

International Nuclear Information System (INIS)

Wang Yongwei; Jun Wang; Bo Zhou; Qiujun Lu

2009-01-01

The objective of this study was to investigate the potential of an electronic nose (E-nose) technique for monitoring egg storage time and quality attributes. An electronic nose was used to distinguish eggs under cool and room-temperature storage by means of principal component analysis (PCA), linear discriminant analysis (LDA), BP neural network (BPNN) and the combination of a genetic algorithm and BP neural network (GANN). Results showed that the E-nose could distinguish eggs of different storage time under cool and room-temperature storage by LDA, PCA, BPNN and GANN; better prediction values were obtained by GANN than by BPNN. Relationships were established between the E-nose signal and egg quality indices (Haugh unit and yolk factor) by quadratic polynomial step regression (QPSR). The prediction models for Haugh unit and yolk factor indicated a good prediction performance. The Haugh unit model had a standard error of prediction of 3.74 and correlation coefficient 0.91; the yolk factor model had a 0.02 SEP and 0.93 correlation coefficient between predicted and measured values respectively.

Projectile-charge-state dependence of 0 degree binary-encounter electron production in 30-MeV Oq++O2 collisions

International Nuclear Information System (INIS)

Zouros, T.J.M.; Richard, P.; Wong, K.L.; Hidmi, H.I.; Sanders, J.M.; Liao, C.; Grabbe, S.; Bhalla, C.P.

1994-01-01

Double-differential cross sections (DDCS's) for the production of binary-encounter electrons (BEE's) are reported for 30-MeV O q+ +O 2 collisions. The BEE DDCS's were measured at θ=0 degree with respect to the beam direction for projectile charge states q=4--8. The measured BEE DDCS's were found to increase with decreasing charge state in agreement with other recent BEE results employing simpler H 2 and He targets. Impulse-approximation calculations of BEE production for θ=0 degree--45 degree are also presented, in which it is assumed that target electrons undergo elastic scattering in the screened Coulomb field of the projectile ion. These calculations are shown to be in agreement with our data at θ=0 degree where only 2s and 2p target electrons are considered

Microsupercapacitors as miniaturized energy-storage components for on-chip electronics

Science.gov (United States)

Kyeremateng, Nana Amponsah; Brousse, Thierry; Pech, David

2017-01-01

The push towards miniaturized electronics calls for the development of miniaturized energy-storage components that can enable sustained, autonomous operation of electronic devices for applications such as wearable gadgets and wireless sensor networks. Microsupercapacitors have been targeted as a viable route for this purpose, because, though storing less energy than microbatteries, they can be charged and discharged much more rapidly and have an almost unlimited lifetime. In this Review, we discuss the progress and the prospects of integrated miniaturized supercapacitors. In particular, we discuss their power performances and emphasize the need of a three-dimensional design to boost their energy-storage capacity. This is obtainable, for example, through self-supported nanostructured electrodes. We also critically evaluate the performance metrics currently used in the literature to characterize microsupercapacitors and offer general guidelines to benchmark performances towards prospective applications.

Analysis of spin depolarizing effects in electron storage rings

International Nuclear Information System (INIS)

Boege, M.

1994-05-01

In this thesis spin depolarizing effects in electron storage rings are analyzed and the depolarizing effects in the HERA electron storage ring are studied in detail. At high beam energies the equilibrium polarization is limited by nonlinear effects. This will be particularly true in the case of HERA, when the socalled ''spin rotators'' are inserted which are designed to provide longitudinal electron polarization for the HERMES experiment in 1994 and later for the H1 and ZEUS experiment. It is very important to quantify the influence of these effects theoretically by a proper modelling of HERA, so that ways can be found to get a high degree of polarization in the real machine. In this thesis HERA is modelled by the Monte-Carlo tracking program SITROS which was originally written by J. Kewisch in 1982 to study the polarization in PETRA. The first part of the thesis is devoted to a detailed description of the fundamental theoretical concepts on which the program is based. Then the approximations which are needed to overcome computing time limitations are explained and their influence on the simulation result is discussed. The systematic and statistical errors are studied in detail. Extensions of the program which allow a comparison of SITROS with the results given by ''linear'' theory are explained. (orig.)

Generation and application of 15 to 30 MeV parametric X-ray by linac

CERN Document Server

Akimoto, T

2002-01-01

15 to 30 MeV parametric X-ray (PXR) was generated using Si single crystal by 45 MeV electron LINAC. To obtain good monochromatic hard X-ray field, the appropriate conditions were determined by theoretical analysis and experiments. The intensity of PXR was increased with increasing electron energy and crystal rotation angle. However, PXR energy is independent of electron energy. By increasing measurement angle, energy of PXR decreased, but its intensity increased. 15 to 30 keV PXR energy and about 10 sup - sup 5 to 10 sup - sup 6 photon/electron of intensity were observed at 15 to 22 deg detection angle under the operation conditions of 45 MeV electron energy and 4 to 8 nA of beam current. The mass attenuation coefficient of photon of Zr, Nb and Mo, in K absorption edge was measured. Application to determine lattice distortion of target sample and off-angle of crystal was investigated. Generation and detection of PXR, measurement of characteristic properties: crystal rotation angle, detection angle, electron e...

Development of a new electron-RI colliding scheme for study of unstable nuclear structure

International Nuclear Information System (INIS)

Wakasugi, M.; Emoto, T.; Ishihara, M.; Koseki, T.; Ohnishi, T.; Suda, T.; Takeda, H.; Yano, Y.; Kurita, K.

2004-01-01

A new method of electron scattering experiment for unstable nuclei is proposed. In this method, the low energy ion beam is injected into the electron storage ring where the transverse potential well made by electron beam exists. The ion beam is three-dimensionally confined by applying longitudinal static mirror potential externally. The ion beam confined on the electron beam axis is regarded as the Self-Confining Radioactive Ion Target (SCRIPT). This idea originally comes from the ion trap phenomenon of the electron storage ring. For the electron scattering experiment, luminosity higher than 10 26 s -1 cm -2 is required for heavy nuclei. In order to test this idea, computer simulation is performed. Limit of the storage of positive charges, change of the ion valences caused by the collisions with the electrons, nuclear decays and capture of residual gas, other interactions and the luminosity are investigated. Demonstration of this idea is under way at the KSR storage ring of Kyoto University with the SCRIPT instrument equipped with forty built-in electrodes. It is expected that the number of ions accumulated and the luminosity of the collisions are about 10 6 and 2x10 25 s -1 cm -2 , respectively, at the electron beam energy of 100 MeV and current of 100 mA(max). (S. Funahashi)

First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

CERN Multimedia

Linac4 Project Team

2013-01-01

On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

Structural and electrical properties of polycrystalline CdSe thin films, before and after irradiation with 6 MeV accelerated electrons

International Nuclear Information System (INIS)

Ion, L.; Antohe, V.A.; Tazlaoanu, C.; Antohe, S.; Scarlat, F.

2004-01-01

Structural and electrical properties of polycrystalline CdSe thin films irradiated with high-energy electrons are analyzed. The samples were prepared by vacuum deposition of CdSe powder onto optical glass substrate. Their structure and the temperature dependence of the electrical resistance were determined, both before and after irradiation with 6 MeV electrons at fluencies up to 10 16 electrons/cm 2 . There were no measurable changes in the crystalline structure of the films after irradiation. Electrical properties are controlled by the defect level of donor type, possibly a selenium vacancy, with two ionizing states having ionization energies of about 0.40 eV and 0.22 eV, respectively. The major effect of the irradiation is to increase significantly the concentration of these defects. (authors)

Compact electron storage ring JESCOS with normalconducting or superconducting magnets for X-ray lithography

International Nuclear Information System (INIS)

Anton, F.; Klein, U.; Krischel, D.; Anderberg, B.

1992-01-01

The layouts of a normal conducting electron storage ring and a storage ring with superconducting bending magnets are presented. The storage rings have a critical wavelength of 1 nm and are designed as compact sources for X-ray lithography. Each ring fits into a shielded room with a diameter of 14 m. (author) 3 refs.; 5 figs.; 1 tab

Construction of 35 MeV DSM at Nihon University

International Nuclear Information System (INIS)

Hayakawa, K.; Sato, K.; Tanaka, T.; Takeda, O.

1988-01-01

High quality electron beam is needed for the excitation of the free electron laser(FEL). Construction of the 35 MeV double-sided microtron for the FEL has been started at 1984. This accelerator will feed a electron beam which has narrow energy width and low emittance. A first one turn beam line has been completed. Beam accelerating experiments and high power microwave tests are performed. (author)

Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun [Radiation Research Dvision for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

2015-05-15

In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

Differential cross sections of the pp -> pp pi sup 0 reaction from 310 to 425 MeV

CERN Document Server

Zlomanczuk, Yu; Brodowski, W; Calén, H; Clement, H; Dyring, J; Ekström, C; Fäldt, G; Fransson, K; Gustafsson, L; Häggström, S; Hoeistad, B; Johanson, J; Johansson, A; Johansson, T; Kilian, K; Kullander, Sven; Kupsc, A; Marciniewski, P; Morosov, B; Moertsell, A; Oelert, W; Ruber, Roger J M Y; Schuberth, U; Sundberg, P; Shwartz, B A; Stepaniak, J; Sukhanov, A; Turowiecki, A; Wagner, G J; Wilhelmi, Z; Wilkin, C; Zabierowski, J; Zernov, A

2000-01-01

Measurements of the differential cross sections of the pp -> pp pi sup 0 reaction at 310, 320, 340, 360, 400 and 425 MeV have been carried out at the CELSIUS storage ring in Uppsala. An attempt has been made to describe the distributions obtained in terms of the five partial waves Ss, Ps, Pp, Sd and Ds. The relative contributions from the different states depend significantly upon the energy. For instance, that of the Ss state drops from about 80% at 310 MeV to around 10% at 425 MeV.

Optical distortions in electron/positron storage rings

International Nuclear Information System (INIS)

Brown, K.L.; Donald, M.; Servranckx, R.

1983-01-01

We have studied the optical distortions in the PEP electron/positron storage ring for various optical configurations using the computer programs DIMAT, HARMON, PATRICIA, and TURTLE. The results are shown graphically by tracing several thousand trajectories from one interaction region to the next using TURTLE and by tracing a few selected rays several hundred turns using the programs DIMAT and PATRICIA. The results show an interesting correlation between the calculated optical cleanliness of a particular lattice configuration and the observed operating characteristics of the machine

26-Day Variations of 7 MeV Electrons at high Latitudes and their Implications on the Heliospheric Magnetic Field

Science.gov (United States)

Sternal, Oliver; Engelbrecht, Eugene; Burger, Renier; Dunzlaff, Phillip; Ferreira, Stefan; Fichtner, Horst; Heber, Bernd; Kopp, Andreas; Potgieter, Marius; Scherer, Klaus

The transport of energetic particles in the heliosphere is usually described by the Parker trans-port equation including the physical processes of diffusion, drift, convection and adiabatic energy changes. The Ulysses spacecraft provides unique insight into the flux of MeV electrons at high latitudes. In this contribution, we compare our model results for the Parker HMF model and the Fisk-type Schwadron-Parker HMF model to Ulysses measurements. The elec-tron flux at high latitudes has been used as a remote sensing method to investigate the imprint of a Fisk-type HMF. We show here for the first time that such an imprint exists and deduce a limitation on the Fisk HMF angle β.

Laser-Electron-Gamma-Source. Progress report, July 1986

International Nuclear Information System (INIS)

Dowell, D.H.; Fineman, B.; Giordano, G.; Kistner, OC.; Matone, G.; Sandorfi, A.M.; Schaerf, C.; Thorn, C.E.; Ziegler, W.

1986-07-01

When completed, the Laser Electron Gamma Source (LEGS) is expected to provide intense beams of monochromatic and polarized (circular or linear) gamma rays with energies up to 500 MeV. The gamma-ray beams will be produced by Compton backscattering uv laser light from the electrons circulating in a storage ring. Progress with installation of the facility is described, particularly the Ar-ion laser and tagging spectrometer. Tests of the tagging spectrometer coponents is reported, and a second laser is described for higher energy operation. Estimates are given of expected beam parameters. Experimental equipment for the planned research projects to be carried out at the LEGS facility is discussed

Large permanent magnet quadrupoles for an electron storage ring

International Nuclear Information System (INIS)

Herb, S.W.

1987-01-01

We have built large high quality permanent magnet quadrupoles for use as interaction region quadrupoles in the Cornell Electron Storage Ring where they must operate in the 10 kG axial field of the CLEO experimental detector. We describe the construction and the magnetic measurement and tuning procedures used to achieve the required field quality and stability. (orig.)

Mechanical properties of organic composite materials irradiated with 2 MeV electrons

International Nuclear Information System (INIS)

Egusa, S.; Kirk, M.A.; Birtcher, R.C.; Argonne National Lab., IL; Hagiwara, M.; Kawanishi, S.

1983-01-01

Four kinds of cloth-filled organic composites (filter: glass or carbon fiber; matrix; epoxy or polyimide resin) were irradiated with 2 MeV electrons at room temperature, and were examined with regard to the mechanical properties. Following irradiation the Young's (tensile) modulus of these composites remains practically unchanged even after irradiation up to 15.000 Mrad. The shear modulus and the ultimate strength, on the other hand, begin to decrease after the absorbed dose reaches about 2.000 Mrad for the glass/epoxy composite and about 5.000-10.000 Mrad for the other composites. This result is ascribed to the decrease in the capacity of load transfer from the matrix to the fiber due to the radiation damage at the interface, and the dose dependence is interpreted and formulated based on the mechanics of composite materials and the target theory used in radiation biology. As to the fracture behavior, the propagation energy increases from the beginning of irradiation. This result is attributed to the radiation-induced decrease in the bonding energy at the interface. (orig.)

Dose errors due to charge storage in electron irradiated plastic phantoms

International Nuclear Information System (INIS)

Galbraith, D.M.; Rawlinson, J.A.; Munro, P.

1984-01-01

Commercial plastics used for radiation dosimetry are good electrical insulators. Used in electron beams, these insulators store charge and produce internal electric fields large enough to measurably alter the electron dose distribution in the plastic. The reading per monitor unit from a cylindrical ion chamber imbedded in a polymethylmethacrylate (PMMA) or polystyrene phantom will increase with accumulated electron dose, the increase being detectable after about 20 Gy of 6-MeV electrons. The magnitude of the effect also depends on the type of the plastic, the thickness of the plastic, the wall thickness of the detector, the diameter and depth of the hole in the plastic, the energy of the electron beam, and the dose rate used. Effects of charge buildup have been documented elsewhere for very low energy electrons at extremely high doses and dose rates. Here we draw attention to the charging effects in plastics at the dose levels encountered in therapy dosimetry where ion chamber or other dosimeter readings may easily increase by 5% to 10% and where a phantom, once charged, will also affect subsequent readings taken in 60 Co beams and high-energy electron and x-ray beams for periods of several days to many months. It is recommended that conducting plastic phantoms replace PMMA and polystyrene phantoms in radiation dosimetry

Fragmentation of molecular ions in slow electron collisions

International Nuclear Information System (INIS)

Novotny, Steffen

2008-01-01

The fragmentation of positively charged hydrogen molecular ions by the capture of slow electrons, the so called dissociative recombination (DR), has been investigated in storage ring experiments at the TSR, Heidelberg, where an unique twin-electron-beam arrangement was combined with high resolution fragment imaging detection. Provided with well directed cold electrons the fragmentation kinematics were measured down to meV collision energies where pronounced rovibrational Feshbach resonances appear in the DR cross section. For thermally excited HD + the fragmentation angle and the kinetic energy release were studied at variable precisely controlled electron collision energies on a dense energy grid from 10 to 80 meV. The anisotropy described for the first time by Legendre polynomials higher 2 nd order and the extracted rotational state contributions were found to vary on a likewise narrow energy scale as the rotationally averaged DR rate coefficient. Ro-vibrationally resolved DR experiments were performed on H 2 + produced in distinct internal excitations by a novel ion source. Both the low-energy DR rate as well as the fragmentation dynamics at selected resonances were measured individually in the lowest two vibrational and first three excited rotational states. State-specific DR rates and angular dependences are reported. (orig.)

Fragmentation of molecular ions in slow electron collisions

Energy Technology Data Exchange (ETDEWEB)

Novotny, Steffen

2008-06-25

The fragmentation of positively charged hydrogen molecular ions by the capture of slow electrons, the so called dissociative recombination (DR), has been investigated in storage ring experiments at the TSR, Heidelberg, where an unique twin-electron-beam arrangement was combined with high resolution fragment imaging detection. Provided with well directed cold electrons the fragmentation kinematics were measured down to meV collision energies where pronounced rovibrational Feshbach resonances appear in the DR cross section. For thermally excited HD{sup +} the fragmentation angle and the kinetic energy release were studied at variable precisely controlled electron collision energies on a dense energy grid from 10 to 80 meV. The anisotropy described for the first time by Legendre polynomials higher 2{sup nd} order and the extracted rotational state contributions were found to vary on a likewise narrow energy scale as the rotationally averaged DR rate coefficient. Ro-vibrationally resolved DR experiments were performed on H{sub 2}{sup +} produced in distinct internal excitations by a novel ion source. Both the low-energy DR rate as well as the fragmentation dynamics at selected resonances were measured individually in the lowest two vibrational and first three excited rotational states. State-specific DR rates and angular dependences are reported. (orig.)

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-08-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in ..gamma..-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4).

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

International Nuclear Information System (INIS)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-01-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in γ-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4). (author)

Enacting laws concerning radiation safety management for students using X-rays and electron beams under 1 MeV

International Nuclear Information System (INIS)

Nishizawa, Kunihide; Shibata, Michihiro; Saze, Takuya

2004-01-01

Laws concerning radiation safety management were analyzed from the point of view of defining precisely what is meant by radiation and what is meant by the subject. There are no laws to protect students from radiation hazards when using X-rays and electron beams under 1 MeV for research and/or education. The Law concerning Technical Standards for Preventing Radiation Hazards gives the authorities the power to enact new rules and regulations that will protect the students. The Radiation Council must take charge for enactment of all laws regarding radiation safety management. (author)

Linac4 crosses the 100 MeV threshold

CERN Multimedia

Corinne Pralavorio

2016-01-01

The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

Energy Technology Data Exchange (ETDEWEB)

Mizumoto, T., E-mail: mizumoto@cr.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Matsuoka, Y. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Mizumura, Y. [Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Tanimori, T. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Kubo, H.; Takada, A.; Iwaki, S.; Sawano, T.; Nakamura, K.; Komura, S.; Nakamura, S.; Kishimoto, T.; Oda, M.; Miyamoto, S.; Takemura, T.; Parker, J.D.; Tomono, D.; Sonoda, S. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Miuchi, K. [Department of Physics, Kobe University, 658-8501 Kobe (Japan); Kurosawa, S. [Institute for Materials Research, Tohoku University, 980-8577 Sendai (Japan)

2015-11-11

For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm{sup 3} TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm){sup 3} medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm){sup 3} ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from ~10% to ~100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.

Radiation damage measurements on nonmetals made during irradiation with 1 to 3 MeV electrons. Final Report

International Nuclear Information System (INIS)

Levy, P.W.

1982-01-01

To investigate the fundamental processes producing radiation damage in nonmetals a unique facility has been developed for making optical absorption, luminescence and other measurements during irradiation with 1 to 3 MeV electrons. Measurements are made with a 13 meter long double beam spectrometer arranged so that all sensitive components, e.g., phototubes, are outside of the irradiation chamber. A computer provdies automatic control and data recording. A 256 point absorption and a 256 point luminescence spectra are recorded as often as every 40 seconds in either the 200-400 or 400-800 mm wavelength range. Samples are irradiated, at temperatures between 20 and 900 C, in an electronically controlled chamber containing He exchange gas and equipped with thin Havar windows to transmit the electron beam and high purity fused silica windows for the spectrophotometer beams. Radiation induced luminescence and absorption in the chamber windows, etc. is eliminated by the double beam spectrophotometer. Studies made with this equipment demonstrate clearly that many of the processes occurring during damage formation are transient

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

International Nuclear Information System (INIS)

Plum, M.

1995-01-01

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

Angular distributions of absorbed dose of Bremsstrahlung and secondary electrons induced by 18-, 28- and 38-MeV electron beams in thick targets.

Science.gov (United States)

Takada, Masashi; Kosako, Kazuaki; Oishi, Koji; Nakamura, Takashi; Sato, Kouichi; Kamiyama, Takashi; Kiyanagi, Yoshiaki

2013-03-01

Angular distributions of absorbed dose of Bremsstrahlung photons and secondary electrons at a wide range of emission angles from 0 to 135°, were experimentally obtained using an ion chamber with a 0.6 cm(3) air volume covered with or without a build-up cap. The Bremsstrahlung photons and electrons were produced by 18-, 28- and 38-MeV electron beams bombarding tungsten, copper, aluminium and carbon targets. The absorbed doses were also calculated from simulated photon and electron energy spectra by multiplying simulated response functions of the ion chambers, simulated with the MCNPX code. Calculated-to-experimental (C/E) dose ratios obtained are from 0.70 to 1.57 for high-Z targets of W and Cu, from 15 to 135° and the C/E range from 0.6 to 1.4 at 0°; however, the values of C/E for low-Z targets of Al and C are from 0.5 to 1.8 from 0 to 135°. Angular distributions at the forward angles decrease with increasing angles; on the other hand, the angular distributions at the backward angles depend on the target species. The dependences of absorbed doses on electron energy and target thickness were compared between the measured and simulated results. The attenuation profiles of absorbed doses of Bremsstrahlung beams at 0, 30 and 135° were also measured.

Application of calorimeters for 5 MeV EB and bremsstrahlung dosimetry

DEFF Research Database (Denmark)

Sato, T.; Takahashi, T.; Saito, T.

1993-01-01

Graphite and water calorimeters, which were developed for use a 10 MeV electron beams (EB) at Riso National Laboratory, were used for process validation and routine dosimeter calibration at a 5 MeV EB. Water calorimeters were used for reference measurements for 5 MeV EB, the response was found...... to be directly proportional to the beam current and the variation among three water calorimeters was less than +/- 2 % in the range of 10 to 40 kGy. CTA, PMMA, RCD dosimeters were calibrated by irradiating the dosimeters and water calorimeters Simultaneously. The water calorimeter was proved to be an useful tool...... at 5 MeV EB. Graphite calorimeters gave reproducible readings within 3.3 % relative errors (95 % confidence level) for X-ray measurement....

Application of calorimeters for 5 MeV EB and bremsstrahlung dosimetry

International Nuclear Information System (INIS)

Sato, Toshio; Takahashi, Toru; Saito, Toshio; Takehisa, Masaaki; Miller, A.

1993-01-01

Graphite and water calorimeters, which were developed for use with 10 MeV electron beams (EB) at Riso National Laboratory, were used for process validation and routine dosimeter calibration at a 5 MeV EB. Water calorimeters were used for reference measurements for 5 MeV EB, the response was found to be directly proportional to the beam current and the variation among three water calorimeters was less than ± 2% in the range of 10 to 40 kGy. CTA PMMA RCD dosimeters were calibrated by irradiating the dosimeters and water calorimeters simultaneously. The water calorimeter was proved to be an useful tool at 5 MeV EB. Graphite calorimeters gave reproducible readings within 3.3 % relative errors (95% confidence level) for X-ray measurement. (Author)

Challenges in designing a very compact 130 MeV Moeller polarimeter for the S-DALINAC

Energy Technology Data Exchange (ETDEWEB)

Bahlo, Thore; Enders, Joachim; Kuerzeder, Thorsten; Pietralla, Norbert; Wissmann, Jan [Institut fuer Kernphysik, TU Darmstadt, Darmstadt (Germany)

2016-07-01

The Superconducting Darmstadt Linear Accelerator is capable of accelerating polarized electron beams produced by the S-DALINAC Polarized Injector (SPIN). For electron energies of up to 14 MeV it is possible to measure the absolute polarization of the electrons with two Mott polarimeters that are already mounted in the injector beamline. Until now it is not possible to measure the absolute electron beam polarization after the passage of the main accelerator. Therefore a Moeller polarimeter for energies between 50 MeV and 130 MeV is currently being developed. The rather low incident beam energy, the variability of the incident beam energy, and spatial restrictions necessitate a compact set-up with large acceptance. The very restrictive boundary conditions introduce technical and geometrical challenges. We will present the design of the target chamber, of the separation dipole magnet as well as the beam dump.

Narrow electron injector for ballistic electron spectroscopy

International Nuclear Information System (INIS)

Kast, M.; Pacher, C.; Strasser, G.; Gornik, E.

2001-01-01

A three-terminal hot electron transistor is used to measure the normal energy distribution of ballistic electrons generated by an electron injector utilizing an improved injector design. A triple barrier resonant tunneling diode with a rectangular transmission function acts as a narrow (1 meV) energy filter. An asymmetric energy distribution with its maximum on the high-energy side with a full width at half maximum of ΔE inj =10 meV is derived. [copyright] 2001 American Institute of Physics

XRD study of yttria stabilized zirconia irradiated with 7.3 MeV Fe, 10 MeV I, 16 MeV Au, 200 MeV Xe and 2.2 GeV Au ions

Energy Technology Data Exchange (ETDEWEB)

Nakano, K.; Yoshizaki, H. [Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Saitoh, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Ishikawa, N. [Tokai Research and Development Center, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Iwase, A., E-mail: iwase@mtr.osakafu-u.ac.jp [Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan)

2016-03-01

To simulate energetic neutron irradiation effects, yttria-stabilized zirconia (YSZ) which is one of the major materials for electrical corrosion potential sensors (ECP sensors) was irradiated with heavy ions at energies ranging from 7.3 MeV to 2.2 GeV. Ion irradiation effects on the lattice structure were analyzed using the X-ray diffraction (XRD). The increase in lattice constant was induced by the ion irradiation. It was dominated by the elastic collision process and not by the electronic excitation process. The lattice disordering which was observed as a broadening of XRD peaks was also induced by the irradiation especially for 200 MeV Xe ion irradiation. The present result suggests that the expansion and/or the disordering of YSZ lattice induced by energetic neutrons may affect the durability of a joint interface between a metal housing and YSZ membrane for the usage of ECP sensors in nuclear power reactors.

Generation of mega-electron-volt electron beams by an ultrafast intense laser pulse

International Nuclear Information System (INIS)

Wang Xiaofang; Saleh, Ned; Krishnan, Mohan; Wang Haiwen; Backus, Sterling; Murnane, Margaret; Kapteyn, Henry; Umstadter, Donald; Wang Quandong; Shen Baifei

2003-01-01

Mega-electron-volt (MeV) electron emission from the interaction of an ultrafast (τ∼29 fs), intense (>10 18 W/cm 2 ) laser pulse with underdense plasmas has been studied. A beam of MeV electrons with a divergence angle as small as 1 deg. is observed in the forward direction, which is correlated with relativistic filamentation of the laser pulse in plasmas. A novel net-energy-gain mechanism is proposed for electron acceleration resulting from the relativistic filamentation and beam breakup. These results suggest an approach for generating a beam of femtosecond, MeV electrons at a kilohertz repetition rate with a compact ultrafast intense laser system

Developments at an electrostatic cryogenic storage ring for electron-cooled keV energy ion beams

International Nuclear Information System (INIS)

Vogel, Stephen

2016-01-01

This work is devoted to final setup activities and the commissioning of an electrostatic cryogenic storage ring (CSR) at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. The first cryogenic operation of CSR in 2015 has been documented and characterized using a set of non-destructive beam diagnostic tools developed within this work. These are (1) the current pick-up system for the determination of the current of the stored ion beam and its velocity, (2) a position pick-up system for measuring the transverse position of the ion beam center at six symmetric locations of the storage ring circumference, and (3) a Schottky pick-up system for the monitoring of coasting ion beams. Despite the requirements imposed by the cryogenic operation, the developed diagnostic system demonstrated its full functionality. First characterizations of the storage ring properties and the performance of the diagnostic system are presented. Based on previous work, an electron cooling system for CSR has been developed and largely realized. With the implementation into CSR in 2016, the electron cooler will enhance the storage ring into a unique experimental facility for electron-ion collision studies. With this CSR is on the track to become the first cryogenic storage ring featuring actively cooled ion beams.

Bunch lengthening with bifurcation in electron storage rings

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-San; Hirata, Kohji [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1996-08-01

The mapping which shows equilibrium particle distribution in synchrotron phase space for electron storage rings is discussed with respect to some localized constant wake function based on the Gaussian approximation. This mapping shows multi-periodic states as well as double bifurcation in dynamical states of the equilibrium bunch length. When moving around parameter space, the system shows a transition/bifurcation which is not always reversible. These results derived by mapping are confirmed by multiparticle tracking. (author)

Electron cloud instabilities in the Proton Storage Ring and Spallation Neutron Source

Directory of Open Access Journals (Sweden)

M. Blaskiewicz

2003-01-01

Full Text Available Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for the Oak Ridge Spallation Neutron Source are examined theoretically, numerically, and experimentally.

Microstructural Parameters in 8 MeV Electron-Irradiated BOMBYX MORI Silk Fibers by Wide-ANGLE X-Ray Scattering Studies (waxs)

Science.gov (United States)

Sangappa, Asha, S.; Sanjeev, Ganesh; Subramanya, G.; Parameswara, P.; Somashekar, R.

2010-01-01

The present work looks into the microstructural modification in electron irradiated Bombyx mori P31 silk fibers. The irradiation process was performed in air at room temperature using 8 MeV electron accelerator at different doses: 0, 25, 50 and 100 kGy. Irradiation of polymer is used to cross-link or degrade the desired component or to fix the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been computed using wide angle X-ray scattering (WAXS) data and employing line profile analysis (LPA) using Fourier transform technique of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of crystal size, lattice strain and enthalpy parameters.

Design study of a far-infrared free electron laser with a 20 MeV RF linear accelerator

International Nuclear Information System (INIS)

Nakata, S.; Tsukishima, C.; Hifumi, T.; Okuda, S.; Sato, S.; Yosojima, Y.

1991-01-01

A FEL in the far-infrared region has been designed using a low energy RF linear accelerator. First we estimate a small signal gain from spontaneous emission using the Madey's theorem. In the calculation following effects are included: an actual field distribution (using a measured magnetic field), beam envelope in the phase space through the undulator, energy spread, and electron beam mis-alignment to the undulator axis. We have developed a code which can simulate three dimensional processes of the electron interaction with multi-mode laser fields in the undulator. From this code we could obtain the time dependent bunching process of electrons and amplification of the laser field. During the calculation we assume an electron beam of 20 MeV, 100 mA with a pulse length of 3 μs, and an undulator of 28 periods, 6 cm periodic length and 2.5 kG peak field. The results from these calculations show that the small-signal gain over 40 % can be obtained, but mis-alignment of the beam severely degrades the gain. The results also show that the output power of several MW can be obtained under the above conditions. Considering the simulation results, a FEL beam line was constructed and the beam size at the undulator was measured. And electrons were focused enough for the FEL experiment. (author)

Shielding considerations for an electron linear accelerator complex for high energy physics and photonics research

International Nuclear Information System (INIS)

Holmes, J.A.; Huntzinger, C.J.

1987-01-01

Radiation shielding considerations for a major high-energy physics and photonics research complex which comprise a 50 MeV electron linear accelerator injector, a 1.0 GeV electron linear accelerator and a 1.3 GeV storage ring are discussed. The facilities will be unique because of the close proximity of personnel to the accelerator beam lines, the need to adapt existing facilities and shielding materials and the application of strict ALARA dose guidelines while providing maximum access and flexibility during a phased construction program

Inter-dependence of the electron beam excitations with the free electron laser stability on the super-ACO storage ring

CERN Document Server

Couprie, Marie Emmanuelle; Nutarelli, D; Renault, E; Billardon, M

1999-01-01

Storage ring free electron lasers have a complex dynamics as compared to the LINAC driven FEL sources since both the laser and the recirculating electron beam behaviours are involved. Electron beam perturbations can strongly affect the FEL operation (start-up, stability) whereas the FEL can stabilize beam instabilities. Experimental analysis together with simulations are reported here. Improvements of the Super-ACO FEL for users is discussed, and consequences are given in terms of electron beam tolerances for a source development for users.

Undulator physics and coherent harmonic generation at the MAX-lab electron storage ring

International Nuclear Information System (INIS)

Werin, Sverker.

1991-01-01

This work presents the undulator and harmonic generation project at the electron storage ring MAX-lab at University of Lund. The theory of undulator radiation, laser coherent harmonic generation, optical klystron amplifiers and FELs is treated in one uniform way, with complete solutions of the necessary equations. The permanent magnet undulator is described in some detail, along with the installation of the undulator in the storage ring. Details regarding the emitted radiation, the electron beam path in the undulator and other results are analysed. Finally harmonic generation using a Nd:YAG laser and the creation of coherent photons at the third harmonic (355 nm) is described. (author)

Modifications in the structural and optical properties of nanocrystalline CaWO4 induced by 8 MeV electron beam irradiation

International Nuclear Information System (INIS)

Aloysius Sabu, N.; Priyanka, K.P.; Ganesh, Sanjeev; Varghese, Thomas

2016-01-01

In this article we report the post irradiation effects in the structural and optical properties of nanocrystalline calcium tungstate synthesized by chemical precipitation and heat treatment. The samples were subjected to different doses of high-energy electron beam obtained from an 8 MeV Microton. Investigations using X-ray diffraction, scanning electron microscopy and Raman spectra confirmed changes in particle size and structural parameters. However, no phase change was detected for irradiated samples. The stretching/compressive strain caused by high energy electrons is responsible for the slight shift in the XRD peaks of irradiated samples. Modifications in the morphology of different samples were confirmed by scanning electron microscopy. Ultraviolet-visible absorption studies showed variations in the optical band gap (4.08–4.25 eV) upon electron-beam irradiation. New photoluminescence behaviour in electron beam irradiated nanocrystalline CaWO 4 was evidenced. A blue shift of the PL peak with increase in intensity was observed in all the irradiated samples. - Highlights: • Calcium tungstate nanocrystals are synthesized by simple chemical precipitation method. • Electron beam induced modifications in the structural and optical properties are investigated. • New photoluminescence behaviour is evidenced due to beam irradiation.

Spin effects in medium-energy electron-3He scattering

International Nuclear Information System (INIS)

van den Brand, J.F.J.; Alarcon, R.; Bauer, T.

1998-01-01

New physics can be accessed by scattering polarized electrons from a polarized 3 He internal gas target. It is discussed how the asymmetries for the reactions 3 vector He(vector e,e'), 3 vector He(vector e,e'p), 3 vector He(vector e,e'n), 3 vector He(vector e,e'd), and 3 vector He(vector e,e'pn) may provide precise information on the S' and the D-wave parts of the 3 He ground-state wave function, the neutron form factors, and the role of spin-dependent reaction mechanism effects. The experiment uses up to 900 MeV (polarized) electrons from the AmPS storage ring in Amsterdam, Netherlands, in combination with large acceptance electron and hadron detectors. (orig.)

The influence of structure depth on image blurring of micrometres-thick specimens in MeV transmission electron imaging.

Science.gov (United States)

Wang, Fang; Sun, Ying; Cao, Meng; Nishi, Ryuji

2016-04-01

This study investigates the influence of structure depth on image blurring of micrometres-thick films by experiment and simulation with a conventional transmission electron microscope (TEM). First, ultra-high-voltage electron microscope (ultra-HVEM) images of nanometer gold particles embedded in thick epoxy-resin films were acquired in the experiment and compared with simulated images. Then, variations of image blurring of gold particles at different depths were evaluated by calculating the particle diameter. The results showed that with a decrease in depth, image blurring increased. This depth-related property was more apparent for thicker specimens. Fortunately, larger particle depth involves less image blurring, even for a 10-μm-thick epoxy-resin film. The quality dependence on depth of a 3D reconstruction of particle structures in thick specimens was revealed by electron tomography. The evolution of image blurring with structure depth is determined mainly by multiple elastic scattering effects. Thick specimens of heavier materials produced more blurring due to a larger lateral spread of electrons after scattering from the structure. Nevertheless, increasing electron energy to 2MeV can reduce blurring and produce an acceptable image quality for thick specimens in the TEM. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of 10 MeV electron linac for radiation processing

International Nuclear Information System (INIS)

Petwal, V.C.; Rao, J.N.; Kaul, A.; Bapna, S.C.; Mulchandani, J.K.; Wanmode, Y.; Pandiyar, M.; Srivastava, P.; Jain, Akhilesh; Hanurkar, P.R.

2006-01-01

A radiation processing facility based on a 10 MeV LINAC is being set-up at RRCAT. In the course of commissioning various experiments have been carried-out to characterize the radiation field generated by the accelerator and subsequently to derive the operating parameters of the facility for radiation processing of various items. Results of the experiments are presented in the paper. (author)

Performance of a Polarized Deuterium Internal Target in a Medium-Energy Electron Storage Ring.

NARCIS (Netherlands)

Zhou, Z.L.; Ferro Luzzi, M.M.E.; van den Brand, J.F.J.; Bulten, H.J.; Alarcon, R.; van Bommel, R.; Botto, T.; Bouwhuis, M.; Buchholz, M.; Choi, S.; Comfort, J.; Doets, M.; Dolfini, S.; Ent, R.; Gaulard, C.; de Jager, C.W.; Lang, J.; de Lange, D.J.; Miller, M.A.; Passchier, E.; Passchier, I.; Poolman, H.R.; Six, E.; Steijger, J.J.M.; Unal, O.; de Vries, H.

1996-01-01

A polarized deuterium target internal to a medium-energy electron storage ring is described in the context of spindependent (e, e′d) and (e ,e′p) experiments. Tensor polarized deuterium was produced in an atomic beam source and injected into a storage cell target. A Breit-Rabi polarimeter was used

Simulation of MeV electron energy deposition in CdS quantum dots absorbed in silicate glass for radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Baharin, R; Hobson, P R; Smith, D R, E-mail: ruzalina.baharin@brunel.ac.u [Centre for Sensors and Instrumentation, School of Engineering and Design, Brunel University, Uxbridge UB8 3PH (United Kingdom)

2010-09-01

We are currently developing 2D dosimeters with optical readout based on CdS or CdS/CdSe core-shell quantum-dots using commercially available materials. In order to understand the limitations on the measurement of a 2D radiation profile the 3D deposited energy profile of MeV energy electrons in CdS quantum-dot-doped silica glass have been studied by Monte Carlo simulation using the CASINO and PENELOPE codes. Profiles for silica glass and CdS quantum-dot-doped silica glass were then compared.

Simulation of MeV electron energy deposition in CdS quantum dots absorbed in silicate glass for radiation dosimetry

International Nuclear Information System (INIS)

Baharin, R; Hobson, P R; Smith, D R

2010-01-01

We are currently developing 2D dosimeters with optical readout based on CdS or CdS/CdSe core-shell quantum-dots using commercially available materials. In order to understand the limitations on the measurement of a 2D radiation profile the 3D deposited energy profile of MeV energy electrons in CdS quantum-dot-doped silica glass have been studied by Monte Carlo simulation using the CASINO and PENELOPE codes. Profiles for silica glass and CdS quantum-dot-doped silica glass were then compared.

A Compact 5 MeV S-Band Electron Linac Based X-Ray Source for Industrial Radiography

CERN Document Server

Auditore, Lucrezia; De Pasquale, Domenico; Emanuele, Umberto; Italiano, Antonio; Trifirò, Antonio; Trimarchi, Marina

2005-01-01

A compact and reliable X-ray source, based on a 5 MeV, 1 kW, S-band electron linac, has been set up at the Dipartimento di Fisica, Universit\\'a di Messina. This source, coupled with a GOS scintillator screen and a CCD camera, represents an innovative transportable system for industrial radiography and X-ray tomography. Optimization of the parameters influencing the e-gamma conversion and the X-ray beam characteristics have been studied by means of the MCNP-4C2 code. The converter choice is the result of the study of the e-gamma conversion performances for different materials and materials thicknesses. Also the converter position with respect to the linac exit window was studied. The chosen converter consists in a Ta-Cu target inserted close to the linac window. The Cu layer acts as a filter both on the electrons from the source and on the low energy X-rays. The X-ray beam angular profile was studied by means of GafChromic films with and without collimation. In the final source project, a collimation system pr...

Absorbed Dose Distributions in Small Copper Wire Insulation due to Multiple-Sided Irradiations by 0.4 MeV Electrons

DEFF Research Database (Denmark)

Miller, Arne; McLaughlin, W. L.; Pedersen, Walther Batsberg

1979-01-01

When scanned electron beams are used to crosslink polymeric insulation of wire and cable, an important goal is to achieve optimum uniformity of absorbed dose distributions. Accurate measurements of dose distributions in a plastic dosimeter simulating a typical insulating material (polyethylene......) surrounding a copper wire core show that equal irradiations from as few as four sides give approximately isotropy and satisfactorily uniform energy depositions around the wire circumference. Electron beams of 0.4 MeV maximum energy were used to irradiate wires having a copper core of 1.0 mm dia....... and insulation thicknesses between 0.4 and 0.8 mm. The plastic dosimeter simulating polyethylene insulations was a thin radiochromic polyvinyl butyral film wrapped several times around the copper wire, such that when unwrapped and analyzed optically on a scanning microspectrophotometer, high-resolution radial...

Dose-response relationship for chromosomal aberrations induced in human lymphocytes by 18 MeV electron beam irradiation

International Nuclear Information System (INIS)

Lashin, E.A.; Elaasar, E.M.; Moustafa, H.F.; Bakir, Y.Y.; Al Zenki, S.D.

1990-01-01

Dose response curves for lymphocyte chromosome aberration frequencies using X- and gamma radiation became an important and reliable indicator as biological dosimeter especially in radiation accidents and occupational over exposures. Nowadays electron beam therapy is frequently used for their advantages in cases of tumours under or near to the body surface. Dose-response curves for these electron beams are rarely published. Human peripheral blood lymphocytes were in vitro irradiated with various low and high doses (0.1 Gy to 4.9 Gy) of 18 MeV electron beams to utilize such a dose-response curve using chromosomal aberration frequencies as a biological indicator. Then we compared the biological curve with physically obtained curves normally used in planning for radiotherapy treatment. It is interesting to find a significant difference between both of them. The biological curve is generally higher in value and the aberrations induced by 93% of a dose is significantly higher and deeper in site than those aberrations induced by the 100% dose calculated physically. If the above observation is confirmed by detailed studies, it would be of importance to the radiotherapist to plan for isodose curves according to biological determinations. (author)

The Unruh effect and quantum fluctuations of electrons in storage rings

International Nuclear Information System (INIS)

Bell, J.S.; Leinaas, J.M.

1987-01-01

The quantum fluctuation of electron orbits in ideal storage rings is a sort of Fulling-Unruh effect (heating by acceleration in vacuum). To spell this out, the effect is analyzed in an appropriate comoving, and so accelerating and rotating, co-ordinate system. The depolarization of the electrons is a related effect, but is greatly complicated by spin-orbit coupling. This analysis confirms the standard result for the polarization, except in the neighbourhood of a narrow resonance. (orig.)

The Unruh effect and quantum fluctuations of electrons in storage rings

International Nuclear Information System (INIS)

Bell, J.S.; Leinaas, J.M.

1995-01-01

The quantum fluctuation of electron orbits in ideal storage rings is a sort of Fulling-Unruh effect (heating by acceleration in vacuum). To spell this out, the effect is analyzed in an appropriate comoving, and so accelerating and rotating, co-ordinate system. The depolarization of the electrons is a related effect, but is greatly complicated by spin-orbit coupling. This analysis confirms the standard result for the polarization, except in the neighbourhood of a narrow resonance. (author)

Effects produced in GaAs by MeV ion bombardment

International Nuclear Information System (INIS)

Wie, C.R.

1985-01-01

The first part of this thesis presents work performed on the ionizing energy beam induced adhesion enhancement of thin (approx.500 A) Au films on GaAs substrates. The ionizing beam, employed in the present thesis, is the MeV ions (i.e., 16 O, 19 F, and 35 Cl), with energies between 1 and 20 MeV. Using the Scratch test for adhesion measurement, and ESCA for chemical analysis of the film substrate interface, the native oxide layer at the interface is shown to play an important role in the adhesion enhancement by the ionizing radiation. A model is discussed that explains the experimental data on the dependence of adhesion enhancement on the energy which was deposited into electronic processes at the interface. The second part of the thesis presents research results on the radiation damage in GaAs crystals produced by MeV ions. Lattice parameter dilatation in the surface layers of the GaAs crystals becomes saturated after a high dose bombardment at room temperature. The strain produced by nuclear collisions is shown to relax partially due to electronic excitation (with a functional dependence on the nuclear and electronic stopping power of bombarding ions. Data on the GaAs and GaP crystals suggest that low temperature recovery stage defects produce major crystal distortion

Construction and operation of a 10 MeV electron accelerator and associated experimental facilities at Brookhaven National Laboratory, Upton, New York. Environmental assessment

International Nuclear Information System (INIS)

1994-02-01

The purpose of this environmental impact statement is to determine whether there would be significant environmental impacts associated with the construction of an experimental facility at Brookhaven National Laboratory for radiation chemistry research and operation of the 10-MeV electron accelerator proposed for it. The document describes the need for action, alternative actions, the affected environment, and potential environmental impacts

Electron--positron storage ring PETRA: plans and status

International Nuclear Information System (INIS)

Voss, G.A.

1977-01-01

Construction of the Electron-Positron Storage Ring PETRA was authorized October 20, 1975. At present most of the civil engineering work is completed and ring installation work is under way. All major components are on order and series production of bending magnets, quadrupoles, vacuum chambers and rf-resonators has started. Start-up of the machine is planned with a fourfold symmetry configuration with four active beam-beam interaction points. Five experimental facilities have been recommended for the first round of experiments scheduled to begin mid 79

The influence of the electron wave function on the Pt Lsub(I) and Lsub(III) ionization probabilities by 3.6 MeV He impact

International Nuclear Information System (INIS)

Ullrich, J.; Dangendorf, V.; Dexheimer, K.; Do, K.; Kelbch, C.; Kelbch, S.; Schadt, W.; Schmidt-Boecking, H.; Stiebing, K.E.; Roesel, F.; Trautmann, D.

1986-01-01

For 3.6 MeV He impact the Lsub(I) and Lsub(III) subshell ionization probabilities of Pt have been measured. Due to relativistic effects in the electron wave functions, the Lsub(I) subshell ionization probability Isub(LI)(b) is strong enhanced at small impact parameters exceeding even Isub(LIII)(b) in nice agreement with the SCA theory. (orig.)

Bunch-shape monitor for a picosecond single-bunch beam of a 35 MeV electron linear accelerator

International Nuclear Information System (INIS)

Hosono, Yoneichi; Nakazawa, Masaharu; Iguchi, Tetsuo

1995-01-01

A non-interactive-type bunch-shape and beam intensity monitor for a 35 MeV electron linear accelerator (linac) has been developed. The monitor consists of an electric SMA-type connector and an Al pipe of 50 mm inner diameter. Test measurements of the present monitor have been made under the conditions of the accelerated charges of lower than 27 nC/pulse and the pulse width ranging from 6 to 30 ps (Full Width at Half Maximum). The results show that the present monitor is applicable to bunch-shape measurement of the picosecond single-bunch beam. The monitor output is also found to be proportional to the beam intensity of more than 0.05 nC/pulse. (author)

Compact toroidal energy storage device with relativistically densified electrons through the use of travelling magnetic waves

International Nuclear Information System (INIS)

Peter, W.; Faehl, R.J.

1983-01-01

A new concept for a small compact multimegajoule energy storage device utilizing relativistically densified electron beam circulating in a torus is presented. The electron cloud is produced through inductive charge injection by a travelling magnetic wave circulating the torus. Parameters are given for two representative toroidal energy storage devices, consisting of 1 m and 32 m in radius respectively, which could store more than 4 x 10 17 electrons and 30' MJ in energy. The concept utilizes the idea that large electric and magnetic fields can be produced by a partially space-charge neutralized intense relativistic electron beam which could become many orders of magnitude greater than the externally applied field confining the beam. In the present approach, the electron cloud densification can be achieved gradually by permitting multiple traversals of the magnetic wave around the torus. The magnetic mirror force acts on the orbital magnetic electron dipole moment and completely penetrates the entire electron cloud. As the electrons gain relativistic energies, the beam can be continuously densified at the front of the travelling wave, where the magnetic field is rising with time. The use of travelling magnetic wave to accelerate an electron cloud and the use of large electric field at the thusly accelerated cloud form the basis for a high beam intensity and hence high energy storage. Technical considerations and several potential applications, which include the driving of a powerful gyrotron, are discussed

Emittance growth induced by electron cloud in proton storage rings

CERN Document Server

Benedetto, Elena; Coppa, G

2006-01-01

In proton and positron storage rings with many closely spaced bunches, a large number of electrons can accumulate in the beam pipe due to various mechanisms (photoemission, residual gas ionization, beam-induced multipacting). The so-formed electron cloud interacts with the positively charged bunches, giving rise to instabilities, emittance growth and losses. This phenomenon has been observed in several existing machines such as the CERN Super Proton Synchrotron (SPS), whose operation has been constrained by the electron-cloud problem, and it is a concern for the Large Hadron Collider (LHC), under construction at CERN. The interaction between the beam and the electron cloud has features which cannot be fully taken into account by the conventional and known theories from accelerators and plasma physics. Computer simulations are indispensable for a proper prediction and understanding of the instability dynamics. The main feature which renders the beam-cloud interactions so peculiar is that the the electron cloud...

High-quality beam generation using an RF gun and a 150 MeV microtron

Science.gov (United States)

Kuroda, R.; Washio, M.; Kashiwagi, S.; Kobuki, T.; Ben-Zvi, I.; Wang, X. J.; Hori, T.; Sakai, F.; Tsunemi, A.; Urakawa, J.; Hirose, T.

2000-11-01

Low-emittance sub-picosecond electron pulses are expected to be used in a wide field, such as free electron laser, laser acceleration, femtosecond X-ray generation by Inverse Compton scattering, pulse radiolysis, etc. In order to produce the low-emittance sub-picosecond electron pulse, we are developing a compact Racetrack Microtron (RTM) with a new 5 MeV injection system adopting a laser photo cathode RF gun (Washio et al., Seventh China-Japan Bilateral Symposium on Radiation Chemistry, October 28, Cengdu, China, 1996). The operation of RTM has been kept under a steady state of beam loading for long pulse mode so far (Washio et al., J. Surf. Sci. Soc. Jpn. 19 (2) (1998) 23). In earlier work (Washio et al., PAC99, March 31, New York, USA, 1999), we have succeeded in the numerical simulation for the case of single short pulse acceleration. Finally, the modified RTM was demonstrated as a useful accelerator for a picosecond electron pulse generation under a transient state of beam loading. In the simulation, a picosecond electron pulse was accelerated to 149.6 MeV in RTM for the injection of 5 MeV electron bunch with a pulse length of 10 ps (FWHM), a charge of 1 nC per pulse, and an emittance of 3 πmm mrad.

Investigation of the effect of some irradiation parameters on the response of various types of dosimeters to electron irradiation

International Nuclear Information System (INIS)

Farah, K.; Kuntz, F.; Kadri, O.; Ghedira, L.

2004-01-01

Several undyed and dyed polymer films are commercially available for dosimetry in intense radiation fields, especially for radiation processing of food and sterilisation of medical devices. The effects of temperature during irradiation and post-irradiation stability, on the response of these dosimeters are of importance to operators of irradiation facilities. The present study investigates the effects of temperature during irradiation by 2.2 MeV electrons beam accelerator and post irradiation storage on the response of several types of dosimeter films. All dosimeters showed a significant effect of temperature during irradiation and post-irradiation storage

Investigation of the effect of some irradiation parameters on the response of various types of dosimeters to electron irradiation

Energy Technology Data Exchange (ETDEWEB)

Farah, K. E-mail: k.farah@cnstn.rnrt.tn; Kuntz, F.; Kadri, O.; Ghedira, L

2004-10-01

Several undyed and dyed polymer films are commercially available for dosimetry in intense radiation fields, especially for radiation processing of food and sterilisation of medical devices. The effects of temperature during irradiation and post-irradiation stability, on the response of these dosimeters are of importance to operators of irradiation facilities. The present study investigates the effects of temperature during irradiation by 2.2 MeV electrons beam accelerator and post irradiation storage on the response of several types of dosimeter films. All dosimeters showed a significant effect of temperature during irradiation and post-irradiation storage.

Electronic structure and electron dynamics at Si(100)

Energy Technology Data Exchange (ETDEWEB)

Weinelt, M. [Universitaet Erlangen-Nuernberg, Lehrstuhl fuer Festkoerperphysik, Erlangen (Germany); Max-Born-Institut, Berlin (Germany); Kutschera, M.; Schmidt, R.; Orth, C.; Fauster, T. [Universitaet Erlangen-Nuernberg, Lehrstuhl fuer Festkoerperphysik, Erlangen (Germany); Rohlfing, M. [International University Bremen, School of Engineering and Science, P.O. Box 750 561, Bremen (Germany)

2005-02-01

The electronic structure and electron dynamics at a Si(100) surface is studied by two-photon photoemission (2PPE). At 90 K the occupied D{sub up} dangling-bond state is located 150{+-}50 meV below the valence-band maximum (VBM) at the center of the surface Brillouin zone anti {gamma} and exhibits an effective hole mass of (0.5{+-}0.15)m{sub e}. The unoccupied D{sub down} band has a local minimum at anti {gamma} at 650{+-}50 meV above the VBM and shows strong dispersion along the dimer rows of the c(4 x 2) reconstructed surface. At 300 K the D{sub down} position shifts comparable to the Si conduction-band minimum by 40 meV to lower energies but the dispersion of the dangling-bond states is independent of temperature. The surface band bending for p-doped silicon is less than 30 meV, while acceptor-type defects cause significant and preparation-dependent band bending on n-doped samples. 2PPE spectra of Si(100) are dominated by interband transitions between the occupied and unoccupied surface states and emission out of transiently and permanently charged surface defects. Including electron-hole interaction in many-body calculations of the quasi-particle band structure leads us to assign a dangling-bond split-off state to a quasi-one-dimensional surface exciton with a binding energy of 130 meV. Electrons resonantly excited to the unoccupied D{sub down} dangling-bond band with an excess energy of about 350 meV need 1.5{+-}0.2 ps to scatter via phonon emission to the band bottom at anti {gamma} and relax within 5 ps with an excited hole in the occupied surface band to form an exciton living for nanoseconds. (orig.)

Alignment of Duke free electron laser storage ring and optical beam delivery system

International Nuclear Information System (INIS)

Emamian, M.; Hower, N.

1999-01-01

Duke Free Electron Laser Laboratory (DFELL) hosts a 1.1 GeV electron beam storage ring facility which is capable of generating beams in the range of nearly monochromatic gamma rays to high peak power infra red (IR) laser. In this report specifications and procedures for alignment of OK-4 /Duke storage ring FEL wiggler and optical cavity mirrors will be discussed. The OK-4 FEL lasing has demonstrated a series of world record in the last few years. In August of this year the OK-4 FEL successfully commissioned to laser at 193.7 nm. Also in this article, alignment of the γ-ray and UV optical beam delivery system that is currently in progress will be described. (authors)

Electron microscopy studies of materials used for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Andrei, Carmen M.

2004-07-01

Concerns over global warming and air pollution have stimulated the concept of the ''Hydrogen Economy'' and the potential extensive use of hydrogen as an energy carrier. Hydrogen storage in a solid matrix has become one of the promising solutions for vehicular applications. In this study, several transmission electron microscopy (TEM) techniques such as high resolution (HR), electron diffraction, energy dispersive X-ray spectroscopy (EDS), electron energy loss spectroscopy (EELS) and energy-filtered transmission electron microscopy (EFT EM) as well as scanning electron microscopy (SEM) have been used to study the microstructure of materials related to hydrogen storage applications. Some of the results are compared with powder X-ray diffraction (PXD) data. A TbNiAl compound processed by the hydrogenation-disproportionation-desorption-recombination (HDDR) route has been studied using a combination of SEM, TEM and PXD. Information about the variations in the composition and surface topography in both disproportionation and recombination stages is given by the SEM backscattered electrons and secondary electrons images. The crystallites that have undergone the recombination process were found smaller in size. The sodium alanate, NaAIH4 is one of the most promising candidate materials for hydrogen storage. Ti additives are effective at reducing the reaction temperatures and improving the efficiency of the kinetics. The microstructure of NaAlH4 with TiF3 additive has been examined after the initial ball milling and after 15 cycles, using TEM, SEM and EDS. The effect of the additive on particle morphology, grain size and distribution of the phases has been studied. The additive has uneven distribution in the sample after initial ball milling. After 15 cycles, EDS maps show some combination of Ti with the alanate phase. No significant change in grain size of the Na/Al rich particles between the ball milled and 15 cycled sample was observed. The LiAlD4

Detector system for e-d scattering experiments on the VEPP-3 storage ring

International Nuclear Information System (INIS)

Isaeva, L.G.; Lazarenko, B.A.; Nikolenko, D.M.; Popov, S.G.; Rachek, I.A.; Ukraintsev, Yu.G.; Tsentalovich, E.P.; Wojtsekhowski, B.B.; Nelubin, V.V.

1993-01-01

Experiments on electron scattering from polarized deuterons were carried out on the VEPP-3 storage ring at the Novosibirsk Institute for Nuclear Physics. The e-D coincidences were detected for elastic scattering experiments, and the p-n coincidences for photo disintegration studies. The tensor analyzing power of the elastic scattering was measured in the range of momentum transfer up to 3 f -1 , and of photo disintegration in the range of photon energy up to 500 MeV. The detector system created for these experiments and the data analysis procedures are described in this paper. (orig.)

Small-sized linear accelerator of 2.5 MeV electrons with a local radiation shield for custom examination of freight transported by motor transport

International Nuclear Information System (INIS)

Baklanov, A.V.; Gavrish, Yu.N.; Klinov, A.P.; Krest'yaninov, A.S.; Nikolaev, V.M.; Fomin, L.P.; Linkenbach, H.A.; Geus, G.; Knospel, W.

2001-01-01

A new development of a small-sized linear accelerator of 2.5 MeV electrons with a local radiation protection is described. The accelerator is intended for movable facilities of radiation custom of the freight transported by motor transport. Main constructive solutions, mass and dimension characteristics and results of preliminary tests of the accelerator parameters and characteristics of radiation protection are presented [ru

Comparison of measured with calculated dose distribution from a 120-MeV electron beam from a laser-plasma accelerator

International Nuclear Information System (INIS)

Lundh, O.; Rechatin, C.; Faure, J.; Ben-Ismaïl, A.; Lim, J.; De Wagter, C.; De Neve, W.; Malka, V.

2012-01-01

Purpose: To evaluate the dose distribution of a 120-MeV laser-plasma accelerated electron beam which may be of potential interest for high-energy electron radiation therapy. Methods: In the interaction between an intense laser pulse and a helium gas jet, a well collimated electron beam with very high energy is produced. A secondary laser beam is used to optically control and to tune the electron beam energy and charge. The potential use of this beam for radiation treatment is evaluated experimentally by measurements of dose deposition in a polystyrene phantom. The results are compared to Monte Carlo simulations using the geant4 code. Results: It has been shown that the laser-plasma accelerated electron beam can deliver a peak dose of more than 1 Gy at the entrance of the phantom in a single laser shot by direct irradiation, without the use of intermediate magnetic transport or focusing. The dose distribution is peaked on axis, with narrow lateral penumbra. Monte Carlo simulations of electron beam propagation and dose deposition indicate that the propagation of the intense electron beam (with large self-fields) can be described by standard models that exclude collective effects in the response of the material. Conclusions: The measurements show that the high-energy electron beams produced by an optically injected laser-plasma accelerator can deliver high enough dose at penetration depths of interest for electron beam radiotherapy of deep-seated tumors. Many engineering issues must be resolved before laser-accelerated electrons can be used for cancer therapy, but they also represent exciting challenges for future research.

Storage ring free electron lasers and saw-tooth instability

CERN Document Server

Dattoli, Giuseppe; Migliorati, M; Palumbo, L; Renieri, A

1999-01-01

We show that Free Electron Lasers (FEL) operating with storage rings may counteract beam instabilities of the Saw Tooth (STI) type. We use a model based on a set of equations that couple those describing the FEL evolution to those accounting for the STI dynamics. The analysis provides a clear picture of the FEL-STI mutual feedback and clarifies the mechanisms of the instability inhibition. The reliability of the results is supported by a comparison with fully numerical codes.

Design of 6 MeV X-band electron linac for dual-head gantry radiotherapy system

Science.gov (United States)

Shin, Seung-wook; Lee, Seung-Hyun; Lee, Jong-Chul; Kim, Huisu; Ha, Donghyup; Ghergherehchi, Mitra; Chai, Jongseo; Lee, Byung-no; Chae, Moonsik

2017-12-01

A compact 6 MeV electron linac is being developed at Sungkyunkwan University, in collaboration with the Korea atomic energy research institute (KAERI). The linac will be used as an X-ray source for a dual-head gantry radiotherapy system. X-band technology has been employed to satisfy the size requirement of the dual-head gantry radiotherapy machine. Among the several options available, we selected a pi/2-mode, standing-wave, side-coupled cavity. This choice of radiofrequency (RF) cavity design is intended to enhance the shunt impedance of each cavity in the linac. An optimum structure of the RF cavity with a high-performance design was determined by applying a genetic algorithm during the optimization procedure. This paper describes the detailed design process for a single normal RF cavity and the entire structure, including the RF power coupler and coupling cavity, as well as the beam dynamics results.

Design and project status of the National Synchrotron Light Source; storage rings (2.5 GeV, 0.7 GeV) for the generation of bright synchrotron radiation sources

International Nuclear Information System (INIS)

van Steenbergen, A.

1980-01-01

Two high intensity storage rings are being constructed at Brookhaven National Laboratory for the generation of intense fluxes of synchrotron radiation in the vuv wavelength region (700 MeV ring, lambda/sub c/ = 31.5 A) and in the x-ray wavelength region (2.5 GeV ring, lambda/sub c/ = 2.5 A). A description is given of the facility, the main features of the storage rings are presented and the basic parameters are enumerated. High field superconducting wigglers, to lower the short wavelength cutoff in the x-ray ring, and undulators, for flux enhancement or a free electron laser experiment will be incorporated and parameters are given here. Special design aspects to optimize the electron storage rings as dedicated synchrotron radiation sources will be emphasized and the status of the project will be given

Study of the /sup 12/N 2. 43 MeV level. [Differential cross sections; 44 MeV /sup 3/He; 52 MeV p

Energy Technology Data Exchange (ETDEWEB)

Cecil, F E; Shepard, J R; Sercely, R R; Peterson, R J [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; King, N S.P. [California Univ., Davis (USA). Crocker Nuclear Lab.

1976-10-11

The differential cross sections have been measured for the reactions /sup 12/C(/sup 3/He, /sup 3/He')/sup 12/C(17.77 MeV 0/sup +/ T = 1) and /sup 12/C(/sup 3/He, t)/sup 12/N(2.43 MeV) at Esub(/sup 3/He) = 44 MeV. The similar shapes of the angular distributions and the relative magnitudes of the cross sections suggest that the /sup 12/N 2.43 MeV level is the 0/sup +/ T = 1 analog to the /sup 12/C 17.77 MeV level. The reaction /sup 14/N(p, t)/sup 12/N(2.43 MeV) at Esub(p) = 52 MeV is also studied. The strength with which this level is excited in this reaction is consistent with reasonable two-step calculations assuming the 2.43 MeV level to have Jsup(..pi..) = 0/sup +/.

Depolarization of the electron spin in storage rings by nonlinear spin-orbit coupling

International Nuclear Information System (INIS)

Kewisch, J.

1985-10-01

Electrons and positrons which circulate in the storage ring are polarized at the emission of synchrotron radiation by the so called Sokolov-Ternov effect. This polarization is on the one hand of large interest for the study of the weak interaction, on the other hand it can be used for the accurate measurement of the beam energy and by this of the mass of elementary particles. The transverse and longitudinal particle vibrations simultaneously excited by the synchrotron radiation however can effect that this polarization is destroyed. This effect is called spin-orbit coupling. For the calculation of the spin-orbit coupling the computer program SITROS was written. This program is a tracking program: The motion of some sample particles and their spin vectors are calculated for some thousand circulations. From this the mean depolarization and by extrapolation the degree of polarization of the equilibrium state is determined. Contrarily to the known program SLIM which is based on perturbational calculations in SITROS the nonlinear forces in the storage ring can be regarded. By this the calculation of depolarizing higher order resonances is made possible. In this thesis the equations of motion for the orbital and spin motion of the electrons are derived which form the base for the program SITROS. The functions of the program and the approximations necessary for the saving of calculational time are explained. The comparison of the SITROS results with the measurement results obtained at the PETRA storage ring shows that the SITROS program is a useful means for the planning and calculation of storage rings with polarized electron beams. (orig.) [de

Novel digital K-edge imaging system with transition radiation from an 855-MeV electron beam

CERN Document Server

Hagenbuck, F; Clawiter, N; Euteneuer, H; Görgen, F; Holl, P; Johann, K; Kiser, K H; Kemmer, J; Kerschner, T; Kettig, O; Koch, H; Kube, G; Lauth, W; Mauhay, H; Schütrumpf, M; Stotter, R; Strüder, L; Walcher, T; Wilms, A; von Zanthier, C; Zemter, M

2001-01-01

A novel K-edge imaging method has been developed at the Mainz Microtron MAMI aiming at a very efficient use of the transition radiation (TR) flux generated by the external 855-MeV electron beam in a foil stack. A fan-like quasi-monochromatic hard X-ray beam is produced from the +or-1-mrad-wide TR cone with a highly oriented pyrolytic graphite (HOPG) crystal. The absorption of the object in front of a 30 mm*10 mm pn charge-coupled device (pn-CCD) photon detector is measured at every pixel by a broad-band energy scan around the K-absorption edge. This is accomplished by a synchronous variation of the lateral crystal position and the electron beam direction which defines also the direction of the TR cone. The system has been checked with a phantom consisting of a 2.5- mu m thick molybdenum sample embedded in a 136- or 272- mu m-thick copper bulk foil. A numerical analysis of the energy spectrum for every pixel demonstrates that data as far as +or-0.75 keV away from the K edge of molybdenum at 20 keV still improv...

ESR response of powder samples of clear fused quartz material to high doses of 10 MeV electrons: possible applications for industrial radiation processing

International Nuclear Information System (INIS)

Aliabadi, R.; Amraei, R.; Ranjbar, A.H.; Rafieian, Sh.; Nasirimoghadam, S.

2010-01-01

Powder samples of clear fused quartz were irradiated by 10 MeV electrons at doses between 6-15 kGy and 25-37 kGy and analyzed with electron spin resonance. The reproducibility of the material dose response curve was studied, in which the irradiated samples were annealed and reused for further investigations. Results indicate a good linearity between the absorbed dose and the ESR intensity of the signals. They also showed that in the reuse processes, the electron spin resonance signal intensity, in both dose ranges was decreased. The thermal fading represented a relative sharp decay at room temperature through 15 days, after which the decay-rate was negligible for a measurement period of 60 days.

Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators

International Nuclear Information System (INIS)

Hsu, Yung-Cheng; Lai, Bo-Lun; Sheu, Rong-Jiun

2016-01-01

This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed. (authors)

The operational procedure of an electron beam accelerator

International Nuclear Information System (INIS)

Lee, Byung Cheol; Choi, Hwa Lim; Yang, Ki Ho; Han, Young Hwan; Kim, Sung Chan

2008-12-01

The KAERI(Korea Atomic Energy of Research Institute) high-power electron beam irradiation facility, operating at the energies between 0.3 MeV and 10 MeV, has provided irradiation services to users in industries, universities, and institute in various fields. This manual is for the operation of an electron beam which is established in KAERI, and describes elementary operation procedures of electron beam between 0.3 Mev and 10 MeV. KAERI Electron Accelerator facility(Daejeon, Korea) consists of two irradiators: one is a low-energy electron beam irradiator operated by normal conducting RF accelerator, the other is medium-energy irradiator operated by superconducting RF accelerator. We explain the check points of prior to operation, operation procedure of this facility and the essential parts of electron beam accelerator

The operational procedure of an electron beam accelerator

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Cheol; Choi, Hwa Lim; Yang, Ki Ho; Han, Young Hwan; Kim, Sung Chan

2008-12-15

The KAERI(Korea Atomic Energy of Research Institute) high-power electron beam irradiation facility, operating at the energies between 0.3 MeV and 10 MeV, has provided irradiation services to users in industries, universities, and institute in various fields. This manual is for the operation of an electron beam which is established in KAERI, and describes elementary operation procedures of electron beam between 0.3 Mev and 10 MeV. KAERI Electron Accelerator facility(Daejeon, Korea) consists of two irradiators: one is a low-energy electron beam irradiator operated by normal conducting RF accelerator, the other is medium-energy irradiator operated by superconducting RF accelerator. We explain the check points of prior to operation, operation procedure of this facility and the essential parts of electron beam accelerator.

The realization of the storage of XML and middleware-based data of electronic medical records

International Nuclear Information System (INIS)

Liu Shuzhen; Gu Peidi; Luo Yanlin

2007-01-01

In this paper, using the technology of XML and middleware to design and implement a unified electronic medical records storage archive management system and giving a common storage management model. Using XML to describe the structure of electronic medical records, transform the medical data from traditional 'business-centered' medical information into a unified 'patient-centered' XML document and using middleware technology to shield the types of the databases at different departments of the hospital and to complete the information integration of the medical data which scattered in different databases, conducive to information sharing between different hospitals. (authors)

Observation of enhanced zero-degree binary encounter electron production with decreasing charge-state q in 30 MeV Oq+ + O2 collisions

International Nuclear Information System (INIS)

Zouros, T.J.M.; Wong, K.L.; Hidmi, H.I.

1993-01-01

We have measured binary encounter electron production in collisions of 30 MeV O q+ projectiles (q=4-8) and O 2 targets. Measured double differential BEe cross-sections are found to increase with decreasing charge-state q, in agreement with similar previously reported zero-degree investigations for H 2 and He targets. However, measurements for the same system but at 25 degrees shows the opposite trend, that BEe cross sections decrease slightly with decreasing charge state

Effect of fission fragment on thermal conductivity via electrons with an energy about 0.5 MeV in fuel rod gap

Directory of Open Access Journals (Sweden)

F Golian

2017-02-01

Full Text Available The heat transfer process from pellet to coolant is one of the important issues in nuclear reactor. In this regard, the fuel to clad gap and its physical and chemical properties are effective factors on heat transfer in nuclear fuel rod discussion. So, the energy distribution function of electrons with an energy about 0.5 MeV in fuel rod gap in Busherhr’s VVER-1000 nuclear reactor was investigated in this paper. Also, the effect of fission fragments such as Krypton, Bromine, Xenon, Rubidium and Cesium on the electron energy distribution function as well as the heat conduction via electrons in the fuel rod gap have been studied. For this purpose, the Fokker- Planck equation governing the stochastic behavior of electrons in absorbing gap element has been applied in order to obtain the energy distribution function of electrons. This equation was solved via Runge-Kutta numerical method. On the other hand, the electron energy distribution function was determined by using Monte Carlo GEANT4 code. It was concluded that these fission fragments have virtually insignificant effect on energy distribution of electrons and therefore, on thermal conductivity via electrons in the fuel to clad gap. It is worth noting that this result is consistent with the results of other experiments. Also, it is shown that electron relaxation in gap leads to decrease in thermal conductivity via electrons

Microwave source development for 9 MeV RF electron LINAC for cargo scanning

International Nuclear Information System (INIS)

Yadav, V.; Chandan, Shiv; Tillu, A.R.; Bhattacharjee, D.; Chavan, R.B.; Dixit, K.P.; Mittal, K.C.; Gantayet, L.M.

2011-01-01

For cargo scanning, high energy X-rays are required. These X-rays can be generated from accelerated electrons. A 9 MeV Cargo scanning RF LINAC has been developed at ECIL, Hyderabad. The Microwave power source required for RF Linac is a klystron-based system generating 5.5 MW peak, 10 kW average, at 2.856 GHz. Various components required for microwave source were identified, procured, tested and integrated into the source. Microwave source was tested on water load, then it was connected to LINAC and RF conditioning and e-beam trials were successfully done. For operating the microwave source, a PC based remote handling system was also designed and developed for operating various power supplies and instruments of the microwave source, including the Klystron modulator, Signal generator and other devices. The accelerator operates in pulse mode, requiring synchronous operation of the Klystron modulator, RF driver amplifier and E-gun modulator. For this purpose, a synchronous trigger generator was designed and developed. This paper describes the development and testing of microwave source and its remote operating system. The results of beam trials are also discussed in this paper. (author)

Preliminary research concerning the use of electron accelerators to improve the conservability and to extend the shelf-life of fruits and vegetables

International Nuclear Information System (INIS)

Minea, R.

1996-01-01

The potential of ionizing radiation treatment for food preservation, shelf-life extension, control of microbial load and reduction of pathogenic microorganism was demonstrated. The irradiations were performed under normal conditions on the Institute of Physics and Technology for Radiation Device's linear electron accelerator, which has the following parameters: 5 μA mean beam current, 6 MeV electron mean energy, pulse period 3.5 μs and dose rates between 100-1500 Gy/min. This research project was aimed at assuring the consumer's acceptance for radiation-treated food and to obtain a significant reduction of food losses. We also propose a promising solution for the radiation processing of some bulk food products at the place of storage, consisting of a mobile electron accelerator. The main characteristics of the mobile electron accelerator are: electron energy 3 to 5 MeV, maximum beam power 5 kW, vertical electron beam; irradiation is possible both with electron beams and with bremsstrahlung. The results of our preliminary research lead to the conclusion that electron-beam irradiation and the use of electron accelerators is a promising solution for food preservation and food safety. Interesting future applications are outlined. (orig.)

Measurement of charge composition of electron flows with an energy above hundreds MeV in inner radiaion belt

International Nuclear Information System (INIS)

Gusev, A.A.; Pugacheva, G.I.

1990-01-01

A detector for studying the charge composition of a high-energy electron component of an internal radiation belt when measuring the precipitation of charged particles in the region of Brazil magnetic anomaly is suggested. The detector is a telescope consisting of two semiconductors and CsI crystal housed into a protection detector in the form of a cup made of plastic scintillator. An absorber of plastic scintillator is placed between semiconductive detections. The detector may record positrons with energy up to 5 MeV in the composition of precipitating particles from the belt in definite detector signal combination and specific energy release 511 keV in CsI crystal. 16 refs.; 3 figs

Reduction of dose enhancement from backscattered radiation at tissue-metal interfaces irradiated with 6MeV electrons

International Nuclear Information System (INIS)

Steel, B.

1996-01-01

Due to Electron Back Scatter (EBS), electron irradiation of tissue having under lying lead shielding results in an increase in dose to the tissue on the entrance side of the lead. In these situations dose increases as high as 80% have been reported in the literature. Saunders (British Journal of Radiology, 47, 467-470) noted that dose enhancement is dependent on atomic number of the under lying material approximately as Z 0.5 , and it increases at lower incident electron energies. In our clinic we use 2mm of lead shielding to protect under lying normal tissue when 6MeV electrons are used to treat lips and ears. The object of this study was to find the thinnest combination of materials to reduce the total dose to an acceptable level, with the provisos that; the patient does not come into contact with the lead or other metals, the finished shield could comfortabley be placed between the patient's lip and teeth, and that the materials are sufficietly malleable to work into custom shields. Various combinations of dental wax and aluminium were trialed. That which proved to give the best compromise between reduction of EBS and total shielding thickness was, 1mm of aluminim on the beam side of the lead with 1mm of dental wax to completely enclose the shield. In practice the manufactured shields are approximately 6 mm thick, and are usually not uncomfortable for the patient. (author)

Plasma production for the 50 MeV plasma lens experiment at LBL

International Nuclear Information System (INIS)

Leemans, W.; van der Geer, B.; de Loos, M.; Conde, M.; Govil, R.; Chattopadhyay, S.

1994-06-01

The Center for Beam Physics at LBL has constructed a Beam Test Facility (BTF) housing a 50 MeV electron beam transport line, which uses the linac injector from the Advanced Light Source, and a terawatt Ti:Al 2 O 3 laser system. The linac operates at 50 MeV and generates 15 ps long electron bunches containing a charge of up to 2 nC. The measured unnormalized beam emittance is 0.33 mm-mrad. These parameters allow for a comprehensive study of focusing of relativistic electron beams with plasma columns, in both the overdense and underdense regime (adiabatic and tapered lenses). A study of adiabatic and/or tapered lenses requires careful control of plasma density and scale lengths of the plasma. We present experimental results on the production of plasmas through resonant two-photon ionization, with parameters relevant to an upcoming plasma lens experiment

Electron Cloud Simulations of a Proton Storage Ring Using Cold Proton Bunches

International Nuclear Information System (INIS)

Sato, Y.; Holmes, Jeffrey A.; Lee, S.Y.; Macek, R.

2008-01-01

Using the ORBIT code we study the sensitivity of electron cloud properties with respect to different proton beam profiles, the secondary electron yield (SEY) parameter, and the proton loss rate. Our model uses a cold proton bunch to generate primary electrons and electromagnetic field for electron cloud dynamics. We study the dependence of the prompt and swept electron signals vs the bunch charge and the recovery of electron clouds after sweeping on the beam loss rate and the SEY. The simulation results are compared with the experimental data measured at the proton storage ring at the Los Alamos National Laboratory. Our simulations indicate that the fractional proton loss rate in the field-free straight section may be an exponential function of proton beam charge and may also be lower than the averaged fractional proton loss rate over the whole ring.

Comparison of measured with calculated dose distribution from a 120-MeV electron beam from a laser-plasma accelerator.

Science.gov (United States)

Lundh, O; Rechatin, C; Faure, J; Ben-Ismaïl, A; Lim, J; De Wagter, C; De Neve, W; Malka, V

2012-06-01

To evaluate the dose distribution of a 120-MeV laser-plasma accelerated electron beam which may be of potential interest for high-energy electron radiation therapy. In the interaction between an intense laser pulse and a helium gas jet, a well collimated electron beam with very high energy is produced. A secondary laser beam is used to optically control and to tune the electron beam energy and charge. The potential use of this beam for radiation treatment is evaluated experimentally by measurements of dose deposition in a polystyrene phantom. The results are compared to Monte Carlo simulations using the geant4 code. It has been shown that the laser-plasma accelerated electron beam can deliver a peak dose of more than 1 Gy at the entrance of the phantom in a single laser shot by direct irradiation, without the use of intermediate magnetic transport or focusing. The dose distribution is peaked on axis, with narrow lateral penumbra. Monte Carlo simulations of electron beam propagation and dose deposition indicate that the propagation of the intense electron beam (with large self-fields) can be described by standard models that exclude collective effects in the response of the material. The measurements show that the high-energy electron beams produced by an optically injected laser-plasma accelerator can deliver high enough dose at penetration depths of interest for electron beam radiotherapy of deep-seated tumors. Many engineering issues must be resolved before laser-accelerated electrons can be used for cancer therapy, but they also represent exciting challenges for future research. © 2012 American Association of Physicists in Medicine.

Low temperature irradiation of iron, zirconium and copper by 10 to 16 MeV protons

Energy Technology Data Exchange (ETDEWEB)

Omar, A M

1978-01-01

A theoretical analysis of scattering and radiation damage parameters is carried out for 14 MeV neutrons and 10-17 MeV protons on Fe, Ni, Cu, Zr, Nb, and Au. Damage energies are computed for the interactions using both elastic and non-elastic data. The results show that proton encounters deposit a greater damage energy than 14 MeV neutrons. To examine the theoretical results, electrical resistivity measurements are undertaken for Fe, Zr and Cu irradiated at 12 to 17.5K with 10 to 16 MeV protons. Post-irradiation annealing is carried out in situ using a closed-cycle helium-cooled cryostat. Values of the resistivity damage rate are compared with values estimated from the theoretical damage-energy results. Also, the observed stage I recovery is analysed in terms of the corresponding recovery reported for electron and fast-neutron irradiations. The relation between the 16 MeV proton data and published data estimated from a fusion reactor spectrum is discussed. It is also shown that protons create a damage structure similar to a superposition of the damage structures generated by electrons and fast neutrons. The sample state of imperfection is shown to influence the induced damage state in proton irradiation.

Observation of magnetic resonances in electron clouds in a positron storage ring

International Nuclear Information System (INIS)

Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, C.M.; Raubenheimer, T.O.; Wang, L.F.

2010-01-01

The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines' performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

The gas bubbles distribution in 600 MeV protons irradiated aluminium

International Nuclear Information System (INIS)

Gavillet, D.; Martin, J.L.; Victoria, M.; Green, W.

1984-01-01

In order to simulate the damage produced by 14 MeV fusion neutrons, thin foils of high purity Al have been irradiated by a proton beam of 580 MeV (120μA). After irradiation at temperatures higher than 0.5 Tm transmission electron microscope observations of gas bubbles distribution were performed. At 200 0 C a uniform distribution of bubbles has been observed inside the grain. The average distance between bubbles and their density have been determined. The gas pressure inside the bubbles has been estimated [fr

Laser-Cooled Ions and Atoms in a Storage Ring

International Nuclear Information System (INIS)

Kleinert, J.; Hannemann, S.; Eike, B.; Eisenbarth, U.; Grieser, M.; Grimm, R.; Gwinner, G.; Karpuk, S.; Saathoff, G.; Schramm, U.; Schwalm, D.; Weidemueller, M.

2003-01-01

We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are achieved by three-dimensional laser cooling of a coasting 9 Be + beam at 7.3 MeV. Laser-cooled, trapped Cs atoms are used as an ultracold precision target for the study of ion-atom interactions with a 74 MeV beam of 12 C 6+ ions.

On-site installation and shielding of a mobile electron accelerator for radiation processing

International Nuclear Information System (INIS)

Catana, D.; Panaitescu, J.; Axinescu, S.; Manolache, D.; Matei, C.; Corcodel, C.; Ulmeanu, M..; Bestea, V.

1995-01-01

The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account. (orig.)

On-site installation and shielding of a mobile electron accelerator for radiation processing

Energy Technology Data Exchange (ETDEWEB)

Catana, D. [Institutul de Fizica Atomica, Bucharest (Romania); Panaitescu, J. [Institutul de Fizica Atomica, Bucharest (Romania); Axinescu, S. [Institutul de Fizica Atomica, Bucharest (Romania); Manolache, D. [Institutul de Fizica Atomica, Bucharest (Romania); Matei, C. [Institutul de Fizica Atomica, Bucharest (Romania); Corcodel, C. [Institutul de Fizica Atomica, Bucharest (Romania); Ulmeanu, M.. [Institutul de Fizica Atomica, Bucharest (Romania); Bestea, V. [Institutul de Fizica Atomica, Bucharest (Romania)

1995-05-01

The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account. (orig.).

FPGA-based upgrade of the read-out electronics for the low energy polarimeter at the cooler synchrotron

Energy Technology Data Exchange (ETDEWEB)

Hempelmann, Nils [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Collaboration: JEDI-Collaboration

2015-07-01

The Cooler Synchrotron (COSY) is a storage ring used for experiments with polarized proton and deuteron beams. The low energy polarimeter is used to determine the vector and tensor polarization of the beam before injection at kinetic energies up to 45 MeV for protons and 75 MeV for deuterons. The polarimeter uses scintillators to measure the energy of both outgoing particles of a scattering reaction and the time between their detection. The present read-out electronics consists of analog NIM modules and is limited in terms of time resolution and the capability for online data analysis. The read-out electronics will be replaced with a a new system based on analog pulse sampling and an FPGA chip for logic operations. The new system will be able to measure the time at which particles arrive to a precision better than 50 ps, facilitating better background reduction using coincidence measurement. In addition to measuring the beam polarization, the system will be used to precisely determine the vector and tensor analyzing powers for deuteron scattering off carbon at a kinetic energy of 75 MeV.

Optimization of the microwave coupler and microwave measurements of the microtron cavity for 20 MeV pre-injector microtron for INDUS-I SRS

International Nuclear Information System (INIS)

Wanmode, Y.D.; Shrivastava, Purushottam; Hannurkar, P.R.

2003-01-01

A 20 MeV microtron was developed indigenously by CAT for pre-injection of 20 MeV electrons to the 450 MeV/700 MeV Booster Synchrotron for INDUS-I and INDUS-II Synchrotron Radiation Sources. The injector microtron uses a high Q microwave cavity for acceleration of electrons. The microwave power is fed to the microtron cavity through an iris type coupler whose dimensions are optimized for the coupling factor and resonant frequency for the accelerator. The present paper gives the procedure details for coupling factor optimization, tuning of the resonant frequency and results achieved. (author)

Spatial distribution of bremsstrahlung in water and water-iron by 22-MeV electron bombardment measured with activation detectors

International Nuclear Information System (INIS)

Nakamura, Takashi; Nishimoto, Takanao; Hirayama, Hideo.

1977-01-01

The spatial distributions of bremsstrahlung in water (1 m thick) and water (60 cm thick)-iron (6.3 cm thick) bombarded by 22-MeV electrons were measured by using a new activation method which we developed. These informations are useful for studying shielding, residual activity and radiation damage of accelerator and target materials. From the measured activities, the bremsstrahlung spectra in water were evaluated with the LYRA and the SAND-II unfolding codes. The evaluated spectra were in good agreement with the analytical calculation by the DIBRE code, except for the higher energy ends. The longitudinal and the lateral distributions of bremsstrahlung flux in water were obtained by integrating the evaluated spectra above 8 MeV. The agreement of the experimental and the calculated flux distributions was very good except for a large angle to beam direction. The total photon number crossing a plane normal to the beam axis attenuates exponentially along the axial depth. The iso-flux contour of bremsstrahlung flux was given by interpolating the flux distribution curves. Only the saturated activities of gold detectors were obtained for water-iron in good experimental accuracy. The spatial distribution of gold saturated activities in water-iron clearly shows the attenuating effect due to strong absorption in iron. (auth.)

{sup 96}Ru(p,{gamma}){sup 97}Rh measurement at the GSI storage ring

Energy Technology Data Exchange (ETDEWEB)

Zhong, Q; Aumann, T; Boretzky, K; Bosch, F; Braeuning, H; Brandau, C; Ershova, O; Geissel, H; Heil, M; Kelic, A; Kozhuharov, C; Langer, C; Bleis, T Le; Litvinov, Y A [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt, 64291 (Germany); Bishop, S; Dillmann, I [Technische Universitaet Muenchen, 85748 Garching (Germany); Blaum, K [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Davinson, T [University of Edinburgh, Edinburgh (United Kingdom); Gyuerky, G [Institute of Nuclear Research of the Hungarian Academy of Sciences (Hungary); Kaeppeler, F, E-mail: r.reifarth@gsi.d [Forschungszentrum Karlsruhe, Institut fuer Kernphysik, Karlsruhe (Germany)

2010-01-01

A pioneering experiment was recently performed at the Experimental Storage Ring (ESR) at GSI. Fully stripped ions of {sup 96}Ru were injected into the storage ring and slowed down to a few MeV per nucleon. The {sup 97}Rh ions from the {sup 96}Ru(p,{gamma}) reaction at a newly developed hydrogen jet target were detected with Double Sided Silicon Strip Detectors (DSSSD) mounted inside a pocket. The experiment and the status of the analysis at a beam energy of 11 MeV per nucleon will be presented.

Food processing using electrons and X-rays

International Nuclear Information System (INIS)

Clouston, J.G.

1985-01-01

The ionizing radiation which will be used as process energy for the preservation of food, will be limited to high energy electrons (less than 10 MeV), X-rays (less than 5 MeV) and gamma rays emitted by cobalt-60 (1.17;1.33 MeV) and cesium -137 (0.663 MeV). When a foodstuff is irradiated with any of these radiations absorption of the radiant energy will initiate a variety of reactions between its atomic and molecular constituents causing permanent chemical, physical and biological changes. This paper focusses on radiation processing using electron or X-ray generators in the range 2 to 10 MeV

Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators.

Science.gov (United States)

Hsu, Yung-Cheng; Lai, Bo-Lun; Sheu, Rong-Jiun

2016-01-01

This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Alanine-EPR dosimetry in 10 MeV electron beam to optimize process parameters for food irradiation

International Nuclear Information System (INIS)

Sanyal, B.; Kumar, S.; Kumar, M.; Mittal, K.C.; Sharma, A.

2011-01-01

Absorbed dose in a food product is determined and controlled by several components of the LINAC irradiation facility as well as the product. Standardization of the parameters characterizing the facility components, process load and the irradiation conditions collectively termed as 'process parameters' are of paramount importance for successful dose delivery to the food products. In the present study alanine-EPR dosimetry system was employed to optimize the process parameters of 10 MeV electron beam of a LINAC facility for commercial irradiation of food. Three sets of experiments were carried out with different food commodities namely, mango, potato and rawa with the available product conveying system of different irradiation geometry like one sided or both sided mode of irradiation. Three dimensional dose distributions into the process load for low dose requiring food commodities (0.25 to 1 kGy) were measured in each experiment. The actual depth dose profile in food product and useful scan width of the electron beam were found out to be satisfactory for commercial radiation processing of food. Finally a scaled up experiment with commercial food product (packets of Rawa) exhibited adequate dose uniformity ratio of 3 proving the feasibility of the facility for large scale radiation processing of food commodities. (author)

Communication: practical and rigorous reduction of the many-electron quantum mechanical Coulomb problem to O(N(2/3)) storage.

Science.gov (United States)

Pederson, Mark R

2015-04-14

It is tacitly accepted that, for practical basis sets consisting of N functions, solution of the two-electron Coulomb problem in quantum mechanics requires storage of O(N(4)) integrals in the small N limit. For localized functions, in the large N limit, or for planewaves, due to closure, the storage can be reduced to O(N(2)) integrals. Here, it is shown that the storage can be further reduced to O(N(2/3)) for separable basis functions. A practical algorithm, that uses standard one-dimensional Gaussian-quadrature sums, is demonstrated. The resulting algorithm allows for the simultaneous storage, or fast reconstruction, of any two-electron Coulomb integral required for a many-electron calculation on processors with limited memory and disk space. For example, for calculations involving a basis of 9171 planewaves, the memory required to effectively store all Coulomb integrals decreases from 2.8 Gbytes to less than 2.4 Mbytes.

Smith-Purcell radiation from a 50 MeV beam

Energy Technology Data Exchange (ETDEWEB)

Brownell, J.H.; Walsh, J. [Dartmouth Coll., Hanover, NH (United States). Dept. of Physics and Astronomy; Kirk, H.G.; Fernow, R.C. [Brookhaven National Lab., Upton, NY (United States). Dept. of Physics; Robertson, S.H. [Univ. of Colorado, Boulder, CO (United States). Dept. of Astrophysics and Geophysics

1996-10-01

A 50 MeV electron beam and a 1 mm period, 5{degree} blaze, echelle grating have been used to produce radiation in the mid-infrared spectral region. The emission is highly collimated and forward-directed. The intensity level in the few ps pulse (2 nJ/sr) indicates a degree of coherent enhancement.

Smith-Purcell radiation from a 50 MeV beam

International Nuclear Information System (INIS)

Brownell, J.H.; Walsh, J.; Kirk, H.G.; Fernow, R.C.; Robertson, S.H.

1996-10-01

A 50 MeV electron beam and a 1 mm period, 5 degree blaze, echelle grating have been used to produce radiation in the mid-infrared spectral region. The emission is highly collimated and forward-directed. The intensity level in the few ps pulse (2 nJ/sr) indicates a degree of coherent enhancement

Laser-Cooled Ions and Atoms in a Storage Ring

Energy Technology Data Exchange (ETDEWEB)

Kleinert, J.; Hannemann, S.; Eike, B.; Eisenbarth, U.; Grieser, M.; Grimm, R.; Gwinner, G.; Karpuk, S.; Saathoff, G.; Schramm, U.; Schwalm, D.; Weidemueller, M., E-mail: m.weidemueller@mpi-hd.mpg.de [Max-Planck-Insitut fuer Kernphysik (Germany)

2003-03-15

We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are achieved by three-dimensional laser cooling of a coasting {sup 9}Be{sup +} beam at 7.3 MeV. Laser-cooled, trapped Cs atoms are used as an ultracold precision target for the study of ion-atom interactions with a 74 MeV beam of {sup 12}C{sup 6+} ions.

Electrical behaviour of butyl acrylate/methyl methacrylate copolymer films irradiated with 1.5 MeV electron beam

Energy Technology Data Exchange (ETDEWEB)

Radwan, R.M. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), P. O. Box 29, Nasr City, Cairo (Egypt)], E-mail: redaradwan_2000@yahoo.com; Fawzy, Y.H.A. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), P. O. Box 29, Nasr City, Cairo (Egypt); El-Hag Ali, A. [Polymer Chemistry Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), P. O. Box 29, Nasr City, Cairo (Egypt)

2008-02-15

Electrical conductivity and dielectric parameters of the (BuA/MMA) copolymer films irradiated with 1.5 MeV electron beam (EB) have been studied. The samples were irradiated with different doses of the electron beam: 5, 10, 50, 125 and 200 kGy. The electrical conductivity of the samples was found to decrease as the irradiation dose increases. The temperature dependence of the direct current (dc) conductivity for unirradiated and irradiated samples has been obtained over a temperature range from 293 to 373 K. The activation energy values were calculated for all samples. Moreover, measurements of the dielectric constant, dielectric loss and alternating current (ac) conductivity were performed at a frequency range from 100 Hz to 5 MHz at room temperature. The results indicated that the EB irradiation has formed some traps in the energy gap, which reduce the movement of the charge carriers. Furthermore, a direct proportional relationship between the activation energy and the irradiation dose was estimated in two regions: below and above the glass transition temperature of the polymer. Dipole relaxation was observed in the samples, and the dose effect was found to shift this relaxation towards higher frequencies.

Study of LiF:Mg,Ti and CaSO4:Dy dosimeters TL response to electron beams of 6 MeV applied to radiotherapy using PMMA and solid water phantoms

International Nuclear Information System (INIS)

Bravim, A.; Sakuraba, R.K.; Cruz, J.C.; Campos, L.L.

2011-01-01

The performance of CaSO 4 :Dy and LiF:Mg,Ti dosimeters to electron beams applied to radiotherapy was investigated. The TL response of these dosimeters was studied for 6 MeV electron beams using PMMA and Solid Water (SW) phantoms. The dosimeters were previously separated in groups according to their TL individual sensitivities to 60 Co gamma-radiation in air under electronic equilibrium conditions. After that, they were irradiated with 6 MeV electron doses of 0.1, 0.5, 1, 5 and 10 Gy using a linear accelerator Clinac 2100C Varian of Hospital Israelita Albert Einstein – HIAE. The electron beam irradiations were performed using a 10 × 10 cm 2 field size, 100 cm source-phantom surface distance and the dosimeters were positioned at the depth of maximum dose (1.2 cm). The TL readings were carried out between 24 and 32 h after irradiation using a Harshaw 3500 TL reader. The TL dose–response of both type of dosimeters and phantoms presented linear behavior on the electron dose range from 0.1 to 5 Gy CaSO 4 :Dy dosimeter is 21 times more sensitive than LiF:Mg,Ti, dosimeter commonly used in clinical dosimetry. The obtained results indicate that the performance of CaSO 4 :Dy dosimeters is similar to LiF:Mg,Ti dosimeters and this material can be an alternative dosimetric material to be used to clinical electron beams dosimetry.

Spin decoherence in electron storage rings. More from a simple model

Energy Technology Data Exchange (ETDEWEB)

Barber, D.P. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Heinemann, K. [The Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Mathematics and Statistics

2015-06-15

This is an addendum to the paper ''Some models of spin coherence and decoherence in storage rings'' by one of the authors (K. Heinemann, DESY Report 97-166 (1997)), in which spin diffusion in simple electron storage rings is studied. In particular, we illustrate in a compact way, namely that the exact formalism of this article delivers a rate of depolarisation which can differ from that obtained by the conventional treatments of spin diffusion which rely on the use of the derivative ∂n/∂η. As a vehicle we consider a ring with a Siberian Snake and electron polarisation in the plane of the ring. For this simple setup with its one-dimensional spin motion, we avoid having to deal directly with the Bloch equation for the polarisation density. Our treatment, which is deliberately pedagogical, shows that the use of ∂n/∂η provides a very good approximation to the rate of spin depolarisation in the model considered. But it then shows that the exact rate of depolarisation can be obtained by replacing ∂n/∂η by another derivative, while giving a heuristic justification for the new derivative.

Controlling the optical field chaos in storage ring free-electron lasers

International Nuclear Information System (INIS)

Wang Wenjie

1995-01-01

The controlling of optical field chaos in a storage ring free-electron laser oscillator is discussed by using a phenomenal model. A novel method (which is called the 'beating method') of controlling chaos in a nonlinear dynamical system described by non-autonomous ordinary differential equations was developed. The result of theoretical analysis and numerical simulation shows that the optical field chaos in a storage ring free-electron laser oscillator can be suppressed and a periodic laser intensity can be obtained when a weak periodic control field is added to the optical cavity. The validity of this method of eliminating chaos is confirmed by the fact that the leading Lyapunov characteristic exponent of the system changes from a positive real number to a negative one. A further research is carried out, and it is found that only when the period of the control field equals to an integral multiple of that of the gain modulation in the optical cavity can the optical field chaos be suppressed. This means that the 'beating method' of controlling chaos is a kind of resonant method. A way to determine the 'best beating position' in the phase trajectory has also been obtained

Irradiation of potatoes - after cooking darkening - Fusarium susceptibility during storage. Part of a coordinated programme on the shelf-life extension of irradiated fruits and vegetables

International Nuclear Information System (INIS)

Sparenberg, H.

1977-10-01

The after-cooking discolouration of Bintje potatoes, cultivated from five different origins in the Netherlands, irradiated by gamma rays or electron was assessed. For comparison, samples of unirradiated potatoes treated by IPC/CIPC sprout inhibitor were also studied. Sprout inhibition and rotting of potatoes treated by different methods were also investigated. It appears that there exist differences in the degree of after-cooking discolouration of potatoes harvested from different origins. Slight discolouration was observed in electron-irradiated potatoes, those exposed to 0.5MeV showed less greying than those treated by 1MeV. Potatoes treated with IPC/CIPC showed the least, and those treated by gamma rays showed the strongest after-cooking darkening. No sprouting occurred in gamma irradiated samples. Sprouting of IPC/CIPC treated samples was minimal during storage but was enhanced after reconditioning. Those treated by electrons showed severe sprouting. Two to 4 weeks reconditioning at 15 0 C of irradiated potatoes, previously held at 7 - 10 0 C for several months, did not reduce the degree of after-cooking discolouration

Absence of large M1 excitations in 208Pb below 8.4 MeV

International Nuclear Information System (INIS)

Holt, R.J.; Jackson, H.E.; Laszewski, R.M.; Specht, J.R.

1979-01-01

A very high-resolution measurement of the 208 Pb(γ-n 0 ) 207 Pb reaction was performed by use of the unique picopulse and the newly-installed neutron flight paths at the ANL electron linac facility. The 7.99-MeV resonance (E/sub n/ = 610 keV) exhibited a level-level interference pattern with the 7.98-MeV, E1 resonance in 208 Pb. 1 figure

An electrostatic storage ring for low kinetic energy electron collisions

Energy Technology Data Exchange (ETDEWEB)

Reddish, T J; Tessier, D R; Sullivan, M R; Thorn, P A [Department of Physics, University of Windsor, Windsor, N9B 3P4 (Canada); Hammond, P; Alderman, A J [School of Physics, CAMSP, University of Western Australia, Perth WA 6009 (Australia); Read, F H [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2009-11-01

The criteria are presented for stable multiple orbits of charged particles in a race-track shaped storage ring and applied to an electrostatic system consisting of two hemispherical deflector analyzers (HDA) connected by two separate sets of cylindrical lenses. The results of charged particle simulations and the formal matrix theory, including aberrations in the energy-dispersive electrostatic 'prisms', are in good agreement with the observed experimental operating conditions for this Electron Recycling Spectrometer (ERS).

η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV

Science.gov (United States)

Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.

2010-11-01

The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.

Thermoluminescence spectra of natural CaF2 irradiated by 10MeV electrons

International Nuclear Information System (INIS)

Manrique, J.; Angulo, S.; Pardo, M.P.; Gastesi, R.; De la Cruz, A.; Perez, A.

2006-01-01

The spectra of thermoluminescence from natural and electron-irradiated fluorite in the 350-800nm spectral range were studied between room temperature and 500 o C. The sample came from Asturias (Spain) and was analyzed by X-ray diffractometry and inductively coupled plasma-mass spectrometry. Glow peaks appeared at 115, 205 and 310 o C. Main emissions occurred at 475, 575, 650 and 745nm, attributed to the Dy +3 ion and, at 410nm, from electron-hole recombination. The fractional glow technique and the general order model were employed to study the emission at 575nm in detail. The results showed that the 115 and 205 o C glow peaks originate at traps with activation energies of 1.6 and 1.9eV, respectively, on the kinetic order of 1.5 and 1.3 and frequency factors of 1.7x10 19 and 2.7x10 19 s -1 , respectively. Spectrally resolved fading produced by storage was observed, and we concluded that the emission was due to large defect complexes. The dosimetric study showed that there was saturation at doses higher than 2kGy

6 MeV RF Linac for cargo scanning and industrial radiography

International Nuclear Information System (INIS)

2017-01-01

RF Linac-based X-ray sources are very widely used for cargo-scanning and industrial X-ray radiography applications. A 6 MeV on-axis coupled-cavity S-band RF linac has been designed, developed and tested successfully at Electron Beam Centre, Navi Mumbai. This facility falls under the purview of BARC Safety Council, which has conducted safety reviews and awarded regulatory clearances for the operation of the linac system. This paper outlines the salient features of the 6 MeV linac, its safety aspects and test results. A brief history of regulatory aspects is also presented

Film dosimetric investigations on the exposure of the eyes in radiation therapy of the head and the cervical region with fast electrons up to 17 MeV

International Nuclear Information System (INIS)

Stecher, M.; Eichler, R.

1978-01-01

Dose distributions in irradiating tumors of the head and the cervical region with 17 MeV electrons were determined in a phantom with films. From the isodoses obtained it can be derived how radiation reaches the eyes and how the dose to the eyes is influenced. Guidance is provided for the reduction of the dose to the eye. (author)

Effective dose per unit fluence calculated for adults and a 7 year old girl in broad antero-posterior beams of monoenergetic electrons of 0.1 to 10 MeV

International Nuclear Information System (INIS)

Schultz, F.W.; Zoetelief, J.

1997-01-01

For broad antero-posterior beams of monoenergetic (0.1-10 MeV) electrons, organ doses per unit fluence were computed through Monte Carlo simulation with reference to male and female adult and a 7 year old girl. Effective doses (E) per unit fluence were calculated for the three phantoms and for an average adult. E increases from about 8 x 10 -14 to about 1.2 x 10 -10 Sv.cm 2 with increasing electron energy. Uncertainties were (often much) better than 6% for the adults, and 18% for the child. E as calculated for the average adult may be used for both males and females as under- or overestimations stay within 25% from E for the average adult. The child's radiation risk is underestimated for electron energies in the range of 0.6 to 3 MeV. This underestimation up to a factor of about 20 is unacceptable for radiological protection purposes. The present results were compared with literature data on operational quantities associated with radiation hazard from weakly penetrating radiation. Neither directional nor personal dose equivalent appears to be a realistic quantity in this case. Both would yield an unnecessarily large safety factor for radiological protection. (author)

A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

CERN Document Server

Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

2005-01-01

American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.

Radiation damage to electronic components

International Nuclear Information System (INIS)

Battisti, S.; Bossart, R.; Schoenbacher, H.; Van de Voorde, M.

1975-01-01

Characteristic properties are presented of some 40 different electronic components (resistors, capacitors, diodes, transistors, and integrated circuits) which were irradiated in a nuclear reactor up to 1015 n/cm 2 (E > 1 MeV). Complete circuits (e.g. RF amplifiers and detectors, mixers, differential amplifiers, voltage-to-frequency converters, oscillators, power supplies) were irradiated near the CERN Intersecting Storage Rings up to 106 rad(RPL) (dose measured with radiophotoluminescent dosimeters) under simulated operational conditions. Representative measured parameters, such as resistance, capacitance, forward voltage, reverse current, toggle frequencies, are given in graphs as a function of radiation dose. The results are discussed in detail and lead to the over-all conclusion that the operation of electronic components and circuits is seriously affected by radiation environments with doses in the order of 10 13 n/cm 2 or 10 4 rad(RPL); some components and circuits fail completely at doses of 10 14 n/cm 2 or 10 5 rad(RPL). (Author)

NAFFS: network attached flash file system for cloud storage on portable consumer electronics

Science.gov (United States)

Han, Lin; Huang, Hao; Xie, Changsheng

Cloud storage technology has become a research hotspot in recent years, while the existing cloud storage services are mainly designed for data storage needs with stable high speed Internet connection. Mobile Internet connections are often unstable and the speed is relatively low. These native features of mobile Internet limit the use of cloud storage in portable consumer electronics. The Network Attached Flash File System (NAFFS) presented the idea of taking the portable device built-in NAND flash memory as the front-end cache of virtualized cloud storage device. Modern portable devices with Internet connection have built-in more than 1GB NAND Flash, which is quite enough for daily data storage. The data transfer rate of NAND flash device is much higher than mobile Internet connections[1], and its non-volatile feature makes it very suitable as the cache device of Internet cloud storage on portable device, which often have unstable power supply and intermittent Internet connection. In the present work, NAFFS is evaluated with several benchmarks, and its performance is compared with traditional network attached file systems, such as NFS. Our evaluation results indicate that the NAFFS achieves an average accessing speed of 3.38MB/s, which is about 3 times faster than directly accessing cloud storage by mobile Internet connection， and offers a more stable interface than that of directly using cloud storage API. Unstable Internet connection and sudden power off condition are tolerable, and no data in cache will be lost in such situation.

Liquid argon as an electron/photon detector in the energy range of 50 MeV to 2 GeV: a Monte Carlo investigation

International Nuclear Information System (INIS)

Goodman, M.S.; Denis, G.; Hall, M.; Karpovsky, A.; Wilson, R.; Gabriel, T.A.; Bishop, B.L.

1980-12-01

Monte Carlo techniques which have been used to study the characteristics of a proposed electron/photon detector based on the total absorption of electromagnetic showers in liquid argon have been investigated. The energy range studied was 50 MeV to 2 GeV. Results are presented on the energy and angular resolution predicted for the device, along with the detailed predictions of the transverse and longitudinal shower distributions. Comparisons are made with other photon detectors, and possible applications are discussed

s-wave threshold in electron attachment - Observations and cross sections in CCl4 and SF6 at ultralow electron energies

Science.gov (United States)

Chutjian, A.; Alajajian, S. H.

1985-01-01

The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data.

Recovery of Mice Thymus after X-Rays and 15 MeV Electrons. Comparative Study of the Cell Population Using Tritiated Thymidine; Regeneration du Thymus chez la Souris Apres Irradiation par des Rayons X et des Electrons de 15 MeV. Etude Comparee de la Population Cellulaire a l'Aide de Thymidine Tritiee; 0412 043e 0414 ; Restauracion del Timo de los Ratones Despues de Irradiarlo con Rayos X y Electrones de 15 MeV. Estudio Comparativo de la Poblacion Celular Utilizando Timidina Tritiada

Energy Technology Data Exchange (ETDEWEB)

Biagini, C.; Paleani Vettori, P. G.; Zito Bignami, R. [Istituto di Radiologia dell' Universita and Comitato Nazionale per l' Energia Nucleare, Rome (Italy)

1962-02-15

The mechanism of recovery from acute radiation damage may be studied by using two types of radiations which show small differences in the acute RBE, and large differences of effect in the recovery phase. As observed in previous experiments, this condition is achieved by comparing the effects in mammals of 150 kVpX-rays and those of 15 MeV electrons produced by a betatron. The present paper presents the results of an autoradiographic study on the behaviour of single classes of cells of the mice thymus by use of tritiated thymidine as DNA precursor. Data are related to the modifications in distribution of the size categories of the cell population and to organ weight. After irradiation the large to small cell ratio is increased ; the incorporation of tritiated thymidine is reduced in large and in small lymphocytes. In the acute phase of effect, no significant differences between X-rays and electrons are observed in cell sizes and in labelling of large cells. A relative change appears in labelling of small cells, a fact that may have a relation with the RBE values of fast electrons, in agreement with the organ weight data. In the recovery, less differentiated cells show active proliferation, but the percentage of mature lymphocytes remains small. After exposure to 15 MeV electrons proliferative activity of large cells is greater, according to the time curves of the thymic atrophy. From the above results, regenerative potentiality appears related to the degree of damage on primitive cells; for a given dose, the latter appears larger after X-rays than after electrons. (author) [French] On peut etudier le mecanisme de la guerison de radiolesions aiguees en utilisant deux types de rayonnements, qui ont a peu pres le meme EBR, mais dont les effets sont tres differents pendant la phase de regeneration. Comme les auteurs l'ont observe dans des experiences anterieures, une bonne methode consiste a comparer, chez des mammiferes, les effets des rayons X de 150 kVp avec ceux des

Sustained performance of 8 MeV Microtron

International Nuclear Information System (INIS)

Sanjeev, Ganesh

2012-01-01

Energetic electrons and intense bremsstrahlung radiation from 8 MeV Microtron are being utilized in variety of collaborative research programs in radiation physics and allied sciences involving premier institutions of the country and sister universities of the region. The first of its kind electron accelerator in the country, set up at Mangalore University in collaboration with RRCAT Indore and BARC Mumbai, has been facilitating researchers since its inception with its inherent simplicity, ease of construction, low cost and excellent beam quality. A bird's eye view on the reliable aspects of the machine, efforts behind the continuous operation of the accelerator and important applications of the accelerator in physical and biological sciences are presented in this paper.

Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

Energy Technology Data Exchange (ETDEWEB)

Weathersby, S. P.; Brown, G.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K., E-mail: lrk@slac.stanford.edu; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); and others

2015-07-15

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

Modification of the microstructure and electronic properties of rutile TiO_2 thin films with 79 MeV Br ion irradiation

International Nuclear Information System (INIS)

Rath, Haripriya; Dash, P.; Singh, U.P.; Avasthi, D.K.; Kanjilal, D.; Mishra, N.C.

2015-01-01

Modifications induced by 79 MeV Br ions in rutile titanium dioxide thin films, synthesized by dc magnetron sputtering are presented. Irradiations did not induce any new XRD peak corresponding to any other phase. The area and the width of the XRD peaks were considerably affected by irradiation, and peaks shifted to lower angles. But the samples retained their crystallinity at the highest fluence (1 × 10"1"3 ions cm"−"2) of irradiation even though the electronic energy loss of 79 MeV Br ions far exceeds the reported threshold value for amorphization of rutile TiO_2. Fitting of the fluence dependence of the XRD peak area to Poisson equation yielded the radius of ion tracks as 2.4 nm. Ion track radius obtained from the simulation based on the thermal spike model matches closely with that obtained from the fluence dependence of the area under XRD peaks. Williamson–Hall analysis of the XRD spectra indicated broadening and shifting of the peaks are a consequence of irradiation induced defect accumulation leading to microstrains, as was also indicated by Raman and UV–Visible absorption study.

Unified 1.9...4.0 MeV linear accelerators with interchangeable accelerating structures for customs inspection

International Nuclear Information System (INIS)

Budtov, A.A.; Klinov, A.P.; Krestianinov, A.S.

2004-01-01

A series of compact linear electron accelerators for 1.9, 2.5 and 4.0 MeV equipped with a local radiation shielding has been designed and constructed in the NPK LUTS, the D.V.Efremov Institute (NIIEFA). The accelerators are intended for mobile facilities used for customs inspection of large-scale containers. Results of optimizing calculations of irradiator parameters and electron dynamics, verified under accelerators testing, are presented in the report. The main design approaches allowing the construction of unified accelerators with interchangeable accelerating structures for energies in the range of 1.9...4.0 MeV are also given

Observation of optical Smith-Purcell radiation at an electron beam energy of 855 MeV

International Nuclear Information System (INIS)

Kube, G.; Backe, H.; Euteneuer, H.; Grendel, A.; Hagenbuck, F.; Hartmann, H.; Kaiser, K.H.; Lauth, W.; Schoepe, H.; Wagner, G.; Walcher, Th.; Kretzschmar, M.

2002-01-01

Smith-Purcell radiation, generated when a beam of charged particles passes close to the surface of a diffraction grating, has been studied in the visible spectral range at wavelengths of 360 and 546 nm with the low emittance 855 MeV electron beam of the Mainz Microtron MAMI. The beam focused to a spot size of 4 μm (full width at half maximum) passed over optical diffraction gratings of echelle profiles with blaze angles of 0.8 deg., 17.27 deg., and 41.12 deg. and grating periods of 0.833 and 9.09 μm. Taking advantage of the specific emission characteristics of Smith-Purcell radiation a clear separation from background components, such as diffracted synchrotron radiation from upstream beam optical elements and transition radiation, was possible. The intensity scales with a modified Bessel function of the first kind as a function of the distance between electron beam and grating surface. Experimental radiation factors have been determined and compared with calculations on the basis of Van den Berg's theory [P.M. Van den Berg, J. Opt. Soc. Am. 63, 689 (1973)]. Fair agreement has been found for gratings with large blaze angles while the measurement with the shallow grating (blaze angle 0.8 deg.) is at variance with this theory. Finally, the optimal operational parameters of a Smith-Purcell radiation source in view of already existing powerful undulator sources are discussed

MeV ion beam interaction with polymer films containing cross-linking agents

International Nuclear Information System (INIS)

Evelyn, A. L.

1999-01-01

Polymer films containing cross linking enhancers were irradiated with MeV alpha particles to determine the effects of MeV ion beam interaction on these materials. The contributed effects from the electronic and nuclear stopping powers were separated by irradiating stacked thin films of polyvinyl chloride (PVC), polystyrene (PS) and polyethersulfone (PES). This layered system allowed most of the effects of the electronic energy deposited to be experienced by the first layers and the last layers to receive most of the effects of the nuclear stopping power. RGA, Raman microprobe analysis, RBS and FTIR measured changes in the chemical structures of the irradiated films. The characterization resolved the effects of the stopping powers on the PVC, PS and PES and the results were compared with those from previously studied polymers that did not contain any cross linking agents

Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures

Energy Technology Data Exchange (ETDEWEB)

Willems van Beveren, L. H., E-mail: laurensw@unimelb.edu.au; Bowers, H.; Ganesan, K.; Johnson, B. C.; McCallum, J. C.; Prawer, S. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Liu, R. [SIMS Facility, Office of the Deputy-Vice Chancellor (Research and Development) Western Sydney University, Locked Bag 1797, Penrith, New South Wales 2751 (Australia)

2016-06-14

Boron implantation with in-situ dynamic annealing is used to produce highly conductive sub-surface layers in type IIa (100) diamond plates for the search of a superconducting phase transition. Here, we demonstrate that high-fluence MeV ion-implantation, at elevated temperatures avoids graphitization and can be used to achieve doping densities of 6 at. %. In order to quantify the diamond crystal damage associated with implantation Raman spectroscopy was performed, demonstrating high temperature annealing recovers the lattice. Additionally, low-temperature electronic transport measurements show evidence of charge carrier densities close to the metal-insulator-transition. After electronic characterization, secondary ion mass spectrometry was performed to map out the ion profile of the implanted plates. The analysis shows close agreement with the simulated ion-profile assuming scaling factors that take into account an average change in diamond density due to device fabrication. Finally, the data show that boron diffusion is negligible during the high temperature annealing process.

The HERMES polarized hydrogen and deuterium gas target in the HERA electron storage ring

International Nuclear Information System (INIS)

Airapetian, A.; Akopov, N.; Akopov, Z.

2005-01-01

The HERMES hydrogen and deuterium nuclear-polarized gas targets have been in use since 1996 with the polarized electron beam of HERA at DESY to study the spin structure of the nucleon. Polarized atoms from a Stern-Gerlach Atomic Beam Source are injected into a storage cell internal to the HERA electron ring. Atoms diffusing from the center of the storage cell into a side tube are analyzed to determine the atomic fraction and the atomic polarizations. The atoms have a nuclear polarization, the axis of which is defined by an external magnetic holding field. The holding field was longitudinal during 1996-2000, and was changed to transverse in 2001. The design of the target is described, the method for analyzing the target polarization is outlined, and the performance of the target in the various running periods is presented

The HERMES polarized hydrogen and deuterium gas target in the HERA electron storage ring

International Nuclear Information System (INIS)

Airapetian, A.; Akopov, N.; Akopov, Z.; Peking University, Beijing

2004-08-01

The HERMES hydrogen and deuterium nuclear-polarized gas targets have been in use since 1996 with the polarized electron beam of HERA at DESY to study the spin structure of the nucleon. Polarized atoms from a Stern-Gerlach Atomic Beam Source are injected into a storage cell internal to the HERA electron ring. Atoms diffusing from the center of the storage cell into a side tube are analyzed to determine the atomic fraction and the atomic polarizations. The atoms have a nuclear polarization, the axis of which is defined by an external magnetic holding field. The holding field was longitudinal during 1996-2000, and was changed to transverse in 2001. The design of the target is described, the method for analyzing the target polarization is outlined, and the performance of the target in the various running periods is presented. (orig.)

Electron beam irradiation effect on GaN HEMT

International Nuclear Information System (INIS)

Lou Yinhong; Guo Hongxia; Zhang Keying; Wang Yuanming; Zhang Fengqi

2011-01-01

In this work, GaN HEMTs (High Electron Mobility Transistor) were irradiated by 0.8 and 1.2 MeV electron beams, and the irradiation effects were investigated. The results show that the device damage caused by 0.8 MeV electrons is more serious than that by 1.2 MeV electrons. Saturation drain current increase and threshold voltage negative shift are due to trapped positive charge from ionization in the AlGaN layer and N, Ga vacancy from non-ionizing energy loss in the GaN layer. Electron traps and trapped positive charges from non-ionizing in the AlGaN layer act as trap-assisted-tunneling centers that increase the gate leakage current.(authors)

Evidence for two narrow pp resonances at 2020 MeV and 2200 MeV

CERN Document Server

Benkheiri, P; Bouquet, B; Briandet, P; D'Almagne, B; Dang-Vu, C; De Rosny, G; Eisenstein, B I; Ferrer, A; Fleury, P; Grossetête, B; Irwin, G; Jacholkowski, A; Lahellec, A; Nguyen, H; Petroff, P; Richard, F; Rivet, P; Roudeau, P; Rougé, A; Rumpf, M; Six, J; Thénard, J M; Treille, D; Volte, A; Yaffe, D; Yiou, T P; Yoshida, H

1977-01-01

From the study of the reaction pi /sup -/p to p/sub F/pp pi /sup -/ using a fast proton (p/sub F/) trigger device in the CERN Omega spectrometer, the authors find evidence for two narrow pp states produced mainly in association with a Delta degrees (1232) and a N degrees (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M/sub 1/=2020+or-3 MeV, Gamma /sub 1 /=24+or-12 MeV and M/sub 2/=2204+or-5 MeV, Gamma /sub 2/=16/sub -16 //sup +20/ MeV. The data are consistent with a small production of the narrow approximately 1935 MeV resonance already reported. Production cross sections for these new pp resonances are given. (8 refs).

Progress in measurement and understanding of beam polarization in electron positron storage rings

International Nuclear Information System (INIS)

Barber, D.P.; Bremer, H.D.; Kewisch, J.; Lewin, H.C.; Limberg, T.; Mais, H.; Ripken, G.; Rossmanith, R.; Schmidt, R.

1983-07-01

A report is presented on the status of attempts to obtain and measure spin polarization in electron-positron storage rings. Experimental results are presented and their relationship to predictions of calculations discussed. Examples of methods for decoupling orbital and spin motion and thus improving polarization are discussed. (orig.)

A sub-50meV spectrometer and energy filter for use in combination with 200kV monochromated (S)TEMs.

Science.gov (United States)

Brink, H A; Barfels, M M G; Burgner, R P; Edwards, B N

2003-09-01

A high-energy resolution post-column spectrometer for the purpose of electron energy loss spectroscopy (EELS) and energy-filtered TEM in combination with a monochromated (S)TEM is presented. The prism aberrations were corrected up to fourth order using multipole elements improving the electron optical energy resolution and increasing the acceptance of the spectrometer for a combination of object area and collection angles. Electronics supplying the prism, drift tube, high-tension reference and critical lenses have been newly designed such that, in combination with the new electron optics, a sub-50 meV energy resolution has been realized, a 10-fold improvement over past post-column spectrometer designs. The first system has been installed on a 200 kV monochromated TEM at the Delft University of Technology. Total system energy resolution of sub-100 meV has been demonstrated. For a 1s exposure the resolution degraded to 110 meV as a result of noise. No further degradation in energy resolution was measured for exposures up to 1 min at 120 kV. Spectral resolution measurements, performed on the pi* peak of the BN K-edge, demonstrated a 350 meV (FWHM) peak width at 200 kV. This measure is predominantly determined by the natural line width of the BN K-edge.

CHEER

International Nuclear Information System (INIS)

Conetti, S.; Edwards, K.W.; Hemingway, R.J.; Johnson, D.E.; McKeown, J.; Mills, F.; Norum, B.; Schriber, S.; Servranckx, R.; Skuja, A.

1980-01-01

The Institute of Particle Physics (IPP) in Canada have received funds from the Natural Sciences and Engineering Research Council (NSERC) to pursue a study which looks at the feasibility of adding an external electron storage ring at one of the long straight sections of the Tevatron. The machine, as currently configured, has a 300 MeV Linac injector, a 300 MeV positron/electron accumulator ring (PEAR), a 2 GeV booster synchrotron, and a 10 GeV storage ring (CHEER) holding 120 mA of either electrons of positrons. (Auth.)

Limits on the production of large transverse momentum direct photons deduced from the measurement of low-mass electron pairs

International Nuclear Information System (INIS)

Cobb, J.H.; Iwata, S.; Palmer, R.B.; Rahm, D.C.; Rehak, P.; Stumer, I.; Fabjan, C.W.; Fowler, E.; Mannelli, I.; Mouzourakis, P.; Nakamura, K.; Nappi, A.; Willis, W.J.; Goldberg, M.; Horwitz, N.; Moneti, G.C.; Lankford, A.J.; Kourkoumelis, C.

1978-01-01

The hadronic production of electron pairs with masses between 200 and 500 MeV and large transverse momentum has been measured at the CERN Intersecting Storage Rings (ISR). The expected relation between low-mass electron pairs and real photons is used to determine the direct hadronic production of photons. Contrary to indications from some previous experiments, the observed spectrum is consistent with expectations from the decay of known mesons, and leads to a value for the ratio of direct photons to π 0 of γ/π 0 =(0.55+-0.92)% for 2 = 55 GeV. (Auth.)

Molecular effects in carbon K-shell Auger-electron production by 0.6-2.0 MeV protons and extraction of an atomic cross section

International Nuclear Information System (INIS)

McDaniel, F.D.; Lapicki, G.

1987-01-01

Carbon K-shell Auger-electron production cross sections are reported for 0.6-2.0 MeV protons incident on CH 4 (methane), C 2 H 2 (acetylene), C 2 H 4 (ethylene), C 2 H 6 (ethane), n-C 4 H 10 (normal butane), i-C 4 H 10 (isobutane), C 6 H 6 (benzene), CO (carbon monoxide), and CO 2 (carbon dioxide). A constant-energy mode 45 0 parallel-plate electrostatic analyzer was used for detection of Auger electrons. The carbon KLL Auger-electron cross sections for all molecules were found to be lower than that found for CH 4 by 9-23%. All carbon KLL Auger-electron data could be brought into agreement when corrected for the chemical shift of the carbon K-shell binding energy in molecules and for intramolecular scattering. KLL Auger-electron production cross sections are compared to first Born and ECPSSR theories and show good agreement with both after the chemical shift of the carbon K-shell binding energy in molecules and the effects of intramolecular scattering are considered. (orig.)

Positron probing of open vacancy volume of phosphorus-vacancy complexes in float-zone n-type silicon irradiated by 0.9-MeV electrons and by 15-MeV protons

Energy Technology Data Exchange (ETDEWEB)

Arutyunov, Nikolay [Department of Physics, Martin Luther University Halle (Germany); Ioffe Physico-Technical Institute, St. Petersburg (Russian Federation); Institute of Ion-Plasma and Laser Technologies (Institute of Electronics), Tashkent (Uzbekistan); Emtsev, Vadim; Oganesyan, Gagik [Ioffe Physico-Technical Institute, St. Petersburg (Russian Federation); Elsayed, Mohamed [Department of Physics, Martin Luther University Halle (Germany); Faculty of Science, Department of Physics, Minia University (Egypt); Krause-Rehberg, Reinhard [Department of Physics, Martin Luther University Halle (Germany); Abrosimov, Nikolay [Leibniz Institute for Crystal Growth, Berlin (Germany); Kozlovski, Vitalii [St. Petersburg State Polytechnical University (Russian Federation)

2017-07-15

For the first time the samples, cut from the same wafer of crystals of float-zone silicon, n-FZ-Si(P) and n-FZ-Si(Bi), were subjected to irradiation with 0.9-MeV electrons and 15-MeV protons at RT for studying them by low-temperature positron annihilation lifetime spectroscopy. Measurements of Hall effect have been used for the materials characterization. The discussion is focused on the open vacancy volume (V{sub op}) of the thermally stable group-V-impurity-vacancy complexes comprising the phosphorus atoms; the bismuth-related vacancy complexes are briefly considered. The data of positron probing of PV pairs (E-centers), divacancies, and the thermally stable defects in the irradiated n-FZ-Si(P) materials are compared. Beyond a reliable detecting of the defect-related positron annihilation lifetime in the course of isochronal annealing at ∝ 500 C, the recovery of concentration of phosphorus-related shallow donor states continues up to ∝650-700 C. The open vacancy volumes V{sub op} to be characterized by long positron lifetimes Δτ{sub 2} ∝271-289 ps in (gr.-V-atom)-V{sub op} complexes are compared with theoretical data available for the vacancies, τ(V{sub 1}), and divacancies, τ(V{sub 2}). The extended semi-vacancies, 2V{sub s-ext}, and relaxed vacancies, 2V{sub inw}, are proposed as the open volume V{sub op} in (gr.-V-atom)-V{sub op} complexes. It is argued that at high annealing temperature the defect P{sub s}-V{sub op}-P{sub s} is decomposed. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Rf systems for high-energy e/sup /minus//e/sup /plus// storage rings

International Nuclear Information System (INIS)

Allen, M.A.; Wilson, P.B.

1974-01-01

Electron or positron beams in a storage ring radiate electromagnetic energy at a rate proportional to the fourth power of the recirculating energy, and this loss must be supplied by an rf system. Furthermore, a substantial overvoltage is required to contain the stored beam against losses due to quantum fluctuations in the emitted photons. As an example, an improvement program, SPEAR II, is now underway to increase the energy of the SPEAR ring to 4.5 GeV. At this energy, the radiation loss per turn is 2.8 MeV, and to maintain a reasonable lifetime against quantum fluctuations, a peak voltage of 7.5 MeV is required. Thus, the SPEAR II rf system is similar to a continuously-operating 7.5 MeV linear accelerator. Furthermore, the available straight-section space in the ring which is suitable for containing the accelerating structures is limited, and this means that a cavity design must be sought with a high shunt impedance per losses will be held to a reasonable level. In the case of SPEAR, about 9 meters of straight section space is available for accelerating cavities, requiring a gradient of close to 1 MV per meter. The PEP 15-GeV ring would require peak accelerating voltages of around 50 MV, with about 60 meters of straight-section space available for accelerating structures. 8 refs

Yields of Radionuclides Created by Photonuclear Reactions on Be, C, Na, Cl, and Ge, Using Bremsstrahlung of 150-MeV Electrons

International Nuclear Information System (INIS)

Dickens, J.K.

2001-01-01

The bremsstrahlung created by 150-MeV electrons impinging on a tantalum radiator was used to study photonuclear reactions on samples containing Be, C, Na, Cl and Ge. For Ge fifteen radioisotopes, ranging in half life between 2.6 min and 271 days, and in mass between 65 and 75, were obtained in sufficient amount to determine their yields quantitatively using known decay gamma-rays. Special equipment is described which was developed to create the bremsstrahlung using a beam-sharing mode, while minimizing the neutron flux on the sample. Relative production rates were determined. These were analyzed to provide absolute average cross sections for production of three reactions

Coherent x-rays and vacuum-ultraviolet radiation from storage-ring-based undulators and free electron lasers

International Nuclear Information System (INIS)

Kim, K.J.

1984-12-01

High-brightness electron storage rings and permanent-magnet technology provide a basis for the development of coherent radiation in the 10- to 1000-A (xuv) spectral range. The most assured route to the production of coherent x-rays and vuv is the simple interaction between properly constrained relativistic electrons and permanent-magnet undulators, a subject that is already well understood and where technology is well advanced. Other techniques are less well developed, but with increasing degrees of technical challenge they will provide additional coherence properties. Transverse optical klystrons (TOKs) provide an opportunity for additional coherence at certain harmonics of longer-wavelength lasers. Free electron lasers (FELs) extend coherence capabilities substantially through two possible routes: one is the development of suitable mirror coatings. Both FEL techniques would provide vuv radiation and soft x rays with extremely narrow spectral content. Research on all of these techniques (undulators, TOKs, and FELs) is possible in a single facility based on a high-brightness electron storage ring, referred to herein as a Coherent xuv Facility (CXF). Individual items from the report were prepared separately for the data base

ANL stochastic-cooling experiments using the FNAL 200-MeV cooling ring

International Nuclear Information System (INIS)

Hogrefe, R.L.; Kellogg, K.D.; Konecny, R.S.; Kramer, S.L.; Simpson, J.D.; Suddeth, D.E.; Hardek, T.W.

1981-01-01

Studies of stochastic momentum cooling are being conducted on the FNAL 200-MeV Storage Ring. The specific goal of the activity is to establish confidence in the theory and simulation methods used to describe the cooling process, and to develop techniques and devices suitable for use in the antiproton-accumulation scheme now planned for construction at FNAL. A summary of the activity, including hardware design, results of experiments, comparison with theory, and implications for the antiproton accumulator are presented

Anisotropic deformation of metallo-dielectric core-shell colloids under MeV ion irradiation

International Nuclear Information System (INIS)

Penninkhof, J.J.; Dillen, T. van; Roorda, S.; Graf, C.; Blaaderen, A. van; Vredenberg, A.M.; Polman, A.

2006-01-01

We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO 2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks

Anisotropic deformation of metallo-dielectric core shell colloids under MeV ion irradiation

Science.gov (United States)

Penninkhof, J. J.; van Dillen, T.; Roorda, S.; Graf, C.; van Blaaderen, A.; Vredenberg, A. M.; Polman, A.

2006-01-01

We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks.

A compact SR light source for x-ray lithography 'AURORA'

International Nuclear Information System (INIS)

Toba, Y.

1990-01-01

A compact synchrotron radiation (SR) light source called AURORA has been developed for industrial use. It is specially designed for X-ray lithography. AURORA consists of a storage ring, injector microtron and SR light beam lines. The storage ring is a superconducting single magnet machine, designed to accelerate a 150 MeV electron beam to 650 MeV and to store as high as 300 mA current. The injector is a racetrack microtron (RTM) producing a pulsed 150 MeV beam. As many as 16 SR light beam channels are available for AURORA. Prototypes of the storage ring and RTM are constructed, and beam commissioning is performed. A hundred and fifty MeV electron beam of a pulsed current 10 μA from the RTM is successfully injected to the ring and accelerated to 600 MeV and 10 mA current stored with a lifetime of more than 20 hours. The half-integer method investigated is shown to work well with the injection efficiency being found to be very high. Improvement of the design is now under way. (N.K.)

Clinical meaning of radiodermatitis considering the surface dose of supervoltage electron beam

Energy Technology Data Exchange (ETDEWEB)

Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Rikimaru, S; Kakishita, M; Kuranishi, M

1975-12-01

In our experience using supervoltage betatron electron beam, the skin surface dose of the electron decreased when the energy became either greater or less than 18 MeV. When we considered 18 MeV to be a 100% dose, the dose with 4 MeV, which was the least amount, corresponded to 81% of the dose. The skin surface dose of 10 MeV betatron electrons or more became greater than the 90% standard tumor dose. An external irradiation of more than 10 MeV should not be applied to neoplasms of which the curative ratio is less than 1.0. Therefore another methods such as intraoperative irradiation, should be used. The surface skin dose about 4 to 6 MeV betatron postoperative irradiation, particularly after resection of breast cancer, was less than the skin dose with 10 MeV. Close care should be taken to prevent hot lesions which are caused by duplication of irradiation fields. It should be kept in mind that the late effects of hot lesions caused by electron beam irradiation with an energy of 10 MeV or more are serious.

RBE of 0.85 MeV neutrons in Guinea pigs with a cerebral form of radiation sickness

International Nuclear Information System (INIS)

Shaporov, V.N.; Sokolova, T.I.; Nasonova, T.A.; Aleshin, S.I.

1989-01-01

The RBE coefficient of neutrons (0.85 MeV) was 1.87 in comparison with that of electron radiation (8 MeV) as determined by the death rate of guinea pigs with the cerebral form of radiation sickness. LD 50/1.5 amounted to 43.2 and 80.7 Gy. The dynamics of clinical symptoms at the height of the disease is discussed

Study of the thermal oxidation of titanium and zirconium under argon ion irradiation in the low MeV range (E = 15 MeV)

International Nuclear Information System (INIS)

Do, N.-L.

2012-01-01

We have shown that argon ion irradiation between 1 and 15 MeV produces damage on both titanium and zirconium surfaces, taking the form of accelerated oxidation and/or craterization effects, varying as a function of the projectile energy and the annealing atmosphere (temperature and pressure) simulating the environmental conditions of the fuel/cladding interface of PWR fuel rods. Using AFM, we have shown that the titanium and zirconium surface is attacked under light argon ion bombardment at high temperature (up to 500 C) in weakly oxidizing medium (under rarefied dry air pressure ranging from 5,7 10 -5 Pa to 5 10 -3 Pa) for a fixed fluence of about 5 10 14 ions.cm -2 . We observed the formation of nano-metric craters over the whole titanium surface irradiated between 2 and 9 MeV and the whole zirconium surface irradiated at 4 MeV, the characteristics of which vary depending on the temperature and the pressure. In the case of the Ar/Ti couple, the superficial damage efficiency increases when the projectile energy decreases from 9 to 2 MeV. Moreover, whereas the titanium surface seems to be transparent under the 15-MeV ion beam, the zirconium surface exhibits numerous micrometric craters surrounded by a wide halo. The crater characteristics (size and superficial density) differ significantly from that observed both in the low energy range (keV) where the energy losses are controlled by ballistic collisions (Sn) and in the high energy range (MeV - GeV) where the energy losses are controlled by electronic excitations (Se), which was not completely unexpected in this intermediate energy range for which combined Sn - Se stopping power effects are possibly foreseen. Using XPS associated to ionic sputtering, we have shown that there is an irradiation effect on thermal oxidation of titanium, enhanced under the argon ion beam between 2 and 9 MeV, and that there is also an energy effect on the oxide thickness and stoichiometry. The study conducted using Spectroscopic

Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC

Energy Technology Data Exchange (ETDEWEB)

Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others

2017-02-11

Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.

A low vertical β mode for the LNLS UVX electron storage ring

International Nuclear Information System (INIS)

Lin, Liu; Tavares, P.

1991-01-01

An operation mode with low vertical betatron function in one of the long dispersion free straight sections of the LNLS UVX Electron Storage Ring is studied for applications with small gap insertions. The flexibility of this lattice is analyzed regarding two aspects: the range of variation of the vertical betatron tune and the ability to set the betatron functions to high/low values in the insertion straights

Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment

International Nuclear Information System (INIS)

Shiu, Almon S.; Tung, Samuel S.; Gastorf, Robert J.; Hogstrom, Kenneth R.; Morrison, William H.; Peters, Lester J.

1996-01-01

Purpose: The purpose of this study is to report that commercially available eye shields (designed for orthovoltage x-rays) are inadequate to protect the ocular structures from penetrating electrons for electron beam energies equal to or greater than 6 MeV. Therefore, a prototype medium size tungsten eye shield was designed and fabricated. The advantages of the tungsten eye shield over lead are discussed. Methods and Materials: Electron beams (6-9 MeV) are often used to irradiate eyelid tumors to curative doses. Eye shields can be placed under the eyelids to protect the globe. Film and thermoluminescent dosimeters (TLDs) were used within a specially constructed polystyrene eye phantom to determine the effectiveness of various commercially available internal eye shields (designed for orthovoltage x-rays). The same procedures were used to evaluate a prototype medium size tungsten eye shield (2.8 mm thick), which was designed and fabricated for protection of the globe from penetrating electrons for electron beam energy equal to 9 MeV. A mini-TLD was used to measure the dose enhancement due to electrons backscattered off the tungsten eye shield, both with or without a dental acrylic coating that is required to reduce discomfort, permit sterilization of the shield, and reduce the dose contribution from backscattered electrons. Results: Transmission of a 6 MeV electron beam through a 1.7 mm thick lead eye shield was found to be 50% on the surface (cornea) of the phantom and 27% at a depth of 6 mm (lens). The thickness of lead required to stop 6-9 MeV electron beams is impractical. In place of lead, a prototype medium size tungsten eye shield was made. For 6 to 9 MeV electrons, the doses measured on the surface (cornea) and at 6 mm (lens) and 21 mm (retina) depths were all less than 5% of the maximum dose of the open field (4 x 4 cm). Electrons backscattered off a tungsten eye shield without acrylic coating increased the lid dose from 85 to 123% at 6 MeV and 87 to 119% at

s-wave threshold in electron attachment - Results in 2-C4F6 and CFCl3 at ultra-low electron energies

Science.gov (United States)

Chutjian, A.; Alajajian, S. H.; Ajello, J. M.; Orient, O. J.

1984-01-01

Electron attachment lineshapes and cross sections are reported for the processes 2-C4F6(-)/2-C4F6 and Cl(-)/CFCl3 at electron energies of 0-120 and 0-140 meV, and at resolutions of 6 and 7 meV (FWHM), respectively. As in previous measurements in CCl4 and SF6, the results show resolution-limited narrow structure in the cross section at electron energies below 15 meV. This structure arises from the divergence of the s-wave cross section in the limit of zero electron energy. Comparisons are given with swarm-measured results, and with collisional ionization (high-Rydberg attachment) data in this energy range.

Calibration of a large multi-element neutron counter in the energy range 85-430 MeV

CERN Document Server

Strong, J A; Esterling, R J; Garvey, J; Green, M G; Harnew, N; Jane, M R; Jobes, M; Mawson, J; McMahon, T; Robertson, A W; Thomas, D H

1978-01-01

Describes the calibration of a large 60 element neutron counter with a threshold of 2.7 MeV equivalent electron energy. The performance of the counter has been measured in the neutron kinetic energy range 8.5-430 MeV using a neutron beam at the CERN Synchrocyclotron. The results obtained for the efficiency as a function of energy are in reasonable agreement with a Monte Carlo calculation. (7 refs).

The 16 MeV - microtron at the Institute for Physics and Technology of Radiation Devices and its application

International Nuclear Information System (INIS)

Catana, D.; Panaitescu, I.; Axinescu, S.; Minea, R.

1992-01-01

The 17-orbit microtron at the Institute for Physics and Technology of Radiation Devices, Bucharest is described. The energy of electrons is 11 MeV in the first accelerating mode and 16 MeV in the second accelerating mode with a pulse beam power of about 400 Kw and a duty ratio of 10 -3 . (Author)

Impact of electron irradiation on particle track etching response in ...

Indian Academy of Sciences (India)

In the present work, attempts have been made to investigate the modification in particle track etching response of polyallyl diglycol carbonate (PADC) due to impact of 2 MeV electrons. PADC samples pre-irradiated to 1, 10, 20, 40, 60, 80 and 100 Mrad doses of 2 MeV electrons were further exposed to 140 MeV 28Si beam ...

Responses of conventional and extended-range neutron detectors in mixed radiation fields around a 150-MeV electron LINAC

International Nuclear Information System (INIS)

Lin, Yu-Chi; Sheu, Rong-Jiun; Chen, Ang-Yu

2015-01-01

This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays

Sustained >100 MeV Gamma-Ray Emission: A Monitor for >300 MeV SEP Protons at the Sun

Science.gov (United States)

Share, G. H.; Murphy, R. J.

2017-12-01

Solar γ radiation is the product of proton and ion interactions in the solar atmosphere. The spectrum and temporal characteristics of the emission provides fundamental information on the ions at the Sun. Until the launch of the Fermi satellite, with its Large Area Telescope (LAT) sensitive to radiation above 100 MeV, most of the γ-ray observations were made in the nuclear energy range with radiation arising from interaction of one to tens of MeV ions produced in solar flares. Since 2008 the LAT has detected 30 high-energy γ-ray events with temporal and spectral characteristics that are distinct from the associated solar flare. We call this radiation Sustained Gamma-Ray Emission (SGRE) and briefly summarize its characteristics reported in a recent paper. The γ-ray spectra are consistent with pion decay radiation produced by protons above 300 MeV. The onset of the radiation most often occurs after the impulsive flare and the emission can last several hours. We find that the number of protons responsible for the SGRE is typically more than 10 times the number of flare-accelerated protons. These characteristics require that there be an additional source of energy to accelerate the protons to hundreds of MeV to produce the SGRE. As 28 of the 30 SGRE events are accompanied by fast CMEs, it is likely that these protons are accelerated by the same shock that produces gradual SEPs. We find that the number of protons >500 MeV in the accompanying SEPs is typically about 50-100 times the number of protons that return to the Sun to produce the SGRE. There also appear to be correlations between the numbers of SEP and SGRE protons and durations of >100 MeV SEP proton and SGRE events. We find that for all SGRE events where there were flare observations, the accompanying impulsive X-radiation reached energies >100 keV. In a limited study of 18 solar events with CME speeds >800 km/s we also find that the median SEP proton flux is 25 times higher when flare hard X-rays exceed 100

Fractionation study: survival of mouse intestinal crypts to exposure of 60Co and 11 MeV electrons

International Nuclear Information System (INIS)

Coffey, C.W.

1975-01-01

The study was conducted to determine a statistical procedure for the quantification of time, dose, fraction relations for mouse intestinal crypt survival after fractionated Co-60 and 11-MeV electron irradiation. In the initial phase of the investigation CDF/1 male mice were exposed to fractionated Co-60 irradiation. A completely randomized experimental design with three factors, total time from initiation to completion of fractionation schedule, number of fractions, and total dose was utilized. The experimental animals were irradiated with a Co-60 panoramic irradiator unit at an absorbed dose rate of approximately 51 rads per minute. Two days after completion of the fractionation schedule, the experimental animals were sacrificed by cervical dislocation. Sections of intestinal jejunum were resected and routine histological preparations performed. The surviving crypts were scored with a compound microscope using a quantitative counting technique. The resulting crypt survival was observed to increase for increasing total times and fraction numbers

Electron cooling of a bunched ion beam in a storage ring

Science.gov (United States)

Zhao, He; Mao, Lijun; Yang, Jiancheng; Xia, Jiawen; Yang, Xiaodong; Li, Jie; Tang, Meitang; Shen, Guodong; Ma, Xiaoming; Wu, Bo; Wang, Geng; Ruan, Shuang; Wang, Kedong; Dong, Ziqiang

2018-02-01

A combination of electron cooling and rf system is an effective method to compress the beam bunch length in storage rings. A simulation code based on multiparticle tracking was developed to calculate the bunched ion beam cooling process, in which the electron cooling, intrabeam scattering (IBS), ion beam space-charge field, transverse and synchrotron motion are considered. Meanwhile, bunched ion beam cooling experiments have been carried out in the main cooling storage ring (CSRm) of the Heavy Ion Research Facility in Lanzhou, to investigate the minimum bunch length obtained by the cooling method, and study the dependence of the minimum bunch length on beam and machine parameters. The experiments show comparable results to those from simulation. Based on these simulations and experiments, we established an analytical model to describe the limitation of the bunch length of the cooled ion beam. It is observed that the IBS effect is dominant for low intensity beams, and the space-charge effect is much more important for high intensity beams. Moreover, the particles will not be bunched for much higher intensity beam. The experimental results in CSRm show a good agreement with the analytical model in the IBS dominated regime. The simulation work offers us comparable results to those from the analytical model both in IBS dominated and space-charge dominated regimes.

Calculation of the energy spectrum of atmospheric gamma-rays between 1 and 1000 MeV

International Nuclear Information System (INIS)

Martin, I.M.; Dutra, S.L.G.; Palmeira, R.A.R.

The energy spectrum of atmospheric gamma-rays at 4 g/cm 2 has been calculated for cut-off rigidities of 4.5, 10 and 16 GV. The considered processes for the production of these gamma-rays were the π 0 decay plus the bremsstrahlung from primary, secondary like splash and re-entrant albedo electrons. The calculations indicated that the spectrum could be fitted to a power law in energy, with the exponential index varying from 1.1 in the energy range 1 - 10 MeV, to 1.4 in the energy range 10 - 200 MeV and 1.8 in the energy range 200 - 1000 MeV. These results are discussed [pt

Effect of Ge, Sn, Sb on the resistance to swelling of austenitic alloys irradiated by 1 MeV electrons

International Nuclear Information System (INIS)

Dubuisson, P.; Levy, V.; Seran, J.L.

1987-01-01

The effect of new solute elements namely Ge, Sn and Sb on the void swelling resistance of austenitic alloys irradiated with 1 MeV electrons has been studied. Except for tin in Ti-modified 316, all solute improve the swelling resistance of base alloys. Tin addition shifts the swelling peak of 316 S.S. to high temperature. In fact, these solute additions have the same qualitative effect on the swelling components: they enhance the void density and decrease strongly void growth rate. This effect is opposite to the one of usual swelling inhibitors such as Si or Ti which decrease the void density. We have explained this influence on the void nucleation and void growth by introducing a strong interaction between vacancies and solute atoms in a void growth model