WorldWideScience

Sample records for clinical electron beams

  1. Electron beams: Physical and clinical aspects

    International Nuclear Information System (INIS)

    Megavoltage electron beams represent an important treatment modality in modern radiotherapy, often providing a unique option in the treatment of superficial tumours (less than 5 cm deep). Electrons have been used in radiotherapy since the early 1950s, first produced by betatrons and then by microtrons and linacs. Modern high energy linacs typically provide, in addition to two megavoltage photon energies, several electron beam energies in the range from 4 to 22 MeV

  2. Dosimetric characteristics of a MOSFET dosimeter for clinical electron beams.

    Science.gov (United States)

    Manigandan, D; Bharanidharan, G; Aruna, P; Devan, K; Elangovan, D; Patil, Vikram; Tamilarasan, R; Vasanthan, S; Ganesan, S

    2009-09-01

    The fundamental dosimetric characteristics of commercially available metal oxide semiconductor field effect transistor (MOSFET) detectors were studied for clinical electron beam irradiations. MOSFET showed excellent linearity against doses measured using an ion chamber in the dose range of 20-630cGy. MOSFET reproducibility is better at high doses compared to low doses. The output factors measured with the MOSFET were within +/-3% when compared with those measured with a parallel plate chamber. From 4 to 12MeV, MOSFETs showed a large angular dependence in the tilt directions and less in the axial directions. MOSFETs do not show any dose-rate dependence between 100 and 600MU/min. However, MOSFETs have shown under-response when the dose per pulse of the beam is decreased. No measurable effect in MOSFET response was observed in the temperature range of 23-40 degrees C. The energy dependence of a MOSFET dosimeter was within +/-3.0% for 6-18MeV electron beams and 5.5% for 4MeV ones. This study shows that MOSFET detectors are suitable for dosimetry of electron beams in the energy range of 4-18MeV. PMID:19128995

  3. Monte Carlo N Particle code - Dose distribution of clinical electron beams in inhomogeneous phantoms

    OpenAIRE

    H A Nedaie; Mosleh-Shirazi, M. A.; Allahverdi, M.

    2013-01-01

    Electron dose distributions calculated using the currently available analytical methods can be associated with large uncertainties. The Monte Carlo method is the most accurate method for dose calculation in electron beams. Most of the clinical electron beam simulation studies have been performed using non- MCNP [Monte Carlo N Particle] codes. Given the differences between Monte Carlo codes, this work aims to evaluate the accuracy of MCNP4C-simulated electron dose distributions in a homogenous...

  4. Investigation of the clinical potential of scattering foil free electron beams

    International Nuclear Information System (INIS)

    Electron beam therapy has been an important radiation therapy modality for many decades. Studies have been conducted recently for more efficient and advanced delivery of electron beam radiation therapy. X-ray contamination is a common problem that exists with all of the advanced electron beam therapy techniques such as Bolus Electron conformal therapy, segmented electron conformal therapy, and modulated electron arc therapy. X-ray contamination could add some limitations to the advancement and clinical utility of those electron modalities. It was previously shown in the literature that the scattering foil is one of the major accelerator parts contributing to the generation of bremsstrahlung photons. Thus, in this work we investigate the dosimetric characteristics of scattering foil free (SFF) electron beams and the feasibility of using those beams for breast cancer boosts. The SFF electron beams were modeled and simulated using the Monte Carlo method. CT scans of six previously treated breast patients were used for the treatment plan generation utilizing our in-house Monte Carlo-based treatment planning system. Electron boost plans with conventional beams and the SFF beams were generated, respectively, for all patients. A significant reduction of the photon component was observed with the removal of the primary scattering foil for beam energies higher than 12 MeV. Flatness was greatly affected but the difference in flatness between conventional and SFF beams was much reduced for small cone sizes, which were often used clinically for breast boosts. It was found that the SFF electron beams could deliver high-quality dose distributions as conventional electron beams for boost treatments of the breast with an added advantage of a further reduced dose to the lung and the heart. (paper)

  5. Evaluation of thermoluminescent dosimeters using water equivalent phantoms for application in clinical electrons beams dosimetry

    International Nuclear Information System (INIS)

    The dosimetry in Radiotherapy provides the calibration of the radiation beam as well as the quality control of the dose in the clinical routine. Its main objective is to determine with greater accuracy the dose absorbed by the tumor. This study aimed to evaluate the behavior of three thermoluminescent dosimeters for the clinical electron beam dosimetry. The performance of the calcium sulfate detector doped with dysprosium (CaSO4: Dy) produced by IPEN was compared with two dosimeters commercially available by Harshaw. Both are named TLD-100, however they differ in their dimensions. The dosimeters were evaluated using water, solid water (RMI-457) and PMMA phantoms in different exposure fields for 4, 6, 9, 12 and 16 MeV electron beam energies. It was also performed measurements in photon beams of 6 and 15 MV (2 and 5 MeV) only for comparison. The dose-response curves were obtained for the 60Co gamma radiation in air and under conditions of electronic equilibrium, both for clinical beam of photons and electrons in maximum dose depths. The sensitivity, reproducibility, intrinsic efficiency and energy dependence response of dosimeters were studied. The CaSO4: Dy showed the same behavior of TLD-100, demonstrating only an advantage in the sensitivity to the beams and radiation doses studied. Thus, the dosimeter produced by IPEN can be considered a new alternative for dosimetry in Radiotherapy departments. (author)

  6. Characterization of a gated fiber-optic-coupled detector for application in clinical electron beam dosimetry

    International Nuclear Information System (INIS)

    Purpose: Assessment of the fundamental dosimetric characteristics of a novel gated fiber-optic-coupled dosimetry system for clinical electron beam irradiation. Methods: The response of fiber-optic-coupled dosimetry system to clinical electron beam, with nominal energy range of 6-20 MeV, was evaluated for reproducibility, linearity, and output dependence on dose rate, dose per pulse, energy, and field size. The validity of the detector system's response was assessed in correspondence with a reference ionization chamber. Results: The fiber-optic-coupled dosimetry system showed little dependence to dose rate variations (coefficient of variation ±0.37%) and dose per pulse changes (with 0.54% of reference chamber measurements). The reproducibility of the system was ±0.55% for dose fractions of ∼100 cGy. Energy dependence was within ±1.67% relative to the reference ionization chamber for the 6-20 MeV nominal electron beam energy range. The system exhibited excellent linear response (R2=1.000) compared to reference ionization chamber in the dose range of 1-1000 cGy. The output factors were within ±0.54% of the corresponding reference ionization chamber measurements. Conclusions: The dosimetric properties of the gated fiber-optic-coupled dosimetry system compare favorably to the corresponding reference ionization chamber measurements and show considerable potential for applications in clinical electron beam radiotherapy.

  7. Clinical use of a commercial Monte Carlo treatment planning system for electron beams

    International Nuclear Information System (INIS)

    In 2002 we fully implemented clinically a commercial Monte Carlo based treatment planning system for electron beams. The software, developed by MDS Nordion (presently Nucletron), is based on Kawrakow's VMC++ algorithm. The Monte Carlo module is integrated with our Theraplan PlusTM treatment planning system. An extensive commissioning process preceded clinical implementation of this software. Using a single virtual 'machine' for each electron beam energy, we can now calculate very accurately the dose distributions and the number of MU for any arbitrary field shape and SSD. This new treatment planning capability has significantly impacted our clinical practice. Since we are more confident of the actual dose delivered to a patient, we now calculate accurate three-dimensional (3D) dose distributions for a greater variety of techniques and anatomical sites than we have in the past. We use the Monte Carlo module to calculate dose for head and neck, breast, chest wall and abdominal treatments with electron beams applied either solo or in conjunction with photons. In some cases patient treatment decisions have been changed, as compared to how such patients would have been treated in the past. In this paper, we present the planning procedure and some clinical examples

  8. Recommendations for clinical electron beam dosimetry: Supplement to the recommendations of Task Group 25

    International Nuclear Information System (INIS)

    The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at 60Co energy, ND,w60Co, together with the theoretical beam quality conversion coefficient kQ for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high-energy electron beams. The use of

  9. Monte Carlo N Particle code - Dose distribution of clinical electron beams in inhomogeneous phantoms

    Directory of Open Access Journals (Sweden)

    H A Nedaie

    2013-01-01

    Full Text Available Electron dose distributions calculated using the currently available analytical methods can be associated with large uncertainties. The Monte Carlo method is the most accurate method for dose calculation in electron beams. Most of the clinical electron beam simulation studies have been performed using non- MCNP [Monte Carlo N Particle] codes. Given the differences between Monte Carlo codes, this work aims to evaluate the accuracy of MCNP4C-simulated electron dose distributions in a homogenous phantom and around inhomogeneities. Different types of phantoms ranging in complexity were used; namely, a homogeneous water phantom and phantoms made of polymethyl methacrylate slabs containing different-sized, low- and high-density inserts of heterogeneous materials. Electron beams with 8 and 15 MeV nominal energy generated by an Elekta Synergy linear accelerator were investigated. Measurements were performed for a 10 cm × 10 cm applicator at a source-to-surface distance of 100 cm. Individual parts of the beam-defining system were introduced into the simulation one at a time in order to show their effect on depth doses. In contrast to the first scattering foil, the secondary scattering foil, X and Y jaws and applicator provide up to 5% of the dose. A 2%/2 mm agreement between MCNP and measurements was found in the homogenous phantom, and in the presence of heterogeneities in the range of 1-3%, being generally within 2% of the measurements for both energies in a "complex" phantom. A full-component simulation is necessary in order to obtain a realistic model of the beam. The MCNP4C results agree well with the measured electron dose distributions.

  10. Clinical application of intensity and energy modulated radiotherapy with photon and electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Xiangkui Mu

    2005-01-01

    In modern, advanced radiotherapy (e.g. intensity modulated photon radiotherapy, IMXT) the delivery time for each fraction becomes prolonged to 10-20 minutes compared with the conventional, commonly 2-5 minutes. The biological effect of this prolongation is not fully known. The large number of beam directions in IMXT commonly leads to a large integral dose in the patient. Electrons would reduce the integral dose but are not suitable for treating deep-seated tumour, due to their limited penetration in tissues. By combining electron and photon beams, the dose distributions may be improved compared with either used alone. One obstacle for using electron beams in clinical routine is that there is no available treatment planning systems that optimise electron beam treatments in a similar way as for IMXT. Protons have an even more pronounced dose fall-off, larger penetration depth and less penumbra widening than electrons and are therefore more suitable for advanced radiotherapy. However, proton facilities optimised for advanced radiotherapy are not commonly available. In some instances electron beams may be an acceptable surrogate. The first part of this study is an experimental in vitro study where the situation in a tumour during fractionated radiotherapy is simulated. The effect of the prolonged fraction time is compared with the predictions by radiobiological models. The second part is a treatment planning study to analyse the mixing of electron and photon beams for at complex target volume in comparison with IMXT. In the next step a research version of an electron beam optimiser was used for the improvement of treatment plans. The aim was to develop a method for translating crude energy and intensity matrices for optimised electrons into a deliverable treatment plan without destroying the dose distribution. In the final part, different methods of treating the spinal canal in medulloblastoma were explored in a treatment planning study that was evaluated with

  11. High energy electron beams characterization using CaSO4:Dy+PTFE Phosphors for clinical therapy applications

    International Nuclear Information System (INIS)

    In the present work high energy electron beam dosimetry from linear accelerator (LINACs) for clinical applications using dysprosium doped calcium sulfate embedded in polytetrafluorethylene (CaSO4:Dy+PTFE) was studied. The irradiations were carried out using high electron beams (6 to 18 MeV) from a linear accelerator (LINAC) Varian, CLINAC 2300C/D, for clinical practice purpose. The electron irradiations were obtained using the water solid in order to guarantee electronic equilibrium conditions (EEC). Field shaping for electron beams was obtained with electron cones. Glow curve and other thermoluminescent characteristics of CaSO4:Dy+PTFE were conducted under high electrons beams irradiations. The TL response of the pellets showed an intensity peak centered at around 215 °C. TL response of CaSO4:Dy+PTFE as a function of high electron absorbed dose showed a linearity in a wide range. To obtain reproducibility characteristic, a set of pellets were exposed repeatedly for the same electron absorbed dose. The results obtained in this study can suggest the applicability of CaSO4:Dy+PTFE pellets for high electron beam dosimetry, provided fading is correctly accounted for. - Highlights: ► Developing of CaSO4:Dy to electron beams dosimetry. ► Characterization of caSO4:Dy to radiation safety in LINACs. ► TL characteristics of CaSO4:Dy for electron beams quality control.

  12. Electron beams in radiation therapy

    International Nuclear Information System (INIS)

    Clinical electron beams in interaction with beam flattening and collimating devices are studied, in order to obtain the means for adequate electron therapy. A treatment planning method for arbitrary field shapes is developed that takes the properties of the collimated electron beams into account. An electron multiple-scattering model is extended to incorporate a model for the loss of electrons with depth, in order to improve electron beam dose planning. A study of ionisation measurements in two different phantom materials yields correction factors for electron beam dosimetry. (Auth.)

  13. A Study on clinical Considerations caused by inevitably Extended SSD for Electron beam therapy

    International Nuclear Information System (INIS)

    We are often faced with the clinical situations that is inevitably extended SSD for electron beam therapy due to anatomical restriction or applicator structure. But there are some difficulties in accurately predicting output and properties. In electron beam treatment , unlike photon beam the decrease in output for extended SSD does not follow inverse-square law accurately because of a loss of side scatter equilibrium, which is particularly significant for small cone size and low energies. The purpose of our study is to analyze the output in changing with the energy, cone size, air gap beyond the standard SSD and to compare inverse-square law factor derived from calculated effective SSD, mominal SSD with measured output factor. In addition, we have analyzed the change of PDD for several cones with different SSDs which range from 100 cm to 120 cm with 5 cm step and with different energies(6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV). In accordance with our study, an extended SSD produces a significant change in beam output, negligible change in depth dose which range from 100 cm to 120 cm SSDs. In order to deliver the more accurate dose to the neoplastic tissue, first of all we recommend inverse-square law using the table of effective SSDs with cone sizes and energies respectively or simply to create a table of extended SSD air gap correction factor. The second we need to have an insight into some change of dose distribution including PPD, penumbra caused by extended SSD for electron beam therapy.

  14. Secondary Electron Perturbations in Farmer Type Ion Chambers for Clinical Proton Beams

    International Nuclear Information System (INIS)

    Monte Carlo calculations of wall and central electrode perturbation correction factors for Farmer type chambers with graphite and A150 walls and graphite and aluminium central electrodes in proton beams due to secondary electrons are performed using EGSnrc Monte Carlo simulations. The wall correction factors exponentially saturate at high energies at about 1.004 for an A150 wall and about 0.985 for a graphite wall. The central electrode correction is unity for a graphite central electrode and saturates exponentially at 0.998 for a 1 mm diameter aluminium central electrode. Experimental data from the literature are in agreement within the standard uncertainties. The calculated data result in an overall perturbation correction factor for a Farmer type chamber with a graphite wall and a central electrode of 0.9965 in high energy clinical proton beams. (author)

  15. High energy electron beams characterization using CaSO{sub 4}:Dy+PTFE Phosphors for clinical therapy applications

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, T., E-mail: trivera@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria, IPN. Av. Legaria 694, Col. Irrigacion. 11500 Mexico DF (Mexico); Espinoza, A.; Von, S.M. [Centro Estatal de Cancerologia de los Servicios de Salud de Nayarit, Enfermeria S/n, Fracc, Fray Junipero Serra, 63169 Tepic Nay (Mexico); Alvarez, R.; Jimenez, Y. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria, IPN. Av. Legaria 694, Col. Irrigacion. 11500 Mexico DF (Mexico)

    2012-07-15

    In the present work high energy electron beam dosimetry from linear accelerator (LINACs) for clinical applications using dysprosium doped calcium sulfate embedded in polytetrafluorethylene (CaSO{sub 4}:Dy+PTFE) was studied. The irradiations were carried out using high electron beams (6 to 18 MeV) from a linear accelerator (LINAC) Varian, CLINAC 2300C/D, for clinical practice purpose. The electron irradiations were obtained using the water solid in order to guarantee electronic equilibrium conditions (EEC). Field shaping for electron beams was obtained with electron cones. Glow curve and other thermoluminescent characteristics of CaSO{sub 4}:Dy+PTFE were conducted under high electrons beams irradiations. The TL response of the pellets showed an intensity peak centered at around 215 Degree-Sign C. TL response of CaSO{sub 4}:Dy+PTFE as a function of high electron absorbed dose showed a linearity in a wide range. To obtain reproducibility characteristic, a set of pellets were exposed repeatedly for the same electron absorbed dose. The results obtained in this study can suggest the applicability of CaSO{sub 4}:Dy+PTFE pellets for high electron beam dosimetry, provided fading is correctly accounted for. - Highlights: Black-Right-Pointing-Pointer Developing of CaSO{sub 4}:Dy to electron beams dosimetry. Black-Right-Pointing-Pointer Characterization of caSO{sub 4}:Dy to radiation safety in LINACs. Black-Right-Pointing-Pointer TL characteristics of CaSO{sub 4}:Dy for electron beams quality control.

  16. Electron beam focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  17. Evaluation of TL response and intrinsic efficiency of TL dosimeters irradiated using different phantoms in clinical electron beam dosimetry

    International Nuclear Information System (INIS)

    The TL response of LiF:Mg,Ti microdosimeters and CaSO4:Dy dosimeters were studied for 12 MeV electron beams using PMMA, liquid water and solid water (SW) phantoms. The different phantom materials affect the electron spectrum incident on the detector and it can alter the response of dosimeters to different radiation types, so this fact should be considered in clinical dosimetry. The dosimeters were irradiated with doses ranging from 0.1 up to 5 Gy using a Varian Clinac 2100C linear accelerator of Hospital Israelita Albert Einstein – HIAE using a 10 × 10 cm2 field size and 100 cm source-phantom surface distance, with the dosimeters positioned at the depth of maximum dose. The TL readings were carried out 24 h after irradiation using a Harshaw 3500 TL reader. This paper aims to compare the TL response relative to 60Co of the dosimeters for different phantoms used in radiotherapy dosimetry. CaSO4:Dy dosimeters presented higher TL sensitivity relative to 60Co and intrinsic efficiency than microLiF:Mg,Ti dosimeters for all phantoms. - Highlights: • TL dose response curves of the dosimeters for clinical electron beams. • Evaluation of dosimeters for different phantoms. • Sensitivity and intrinsic TL efficiency of the dosimeters for clinical electron beams. • Effect of phantom materials in clinical electron beam dosimetry

  18. Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

    International Nuclear Information System (INIS)

    The DL-Alanine (C3H7NO2) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm2; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1σ), and the energy dependence response, to the same doses, is better 3% (1σ) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

  19. Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber F. [Faculdade Metodo de Sao Paulo (FAMESP), SP (Brazil). Radiologia; Campos, Leticia L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm{sup 2}; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1{sigma}), and the energy dependence response, to the same doses, is better 3% (1{sigma}) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

  20. Extrapolation chamber mounted on perspex for calibration of high energy photon and electron beams from a clinical linear accelerator

    Directory of Open Access Journals (Sweden)

    Ravichandran R

    2009-01-01

    Full Text Available The objective of the present study is to establish radiation standards for absorbed doses, for clinical high energy linear accelerator beams. In the nonavailability of a cobalt-60 beam for arriving at Nd, water values for thimble chambers, we investigated the efficacy of perspex mounted extrapolation chamber (EC used earlier for low energy x-rays and beta dosimetry. Extrapolation chamber with facility for achieving variable electrode separations 10.5mm to 0.5mm using micrometer screw was used for calibrations. Photon beams 6 MV and 15 MV and electron beams 6 MeV and 15 MeV from Varian Clinac linacs were calibrated. Absorbed Dose estimates to Perspex were converted into dose to solid water for comparison with FC 65 ionisation chamber measurements in water. Measurements made during the period December 2006 to June 2008 are considered for evaluation. Uncorrected ionization readings of EC for all the radiation beams over the entire period were within 2% showing the consistency of measurements. Absorbed doses estimated by EC were in good agreement with in-water calibrations within 2% for photons and electron beams. The present results suggest that extrapolation chambers can be considered as an independent measuring system for absorbed dose in addition to Farmer type ion chambers. In the absence of standard beam quality (Co-60 radiations as reference Quality for Nd,water the possibility of keeping EC as Primary Standards for absorbed dose calibrations in high energy radiation beams from linacs should be explored. As there are neither Standard Laboratories nor SSDL available in our country, we look forward to keep EC as Local Standard for hospital chamber calibrations. We are also participating in the IAEA mailed TLD intercomparison programme for quality audit of existing status of radiation dosimetry in high energy linac beams. The performance of EC has to be confirmed with cobalt-60 beams by a separate study, as linacs are susceptible for minor

  1. Electron beam welding

    International Nuclear Information System (INIS)

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  2. Estimation of absorbed doses in high energy photon and electron beams from a clinical linear accelerator using extrapolation chamber

    International Nuclear Information System (INIS)

    Calibration of photon and electron beams from a medical linear accelerator is carried out using absorbed dose calibrated gas cavity chambers in water phantoms and applying different international protocols. Bohm and Schneider developed extrapolation chamber (EC), which are specially designed parallel plate ionization chambers capable of measuring accurately the differential specific charge (dq/dm) by varying air mass in cavity by precise control of electrode separation. Zankowski and Podgorsak reported the efficacy of specially built extrapolation chambers as an integral part of po-lystyrene and solid water phantom to measure absorbed in cobalt-60 gamma beam, 4 to 18 MV x-rays and for 6 to 22 MeV electron beams. Mehenna Arib3 reported their experience in performing absolute dosimetry with high energy photon beams using a commercially available Perspex embedded extrapolation chamber and compared with water measurements. If realization of absorbed dose using these chambers is achieved from first principles, this chamber could become a departmental standard. In our institution we do not have standard cobalt-60 machine for determination of Nd, water factors for thimble chambers and no secondary standards laboratory in this country for traceability of our beam level dosimeters. Therefore we investigated the role of extrapolation chamber (EC) for measurement of absorbed doses with clinical radiotherapy beams

  3. Electron Beam for LHC

    CERN Document Server

    Krasny, M W

    2005-01-01

    A method of delivering a monochromatic electron beam to the LHC interaction points is proposed. In this method, heavy ions are used as carriers of the projectile electrons. Acceleration, storage and collision-stability aspects of such a hybrid beam is discussed and a new beam-cooling method is presented. This discussion is followed by a proposal of the Parasitic Ion-Electron collider at LHC (PIE@LHC). The PIE@LHC provides an opportunity, for the present LHC detectors, to enlarge the scope of their research program by including the program of electron-proton and electron-nucleuscollisions with minor machine and detector investments.

  4. Radiotherapy in the management of keloids. Clinical experience with electron beam irradiation and comparison with X-ray therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maarouf, M. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany); Dept. of Stereotactic and Functional Neurosurgery, Univ. of Cologne (Germany); Schleicher, U.; Schmachtenberg, A.; Ammon, J. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany)

    2002-06-01

    Background: Aim of this study was to evaluate the advantages of electron beam irradiation compared to kilovoltage X-ray therapy in the treatment of keloids. Furthermore, the risk of developing malignancy following keloid radiotherapy was assessed. Patients and Methods: An automatic water phantom was used to evaluate the dose distribution in tissue. Furthermore, a series of measurements was done on the patients using thermoluminescence dosimeters (TLD) to estimate the doses absorbed by the organs at risk. We also report our clinical experience with electron beam radiation of 134 keloids following surgical excision. Results: Electron beam irradiation offers a high control rate (84%) with minimal side effects for keloids. Electron irradiation provides better dose distribution in tissue, and therefore less radiation burden to the organs at risk. After a mean follow-up period of 7.2 years, no severe side effects or malignancies were observed after keloid radiotherapy. Conclusions: Electron radiation therapy is superior to kilovoltage irradiation for treating keloids due to better dose distribution in tissue. In agreement with the literature, no cases of malignancy were observed after keloid irradiation. (orig.)

  5. Secondary electron perturbations in Farmer type ion chambers for clinical proton beams

    International Nuclear Information System (INIS)

    Dosimetry of proton therapy has reached a reasonable level of consistency with the introduction of absorbed dose based protocols by the IAEA and the ICRU. Both recommendations adopted the assumption from earlier recommendations that ion chamber perturbation factors in proton beams are unity for all ionisation chamber types. However, early experiments indicated a difference in response of up to 2% between ion chambers with a graphite wall and those with an A150 tissue equivalent wall. A later experiment demonstrated that Farmer type chambers with graphite and A150 walls exhibit on average a difference in response of 0.5%. Monte Carlo simulations showed that secondary electrons are responsible for this effect but the uncertainty of those simulations was rather large due to limitations in available computation time and they were performed with EGS4. Another potential issue is the central electrode effect of chambers with an aluminium central electrode. Two experimental papers indicate that the perturbation factor due to the aluminium electrode is unity within the experimental uncertainties. No Monte Carlo simulations have been reported on this. It is worth to note that in high-energy electron beams, the presently accepted value of the aluminium central electrode perturbation factor is 0.998. Method: Monte Carlo simulations: Simulations of electron transport were performed assuming that the proton spectrum over the geometry of the cavity geometry does not change. This can be retrospectively justified if the resulting perturbation factors are only slowly varying as a function of energy. The modelled geometry is a cylinder with length 24 mm, diameter 6.4 mm and wall thickness of 0.38 mm, i.e. dimensions close to that of Farmer type chambers. Both graphite and A150 as wall material is modelled. The central electrode was modelled as a 1 mm diameter and 20 mm long cylinder at the centre of the cavity protruding from its base. Electron recoil spectra in the cavity, central

  6. The performance of a multi-guard ring structure (MGR) diode for dosimetry in clinical photon and electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, H.J.; Nascimento, C.R. [Nuclear Energy Department, UPFE, Recife-PE (Brazil); Kalil, L.F. [CECAN, Natal-RN (Brazil); Camargo, F.; Bueno, C.C. [Pontificia Universidade Catolica de Sao Paulo, Depto. de Fisica (Brazil)]. e-mail: hjkhoury@ufpe.br

    2007-07-01

    Full text: In clinical dosimetry the accuracy of the dose delivery on the radiotherapy procedures must be as accurate as +5%. This fact demands sophisticated dose planning systems and tools for dose verifications. Currently the ionization chamber is used for a dosimetry of photon and electron beams. However, measurements of doses in radiation fields with steep dose gradients and interface doses are quite complicated to be done with ionization chambers due to their physical size and limited spatial resolution. Diode detectors are used in areas of strong gradients to achieve better spatial resolution. The semiconductor detectors are attractive for applications in radiation dosimetry due to their high sensitivity, high density, small dimensions and its ability to operate in passive (unbiased) and active (biased) mode. The most suitable semiconductor for room temperature radiation dosimetry is silicon. These detectors yield a resolution of the order of a few millimeters. One of the problems of the use of these detectors in high rate radiation fields is the damage produced by the radiation in their response. This work examines the possibility of using a rad-hard silicon diode with a multi-guard ring structure (MGR), developed in the framework of R and D programs for the future CMS experiment at Large Hadron Collider (LHC) for clinical photon and electron beam dosimetry. This silicon diode presents a low leakage current and excellent timing properties. The diode was encapsulated in a polymer plastic and it was connected in the photovoltaic mode to the input of an integrating electrometer, Standard Imaging model CDX 2000A. The response of the diode was evaluated for the a 6MV and 1 5MV photon beam and 6MeV, MeV, 9MeV, 12MeV and 15MeV electron beam from a Clinac 2100-C accelerator of Varian Medical Systems. The results showed an excellent linear behavior of the dose-response curves, with a correlation coefficient of 0.99999, for all the beam energies studied. The results

  7. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G; Thorn, A

    2013-01-01

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  8. First macro Monte Carlo based commercial dose calculation module for electron beam treatment planning—new issues for clinical consideration

    Science.gov (United States)

    Ding, George X.; Duggan, Dennis M.; Coffey, Charles W.; Shokrani, Parvaneh; Cygler, Joanna E.

    2006-06-01

    The purpose of this study is to present our experience of commissioning, testing and use of the first commercial macro Monte Carlo based dose calculation algorithm for electron beam treatment planning and to investigate new issues regarding dose reporting (dose-to-water versus dose-to-medium) as well as statistical uncertainties for the calculations arising when Monte Carlo based systems are used in patient dose calculations. All phantoms studied were obtained by CT scan. The calculated dose distributions and monitor units were validated against measurements with film and ionization chambers in phantoms containing two-dimensional (2D) and three-dimensional (3D) type low- and high-density inhomogeneities at different source-to-surface distances. Beam energies ranged from 6 to 18 MeV. New required experimental input data for commissioning are presented. The result of validation shows an excellent agreement between calculated and measured dose distributions. The calculated monitor units were within 2% of measured values except in the case of a 6 MeV beam and small cutout fields at extended SSDs (>110 cm). The investigation on the new issue of dose reporting demonstrates the differences up to 4% for lung and 12% for bone when 'dose-to-medium' is calculated and reported instead of 'dose-to-water' as done in a conventional system. The accuracy of the Monte Carlo calculation is shown to be clinically acceptable even for very complex 3D-type inhomogeneities. As Monte Carlo based treatment planning systems begin to enter clinical practice, new issues, such as dose reporting and statistical variations, may be clinically significant. Therefore it is imperative that a consistent approach to dose reporting is used.

  9. First macro Monte Carlo based commercial dose calculation module for electron beam treatment planning-new issues for clinical consideration

    International Nuclear Information System (INIS)

    The purpose of this study is to present our experience of commissioning, testing and use of the first commercial macro Monte Carlo based dose calculation algorithm for electron beam treatment planning and to investigate new issues regarding dose reporting (dose-to-water versus dose-to-medium) as well as statistical uncertainties for the calculations arising when Monte Carlo based systems are used in patient dose calculations. All phantoms studied were obtained by CT scan. The calculated dose distributions and monitor units were validated against measurements with film and ionization chambers in phantoms containing two-dimensional (2D) and three-dimensional (3D) type low- and high-density inhomogeneities at different source-to-surface distances. Beam energies ranged from 6 to 18 MeV. New required experimental input data for commissioning are presented. The result of validation shows an excellent agreement between calculated and measured dose distributions. The calculated monitor units were within 2% of measured values except in the case of a 6 MeV beam and small cutout fields at extended SSDs (>110 cm). The investigation on the new issue of dose reporting demonstrates the differences up to 4% for lung and 12% for bone when 'dose-to-medium' is calculated and reported instead of 'dose-to-water' as done in a conventional system. The accuracy of the Monte Carlo calculation is shown to be clinically acceptable even for very complex 3D-type inhomogeneities. As Monte Carlo based treatment planning systems begin to enter clinical practice, new issues, such as dose reporting and statistical variations, may be clinically significant. Therefore it is imperative that a consistent approach to dose reporting is used

  10. Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Zobač, Martin

    Brno : ISI AS CR, 2006 - (Müllerová, I.), s. 15-16 ISBN 80-239-6285-X. [Recent Trends in Charged Particle Optics and Surface Physics Instrumentation /10./. Skalský dvůr (CZ), 22.05.2006-26.05.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam drilling * quartz glass Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  11. Electron beam processing system

    International Nuclear Information System (INIS)

    Electron beam Processing Systems (EPS) are used as useful and powerful tools in many industrial application fields such as the production of cross-linked wire, rubber tire, heat shrinkable film and tubing, curing, degradation of polymers, sterilization and environmental application. In this paper, the feature and application fields, the selection of machine ratings and safety measures of EPS will be described. (author)

  12. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  13. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  14. Tracheomalacia before and after aortosternopexy: dynamic and quantitative assessment by electron-beam computed tomography with clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kao, S.C.S. [Dept. of Radiology, The Univ. of Iowa Coll. of Medicine, Iowa City, IA (United States); Kimura, K. [Dept. of Surgery, The Univ. of Iowa Coll. of Medinice, Iowa City, IA (United States); Smith, W.L. [Dept. of Radiology, The Univ. of Iowa Coll. of Medicine, Iowa City, IA (United States); Sato, Y. [Dept. of Radiology, The Univ. of Iowa Coll. of Medicine, Iowa City, IA (United States)

    1995-11-01

    To correlate the dynamics of tracheal collapse with clinical upper airway obstruction before and after aortosternopexy, seven boys and three girls (mean age, 10 months) underwent dynamic evaluation of the trachea by electron-beam computed tomography (EBCT). The site, extent, and severity of collapse were correlated with symptomatology and details of operative procedure. When >50% area collapse was used as the criterion for tracheomalacia, segmental involvement occurred above the aortic arch in all patients, extending to the aortic arch level in only four. Tracheomalacia involved two or fewer 8-mm levels in seven patients and more than two levels in three. Eight patients underwent one aortosternopexy procedure, resulting in clinical improvement in six and correlating well with EBCT findings. Of the remaining two patients who had single aortosternopexy and did not show clinical and radiographic improvement, one required operative repair of a vascular ring and the other continued to have recurrent respiratory tract infections. On the basis of EBCT findings, two patients required additional innominate arteriopexies: One improved, and the other remained symptomatic, requiring tracheostomy. EBCT is a noninvasive modality that allows preoperative diagnosis of tracheomalacia. More importantly, the operative decision and technique are guided by an objective and quantitative assessment of tracheal collapse. (orig.)

  15. Electron beam instabilities in gyrotron beam tunnels

    International Nuclear Information System (INIS)

    Electron beam instabilities occurring in a gyrotron electron beam can induce an energy spread which might significantly deteriorate the gyrotron efficiency. Three types of instabilities are considered to explain the important discrepancy found between the theoretical and experimental efficiency in the case of quasi-optical gyrotrons (QOG): the electron cyclotron maser instability, the Bernstein instability and the Langmuir instability. The low magnetic field gradient in drift tubes of QOG makes that the electron cyclotron maser instability can develop in the drift tube at very low electron beam currents. Experimental measurements show that with a proper choice of absorbing structures in the beam tunnel, this instability can be suppressed. At high beam currents, the electrostatic Bernstein instability can induce a significant energy spread at the entrance of the interaction region. The induced energy spread scales approximately linearly with the electron beam density and for QOG one observes that the beam density is significantly higher than the beam density of an equivalent cylindrical cavity gyrotron. (author) figs., tabs., refs

  16. Uncertainties on measurements of absorbed-dose-to-water, from clinical high- energy electron beams: a comparison with the IAEA protocols

    International Nuclear Information System (INIS)

    A pilot study was performed to verify the troubles involved in the implementation of dosimetric protocol TRS 398 for absorbed-dose-to-water, using clinical high-energy electron beams and to accomplish an detailed evaluation of uncertainty chain components associated to the measurement, which ones were not treated in the IAEA protocols, aimed the standardization of technical procedures. (author)

  17. Relativistic electron beams above thunderclouds

    DEFF Research Database (Denmark)

    Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.;

    2011-01-01

    Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of...... electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds is...

  18. Relativistic electron beams above thunderclouds

    Directory of Open Access Journals (Sweden)

    M. Füllekrug

    2011-05-01

    Full Text Available Non-luminous relativistic electron beams above thunderclouds are detected by radio remote sensing with low frequency radio signals from 40–400 kHz. The electron beams occur 2–9 ms after positive cloud-to-ground lightning discharges at heights between 22–72 km above thunderclouds. The positive lightning discharges also cause sprites which occur either above or before the electron beam. One electron beam was detected without any luminous sprite occurrence which suggests that electron beams may also occur independently. Numerical simulations show that the beamed electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of 7 MeV to transport a total charge of 10 mC upwards. The impulsive current associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

  19. Self accelerating electron Airy beams

    CERN Document Server

    Voloch-Bloch, Noa; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-01-01

    We report the first experimental generation and observation of Airy beams of free electrons. The electron Airy beams are generated by diffraction of electrons through a nanoscale hologram, that imprints a cubic phase modulation on the beams' transverse plane. We observed the spatial evolution dynamics of an arc-shaped, self accelerating and shape preserving electron Airy beams. We directly observed the ability of electrons to self-heal, restoring their original shape after passing an obstacle. This electromagnetic method opens up new avenues for steering electrons, like their photonic counterparts, since their wave packets can be imprinted with arbitrary shapes or trajectories. Furthermore, these beams can be easily manipulated using magnetic or electric potentials. It is also possible to efficiently self mix narrow beams having opposite signs of acceleration, hence obtaining a new type of electron interferometer.

  20. Electron beam lithography for nanofabrication

    OpenAIRE

    Rius Suñé, Gemma

    2008-01-01

    Electron beam lithography (EBL) has consolidated as one of the most common techniques for patterning at the nanoscale meter range. It has enabled the nanofabrication of structures and devices within the research field of nanotechnology and nanoscience. EBL is based on the definition of submicronic features by the scanning of a focused energetic beam of electrons on a resist. The nature of electrons and the development of extremely fine beams and its flexible control provide the platform to sa...

  1. Intense electron and ion beams

    CERN Document Server

    Molokovsky, Sergey Ivanovich

    2005-01-01

    Intense Ion and Electron Beams treats intense charged-particle beams used in vacuum tubes, particle beam technology and experimental installations such as free electron lasers and accelerators. It addresses, among other things, the physics and basic theory of intense charged-particle beams; computation and design of charged-particle guns and focusing systems; multiple-beam charged-particle systems; and experimental methods for investigating intense particle beams. The coverage is carefully balanced between the physics of intense charged-particle beams and the design of optical systems for their formation and focusing. It can be recommended to all scientists studying or applying vacuum electronics and charged-particle beam technology, including students, engineers and researchers.

  2. Monitor tables for electron beams in radiotherapy

    International Nuclear Information System (INIS)

    The application of electron beams in radiotherapy is still based on tables of monitor units, although 3-D treatment planning systems for electron beams are available. This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate. However, the increasing clinical need for higher dosimetric precision and for more conformal electron beams leads to the requirement for more sophisticated tables of monitor units. The present paper summarizes and discusses the main aspects concerning the preparation of tables of monitor units for electron beams. The measurement equipment and procedures for measuring basic beam data needed for tables of monitor units for electron beams are described for a standard radiation therapy linac. The design of tables of monitor units for standard electron applicators is presented; this design can be extended for individual electron inserts, to variable applicator surface distances, to oblique beam incidence, and the use of bolus material. Typical data of an Elekta linac are presented in various tables. (orig.)

  3. An rf electron beam buncher

    International Nuclear Information System (INIS)

    A method is described for producing density modulations on an intense relativistic electron beam by the use of rf fields in a betatron configuration. In concept, a device embodying this method should be capable of producing short (1-10 ns) electron bunches from a long (10-100 ns) beam, and is expected to be relatively compact and to operate efficiently on low power and energy. The method requires that the azimuthal phase velocity of the rf wave equal the electron beam velocity. Depending on phase relative to the rf wave, electrons in the beam gain or lose energy and form bunches by the negative mass effect. The dynamics of the electrons in the combined rf wave and betatron field have been analyzed. An example of an rf electron beam buncher is given

  4. Accuracy of the phase space evolution dose calculation model for clinical 25 MeV electron beams

    International Nuclear Information System (INIS)

    The phase space evolution (PSE) model is a dose calculation model for electron beams in radiation oncology developed with the aim of a higher accuracy than the commonly used pencil beam (PB) models and with shorter calculation times than needed for Monte Carlo (MC) calculations. In this paper the accuracy of the PSE model has been investigated for 25 MeV electron beams of a MM50 racetrack microtron (Scanditronix Medical AB, Sweden) and compared with the results of a PB model. Measurements have been performed for tests like non-standard SSD, irregularly shaped fields, oblique incidence and in phantoms with heterogeneities of air, bone and lung. MC calculations have been performed as well, to reveal possible errors in the measurements and/or possible inaccuracies in the interaction data used for the bone and lung substitute materials. Results show a good agreement between PSE calculated dose distributions and measurements. For all points the differences - in absolute dose - were generally well within 3% and 3 mm. However, the PSE model was found to be less accurate in large regions of low-density material and errors of up to 6% were found for the lung phantom. Results of the PB model show larger deviations, with differences of up to 6% and 6 mm and of up to 10% for the lung phantom; at shortened SSDs the dose was overestimated by up to 6%. The agreement between MC calculations and measurement was good. For the bone and the lung phantom maximum deviations of 4% and 3% were found, caused by uncertainties about the actual interaction data. In conclusion, using the phase space evolution model, absolute 3D dose distributions of 25 MeV electron beams can be calculated with sufficient accuracy in most cases. The accuracy is significantly better than for a pencil beam model. In regions of lung tissue, a Monte Carlo model yields more accurate results than the current implementation of the PSE model. (author)

  5. Accuracy of the phase space evolution dose calculation model for clinical 25 MeV electron beams

    Science.gov (United States)

    Korevaar, Erik W.; Akhiat, Abdelhafid; Heijmen, Ben J. M.; Huizenga, Henk

    2000-10-01

    The phase space evolution (PSE) model is a dose calculation model for electron beams in radiation oncology developed with the aim of a higher accuracy than the commonly used pencil beam (PB) models and with shorter calculation times than needed for Monte Carlo (MC) calculations. In this paper the accuracy of the PSE model has been investigated for 25 MeV electron beams of a MM50 racetrack microtron (Scanditronix Medical AB, Sweden) and compared with the results of a PB model. Measurements have been performed for tests like non-standard SSD, irregularly shaped fields, oblique incidence and in phantoms with heterogeneities of air, bone and lung. MC calculations have been performed as well, to reveal possible errors in the measurements and/or possible inaccuracies in the interaction data used for the bone and lung substitute materials. Results show a good agreement between PSE calculated dose distributions and measurements. For all points the differences - in absolute dose - were generally well within 3% and 3 mm. However, the PSE model was found to be less accurate in large regions of low-density material and errors of up to 6% were found for the lung phantom. Results of the PB model show larger deviations, with differences of up to 6% and 6 mm and of up to 10% for the lung phantom; at shortened SSDs the dose was overestimated by up to 6%. The agreement between MC calculations and measurement was good. For the bone and the lung phantom maximum deviations of 4% and 3% were found, caused by uncertainties about the actual interaction data. In conclusion, using the phase space evolution model, absolute 3D dose distributions of 25 MeV electron beams can be calculated with sufficient accuracy in most cases. The accuracy is significantly better than for a pencil beam model. In regions of lung tissue, a Monte Carlo model yields more accurate results than the current implementation of the PSE model.

  6. Introduction to electron beam processing

    International Nuclear Information System (INIS)

    The contents are general features in the irradiation of polymers, electron beam machines - low energy, medium energy, high energy; application of EB machine in industries, engineering of EB processing, dosimetry of EB (electron beam) safe operation of EB machine, recent topics on EB processing under development. 3 tabs., 4 figs., 17 refs

  7. Determination of Energy of a Clinical Electron Beam as Part of a Routine Quality Assurance and Audit System

    Science.gov (United States)

    Hernández-Bello, Jimmy; D'Souza, Derek; Rossenberg, Ivan

    2002-08-01

    A method to determine the electron beam energy and an electron audit based on the current IPEM electron Code of Practice has been devised. During the commissioning on the new Varian 2100CD linear accelerator in The Middlesex Hospital, two methods were devised for the determination of electron energy. The first method involves the use of a two-depth method, whereby the ratio of ionisation (presented as a percentage) measured by an ion chamber at two depths in solid water is used to compare against the baseline ionisation depth value for that energy. The second method involves the irradiation of an X-ray film in solid water to obtain a depth dose curve and, hence determine the half value depth and practical range of the electrons. The results showed that the two-depth method has a better accuracy, repeatability, reliability and consistency than the X-ray method. The results for the electron audit showed that electron absolute outputs are obtained from ionisation measurements in solid water, where the energy-range parameters such as practical range and the depth at which ionisation is 50% of that at the maximum for the depth-ionisation curve are determined.

  8. Determination of energy of a clinical electron beam as part of a routine quality assurance and audit system

    International Nuclear Information System (INIS)

    A method to determine the electron beam energy and an electron audit based on the current IPEM electron Code of Practice has been devised. During the commissioning on the new Varian 2100CD linear accelerator in The Middlesex Hospital, two methods were devised for the determination of electron energy. The first method involves the use of a two-depth method, whereby the ratio of ionisation (presented as a percentage) measured by an ion chamber at two depths in solid water is used to compare against the baseline ionisation depth value for that energy. The second method involves the irradiation of an X-ray film in solid water to obtain a depth dose curve and, hence determine the half value depth and practical range of the electrons. The results showed that the two-depth method has a better accuracy, repeatability, reliability and consistency than the X-ray method. The results for the electron audit showed that electron absolute outputs are obtained from ionisation measurements in solid water, where the energy-range parameters such as practical range and the depth at which ionisation is 50% of that at the maximum for the depth-ionisation curve are determined

  9. Collimation with hollow electron beams

    CERN Document Server

    Stancari, G; Annala, G; Kuznetsov, G; Shiltsev, V; Still, D A; Vorobiev, L G

    2011-01-01

    A novel concept of controlled halo removal for intense high-energy beams in storage rings and colliders is presented. It is based on the interaction of the circulating beam with a 5-keV, magnetically confined, pulsed hollow electron beam in a 2-m-long section of the ring. The electrons enclose the circulating beam, kicking halo particles transversely and leaving the beam core unperturbed. By acting as a tunable diffusion enhancer and not as a hard aperture limitation, the hollow electron beam collimator extends conventional collimation systems beyond the intensity limits imposed by tolerable losses. The concept was tested experimentally at the Fermilab Tevatron proton-antiproton collider. The first results on the collimation of 980-GeV antiprotons are presented.

  10. Relativistic electron beams above thunderclouds

    Directory of Open Access Journals (Sweden)

    M. Füllekrug

    2011-08-01

    Full Text Available Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency ∼40–400 kHz which they radiate. The electron beams occur ∼2–9 ms after positive cloud-to-ground lightning discharges at heights between ∼22–72 km above thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of ∼7 MeV to transport a total charge of ∼−10 mC upwards. The impulsive current ∼3 × 10−3 Am−2 associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

  11. Generation of electron Airy beams.

    Science.gov (United States)

    Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-02-21

    Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories. PMID:23426323

  12. Special Technologies Related to Electron Beam Welding

    Institute of Scientific and Technical Information of China (English)

    Zhao; Haiyan; Cai; Zhipeng; Wang; Xichang

    2007-01-01

    In order to improve the manufacturing quality of electron beam welding,some technologies are developed by using the special features of electron beam.Comparing with the conventional electron beam welding,the usage of multi-beam technology and micro-beam technology are introduced.In addition.the development of beam diagnostic system is also presented.

  13. Method of electron beam investigation

    Directory of Open Access Journals (Sweden)

    М. V. Derenovsky

    1967-12-01

    Full Text Available In this article the possibility of electron beam testing by a modified method of moving right edge is considered. The description of the working set made for the continuous indication of radial current density distribution on an oscilloscope is given. As an exemple the results of beam measurement under continuous operation are presented.

  14. METHOD OF ELECTRON BEAM PROCESSING

    DEFF Research Database (Denmark)

    2003-01-01

    As a rule, electron beam welding takes place in a vacuum. However, this means that the workpieces in question have to be placed in a vacuum chamber and have to be removed therefrom after welding. This is time−consuming and a serious limitation of a process the greatest advantage of which is the...... option of welding workpieces of large thicknesses. Therefore the idea is to guide the electron beam (2) to the workpiece via a hollow wire, said wire thereby acting as a prolongation of the vacuum chamber (4) down to workpiece. Thus, a workpiece need not be placed inside the vacuum chamber, thereby...... exploiting the potential of electron beam processing to a greater degree than previously possible, for example by means of electron beam welding...

  15. Beam Characterizations at Femtosecond Electron Beam Facility

    CERN Document Server

    Rimjaem, Sakhorn; Kangrang, Nopadol; Kusoljariyakul, Keerati; Rhodes, Michael W; Saisut, Jatuporn; Thongbai, Chitrlada; Vilaithong, Thiraphat; Wichaisirimongkol, Pathom; Wiedemann, Helmut

    2005-01-01

    The SURIYA project at the Fast Neutron Research Facility (FNRF) has been established and is being commissioning to generate femtosecond electron pulses. Theses short pulses are produced by a system consisting of an S-band thermionic cathode RF-gun, an alpha magnet as a magnetic bunch compressor, and a linear accelerator. The characteristics of its major components and the beam characterizations as well as the preliminary experimental results will be presented and discussed.

  16. Assessment of CaSO4:Dy and LiF:Mg,Ti thermoluminescent dosimeters performance in the dosimetry of clinical electron beams

    International Nuclear Information System (INIS)

    The assessment of the performance of CaS04:Dy thermoluminescent detectors produced by IPEN in the dosimetry of clinical electron beams aims to propose an alternative to the LiF:Mg,Ti commercial dosimeters (TLD-100) largely applied in radiation therapy. The two types of thermoluminescent dosimeters were characterised with the use of PMMA, RMI-457 type solid water and water phantoms in radiation fields of 4, 6, 9, 12 and 16 MeV electrons of nominal energies in which the dose-response curves were obtained and the surface and depth doses were determined. The thermoluminescent response dependency with the electron nominal energies and the applied phantom were studied. The CaS04:Dy presented the same behaviour than the LiF:Mg,Ti in such a way that its application as an alternative to the TLD-100 pellets in the radiation therapy dosimetry of electron beams is viable and presents the significantly higher sensitivity to the electron radiation as its main advantage. (author)

  17. Electron beam micromachining of plastics

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor

    2014-01-01

    Roč. 49, 5-6 (2014), s. 310-314. ISSN 0861-4717 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA MŠk EE.2.3.20.0103 Institutional support: RVO:68081731 Keywords : micromachining of plastics * Electron beam Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  18. Low voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

  19. Low voltage electron beam accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ochi, Masafumi [Iwasaki Electric Co., Ltd., Tokyo (Japan)

    2003-02-01

    Widely used electron accelerators in industries are the electron beams with acceleration voltage at 300 kV or less. The typical examples are shown on manufactures in Japan, equipment configuration, operation, determination of process parameters, and basic maintenance requirement of the electron beam processors. New electron beam processors with acceleration voltage around 100 kV were introduced maintaining the relatively high dose speed capability of around 10,000 kGy x mpm at production by ESI (Energy Science Inc. USA, Iwasaki Electric Group). The application field like printing and coating for packaging requires treating thickness of 30 micron or less. It does not require high voltage over 110 kV. Also recently developed is a miniature bulb type electron beam tube with energy less than 60 kV. The new application area for this new electron beam tube is being searched. The drive force of this technology to spread in the industries would be further development of new application, process and market as well as the price reduction of the equipment, upon which further acknowledgement and acceptance of the technology to societies and industries would entirely depend. (Y. Tanaka)

  20. Electron beam ion source and electron beam ion trap (invited).

    Science.gov (United States)

    Becker, Reinard; Kester, Oliver

    2010-02-01

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not "sorcery" but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future. PMID:20192368

  1. Electron beam modeling on LTX

    Science.gov (United States)

    Szalkowski, Gregory; Majeski, Richard; Schmitt, John

    2014-10-01

    The lithium tokamak experiment (LTX) is a low aspect ratio tokamak with a steel clad copper shell that can be heated to 300-400 °C and coated with lithium. The lithium coating has been shown to decrease impurities in the plasma and decrease the recycling coefficient, improving plasma performance. The coating is applied to the walls by heating the shells, then using an electron beam to evaporate a pool of lithium located at the bottom of the shell. The beam is steered using the magnetic field generated by the field coils. This method allows for rapid evaporation of the lithium, producing a 50-100 nm coating in approximately 5 minutes. The current electron beam system can only coat half of the shell surface. A new electron beam system has been installed on LTX to coat the remaining shell surface. A model of this electron gun has been created using the AMaze program series (Field Precision LCC). The model will be used to find the magnetic fields needed to steer the electron beam produced by the gun to the lithium pool. The model will also show the electropotential produced both at the electron gun head and in the vessel. The model may also be used to find the dispersion of the beam and therefore the effective power density of the beam as it impacts the lithium pool. Supported by US DOE Contracts DE-AC02-09CH11466 and DE-AC52-07NA27344 and in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship.

  2. Electron beam linac simulations, 1985

    International Nuclear Information System (INIS)

    The results of particle simulation studies of electron beam problems for the year 1985 are summarized. Although the main subjects this year were mostly the same as in previous years, namely foilless diodes, accelerating gaps, and beam extraction, a major new element this year was the addition of IFR (ion-focused-regime) channels to the various components of a linac beam line. Of particular interest may be the new results obtained for IFR autoacceleration gaps (relevant to MIMI), and the studies of extraction from a guide magnetic field onto an IFR propagation channel (relevant to RADLAC II). 49 figs., 20 refs

  3. Electron beam solenoid reactor concept

    International Nuclear Information System (INIS)

    The electron Beam Heated Solenoid (EBHS) reactor is a linear magnetically confined fusion device in which the bulk or all of the heating is provided by a relativistic electron beam (REB). The high efficiency and established technology of the REB generator and the ability to vary the coupling length make this heating technique compatible with several radial and axial enery loss reduction options including multiple-mirrors, electrostatic and gas end-plug techniques. This paper addresses several of the fundamental technical issues and provides a current evaluation of the concept. The enhanced confinement of the high energy plasma ions due to nonadiabatic scattering in the multiple mirror geometry indicates the possibility of reactors of the 150 to 300 meter length operating at temperatures > 10 keV. A 275 meter EBHS reactor with a plasma Q of 11.3 requiring 33 MJ of beam eneergy is presented

  4. Multipass autogenous electron beam welding

    International Nuclear Information System (INIS)

    A multipass, autogenous welding procedure was developed for 7.6 mm (0.3 in.) wall thickness Type 304L stainless steel cylinders. The joint geometry has a 1.5 mm (0.06 in.) root-face width and a rectangular stepped groove that is 0.762 mm (0.03 in.) wide at the top of the root face and extends 1.5 mm in height, terminating into a groove width of 1.27 mm which extends to the outside of the 1.27 mm high weld-boss. One weld pass is made on the root, three passes on the 0.762 mm wide groove and three passes to complete the weld. Multipass, autogenous, electron beam welds maintain the characteristic high depth-to-width ratios and low heat input of single-pass, electron beam welds. The increased part distortion (which is still much less than from arc processes) in multipass weldments is corrected by a preweld machined compensation. Mechanical properties of multipass welds compare well with single-pass welds. The yield strength of welds in aluminum alloy 5083 is approximately the same for single-pass or multipass electron beam and gas, metal-arc welds. The incidence and size of porosity is less in multipass electron beam welding of aluminum as compared to gas, metal-arc welds. The multipass, autogenous, electron beam welding method has proven to be a reliable way to make some difficult welds in multilayer parts or in an instance where inside part temperature or weld underbead must be controlled and weld discontinuities must be minimized

  5. Free-electron laser beam

    International Nuclear Information System (INIS)

    The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7μm FEL beam. Cancer cells are considered diagnosed by FEL beam of far-infrared-THz range. The FEL beam CT is expected to have a wide variety of application without the radiation exposure and its resolution is equal or superior to that of usual imaging techniques. (N.I.)

  6. From Electron Beams to Photon Beams

    International Nuclear Information System (INIS)

    n this article I try to report at the best the events and the emotions I experienced, together with my colleagues, when I was a young researcher working at the Frascati Center of CNEN. In the middle of 70’s the high energy physics activities carried out in Frascati were transferred from CNEN to INFN (Istituto Nazionale Fisica Nucleare) and the personnel had the chance to chose to continue to work at the CNEN (obviously in a different research field) or to continue to work in high energy physics, but at the INFN. I decided to remain at the CNEN and, consequently, I had to change my research activity. I moved from the high energy accelerators research field to the lasers research field in which, at that time at the CNEN, a new interesting project on “uranium laser isotope separation” was just starting. This article is focused on the theoretical and experimental development activity, carried out in the years 70’s-80’s at the CNEN Frascati Center, on a quite particular kind of laser to be utilized in that project. In this laser the active medium is not made of atoms or molecules but is a beam of free electrons running along a spatially periodic magnetic structure: this laser is the “Free Electron Laser”

  7. WELD FORMATION CONTROL AT ELECTRON BEAM WELDING WITH BEAM OSCILLATIONS

    OpenAIRE

    Trushnikov, Dmitriy; Koleva, Elena; Mladenov, Georgy; Shcherbakov, A.

    2014-01-01

    Electron beam welding is used extensively to produce essential machine parts. The control of the basic beam parameters beam power or beam current at constant accelerating voltage, welding speed, current of focusing lens and distance between electron gun and welded sample surface is not enough to obtain at most of the regimes sound welds. Control of the focus position using analysis of the high frequency component of the current, collected by plasma, at periodic interactions on the beam (the o...

  8. Contributions of the different ion chamber walls to the fluence perturbation in clinical electron beams: A Monte Carlo study of the NACP-02 parallel-plate chamber

    International Nuclear Information System (INIS)

    Parallel-plate ionization chambers are widely used and highly recommended in clinical electron dosimetry. They are constructed to minimize possible electron fluence perturbations due to the presence of the chamber walls and the air-filled cavity itself, therefore the wall correction factor pwall is assumed to be unity in all current dosimetry protocols independent of electron energy and depth. Already early experimental investigations have given considerable evidence that the perturbations are not always negligible. Especially the back wall was identified as a source of fluence perturbation as the electrons that are backscattered from the rear wall make a significant contribution to the dose within the active volume of the chamber. The influence of different backscattering materials behind the cavity of parallel-plate chambers was experimentally investigated by Hunt et. al. and Klevenhagen. According to their results, the electron backscatter is proportional to the atomic number of the scatterer and inversely proportional to the electron energy. Especially the rear wall of the NACP chamber is quite massive (thickness: 5.6 mm) and consists of graphite, which has an atomic number Z = 6 which is about 10% smaller than the effective atomic number of water. So the wall perturbation concerning the back wall directly reflects the backscatter deficiency due to the back wall of the NACP chamber. Several years ago McEwen reinvestigated the backscattering of different parallel-plate chambers in clinical electron beams and determined the wall perturbation correction due to the rear wall of the NACP chamber experimentally. Monte Carlo simulations are a good tool for investigating perturbation corrections of ionization chambers. For the NACP chamber several studies have been performed during the last years. In all studies the wall perturbation for the whole chamber was calculated, resulting in significant larger values than those measured by McEwen. In the light of these

  9. Electron beam grafting of polymers

    International Nuclear Information System (INIS)

    Electron beam (EB) grafting has been a well known technique for modifying the surfaces of materials for many years. Commercial implementation has been quite successful in a few, narrow niche markets. Irradiation grafting is being used to control ion flow through battery separator membranes, to modify the hydrophilic and hydrophobic properties of semi-permeable membranes and non-woven fabrics, to enhance the bio-compatibility of materials used in the medical device area, and to impart release properties to films and papers. The use of grafting to modify the bulk properties of materials has not as yet emerged as a widely accepted commercial practice. The development of lower voltage, more cost-effective self-shielded electron beam equipment presents opportunities for enhanced commercial development. The technology used in grafting is very specific to the selection of the base polymer and to the choice of the graft monomers. Different combinations can yield vastly different performance properties

  10. Dosimetry for electron beam sterilization

    International Nuclear Information System (INIS)

    According to ISO 11137-1 (sect 4.3.4) dosimetry used in the development, validation and routine control of the sterilization process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. It can only be obtained through calibration of the dosimeters. In presented lecture different types of dosimeter systems for electron beams (calorimeters, radiochromic film dosimeters, alanine / EPR) and their calibration are described

  11. Electron beam gaseous pollutants treatment

    International Nuclear Information System (INIS)

    Emission of gaseous pollutants, mostly during combustion of fossil fuels, creates a threat to the environment. New, economical technologies are needed for flue gas treatment. A physico-chemical basis of the process using electron beam for the simultaneous removal of sulfur and nitrogen oxides and volatile organic compounds are presented in this report. Development of the process and its upscaling has been discussed. (author)

  12. Physics with polarized electron beams

    International Nuclear Information System (INIS)

    As a distinct field, elementary particle physics is now approximately forty years old. In all that time, only a few of the thousands of experiments that have been performed have made use of spin polarized particle beams. There are two reasons for this lack of interest. The first is that spin polarized beams are difficult to produce, accelerate, and transport. The second reason is that any physical process that can occur during the collision of a polarized particle with another (polarized or not) can also occur during the collision of unpolarized particles. One might ask then, why has any effort been expended on the subject? The answer, at least in the case of polarized electron beams, is that electron accelerators and storage rings have in recent years achieved sufficient energy to begin to probe the weak interaction directly. The weak interaction distinguishes between left- and right-handed fermionic currents. Left-handed particles interact in a fundamentally different way than their right-handed counterparts. If the experimenter wishes to explore or exploit this difference, he (or she) must either prepare the spin state of the incident particles or analyze the spin state of outgoing particles. For reasons, of generality and improved statistical precision, the former is usually preferable to the latter. The first of these lectures will review some of the techniques necessary for the production, transport, and monitoring of polarized electron (or positron) beams. The second lecture will survey some of the physics possibilities of polarized electron--positron collisions. 33 refs., 26 figs., 5 tabs

  13. Electron Beam Curing of Advanced Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The fundamental concept of electron beam method and the application in cure of composites are elaborated in this paper. The components of electron beam curing system are introduced. The mechanisms of interaction between electron beam and polymer matrix composites are presented. Recent studies reported including work of authors themselves on electron beam curing of composites are also discussed. Moreover, the authors believe that it is necessary to do the basic research about understanding how electron beam affects cured network and the mechanical/physical properties of the composites, for establishing a quantitative or semi-quantitative formulation.

  14. Collimation Studies with Hollow Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, G.; Annala, G.; Johnson, T.R.; Saewert, G.W.; Shiltsev, V.; Still, D.A.; Valishev, A.; /Fermilab

    2011-08-01

    Recent experimental studies at the Fermilab Tevatron collider have shown that magnetically confined hollow electron beams can act as a new kind of collimator for high-intensity beams in storage rings. In a hollow electron beam collimator, electrons enclose the circulating beam. Their electric charge kicks halo particles transversely. If their distribution is axially symmetric, the beam core is unaffected. This device is complementary to conventional two-stage collimation systems: the electron beam can be placed arbitrarily close to the circulating beam; and particle removal is smooth, so that the device is a diffusion enhancer rather than a hard aperture limitation. The concept was tested in the Tevatron collider using a hollow electron gun installed in one of the existing electron lenses. We describe some of the technical aspects of hollow-beam scraping and the results of recent measurements.

  15. Control And Transport Of Intense Electron Beams

    CERN Document Server

    Li, H

    2004-01-01

    The transport of intense beams for advanced accelerator applications with high-intensity beams such as heavy-ion inertial fusion, spallation neutron sources, and intense light sources requires tight control of beam characteristics over long distances. The University of Maryland Electron Ring (UMER), which uses low energy, high current electron beams to model the transport physics of intense space-charge-dominated beams, employs real-time beam characterization and control in order to optimize beam quality throughout the strong focusing lattice. We describe in this dissertation the main beam control techniques used in UMER, which include optimal beam steering by quadrupole scans, beam rotation correction using a skew corrector, rms envelope matching and optimization, empirical envelope matching, beam injection, and phase space reconstruction using a tomographic method. Using these control techniques, we achieved the design goals for UMER. The procedure is not only indispensable for optimum beam transport over l...

  16. Low Emittance Electron Beam Studies

    Energy Technology Data Exchange (ETDEWEB)

    Tikhoplav, Rodion

    2006-04-01

    We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*{sub 01} mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

  17. The electron test accelerator beam injector

    International Nuclear Information System (INIS)

    A beam chopper and buncher system has been designed to improve the capture efficiency and reduce the beam spill in the Electron Test Accelerator. The buncher increases the dc beam capture from 30 to 70%. 100% beam transmission through the accelerator structures is obtained with the chopper. This report describes results of experimental tests with the beam injector. Results from computer modeling and from measurements with prototypes that have led to the design of the beam chopper and buncher system are discussed

  18. Dosimetry for electron beam application

    International Nuclear Information System (INIS)

    This report describes two aspects of electron beam dosimetry, on one hand development of film dosimeters and measurements of their properties, and on the other hand development of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimeters have been developed in this department, and the properties of these and commercially available dosimeters have been measured and found to be comparable. Calorimeters which are in use for routine measurements, are being investigated with reference to their application as standardizing instruments, and new calorimeters are being developed. (author)

  19. Electron Beam Lithography for nano-patterning

    DEFF Research Database (Denmark)

    Greibe, Tine; Anhøj, Thomas Aarøe; Khomtchenko, Elena;

    2014-01-01

    Electron beam lithography is a versatile tool for fabrication of nano-sized patterns. The patterns are generated by scanning a focused beam of high-energy electrons onto a substrate coated with a thin layer of electron-sensitive polymer (resist), i.e. by directly writing custom-made patterns in a...... polymer. Electron beam lithography is a suitable method for nano-sized production, research, or development of semiconductor components on a low-volume level. Here, we present electron beam lithography available at DTU Danchip. We expertize a JEOL 9500FZ with electrons accelerated to an energy of 100ke...

  20. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  1. Modern developments in electron-beam fluorescence

    Science.gov (United States)

    Cattolica, Robert J.

    Recent developments in the area of electron-beam fluorescence are discussed with special attention given to the experience in the use of the electron-beam fluorescence in flight research. A new measurement approach, called electron-photon fluorescence (EPF), is described, and it is shown that EPF offers the potential of overcoming some of the disadvantages of electron-beam fluorescence in high-density flows. Examples of using the EPF technique are presented.

  2. Electron beam processing of rubbers

    International Nuclear Information System (INIS)

    At present, the country producing natural rubber most is Malaysia, but the future share of natural rubber production of Malaysia is likely to decrease, while the share of Indonesia is expected to increase because the area of rubber plantation is increasing. Indonesia exports natural rubber as a raw material, and imports natural rubber products such as tires, belts and surgical gloves. Indonesia would obtain more foreign currency if it could export rubber products, and the future success in the export of rubber products is dependent on the development of new rubber technology. In this connection, two electron beam processings of rubbers are discussed in this paper, that is, tire production and the radiation vulcanization of natural rubber latex. Both processings are deeply related to the cross-linking of rubbers. The physical properties of natural rubber change by cross-linking, namely, the solvent resistance, tensile strength and hardness increase, and the elongation at breaking down decreases. About ten medium energy electron beam machines are used for tire production in Japan. The merits of radiation vulcanized natural rubber latex are shown. Its industrial application is explained. (K.I.)

  3. Definition of Beam Diameter for Electron Beam Welding

    International Nuclear Information System (INIS)

    It is useful to characterize the dimensions of the electron beam during process development for electron beam welding applications. Analysis of the behavior of electron beam welds is simplest when a single number can be assigned to the beam properties that describes the size of the beam spot; this value we generically call the 'beam diameter'. This approach has worked well for most applications and electron beam welding machines with the weld dimensions (width and depth) correlating well with the beam diameter. However, in recent weld development for a refractory alloy, Ta-10W, welded with a low voltage electron beam machine (LVEB), it was found that the weld dimensions (weld penetration and weld width) did not correlate well with the beam diameter and especially with the experimentally determined sharp focus point. These data suggest that the presently used definition of beam diameter may not be optimal for all applications. The possible reasons for this discrepancy and a suggested possible alternative diameter definition is the subject of this paper.

  4. Definition of Beam Diameter for Electron Beam Welding

    Energy Technology Data Exchange (ETDEWEB)

    Burgardt, Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pierce, Stanley W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    It is useful to characterize the dimensions of the electron beam during process development for electron beam welding applications. Analysis of the behavior of electron beam welds is simplest when a single number can be assigned to the beam properties that describes the size of the beam spot; this value we generically call the “beam diameter”. This approach has worked well for most applications and electron beam welding machines with the weld dimensions (width and depth) correlating well with the beam diameter. However, in recent weld development for a refractory alloy, Ta-10W, welded with a low voltage electron beam machine (LVEB), it was found that the weld dimensions (weld penetration and weld width) did not correlate well with the beam diameter and especially with the experimentally determined sharp focus point. These data suggest that the presently used definition of beam diameter may not be optimal for all applications. The possible reasons for this discrepancy and a suggested possible alternative diameter definition is the subject of this paper.

  5. Report of the AAPM Task Group No. 105: Issues associated with clinical implementation of Monte Carlo-based photon and electron external beam treatment planning

    International Nuclear Information System (INIS)

    The Monte Carlo (MC) method has been shown through many research studies to calculate accurate dose distributions for clinical radiotherapy, particularly in heterogeneous patient tissues where the effects of electron transport cannot be accurately handled with conventional, deterministic dose algorithms. Despite its proven accuracy and the potential for improved dose distributions to influence treatment outcomes, the long calculation times previously associated with MC simulation rendered this method impractical for routine clinical treatment planning. However, the development of faster codes optimized for radiotherapy calculations and improvements in computer processor technology have substantially reduced calculation times to, in some instances, within minutes on a single processor. These advances have motivated several major treatment planning system vendors to embark upon the path of MC techniques. Several commercial vendors have already released or are currently in the process of releasing MC algorithms for photon and/or electron beam treatment planning. Consequently, the accessibility and use of MC treatment planning algorithms may well become widespread in the radiotherapy community. With MC simulation, dose is computed stochastically using first principles; this method is therefore quite different from conventional dose algorithms. Issues such as statistical uncertainties, the use of variance reduction techniques, the ability to account for geometric details in the accelerator treatment head simulation, and other features, are all unique components of a MC treatment planning algorithm. Successful implementation by the clinical physicist of such a system will require an understanding of the basic principles of MC techniques. The purpose of this report, while providing education and review on the use of MC simulation in radiotherapy planning, is to set out, for both users and developers, the salient issues associated with clinical implementation and

  6. Experimental Device for Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Zobač, Martin; Dupák, Jan; Vlček, Ivan

    2006-01-01

    Roč. 41, 5-6 (2006), s. 272-275. ISSN 0861-4717. [EBT 2006 - International Conference on Electron Beam Technologies /8./. Varna, 05.06.2006-10.06.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam drilling * quartz glass Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  7. Electron beam treatment of industrial wastewater

    International Nuclear Information System (INIS)

    For industrial wastewater with low impurity levels such as contaminated ground water, cleaning water and etc., purification only with electron beam is possible, but it should be managed carefully with reducing required irradiation doses as low as possible. Also for industrial wastewater with high impurity levels such as dyeing wastewater, leachate and etc., purification only with electron beam requires high amount of doses and far beyond economies. Electron beam treatment combined with conventional purification methods such as coagulation, biological treatment, etc. is suitable for reduction of non-biodegradable impurities in wastewater and will extend the application area of electron beam. A pilot plant with electron beam for treating 1,000 m3/day of wastewater from dyeing industries has constructed and operated continuously since Oct 1998. Electron beam irradiation instead of chemical treatment shows much improvement in removing impurities and increases the efficiency of biological treatment. Actual plant is under consideration based upon the experimental results. (author)

  8. Electron beam sterilization for dishes

    International Nuclear Information System (INIS)

    Modern biological science often needs various fine strike devices which are often made from non-toxic transparent plastic. The application of high temperature steam to the sterilization as a traditional methods often causes deformation and colour change. When chemicals are applied to the sterilization residure of chemical grain often causes toxicity. Only application of radiation to the sterilization can overcome this faults and carry out with sterility assurance at room temperature. In this research 1.3 MeV electron beam coming from Model JJ-2 accelerator was applied for sterilization to 96-well tissue culture plates. After clean packaging the plates were irradiated with 31.7 XGy and operational voltage 1.3 MeV and 100 μA on the PY device. Repeated tests demonstrate that the products are sterile. The output is 2 x 105 pieces for each year. (author)

  9. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  10. Shielding in electron beams used in radiotherapy

    International Nuclear Information System (INIS)

    The interactions of electron beams with initial energies between 7 and 30 MeV have been studied in various materials including polystyrene, aluminium, copper and lead. The following experimental results have been found: estimation of measurement point displacement in a cylindrical chamber and of its variations with electron beam energy, empirical relations between the energy at the surface and the practical range of the electrons in various materials, an estimation of the relative ionisation due to the 'bremsstrahlung' measured behind different materials with beam complete shielding. Improvement of electron beam collimation is suggested after analysis of the dose distribution behind partial shielding

  11. Low-Dose (10-Gy) Total Skin Electron Beam Therapy for Cutaneous T-Cell Lymphoma: An Open Clinical Study and Pooled Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kamstrup, Maria R., E-mail: mkam0004@bbh.regionh.dk [Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Gniadecki, Robert [Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Iversen, Lars [Department of Dermatology, Aarhus University Hospital, Aarhus (Denmark); Skov, Lone [Department of Dermatology, Gentofte Hospital, University of Copenhagen, Copenhagen (Denmark); Petersen, Peter Meidahl [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Loft, Annika [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Specht, Lena [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2015-05-01

    Purpose: Cutaneous T-cell lymphomas (CTCLs) are dominated by mycosis fungoides (MF) and Sézary syndrome (SS), and durable disease control is a therapeutic challenge. Standard total skin electron beam therapy (TSEBT) is an effective skin-directed therapy, but the possibility of retreatments is limited to 2 to 3 courses in a lifetime due to skin toxicity. This study aimed to determine the clinical effect of low-dose TSEBT in patients with MF and SS. Methods and Materials: In an open clinical study, 21 patients with MF/SS stages IB to IV were treated with low-dose TSEBT over <2.5 weeks, receiving a total dose of 10 Gy in 10 fractions. Data from 10 of these patients were published previously but were included in the current pooled data analysis. Outcome measures were response rate, duration of response, and toxicity. Results: The overall response rate was 95% with a complete cutaneous response or a very good partial response rate (<1% skin involvement with patches or plaques) documented in 57% of the patients. Median duration of overall cutaneous response was 174 days (5.8 months; range: 60-675 days). TSEBT-related acute adverse events (grade 1 or 2) were observed in 60% of patients. Conclusions: Low-dose (10-Gy) TSEBT offers a high overall response rate and is relatively safe. With this approach, reirradiation at times of relapse or progression is likely to be less toxic than standard dose TSEBT. It remains to be established whether adjuvant and combination treatments can prolong the beneficial effects of low-dose TSEBT.

  12. Low-Dose (10-Gy) Total Skin Electron Beam Therapy for Cutaneous T-Cell Lymphoma: An Open Clinical Study and Pooled Data Analysis

    International Nuclear Information System (INIS)

    Purpose: Cutaneous T-cell lymphomas (CTCLs) are dominated by mycosis fungoides (MF) and Sézary syndrome (SS), and durable disease control is a therapeutic challenge. Standard total skin electron beam therapy (TSEBT) is an effective skin-directed therapy, but the possibility of retreatments is limited to 2 to 3 courses in a lifetime due to skin toxicity. This study aimed to determine the clinical effect of low-dose TSEBT in patients with MF and SS. Methods and Materials: In an open clinical study, 21 patients with MF/SS stages IB to IV were treated with low-dose TSEBT over <2.5 weeks, receiving a total dose of 10 Gy in 10 fractions. Data from 10 of these patients were published previously but were included in the current pooled data analysis. Outcome measures were response rate, duration of response, and toxicity. Results: The overall response rate was 95% with a complete cutaneous response or a very good partial response rate (<1% skin involvement with patches or plaques) documented in 57% of the patients. Median duration of overall cutaneous response was 174 days (5.8 months; range: 60-675 days). TSEBT-related acute adverse events (grade 1 or 2) were observed in 60% of patients. Conclusions: Low-dose (10-Gy) TSEBT offers a high overall response rate and is relatively safe. With this approach, reirradiation at times of relapse or progression is likely to be less toxic than standard dose TSEBT. It remains to be established whether adjuvant and combination treatments can prolong the beneficial effects of low-dose TSEBT

  13. Optics of electron beam in the Recycler

    International Nuclear Information System (INIS)

    Electron cooling of 8.9 GeV/c antiprotons in the Recycler ring (Fermilab) requires high current and good quality of the DC electron beam. Electron trajectories of ∼0.2 A or higher DC electron beam have to be parallel in the cooling section, within ∼0.2 mrad, making the beam envelope cylindrical. These requirements yielded a specific scheme of the electron transport from a gun to the cooling section, with electrostatic acceleration and deceleration in the Pelletron. Recuperation of the DC beam limits beam losses at as tiny level as ∼0.001%, setting strict requirements on the return electron line to the Pelletron and a collector. To smooth the beam envelope in the cooling section, it has to be linear and known at the transport start. Also, strength of the relevant optic elements has to be measured with good accuracy. Beam-based optic measurements are being carried out and analyzed to get this information. They include beam simulations in the Pelletron, differential optic (beam response) measurements and simulation, beam profile measurements with optical transition radiation, envelope measurements and analysis with orifice scrapers. Current results for the first half-year of commissioning are presented. Although electron cooling is already routinely used for pbar stacking, its efficiency is expected to be improved

  14. Electron beam coherence measurements using diffracted beam interferometry/holography.

    Science.gov (United States)

    Herring, Rodney A

    2009-06-01

    The intensity and coherence of elastically and inelastically scattered electrons have been studied by the interference of electron-diffracted beams using a method of diffracted beam interferometry/holography (DBI/H). In the interferograms produced, fringes were found to exist from low to high scattering angles. The intensity and coherence of the fringes are useful for understanding the contrast mismatch between experimental and simulated images found in atomic resolution images of crystals produced by transmission electron microscopy (TEM) and annular dark-field (ADF) scanning transmission electron microscopy (STEM). The fringes disappear when the interfering beams are separated from an exact overlay position, which produces a measurement of the beam's lateral coherence and holds promise for measuring the coherence of the respective quasi-particles associated with the energy loss electrons. PMID:19141592

  15. Making electron beams for the SLC linac

    International Nuclear Information System (INIS)

    A source of high-intensity, single-bunch electron beams has been developed at SLAC for the SLC. The properties of these beams have been studied extensively utilizing the first 100-m of the SLAC linac and the computer-based control system being developed for the SLC. The source is described and the properties of the beams are summarized. (orig.)

  16. A directly heated electron beam line source

    International Nuclear Information System (INIS)

    A 140-mm cathode length, Electron Beam Line Source with a high degree of focusing of the beam is constructed. The design principles and basic characteristic considerations for electron beam line source consists of parallel plate electrode geometric array as well as a beam power of 35kW are worked out. The dimensions of the beam at the work site are 1.25xl00mm. The gun is designed basically for the study of evaporation and deposition characteristic of refractory metals for laboratory use. However, it may be equally used for melting and casting of these metals. (author)

  17. Experimental Study of Using Wax Wedge Filter in Electron Beams

    International Nuclear Information System (INIS)

    Wedged beams are often been used in clinical photon radiotherapy to compensate missing tissues and dose gradients. In this work, we designed a wedge filter made of wax to be implemented in electron beams radiotherapy. Measurements were carried out for a hexahedral high-energy electron beams (5-14 MeV) generated by Siemens Mevatron linear accelerator by using radiographic film dosimetry for off-axis dose profiles and depth doses measurements. This study showed that there was a large difference between open and wedged PDD and this difference was decreased with electron beams energy increase. Therefore, we recommend using wax wedge filters with higher electron energies, and take into account the increase in the surface dose and the decrease of the depth of maximum dose when used with low electron energies.

  18. Calibration of photon and electron beams

    International Nuclear Information System (INIS)

    Modern radiotherapy relies on accurate dose delivery to the prescribed target volume. The ICRU has recommended an overall accuracy in tumour dose delivery of (+-5)%, based on an analysis of dose response data and on an evaluation of errors in dose delivery in a clinical setting. Considering all uncertainties involved in the dose delivery to the patient, the ±5% accuracy recommendation is by no means easy to attain. Before clinical use, the output of photon and electron beams produced by external beam radiotherapy machines must be calibrated. This basic output calibration is but one, albeit very important, of the links constituting the chain representing an accurate dose delivery to the patient. The other links refer to: the procedures for measurement of relative dose data, equipment commissioning and quality assurance; treatment planning; and the actual patient set-up on the treatment machine. The basic output for a radiotherapy machine is usually stated as the dose rate for a point P at a reference depth zref (often the depth of dose maximum zmax) in a water phantom for a nominal source to surface distance (SSD) or source to axis distance (SAD) and a reference field size (often 10 x 10 cm2) on the phantom surface or the isocentre. The output for kilovoltage X ray generators and teletherapy units is usually given in Gy/min, while for clinical accelerators it is given in Gy/MU. For superficial and orthovoltage beams and occasionally for beams produced by teletherapy radioisotope machines, the basic beam output may also be stated as the air kerma rate in air (Gy/min) at a given distance from the source and for a given nominal collimator or applicator setting. The basic output calibration of photon and electron beams is carried out with radiation dosimeters and special radiation dosimetry techniques. Radiation dosimetry refers to a determination by measurement and/or calculation of the absorbed dose or some other physically relevant quantity, such as air kerma

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Electron beam sterilisation of heterogeneous medical devices

    Science.gov (United States)

    Sadat, T.; Morisseau, MrD.; Ross, MissA.

    1993-07-01

    Electron beam radiation is used in the sterilisation of medical disposable devices. High energy, 10 MeV, electron beam linear accelerators are in use worldwide for this purpose. The dose distribution achieved in the products treated influences the efficiency of treatment. This paper looks at the dose distribution achieved with such machines and the methods used to define it in heterogeneous products.

  1. Electron beam sterilisation of heterogeneous medical devices

    International Nuclear Information System (INIS)

    Electron beam radiation is used in the sterilization of medical disposable devices. High energy, 10 MeV, electron beam linear accelerators are in use worldwide for this purpose. The dose distribution achieved in the products treated influences the efficiency of treatment. This paper looks at the dose distribution achieved with such machines and the methods used to define it in heterogeneous products. (author)

  2. Peculiar rotation of electron vortex beams.

    Science.gov (United States)

    Schachinger, T; Löffler, S; Stöger-Pollach, M; Schattschneider, P

    2015-11-01

    Standard electron optics predicts Larmor image rotation in the magnetic lens field of a TEM. Introducing the possibility to produce electron vortex beams with quantized orbital angular momentum brought up the question of their rotational dynamics in the presence of a magnetic field. Recently, it has been shown that electron vortex beams can be prepared as free electron Landau states showing peculiar rotational dynamics, including no and cyclotron (double-Larmor) rotation. Additionally very fast Gouy rotation of electron vortex beams has been observed. In this work a model is developed which reveals that the rotational dynamics of electron vortices are a combination of slow Larmor and fast Gouy rotations and that the Landau states naturally occur in the transition region in between the two regimes. This more general picture is confirmed by experimental data showing an extended set of peculiar rotations, including no, cyclotron, Larmor and rapid Gouy rotations all present in one single convergent electron vortex beam. PMID:26103046

  3. Influence of electron beam parameters on coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Wang G.; Hao, Y.; Litvinenko, V.N.; Webb, S.

    2012-05-20

    Coherent electron cooling (CeC) promises to revolutionize the cooling of high energy hadron beams. The intricate dynamics of the CeC depends both on the local density and energy distribution of the beam. The variations of the local density (beam current) are inevitable in any realistic beam. Hence, in this paper we propose a novel method of beam conditioning. The conditioning provides compensation of effect from such variation by a correlated energy modulation. We use our analytical FEL model for an electron bunch with Gaussian line charge density and cosine-type energy variation along bunch. We analyze the phase variation between the electron density modulation at the exit of the FEL-amplifier and the ions inducing it in the modulator as a function of the peak current and the electron beam energy. Based on this analysis, electron bunch parameters for optimal CeC cooling are found numerically.

  4. Electron beam emission and interaction of double-beam gyrotron

    International Nuclear Information System (INIS)

    Highlights: ► The complete electrical design of electron gun and interaction structure of double-beam gyrotron. ► EGUN code is used for the simulation of electron gun of double-beam gyrotron. ► MAGIC code is used for the simulation of interaction structure of double-beam gyrotron. ► Design validations with other codes. - Abstract: This paper presents the numerical simulation of a double-beam magnetron injection gun (DB-MIG) and beam-wave interaction for 60 GHz, 500 kW gyrotron. The beam-wave interaction calculations, power and frequency growth estimation are performed by using PIC code MAGIC. The maximum output power of 510 kW at 41.5% efficiency, beam currents of 6 A and 12 A, electron beam velocity ratios of 1.41 and 1.25 and beam voltage of 69 kV are estimated. To obtain the design parameters, the DB-MIG with maximum transverse velocity spread less than 5% is designed. The computer simulations are performed by using the commercially available code EGUN and the in-house developed code MIGANS. The simulated results of DB-MIG design obtained by using the EGUN code are also validated with another trajectory code TRAK, which are in good agreement.

  5. Electron beam processing of wastewater in Malaysia

    International Nuclear Information System (INIS)

    Electron beam processing technology started in Malaysia in 1991 when two accelerators were installed through JICA cooperation to perform medical product sterilization project. Since then several private companies have installed electron accelerators to develop in removing volatile organic materials and to demonstrate flue gas treatment. In this country report, effort on electron beam processing of wastewater or contaminated groundwater is presented: After de-coloration tests using gamma rays as function of radiation doses, electron beam treatment of textile industry wastewater as function of beam energy and current intensity as well as with combined treatment such as aeration or biological treatment to examine the effectiveness in color and BOD or COD change has been carried out and the main results are reported. Furthermore, the present technique was examined to apply in river water treatment for use as drinking water. Techno-economic feasibility study for recycling of industrial waste water using electron beam technology is now underway. (S. Ohno)

  6. Industrial applications of electron beam technology

    International Nuclear Information System (INIS)

    Electron beam technology was first introduced in Malaysia in 1989 with the conclusion of the bilateral cooperation between the Malaysian Institute for Nuclear Technology Research (MINT) and Japan International Co-operation Agency (JICA) on Radiation Application Projects. Two electron beam accelerators with energy of 3.0 MeV and 200 keV were installed at MINT. These two accelerators pave the way for R and D to be carried out in radiation processing of polymers for cross-linking and surface curing. In 1994, another electron beam accelerator was installed in the private sector for cross-linking of home appliance wires. Since then, two more accelerators were installed in the private sector for cross-linking of heat shrinkable plastic films. Recently, a local company has acquired a low energy electron beam machine for cross-linking of plastic film. Within a period of 7 years, industrial applications of electron beam technology in Malaysia have increased significantly

  7. Electron beam treatment of wastewater

    International Nuclear Information System (INIS)

    Supernatant comes from dewaterization of sewage sludge, and contains biologically nondegradable organics so that it is hard to be treated by conventional activated sludge. By electron beam (EB) irradiation, any kinds of organics in water can be oxidized to biodegradable organic acids. We studied the treatment of supernatant by application of this effect. The direct irradiation of the original supernatant was found not to be so effective to decrease COD. In order to increase the irradiation effect, supernatant was pretreated biologically to decrease the biodegradable organics in it. The chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were decreased from 800 and 910 mg/L to 78 and 5 mg/L by this pretreatment, respectively. This pretreated supernatant was irradiated by EB of 2 MeV using a batch type reactor. The COD was gradually decreased with dose. In contrast, BOD was increased markedly, indicating increase in biodegradability. The irradiated sample water was treated biologically again. After the final biological treatment, COD was decreased below 30 mg/L in the case of 10 - 12 kGy irradiation. Finally, the initial COD of 800 mg/L was decreased below 30 mg/L by the combination of EB irradiation and biological treatment. The cost of irradiation for this process was evaluated preliminarily. (author)

  8. Application of electron beam irradiation, (1). Development and application of electron beam processors

    International Nuclear Information System (INIS)

    This paper deals with characteristics, equipment (principle and kinds), present conditions, and future issues in the application of electron beam irradiation. Characteristics of electron beams are described in terms of the following: chemical and biological effects of radiation; energy and penetrating power of electron beams; and principle and kinds of electron beam accelerator. Industrial application of electron beam irradiation has advantages of high speed procedure and producibility, less energy, avoidance of poisonous gas, and extreme reduction of organic solvents to be used. The present application of electron beam irradiation cen be divided into the following: (1) hardening of resin or coated membrane; (2) improvement of macromolecular materials; (3) environmental protection; (4) sterilization; (5) food sterilization. The present equipment for electron beam irradiation is introduced according to low energy, medium energy, and high energy equipment. Finally, future issues focuses on (1) the improvement of traceability system and development of electron dosimetric techniques and (2) food sterilization. (N.K.)

  9. Electron beam curing of polymer matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Wheeler, D. [Sandia National Lab., Albuquerque, NM (United States); Saunders, C. [AECL Technologies, Inc., Rockville, MD (United States)] [and others

    1998-01-08

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world`s largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide.

  10. Electron beam curing of polymer matrix composites

    International Nuclear Information System (INIS)

    The purpose of the CRADA was to conduct research and development activities to better understand and utilize the electron beam PMC curing technology. This technology will be used to replace or supplement existing PMC thermal curing processes in Department of Energy (DOE) Defense Programs (DP) projects and American aircraft and aerospace industries. This effort involved Lockheed Martin Energy Systems, Inc./Lockheed Martin Energy Research Corp. (Contractor), Sandia National Laboratories, and ten industrial Participants including four major aircraft and aerospace companies, three advanced materials companies, and three electron beam processing organizations. The technical objective of the CRADA was to synthesize and/or modify high performance, electron beam curable materials that meet specific end-use application requirements. There were six tasks in this CRADA including: Electron beam materials development; Electron beam database development; Economic analysis; Low-cost Electron Beam tooling development; Electron beam curing systems integration; and Demonstration articles/prototype structures development. The contractor managed, participated and integrated all the tasks, and optimized the project efforts through the coordination, exchange, and dissemination of information to the project participants. Members of the Contractor team were also the principal inventors on several electron beam related patents and a 1997 R and D 100 Award winner on Electron-Beam-Curable Cationic Epoxy Resins. The CRADA achieved a major breakthrough for the composites industry by having successfully developed high-performance electron beam curable cationic epoxy resins for use in composites, adhesives, tooling compounds, potting compounds, syntactic foams, etc. UCB Chemicals, the world's largest supplier of radiation-curable polymers, has acquired a license to produce and sell these resins worldwide

  11. Electron beam conditioning by Thomson scattering

    OpenAIRE

    Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2003-01-01

    A method is proposed for conditioning electron beams via Thomson scattering. The conditioning provides a quadratic correlation between the electron energy deviation and the betatron amplitude of the electrons, which results in enhanced gain in free-electron lasers. Quantum effects imply conditioning must occur at high laser fluence and moderate electron energy. Conditioning of x-ray free-electron lasers should be achievable with present laser technology, leading to significant size and c...

  12. The clinical case for proton beam therapy

    International Nuclear Information System (INIS)

    Over the past 20 years, several proton beam treatment programs have been implemented throughout the United States. Increasingly, the number of new programs under development is growing. Proton beam therapy has the potential for improving tumor control and survival through dose escalation. It also has potential for reducing harm to normal organs through dose reduction. However, proton beam therapy is more costly than conventional x-ray therapy. This increased cost may be offset by improved function, improved quality of life, and reduced costs related to treating the late effects of therapy. Clinical research opportunities are abundant to determine which patients will gain the most benefit from proton beam therapy. We review the clinical case for proton beam therapy. Proton beam therapy is a technically advanced and promising form of radiation therapy

  13. The clinical case for proton beam therapy

    Directory of Open Access Journals (Sweden)

    Foote Robert L

    2012-10-01

    Full Text Available Abstract Over the past 20 years, several proton beam treatment programs have been implemented throughout the United States. Increasingly, the number of new programs under development is growing. Proton beam therapy has the potential for improving tumor control and survival through dose escalation. It also has potential for reducing harm to normal organs through dose reduction. However, proton beam therapy is more costly than conventional x-ray therapy. This increased cost may be offset by improved function, improved quality of life, and reduced costs related to treating the late effects of therapy. Clinical research opportunities are abundant to determine which patients will gain the most benefit from proton beam therapy. We review the clinical case for proton beam therapy. Summary sentence Proton beam therapy is a technically advanced and promising form of radiation therapy.

  14. Intense relativistic electron beam: generation and propagation

    International Nuclear Information System (INIS)

    A general review of relativistic electron beam extracted from explosive field emission diode has been presented here. The beam current in the diode gap taking into account cathode and anode plasma expansion velocity and excluding the self magnetic field effect is directly proportional to gap voltage V3/2 and inversely proportional to the square of the effective diode gap (d-vt). In the limit of high current, self magnetic field focusing effect comes into play and results in a critical current at which pinching will take place. When the diode current exceeds the critical current, the electron flow is in the para-potential regime. Different diode geometries such as planner, coaxial, rod-pinched, reflex triode are discussed qualitatively. When the beam is injected into a vacuum drift tube the propagation of the beam is only possible in presence of a strong axial magnetic field which prevents the beam expansion in the radial direction. If the beam is injected in the drift tube filled with dense plasma, then the redistribution of the plasma electrons effectively neutralizes the beam space charge, resulting subsequent propagation of the beam along the drift tube. The beam propagation through neutral gas is similar to the plasma filled drift tube. In this case both the neutral gas pressure and the beam current regulate the transmission of the REB. (author)

  15. Plasma heating with crossing relativistic electron beams

    Science.gov (United States)

    Ratan, Naren; Sircombe, Nathan; Ceurvorst, Luke; Kasim, Muhammad; Sadler, James; Bingham, Robert; Trines, Raoul; Norreys, Peter

    2015-11-01

    Plasma heating by relativistic electron beams is a powerful tool with applications including the heating of inertial confinement fusion targets and the study of matter in extreme conditions. We discuss the use of two relativistic electron beams to efficiently heat the plasma ions where the beams cross by using beam-plasma instabilities and non-linear wave coupling between Langmuir and ion-acoustic waves. Energy from the electron beams is coupled to the plasma ions as the beams become unstable and drive Langmuir waves which couple non-linearly to ion-acoustic waves which are then damped . Results of linear growth rate calculations are presented for the system of two crossing electron beams demonstrating a broad spectrum of unstable modes. Relativistic Vlasov-Maxwell simulations in two space and two momentum dimensions have been performed which demonstrate the non-linear coupling of the electron beam energy into ion-acoustic waves and the energy cascade to the background ions. Time-frequency analysis is applied to analyze the non-linear coupling between Langmuir and ion-acoustic waves in wave phase space. Structural properties of the strong turbulence produced at late times are analyzed.

  16. Recent developments in electron beam machine technology

    International Nuclear Information System (INIS)

    Electron beam accelerator provides ionisation energy for industrial processing. Electron beam accelerators are increasingly used for decontamination, conservation and disinfestation of food, for sterilization of medical products, and for polymerisation of materials. These machines are easy to install into a production factory as the radiation stops as soon as the machine is switched off. This safety advantage, together with the flexibility of use of these highly automated machines, has allowed the electron beam accelerator to become an important production tool. (author). 23 refs., 6 figs., 2 tabs

  17. Electron multipacting in long-bunch beam

    OpenAIRE

    Kai-Wei, Li

    2015-01-01

    The electron multipacting is an important factor for the development of the electron cloud. There is a trailing-edge multipacting in the tail of the long-bunch beam. It can be described by the energy gain and motion of electrons. The analyses are in agreement with the simulation.

  18. Development of applicators for intraoperative electron beam irradiation

    International Nuclear Information System (INIS)

    A set of applicator units for intraoperative electron beam irradiation has been developed, and is utilized for clinical practice. The applicator system includes a lead tube, a lead containing acrylic cone, and attachment devices. The lead tube is attached to a commercially available electron tube, and the acrylic cone is placed at the tip of the lead tube for better visualization of treatment fields. Measurements before clinical applications revealed that the system provides clinically acceptable dose distribution for intraoperative electron beam irradiation. Clinical utilization suggests the following advantages of the applicator: 1) Sterilization is easy. 2) It is inexpensive and easy to handle. 3) Treatment fields are clearly visualized using endoscopy. The acrylic cone is useful to verify relations between treatment fields and outer structures. 4) It is safe since collision inter-locking is available. (author)

  19. Intense electron beam propagation into vacuum

    International Nuclear Information System (INIS)

    The authors have performed experimental and theoretical studies of the propagation of an intense electron beam (1 MeV, 27 kA, 30 ns) into a long evacuated drift cube. In one case the beam propagates because an applied axial magnetic field immerses the entire system. In the second case a localized source of ions for charge neutralization enables the beam is propagate. In the case of a magnetically confined beam, experimental results for current propagation as a function of uniform applied magnetic field (0-1.2 Tesla) are presented for various drift tube diameters, cathode geometries, and anode aperture sizes. An analytic model of laminar beam flow is presented which predicts the space charge limited current of a solid intense relativistic electron beam (IREB) propagating in a grounded drift tube as a function of tube and diode sizes and applied magnetic field. Comparisons between the experimental and theoretical results are discussed

  20. The Continuous Electron Beam Accelerator Facility

    International Nuclear Information System (INIS)

    On February 13, 1987, construction started on the Continuous Electron Beam Accelerator Facility - a 4-GeV, 200-μA, continuous beam, electron accelerator facility designed for nuclear physics research. The machine has a racetrack configuration with two antiparallel, 500-MeV, superconducting linac segments connected by beam lines to allow four passes of recirculation. The accelerating structure consists of 1500-MHz, five-cell niobium cavities developed at Cornell University. A liquid helium cryogenic system cools the cavities to an operating temperature of 2 K. Beam extraction after any three of the four passes allows simultaneous delivery of up to three beams of independently variable currents and different, but correlated, energies to the three experimental areas. Beam breakup thresholds exceed the design current by nearly two orders of magnitude. Project completion and the start of physics operations are scheduled for 1993. The total estimated cost is $255 million

  1. Electron Beam Scanning in Industrial Applications

    Science.gov (United States)

    Jongen, Yves; Herer, Arnold

    1996-05-01

    Scanned electron beams are used within many industries for applications such as sterilization of medical disposables, crosslinking of wire and cables insulating jackets, polymerization and degradation of resins and biomaterials, modification of semiconductors, coloration of gemstones and glasses, removal of oxides from coal plant flue gasses, and the curing of advanced composites and other molded forms. X-rays generated from scanned electron beams make yet other applications, such as food irradiation, viable. Typical accelerators for these applications range in beam energy from 0.5MeV to 10 MeV, with beam powers between 5 to 500kW and scanning widths between 20 and 300 cm. Since precise control of dose delivery is required in many of these applications, the integration of beam characteristics, product conveyance, and beam scanning mechanisms must be well understood and optimized. Fundamental issues and some case examples are presented.

  2. Beam-edge modifier for abutting electron fields

    International Nuclear Information System (INIS)

    Abutment of unmodified electron fields to irradiate large areas can lead to significant dose inhomogeneities in the region of junction of the fields. In this paper we describe the design and dosimetric characteristics of a device developed to broaden the electron beam penumbra and thereby to improve the dose uniformity in the overlap region. The device is a high-density triangular-toothed comb capable of reducing the beam intensity without seriously degrading the beam energy. The effect of the comb is such that a single device will generate a beam penumbra which is broad and very nearly linear at all depths for all clinically used beam energies. Results are shown for various field configurations and energies. With a gap of 5.0 cm between the treatment cone and phantom surface the dose ''ripple'' in the region beneath the teeth was found not to exceed +- 5% at 0.5-cm depth

  3. Making electron beams for the SLC linac

    International Nuclear Information System (INIS)

    A source of high-intensity, single-bunch electron beams has been developed at SLAC for the SLC. The properties of these beams have been studied extensively utilizing the first 100-m of the SLAC linac and the computer-based control system being developed for the SLC. The source is described and the properties of the beams are summarized. 9 references, 2 figures, 1 table

  4. Runaway electron beam in atmospheric pressure discharges

    Science.gov (United States)

    Oreshkin, E. V.; Barengolts, S. A.; Chaikovsky, S. A.; Oreshkin, V. I.

    2015-11-01

    A numerical simulation was performed to study the formation of a runaway electron (RAE) beam from an individual emission zone in atmospheric pressure air discharges with a highly overvolted interelectrode gap. It is shown that the formation of a RAE beam in discharges at high overvoltages is much contributed by avalanche processes.

  5. Electron beam experiments at Maryland University

    International Nuclear Information System (INIS)

    An experimental study of the stability of intense electron beams is described. The purpose is to determine the emittance growth associated with aberrations arising from the non-uniform transverse density distribution in the beam, and to compare measurements with the results of computer simulations

  6. Blood irradiation with accelerator produced electron beams

    International Nuclear Information System (INIS)

    Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV electron beam are measured in a phantom study. Doses have been verified with ionization chambers and commercial diode detectors. Results show that the blood product volume can be given a relatively homogeneous dose to within 6% using 20 MeV electrons without the need to rotate the blood bags or the beam entry point. The irradiation process takes approximately 6.5 minutes for 30 Gy applied dose to complete as opposed to 12 minutes for a dual field x-ray field irradiation at our centre. Electron beams can be used to satisfactorily irradiate blood and blood products in a minimal amount of time. (author)

  7. Copper alloy surface treatment by electron beams

    International Nuclear Information System (INIS)

    A basic study on copper alloy surface fusion treatment by electron beams is presented. Geometry, microstructure and hardness evolution of transformed domains in relation to the used parameters is established

  8. Electron-beam initiated HF lasers

    International Nuclear Information System (INIS)

    Electron beams were used to ignite hydrogen/fluorine mixtures, producing laser energies up to 4.2 kJ, and giving hope that this approach may soon produce energy levels suitable for laser-fusion studies. (auth)

  9. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests

  10. Electron beam, laser beam and plasma arc welding studies

    Science.gov (United States)

    Banas, C. M.

    1974-01-01

    This program was undertaken as an initial step in establishing an evaluation framework which would permit a priori selection of advanced welding processes for specific applications. To this end, a direct comparison of laser beam, electron beam and arc welding of Ti-6Al-4V alloy was undertaken. Ti-6Al-4V was selected for use in view of its established welding characteristics and its importance in aerospace applications.

  11. Electron-Beam Ion Source MIS-1

    International Nuclear Information System (INIS)

    INP develops and produces electron-beam ion sources of multicharged ions. These ion sources provide a high density of the electron beam in the ionization area at the ion trap ≥ 103 A/cm2. They produce multicharge ions of various elements, both gaseous and solid ones. These ion sources successfully employ the technique of the dozed inlet of solid elements atoms into the ion trap

  12. Ion beam processing of advanced electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  13. Ion beam processing of advanced electronic materials

    International Nuclear Information System (INIS)

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases

  14. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    OpenAIRE

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for b...

  15. Mechanistic studies of electron beam induced organic reactions for electron beam resist materials

    International Nuclear Information System (INIS)

    Triphenylsulfonium methanesulfonate in the solid state was irradiated with an electron beam and the radiolytic products were characterized spectroscopically and chromatographically. The electron beam irradiation of the salt offered a new benzene-substituted sulfonium salt, together with methanesulfonic acids, diphenyl sulfides, and 2-, 3- and 4-phenylthiobyphenyls known as photoproducts of triphenylsulfonium salts. The formation of the salt appears to be due to the nature of electron beam induced reactions. (author)

  16. A reflex electron beam discharge as a plasma source for electron beam generation

    International Nuclear Information System (INIS)

    A reflex electron beam glow discharge has been used as a plasma source for the generation of broad-area electron beams. An electron current of 120 A (12 A/cm/sup 2/) was extracted from the plasma in 10 μs pulses and accelerated to energies greater than 1 keV in the gap between two grids. The scaling of the scheme for the generation of multikiloamp high-energy beams is discussed

  17. Primary beams of an electron beam ion source (EBIS)

    International Nuclear Information System (INIS)

    Electron guns for the ion sources of the SATURN II facility were tested and compared with models. The guns tested were a gun with 36 mm diameter cathode, 7 mm, 4 mm, 4 mm with insulated Whenelt, and 8 mm. A lanthanium hexaboride cathode is presented. For the primary ion beams, zeolite and plasma sources were realized. In DIONE, which will replace CRYEBIS as ion source in SATURNE, the density of the electron beam compressed within the maximum magnetic field can be evaluated. Results indicate a factor of 3 improvement compared with CRYEBIS. Lithium sources can be used, but gas sources do not produce significant improvements

  18. Plasma heating by a relativistic electron beam

    International Nuclear Information System (INIS)

    This thesis is devoted to the interaction of a Relativistic Electron Beam (REB) with a plasma. The goal of the experiment described herein is to study in detail the mechanism of energy transfer from the beam to the plasma. The beam particles have an energy of 800 keV, a current of 6 kA, a diameter of 3 cm and an adjustable pulse length of 50-150 ns. This beam is injected into cold hydrogen and helium plasmas with densities ranging from 1018 to 1020 m-3. First, the technical aspects of the experiment are described. Then measurements on the hf fields excited by the REB-plasma are presented (optical line profiles and spectra of beam electrons). The final section is devoted to plasma heating. (Auth.)

  19. Nonlinear wave scattering and electron beam relaxation

    Science.gov (United States)

    Muschietti, L.; Dum, C. T.

    1991-01-01

    The role played by nonlinear scattering during the relaxation of a warm electron beam is investigated through a numerical code based on kinetic equations. The code encompasses the quasi-linear wave-electron interaction and wave-wave scattering off ion clouds. Ions with velocities 2 nu sub i (nu sub i being the ion thermal velocity) are found to be the most efficient for scattering the Langmuir waves off their polarization clouds. The transfer rate of the spectrum out of resonance with the beam is larger by a factor 3 compared to usual estimates. The changes produced in the dispersion relation by the presence of the beam electrons dramatically alter the characteristics of the secondary spectrum. In a late phase the classic condensate K of about 0 is depleted, with the formation of a new condensate in resonance with the flat-topped beam distribution, which follows from the fact that the mere presence of the beam electrons creates a minimum in the frequency-wave-number relation. For strong and slow beams, the predictions of the code are found to be in excellent agreement with the results of the particle simulation if a dispersion relation that includes the beam is used.

  20. Pulsed electron beams in transient plasmas

    International Nuclear Information System (INIS)

    In the present work a large variety of experimental investigation is reviewed, having in common pulsed electron beams in transient plasmas. The simulation of nuclear pumping of plasma recombination lasers using pulsed electron beams led to the optimization of a coaxial discharge geometry which allowed lasing at the 585.3 nm transition in Ne I, Ne-H2 mixtures. In a detailed investigation of the cathode sheaths by superposition of two discharges, a simple and accurate method to measure the sheath width has been worked out and a new way of pulsed electron beam generation has been discovered. The electron beam (280 A peak current, 10 ns pulse duration, diameter less than 100 μm over a few centimeters length) is produced in a pseudospark-like discharge without inner diaphragms by the synergy of two discharges. Its parameters can be efficiently controlled by the preionization discharge. The exceptional radial stability of this beam along the discharge tube access opens the possibility to use the device as a pulsed high-density ion trap. The extension of this research helped to discover and to explain the (Cruise) effect, namely the capture and guiding of the electron beam by dielectric fibres. (author) 10 figs., 64 refs

  1. Medical beam monitor-Pre-clinical evaluation and future applications

    International Nuclear Information System (INIS)

    Future medical ion beam applications for cancer therapy which are based on scanning technology will require advanced beam diagnostics equipment. For a precise analysis of beam parameters we want to resolve time structures in the range of microseconds to nanoseconds. A prototype of an advanced beam monitor was developed by University of Applied Sciences Wiener Neustadt and its research subsidiary Fotec in co-operation with CERN RD42, Ohio State University and the Jozef Stefan Institute in Ljubljana. The detector is based on polycrystalline Chemical Vapor Deposition (pCVD) diamond substrates and is equipped with readout electronics up to 2 GHz analog bandwidth. In this paper we present the design of the pCVD-detector system and results of tests performed in various particle accelerator based facilities. Measurements performed in clinical high energy photon beams agreed within 1.2% with results obtained by standard ionization chambers

  2. Electron beam direct write: shaped beam overcomes resolution concerns

    Science.gov (United States)

    Stolberg, Ines; Pain, Laurent; Kretz, Johannes; Boettcher, Monika; Doering, Hans-Joachim; Gramss, Juergen; Hahmann, Peter

    2007-02-01

    In semiconductor industry time to market is one of the key success factors. Therefore fast prototyping and low-volume production will become extremely important for developing process technologies that are well ahead of the current technological level. Electron Beam Lithography has been launched for industrial use as a direct write technology for these types of applications. However, limited throughput rates and high tool complexity have been seen as the major concerns restricting the industrial use of this technology. Nowadays this begins to change. Variable Shaped Beam (VSB) writers have been established in Electron Beam Direct Write (EBDW) on Si or GaAs. In the paper semiconductor industry requirements to EBDW will be outlined. Behind this background the Vistec SB3050 lithography system will be reviewed. The achieved resolution enhancement of the VSB system down to the 22nm node exposure capability will be discussed in detail; application examples will be given. Combining EBDW in a Mix and Match technology with optical lithography is one way to utilize the high flexibility advantage of this technology and to overcome existing throughput concerns. However, to some extend a common Single Electron Beam Technology (SBT) will always be limited in throughput. Therefore Vistec's approach of a system that is based on the massive parallelisation of beams (MBT), which was initially pursued in a European Project, will also be discussed.

  3. Relativistic electron beam plasma heating experiment

    International Nuclear Information System (INIS)

    An intense (5 x 105 Amp/cm2), relativistic (5 MeV), electron beam will be used to investigate the heating of small volumes (approx. 5 to 10 cm3) of dense plasma (1017 to 1018 electrons/cm3) to kilovolt temperatures via the electrostatic two-stream instability

  4. Holographic generation of highly twisted electron beams

    CERN Document Server

    Grillo, Vincenzo; Mafakheri, Erfan; Frabboni, Stefano; Karimi, Ebrahim; Boyd, Robert W

    2014-01-01

    Free electrons can possess an intrinsic orbital angular momentum, similar to those in an electron cloud, upon free-space propagation. The wavefront corresponding to the electron's wavefunction forms a helical structure with a number of twists given by the \\emph{angular speed}. Beams with a high number of twists are of particular interest because they carry a high magnetic moment about the propagation axis. Among several different techniques, electron holography seems to be a promising approach to shape a \\emph{conventional} electron beam into a helical form with large values of angular momentum. Here, we propose and manufacture a nano-fabricated phase hologram for generating a beam of this kind with an orbital angular momentum up to 200$\\hbar$. Based on a novel technique the value of orbital angular momentum of the generated beam are measured, then compared with simulations. Our work, apart from the technological achievements, may lead to a way of generating electron beams with a high quanta of magnetic momen...

  5. Ribbon electron beam formation by a forevacuum plasma electron source

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, A. S., E-mail: klimov@main.tusur.ru; Burdovitsin, V. A. [Tomsk State University of Control System and Radioelectronics (Russian Federation); Grishkov, A. A. [SB RAS, Institute of High Current Electronics (Russian Federation); Oks, E. M.; Zenin, A. A.; Yushkov, Yu. G. [Tomsk State University of Control System and Radioelectronics (Russian Federation)

    2016-01-15

    Results of the numerical analysis and experimental research on ribbon electron beam generation based on hollow cathode discharge at forevacuum gas pressure are presented. Geometry of the accelerating gap has modified. It lets us focus the ribbon electron beam and to transport it on a distance of several tens of centimeters in the absence of an axial magnetic field. The results of numerical simulations are confirmed by the experiment.

  6. Green coffee decontamination by electron beam irradiation

    International Nuclear Information System (INIS)

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties

  7. Green coffee decontamination by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nemtanu, Monica R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)]. E-mail: monica@infim.ro; Brasoveanu, Mirela [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania); Grecu, Maria Nicoleta [National Institute for Materials Physics, RO 77 125, Bucharest-Magurele (Romania); Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor St., P.O. Box MG-36, RO 76 900, Bucharest-Magurele (Romania)

    2005-10-15

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties.

  8. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 pm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 run. We demonstrate how the EBL system can...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  9. Modelling of electron beam induced nanowire attraction

    Science.gov (United States)

    Bitzer, Lucas A.; Speich, Claudia; Schäfer, David; Erni, Daniel; Prost, Werner; Tegude, Franz J.; Benson, Niels; Schmechel, Roland

    2016-04-01

    Scanning electron microscope (SEM) induced nanowire (NW) attraction or bundling is a well known effect, which is mainly ascribed to structural or material dependent properties. However, there have also been recent reports of electron beam induced nanowire bending by SEM imaging, which is not fully explained by the current models, especially when considering the electro-dynamic interaction between NWs. In this article, we contribute to the understanding of this phenomenon, by introducing an electro-dynamic model based on capacitor and Lorentz force interaction, where the active NW bending is stimulated by an electromagnetic force between individual wires. The model includes geometrical, electrical, and mechanical NW parameters, as well as the influence of the electron beam source parameters and is validated using in-situ observations of electron beam induced GaAs nanowire (NW) bending by SEM imaging.

  10. Small field electron beam dosimetry using MOSFET detector.

    Science.gov (United States)

    Amin, Md Nurul; Heaton, Robert; Norrlinger, Bern; Islam, Mohammad K

    2011-01-01

    The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth-dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small field electron beam dosimetry. Since modern radiotherapy departments are becoming filmless in favor of electronic imaging, an alternate and readily available clinical dosimeter needs to be explored. We have studied the performance of MOSFET as a relative dosimeter in small field electron beams. The reproducibility, linearity and sensitivity of a high-sensitivity microMOSFET were investigated for clinical electron beams. In addition, the percent depth doses, output factors and profiles have been measured in a water tank with MOSFET and compared with those measured by an ion chamber for a range of field sizes from 1 cm diameter to 10 cm × 10 cm for 6, 12, 16 and 20 MeV beams. Similar comparative measurements were also per-formed with MOSFET and films in solid water phantom. The MOSFET sensitivity was found to be practically constant over the range of field sizes investigated. The dose response was found to be linear and reproducible (within ± 1% for 100 cGy). An excellent agreement was observed among the central axis depth dose curves measured using MOSFET, film and ion chamber. The output factors measured with MOSFET for small fields agreed to within 3% with those measured by film dosimetry. Overall results indicate that MOSFET can be utilized to perform dosimetry for small field electron beam. PMID:21330970

  11. Electron beam curable polymer thick film

    International Nuclear Information System (INIS)

    Currently, most printed circuit boards are produced by the selective etching of copper clads laminated on dielectric substrates such as paper/phenolic resion or nonwoven glass/epoxy resin composites. After the etchig, various components such as transistors and capacitors are mounted on the boards by soldering. But these are troublesome works, therefore, as an alternative, printing method has been investigated recently. In the printing method, conductor circuits and resistors can be made by printing and curing of the specially prepared paste on dielectric substrates. In the near future, also capacitors are made by same method. Usually, conductor paste, resistor paste and dielectric paste are employed, and in this case, the printing is screen printing, and the curing is done thermally. In order to avoid heating and the deterioration of substrates, attention was paid to electron beam curing, and electron beam curable polymer thick film system was developed. The electron beam curable paste is the milled mixture of a filler and an electron beam curable binder of oligomer/monomer. The major advantage of electron beam curable polymer thick film, the typical data of a printed resistor of this type and its trial are reported. (K.I.)

  12. Artificial charging of spacecraft due to electron beam emission

    International Nuclear Information System (INIS)

    Electron beams on a spacecraft can be used to simulate positive charging from energetic ions whether natural (Jovian) or artificial (particle beams). Plasma environment dependent charging effects during electron beam operations on SCATHA are discussed

  13. Electron beam treatment of textile dyeing wastewater

    International Nuclear Information System (INIS)

    A pilot plant with e-beam for treating 1,000m3/day of dyeing wastewater were constructed and started in operation from 1998, together with the biological treatment facility. The wastewater from various stages of the existing purification process can be treated with electron beam in this plant, and it will give rise to elaborate the optimal technology of the electron beam treatment of wastewater with increased reliability at instant changes in the composition of wastewater. Installation of the e-beam treatment results in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable to reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in flow rate limit of existing facilities by 30-40%. Commercial plants for treating over 10,000m3/day each, based upon this pilot experimental result, will start in construction from 2001 by the support of IAEA and Korean Government. (author)

  14. First test of BNL electron beam ion source with high current density electron beam

    Science.gov (United States)

    Pikin, Alexander; Alessi, James G.; Beebe, Edward N.; Shornikov, Andrey; Mertzig, Robert; Wenander, Fredrik; Scrivens, Richard

    2015-01-01

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm2 and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given.

  15. Dosimetry for Electron Beam Applications

    DEFF Research Database (Denmark)

    Miller, Arne

    1983-01-01

    This report describes two aspects of electron bean dosimetry, on one hand developaent of thin fil« dosimeters and measurements of their properties, and on the other hand developaent of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimet...

  16. Total scalp irradiation using fixed photon and arc electron beams

    International Nuclear Information System (INIS)

    Full text: The main difficulty encountered for radical radiotherapy to the whole scalp is reducing the dose to normal brain tissue, while maintaining uniform dose coverage to the entire scalp. Complicating this is the fact that multiple portals need to be employed (Able C, et al. Int. J. Rad. Oncol. Biol. Phys. 21 :1065- 1072; 1991). The technique adopted at the Liverpool Cancer Therapy Centre is the one developed at the University of California, San Francisco (Akazawa C, Med. Dos. 14:129-131, 1989). Lateral opposed photon fields and abutting electron fields are used with the same field centre for reproducibility. We employed this technique in the treatment of angiosarcoma of the scalp for one patient and produced acceptable clinical results. This study assesses the radiation dosimetry of two new techniques utilising electron arc therapy. The first technique treats the apex of the head with laterally opposed photon fields and the remaining area with an electron arc beam. The photon fields are used asymmetrically to counteract beam divergence effects and hence improve the dose uniformity in the junction region. The second technique solely employs electrons. A fixed electron field treats the apex of the head, while the arc electron beam covers the remaining scalp region. Arc electron beams were commissioned on the Varian Cadplan treatment planning system and the algorithm was then employed to calculate dosage distributions for the two new treatment techniques

  17. Electron beam processing of combustion flue gases

    International Nuclear Information System (INIS)

    This report contains the papers presented at the consultants' meeting on electron beam processing of combustion flue gases. The meeting provided an excellent opportunity for exchanging information and reviewing the current status of technology development. Characteristics of the electron beam processing recognized by the meeting are: capability of simultaneous removals of SO2 and NOx, safe technology and simplicity of control, dry process without waste water to be treated, cost benefit of electron beam processing compared with conventional technology and the conversion of SO2 and NOx to a by-product that can be used as agricultural fertilizer. A separate abstract was prepared for each of the 22 papers in this technical report

  18. Patient radiation doses for electron beam CT

    International Nuclear Information System (INIS)

    A Monte Carlo based computer model has been developed for electron beam computed tomography (EBCT) to calculate organ and effective doses in a humanoid hermaphrodite phantom. The program has been validated by comparison with experimental measurements of the CT dose index in standard head and body CT dose phantoms; agreement to better than 8% has been found. The robustness of the model has been established by varying the input parameters. The amount of energy deposited at the 12:00 position of the standard body CT dose phantom is most susceptible to rotation angle, whereas that in the central region is strongly influenced by the beam quality. The program has been used to investigate the changes in organ absorbed doses arising from partial and full rotation about supine and prone subjects. Superficial organs experience the largest changes in absorbed dose with a change in subject orientation and for partial rotation. Effective doses for typical clinical scan protocols have been calculated and compared with values obtained using existing dosimetry techniques based on full rotation. Calculations which make use of Monte Carlo conversion factors for the scanner that best matches the EBCT dosimetric characteristics consistently overestimate the effective dose in supine subjects by typically 20%, and underestimate the effective dose in prone subjects by typically 13%. These factors can therefore be used to correct values obtained in this way. Empirical dosimetric techniques based on the dose-length product yield errors as great as 77%. This is due to the sensitivity of the dose length product to individual scan lengths. The magnitude of these errors is reduced if empirical dosimetric techniques based on the average absorbed dose in the irradiated volume (CTDIvol) are used. Therefore conversion factors specific to EBCT have been calculated to convert the CTDIvol to an effective dose

  19. A high brightness electron beam for Free Electron Lasers

    NARCIS (Netherlands)

    Oerle, van Bartholomeus Mathias

    1997-01-01

    In a free electron laser, coherent radiation is generated by letting an electron beam propagate through an alternating magnetic field. The magnetic field is created by a linear array of magnets, which is called an undulator or a wiggler. The wavelength of the laser radiation depends on the amplitude

  20. Beam profile for Malaysian electron accelerator

    International Nuclear Information System (INIS)

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

  1. Solid waste electron beam treatment

    International Nuclear Information System (INIS)

    The possible applications of electron accelerators for solid waste treatment are discussed in the report. The elaborated technologies allow to recycle of materials (e.g. cellulosic materials in municipal waste), improve their hygienic standards (agricultural usage of sludge from municipal waste water treatment) and reduce harmful to environment chemical usage (cellulose degradation). These are environment friendly advanced technologies which meets demands waste recycling. (author)

  2. Tesla-transformer-type electron beam accelerator

    International Nuclear Information System (INIS)

    An electron-beam Tesla-transformer accelerator is described. It consists of the primary storage energy system. Tesla transformer, oil Blumlein pulse form line, and the vacuum diode. The experiments of initial stage showed that diode voltage rises up to about 500 kV with an input of 20 kV and the maximum electron-beam current is about 9 kA, the pulse width is about 50 ns. This device can operate stably and be set up easily

  3. Electron beam induced growth of tin whiskers

    International Nuclear Information System (INIS)

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols

  4. Electron beam induced growth of tin whiskers

    Science.gov (United States)

    Vasko, A. C.; Warrell, G. R.; Parsai, E. I.; Karpov, V. G.; Shvydka, Diana

    2015-09-01

    We have investigated the influence of electron irradiation on tin whisker growth. Sputtered tin samples exposed to electron beam of 6 MeV energy exhibited fast whisker growth, while control samples did not grow any whiskers. The statistics of e-beam induced whiskers was found to follow the log-normal distribution. The observed accelerated whisker growth is attributed to electrostatic effects due to charges trapped in an insulating substrate. These results offer promise for establishing whisker-related accelerated life testing protocols.

  5. Electron-beam distillation of natural polymers

    International Nuclear Information System (INIS)

    Pyrolysis of cellulose, lignin, and chitin may be upgraded by the use of an electron-beam irradiation. The radiation-thermal destruction mode does more probable production of liquid low-molecular-weight products instead of solid pyrolitic oligomers. Furans, methoxyphenols, and pyridines are dominant products of high-temperature radiolysis of cellulose, lignin, and chitin, respectively. The mechanism of chain destruction of natural polymers is considered. - Highlights: • Pyrolysis of cellulose, lignin, and chitin upgraded by electron-beam distillation. • Distillation of cellulose results in furans obtaining. • Phenols and pyridines are dominant products from lignin and chitin, respectively

  6. Optimisation of electron beam characteristics by simulated annealing

    International Nuclear Information System (INIS)

    Full text: With the development of technology in the field of treatment beam delivery, the possibility of tailoring radiation beams (via manipulation of the beam's phase space) is foreseeable. This investigation involved evaluating a method for determining the characteristics of pure electron beams which provided dose distributions that best approximated desired distributions. The aim is to determine which degrees of freedom are advantageous and worth pursuing in a clinical setting. A simulated annealing routine was developed to determine optimum electron beam characteristics. A set of beam elements are defined at the surface of a homogeneous water equivalent phantom defining discrete positions and angles of incidence, and electron energies. The optimal weighting of these elements is determined by the (generally approximate) solution to the linear equation, Dw = d, where d represents the dose distribution calculated over the phantom, w the vector of (50 - 2x104) beam element relative weights, and D a normalised matrix of dose deposition kernels. In the iterative annealing procedure, beam elements are randomly selected and beam weighting distributions are sampled and used to perturb the selected elements. Perturbations are accepted or rejected according to standard simulated annealing criteria. The result (after the algorithm has terminated due to meeting an iteration or optimisation specification) is an approximate solution for the beam weight vector (w) specified by the above equation. This technique has been applied for several sample dose distributions and phase space restrictions. An example is given of the phase space obtained when endeavouring to conform to a rectangular 100% dose region with polyenergetic though normally incident electrons. For regular distributions, intuitive conclusions regarding the benefits of energy/angular manipulation may be made, whereas for complex distributions, variations in intensity over beam elements of varying energy and

  7. Electron-beam-excited gas laser research

    International Nuclear Information System (INIS)

    Net energy gain in laser fusion places requirements on the laser that are not realized by any existing laser. Utilization of relativistic electron beams (REB's), a relatively new source for the excitation of gas laser media, may lead to new lasers that could satisfy these requirements. Already REB's have been utilized to excite gas laser media and produce gas lasers that have not been produced as successfully any other way. Electron-beam-excitation has produced electronic-transition dimer lasers that have not yet been produced by any other excitation scheme (for example, Xe2/ sup *(1)/, Kr:O(21S)/sup 2/, KrF/sup *(3)/). In addition, REB's have initiated chemical reactions to produce HF laser radiation with unique and promising results. Relativistic-electron-beam gas-laser research is continuing to lead to new lasers with unique properties. Results of work carried out at Sandia Laboratories in this pioneering effort of electron-beam-excited-gas lasers are reviewed. (U.S.)

  8. Electron-beam diagnostic for space-charge measurement of an ion beam

    OpenAIRE

    Roy, Prabir K.; Yu, Simon S.; Henestroza, Enrique; Eylon, Shmuel; Shuman, Derek B.; Ludvig, Jozsef; Bieniosek, Frank M.; Waldron, William L.; Greenway, Wayne G.; Vanecek, David L.; Hannink, Ryan; Amezcua, Monserrat

    2003-01-01

    An electron beam diagnostic system for measuring the charge distribution of an ion beam without changing its properties is presently under development for Heavy Ion Fusion (HIF) beam physics studies. Conventional diagnostics require temporary insertion of sensors into the beam, but these capture it, or significantly alter its properties. In this new diagnostic a low energy, low current electron beam is scanned transversely across the ion beam; the measured electron beam deflection is use...

  9. Dual scattering foil design for poly-energetic electron beams.

    Science.gov (United States)

    Kainz, K K; Antolak, J A; Almond, P R; Bloch, C D; Hogstrom, K R

    2005-03-01

    The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly

  10. Dual scattering foil design for poly-energetic electron beams

    International Nuclear Information System (INIS)

    The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly

  11. Proposed LLNL electron beam ion trap

    International Nuclear Information System (INIS)

    The interaction of energetic electrons with highly charged ions is of great importance to several research fields such as astrophysics, laser fusion and magnetic fusion. In spite of this importance there are almost no measurements of electron interaction cross sections for ions more than a few times ionized. To address this problem an electron beam ion trap (EBIT) is being developed at LLNL. The device is essentially an EBIS except that it is not intended as a source of extracted ions. Instead the (variable energy) electron beam interacting with the confined ions will be used to obtain measurements of ionization cross sections, dielectronic recombination cross sections, radiative recombination cross sections, energy levels and oscillator strengths. Charge-exchange recombinaion cross sections with neutral gasses could also be measured. The goal is to produce and study elements in many different charge states up to He-like xenon and Ne-like uranium. 5 refs., 2 figs

  12. Electron beam diagnostic for profiling high power beams

    Science.gov (United States)

    Elmer, John W.; Palmer, Todd A.; Teruya, Alan T.

    2008-03-25

    A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

  13. Electron cooling of heavy ion beams

    International Nuclear Information System (INIS)

    An introduction to the concept of phase-space compression of heavy-ion beams by electron cooling is given. Emphasis is put on a simple rather than a rigorous theoretical treatment of the underlying ideas. Some practical aspects are discussed in connection with a presentation of the designed cooling device for the ESR project of GSI Darmstadt. The problems of cooling-electron capture are briefly addressed. (HSI)

  14. The ESTRO-EQUAL results for photon and electron beams checks in European radiotherapy beams

    International Nuclear Information System (INIS)

    Background and purpose: European Society for Therapeutic Radiology and Oncology (ESTRO) has set up a Quality Assurance network for radiotherapy (EQUAL) carrying out dosimetry audit. Some of the work is done in cooperation with the IAEA. The network deals with measurements performed with mailed TLD irradiated in reference and non-reference conditions, for on-axis points in photons and electrons beams. Material and methods: The LiF DTL937 (Philitech, France) was used and read with the PCL3 automatic reader (FIMEL-PTW). The participating centres irradiate the TLD capsules to an absorbed dose of 2 Gy determined with the Treatment Planning System used in clinical routine. Results: Statistical data from the participating centres on their radiotherapy structure such as number of machines and beams qualities available, dosimetry protocols and equipment in use were analysed. 23 European and 2 Mediterranean Basin countries participated. Photons beam audit: 282 centres and 757 beams have been checked; 11% 60Co beams and 89 % of X-ray beams. Compared to the EQUAL reference dosimetry 1.4 % of the reference beam output dose values and 3% of the percentage depth doses are outside the tolerance level (deviation > ± 5%). The standard deviation for the reference beam output is 1.8 %. Five percent of the rectangular field dose checks and 4 % the wedge transmission factors had deviations > ± 5%. The analysis of the global results shows deviations > ± 5% in at least 1 point for 133 out of the 757 beams, mainly for large and rectangular fields and for wedged beams. At least 45 of these centres had one 'real dosimetric' problem in one or more parameters, which corresponds to 7% of the checked beams. Electron beam audit: 97 centres and 277 beams have been checked. 1.0 % of the reference beam output values (field size 10 cm x 10 cm) and about 2 % of the beam output for the others field sizes (15 cm x 20 cm, and 7 cm x 7 cm) are outside tolerance level (deviation > ± 5%). The standard

  15. Radiative cooling of relativistic electron beams

    International Nuclear Information System (INIS)

    Modern high-energy particle accelerators and synchrotron light sources demand smaller and smaller beam emittances in order to achieve higher luminosity or better brightness. For light particles such as electrons and positrons, radiation damping is a natural and effective way to obtain low emittance beams. However, the quantum aspect of radiation introduces random noise into the damped beams, yielding equilibrium emittances which depend upon the design of a specific machine. In this dissertation, the author attempts to make a complete analysis of the process of radiation damping and quantum excitation in various accelerator systems, such as bending magnets, focusing channels and laser fields. Because radiation is formed over a finite time and emitted in quanta of discrete energies, he invokes the quantum mechanical approach whenever the quasiclassical picture of radiation is insufficient. He shows that radiation damping in a focusing system is fundamentally different from that in a bending system. Quantum excitation to the transverse dimensions is absent in a straight, continuous focusing channel, and is exponentially suppressed in a focusing-dominated ring. Thus, the transverse normalized emittances in such systems can in principle be damped to the Compton wavelength of the electron, limited only by the Heisenberg uncertainty principle. In addition, he investigates methods of rapid damping such as radiative laser cooling. He proposes a laser-electron storage ring (LESR) where the electron beam in a compact storage ring repetitively interacts with an intense laser pulse stored in an optical resonator. The laser-electron interaction gives rise to rapid cooling of electron beams and can be used to overcome the space charge effects encountered in a medium energy circular machine. Applications to the designs of low emittance damping rings and compact x-ray sources are also explored

  16. Electron Beam Production by Pyroelectric Crystals

    CERN Document Server

    Brownridge, J D; Brownridge, James D.; Shafroth, Stephen M.

    2002-01-01

    Pyroelectric crystals are used to produce self-focused electron beams with energies greater than 170 keV. No high voltage power supply or electron gun is needed. The system works by simply changing the temperature of a crystal of LiNbO3 or LiTaO3 by about 100oC in dilute gas. Electron beam energy spectra as well as positive-ion-beam energy spectra and profiles are shown. A change in the crystal temperature of 100oC will cause a spontaneous change in polarization. The change in polarization will be manifested by a change in charge on the surface of the crystal. It is this uncompensated charge that produces the electric field, which accelerates the electrons, or the positive ions and gives rise to the plasma, which in turn focuses them. The source of the accelerated electrons or positive ions is gas molecules ionized near the crystal surface. When the crystal surface is negative electrons are accelerated away from it and positive ions are attracted to the surface. These positive ions reduce the net negative cha...

  17. Windowless Electron Beam Experimental Irradiation WEBExplr

    International Nuclear Information System (INIS)

    The design of the MYRRHA/XT-ADS, the European eXperimental Accelerator Driven System for the demonstration of Transmutation, includes a high power windowless spallation target operating with liquid LBE (Lead-Bismuth Eutectic) that will be irradiated with a 600 MeV proton beam at currents of up to 2.5 mA. When considering such a high power windowless target design, a number of questions need to be addressed, such as the stability of the free surface flow and its ability to remove the power deposited by the proton beam by forced convection, the compatibility of a large hot LBE reservoir with the beam line vacuum and the outgassing of the LBE in the spallation target circuit. These issues have been studied during previous experiments supported by numerical simulations. Another crucial point in the development of the spallation target is the demonstration of the safe and stable operation of the free LBE surface during irradiation with a high power proton beam. As a first step in this program, the WEBExpIr (Windowless target Electron Beam Experimental Irradiation) experiment was set up. The purpose of the WEBExpIr experiment was to investigate the influence of LBE surface heating caused by a charged particle beam in a situation representative of the MYRRHA/XT-ADS. More in particular, we wanted to assess possible free surface distortion or shockwave effects in nominal conditions and during sudden beam on/off transient situations, as well as possible enhanced evaporation

  18. Electron beam flue gas treatment process. Review

    International Nuclear Information System (INIS)

    The basis of the process for electron beam flue gas treatment are presented in the report. In tabular form the history of the research is reviewed. Main dependences of SO2 and NOx removal efficiencies on different physico-chemical parameters are discussed. Trends concerning industrial process implementation are presented in the paper,finally. (author). 74 refs, 11 figs, 1 tab

  19. Radiation dermatitis following electron beam therapy

    International Nuclear Information System (INIS)

    Ten patients, who had been treated for mycosis fungoides with electron beam radiation ten or more years previously, were examined for signs of radiation dermatitis. Although most patients had had acute radiation dermatitis, only a few manifested signs of mild chronic changes after having received between 1,000 and 2,800 rads

  20. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  1. The CMS Beam Halo Monitor electronics

    Science.gov (United States)

    Tosi, N.; Dabrowski, A. E.; Fabbri, F.; Grassi, T.; Hughes, E.; Mans, J.; Montanari, A.; Orfanelli, S.; Rusack, R.; Torromeo, G.; Stickland, D. P.; Stifter, K.

    2016-02-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes (PMTs). The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few nanosecond resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is read out via IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, providing online feedback on the beam quality. A dedicated calibration monitoring system has been designed to generate short triggered pulses of light to monitor the efficiency of the system. The electronics has been in operation since the first LHC beams of Run II and has served as the first demonstration of the new QIE10, Microsemi Igloo2 FPGA and high-speed 5 Gbps link with LHC data.

  2. Electron beam puts a shine on leather

    International Nuclear Information System (INIS)

    A technique for curing leather using either ultraviolet or electron-beam radiation has been developed. This type of radiation curing saves at least 60 percent of the energy cost of conventional leather finishing and can also result in considerable savings in plant space and labor. The implications of the new technology in international balance of trade are discussed

  3. Electron beam ion traps and their applications

    Institute of Scientific and Technical Information of China (English)

    ZOU Ya-Ming; Roger HUTTON

    2003-01-01

    A brief introduction to the historical background and current status of electron beam ion traps (EBITs)is presented. The structure and principles of an EBIT for producing highly charged ions are described. Finally,EBITs as a potential tool in hot-plasma diagnostics and in studying frontier problems of highly charged ion physicsare discussed.

  4. Penetration of electronic beams in ionizing media

    International Nuclear Information System (INIS)

    It is studied the penetration of an electron beam in an ionizable medium by means of a generalized kinetic equation. This equation is related to elastic collisions, processes of creation and destruction of particles. By integrating numerically the transport equation, it can be evaluated the relative effects of all the processes involved in the evolution of the system. (A.C.A.S.)

  5. Electron beam removal of gaseous organic pollutants

    International Nuclear Information System (INIS)

    This paper briefly reviews the VOC treatment by using electron beam technology carried out in the Institute of Nuclear Chemistry and Technology. VOC destruction was studied from experimental scale to pilot scale. Organic compounds as studied objects included chlorinated aliphatic compounds, aromatic and polynuclear aromatic hydrocarbons (PAHs). The possibility of VOC destruction by using EB technology was theoretically analyzed in this paper. (author)

  6. Electronic beam computer tomography and transthoracical echocardiography in postoperative after-treatment after orthoheart transplantation, clinical study before, during and after rejection therapy

    International Nuclear Information System (INIS)

    Nine pacemaker-stimulated patients with mild acute rejection were examined before, during, one week and six weeks (where the biopsy showed no rejection) after rejection therapy (methylprednisolon 1000 mg for three) with transthoracical echocardiography and electronic beam computer tomography (EBT). Ten patients with mild acute rejection without pacemaker stimulation were compared with the stimulated patients. The ejection fraction (EF) increased during therapy and decreased one week after therapy significantly in the stimulated, slightly in the control group. There were no echocardiographic parameters (EF, left and right ventricular diameters, wall thickness, flow and pressure above aortic and pulmonary valves) which showed significant differences before and six weeks after therapy. The EBT showed a significant decrease of left ventricular wall thickness and left ventricular mass. Transthoracical echocardiography seems to be no predicative method in the diagnosis mild acute heart allograft rejection. EBT could be a practicable noninvasive method to state acute heart allograft rejections. The effect of the methylprednisolone therapy could be associated with rejection. (author)

  7. Quality Assesment Of Photon And Electron Beams From Siemens PRIMUS Radiotherapy Accelerator

    International Nuclear Information System (INIS)

    There are two types of radiation from SIEMENS Primus Radiotherapy Accelerator at the National Cancer Hospital (K Hospital): electron and photon beams. Electron beams with four different energies of 6; 9; 12 and 15 MeV. Photon beams with two different energies: 6 MV and 15 MV. The symmetry as well as flatness of profiles created by all these beams are very important factors using in clinical practice. This report presents the method using water phantom to define absorbed dose distribution in medium of all beams. This is an effective and accurate method to define quality of radiation beams with different field sizes using in radiotherapy. (author)

  8. Ion beam therapy fundamentals, technology, clinical applications

    CERN Document Server

    2012-01-01

    The book provides a detailed, up-to-date account of the basics, the technology, and the clinical use of ion beams for radiation therapy. Theoretical background, technical components, and patient treatment schemes are delineated by the leading experts that helped to develop this field from a research niche to its current highly sophisticated and powerful clinical treatment level used to the benefit of cancer patients worldwide. Rather than being a side-by-side collection of articles, this book consists of related chapters. It is a common achievement by 76 experts from around the world. Their expertise reflects the diversity of the field with radiation therapy, medical and accelerator physics, radiobiology, computer science, engineering, and health economics. The book addresses a similarly broad audience ranging from professionals that need to know more about this novel treatment modality or consider to enter the field of ion beam therapy as a researcher. However, it is also written for the interested public an...

  9. The Stockholm Electron Beam Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, E.; Liljeby, L.; Engstroem, A.; Bjoerkhage, M. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden))

    1993-03-01

    The electron beam ion source, CRYSIS, produces highly charged ions for injection into the heavy ion storage ring - CRYRING at the Manne Siegbahn Institute, and for low energy atomic physics experiments. It will also provide highly charged ions for the Stockholm-Mainz Penning trap scheduled for installation at MSI in early 1993. CRYSIS has produced ions up to Ar[sup 18+] and [sup 136]Xe[sup 49+] using electron beam currents of typically I[sub e] = 200-300 mA and current density j[sub e] = 100-200 A/cm[sup 2]. Continuous electron beams of energy E = 19 keV and current I[sub e] = 600 mA have been propagated through the source with transmission greater than 99.9%. Test beams of He[sup 2+] and N[sup 7+] extracted from the source in 50-100 [mu]s pulses have been injected into CRYRING with the entire CRYSIS platform raised to 20 kV. Ions of charge up to [sup 136]Xe[sup 44+] extracted in extended 50-100 ms pulses have been used in coincidence-type atomic physics experiments. The status of CRYSIS as of March 15, 1992 is reported. Improvements, modes of operation, and results are discussed. (orig.).

  10. Relativistic-electron-beam-induced fusion

    International Nuclear Information System (INIS)

    The interaction of a focussed relativistic electron beam (REB) with a solid target has been investigated. The beam performance of the REB generator ''REIDEN III'' is 500 kV, 80 kA at a focal spot of 1.5 mm diameter, which gives 2X1012Wcm-2. High-temperature dense plasmas are produced at the focal point on the solid target. It expands radially along the target surface. The measured electron temperature (1-2 keV) and the ion energy (approximately 2 keV) endorse the existence of enhanced REB absorption in a dense plasma. The neutrons observed (approximately 109/shot, 2.45 MeV) in the case of a CD2 target are of thermonuclear origin and compatible with the plasma temperature. On the assumption that the electron beam of radius r is stopped at a length Λ and deposits its energy, the energy balance equation is approximately given by πr2Λn1kT=IVtau. On inserting beam current I, voltage V, pulse time tau and density n1, the energy deposition distance Λ can be estimated. For a fusion temperature of 1 keV, the distance Λ must be two orders of magnitude shorter than the simple classical stopping length, which seems to be due to non-linear coupling. A pellet implosion experiment of a multi-structure target has been performed. (author)

  11. Beam position monitoring electronics system for LEHIPA

    International Nuclear Information System (INIS)

    The primary function of beam position monitoring system (BPM) is to determine the position of the beam with respect to the centre of beam pipe. The present system is VME based and mainly consists of two VME boards one Analog and one Digital. The system has been developed for 352.21 MHz Low Energy High Intensity Proton Accelerator (LEHIPA). The electronic system processes the signals coming from the sensor which incorporates four button pick-ups placed orthogonally around the beam pipe. The fundamental component of the beam signal is extracted from the signals from the sensor and amplified with gain stabilized amplifiers on the analog board. Offset tone based technique has been used for the stabilization of the gain of the amplifiers against changes in temperature, power supply, etc. The filtered and amplified signals are given to the digital board for digitization and further processing. The signal processing consists of demodulation in I-Q domain followed by CORDIC which gives the signal information in the form of amplitude and phase. The stabilization of the gain is also carried out in the digital domain. The phase information can be utilized for energy gain measurements. The amplitudes give the position of the beam which is calculated online in FPGA using difference over sum method. The EPICS system has been chosen as the basic framework for command control. The hardware architecture is as per standard VME crate. (author)

  12. Simulation of Electron-Beam Generating Plasma at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    OUYANG Liang; LI Hong; LI Benben; ZHOU Junqing; YAN Hong; SU Tie; WANG Huihui; LIUWandong

    2007-01-01

    As electron-beam generating plasma is widely applied,the software tool EGS4(Electron-Gamma Shower) was used to simulate the transmission and energy deposition of electron-beam in air.The simulation results indicated that the range of the electron-beam was inversely proportional to the gas pressure in a wide range of gas pressure,and the electron-beam of 200 keV could generate a plasma with a density 1011 cm-3 in air of latm.In addition,the energy distribution of the beam-electron and plasma density profile produced by the beam were achieved.

  13. Generation and study of relativistic electron beam

    International Nuclear Information System (INIS)

    Pulsed Electron Beam (REB) technology has progressed rapidly in recent years because of applications in various fields like radiation sources, high power laser development, plasma heating and fusion research. The REB development programme at the Plasma Physics Section of Bhabha Atomic Research Centre, Bombay, has been described. The design features of the 375 KV, 3500 A, 75 Joule REB generator are discussed. The diagnostic equipment developed for the studies is described. The present experimental studies and some preliminary results on beam characterisation are presented. (author)

  14. Electron Accelerators for Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lia Merminga

    2007-10-10

    The summary of this paper is that to optimize the design of an electron drive, one must: (a) specify carefully the user requirements--beam energy, beam power, duty factor, and longitudinal and transverse emittance; (b) evaluate different machine options including capital cost, 10-year operating cost and delivery time. The author is convinced elegant solutions are available with existing technology. There are several design options and technology choices. Decisions will depend on system optimization, in-house infrastructure and expertise (e.g. cryogenics, SRF, lasers), synergy with other programs.

  15. Multi-electron beam system for high resolution electron beam induced deposition

    OpenAIRE

    Van Bruggen, M.J.

    2008-01-01

    The development of a multi-electron beam system is described which is dedicated for electron beam induced deposition (EBID) with sub-10 nm resolution. EBID is a promising mask-less nanolithography technique which has the potential to become a viable technique for the fabrication of 20-2 nm structures after 2013, as described by the International Technology Roadmap for Semiconductors (ITRS), or can be used for rapid prototyping in research applications. The key point is to combine the throughp...

  16. Transverse electron beam diagnostics at REGAE

    International Nuclear Information System (INIS)

    The use of high-intensity electron and X-ray pulsed sources allows for the direct observation of atomic motions as they occur. While the production of such high coherent, brilliant, short X-ray pulses requires large-scale and costly accelerator facilities, it is feasible to employ a high-intensity source of electrons by exploiting a more compact design. The Relativistic Electron Gun for Atomic Exploration (REGAE) facility is a small linear accelerator at DESY, Hamburg, equipped with a photocathode radio frequency (RF) gun that produces relativistic ultra-short (<100 fs), low charge (<1 pC) electron bunches of high coherence. By means of time-resolved diffraction experiments, such an electron source can probe ultrafast laser-induced atomic structural changes that occur with a temporal resolution of ∝100 fs. A comprehensive characterization of the electron beam, for every pulse, is of fundamental importance to study the atomic motions with the desired resolution and quality. This thesis reports on the transversal diagnostics of the electron beam with an emphasis on a scintillator-based beam profile monitor. The diagnostics is capable of evaluating the beam parameters such as charge, energy, energy spread and transverse profile, at very low charges and on a shot-to-shot basis. A full characterization of the scintillator's emission, the optical setup and the detector (camera) of the profile monitor is presented, from which an absolute charge calibration of the system is derived. The profile monitor is specially developed to accommodate more applications, such as dark current suppression, overlapping the electron probe and the laser pump within 1 ns accuracy, as well as charge and transverse emittance measurements. For the determination of the transverse emittance two techniques were applied. The first one introduces a new method that exploits a diffraction pattern to measure the emittance, while the second one is based on a version of the Pepper-pot technique. A

  17. Transverse electron beam diagnostics at REGAE

    Energy Technology Data Exchange (ETDEWEB)

    Bayesteh, Shima

    2014-12-15

    The use of high-intensity electron and X-ray pulsed sources allows for the direct observation of atomic motions as they occur. While the production of such high coherent, brilliant, short X-ray pulses requires large-scale and costly accelerator facilities, it is feasible to employ a high-intensity source of electrons by exploiting a more compact design. The Relativistic Electron Gun for Atomic Exploration (REGAE) facility is a small linear accelerator at DESY, Hamburg, equipped with a photocathode radio frequency (RF) gun that produces relativistic ultra-short (<100 fs), low charge (<1 pC) electron bunches of high coherence. By means of time-resolved diffraction experiments, such an electron source can probe ultrafast laser-induced atomic structural changes that occur with a temporal resolution of ∝100 fs. A comprehensive characterization of the electron beam, for every pulse, is of fundamental importance to study the atomic motions with the desired resolution and quality. This thesis reports on the transversal diagnostics of the electron beam with an emphasis on a scintillator-based beam profile monitor. The diagnostics is capable of evaluating the beam parameters such as charge, energy, energy spread and transverse profile, at very low charges and on a shot-to-shot basis. A full characterization of the scintillator's emission, the optical setup and the detector (camera) of the profile monitor is presented, from which an absolute charge calibration of the system is derived. The profile monitor is specially developed to accommodate more applications, such as dark current suppression, overlapping the electron probe and the laser pump within 1 ns accuracy, as well as charge and transverse emittance measurements. For the determination of the transverse emittance two techniques were applied. The first one introduces a new method that exploits a diffraction pattern to measure the emittance, while the second one is based on a version of the Pepper-pot technique. A

  18. A comparison of beam characteristics for gated and nongated clinical x-ray beams.

    Science.gov (United States)

    Ramsey, C R; Cordrey, I L; Oliver, A L

    1999-10-01

    Respiratory gating has only recently been applied to conventional external beam radiotherapy. In order for respiratory gating to be used clinically, an evaluation of the dosimetric effects of small units of delivered dose must be performed. The purpose of this study is to systematically evaluate the effect of various gating sequences on x-ray central axis output, ionization ratios (nominal accelerating potential), beam flatness, and beam symmetry. Measurements were taken for 6 and 18 MV photons on a linear accelerator that generates the gate by using a gridded electron gun to stop the electron flow to the wave-guide. The beam output, energy, flatness, and symmetry did not vary by more than 0.8 percent in most of the gating sequences. The maximum output deviations (0.8 percent), flatness deviations (1.9 percent), and symmetry deviations (0.8 percent) occurred when a low number of monitor units (<5 MU) were delivered in the gating window. Although these deviations are not clinically significant, each linear accelerator should be evaluated carefully before clinical implementation. PMID:10535624

  19. Electron beam irradiation in polymeric systems

    International Nuclear Information System (INIS)

    The electron beam applications in the chemistry of polymers, such as the production of acrylamide polymers, which are of great interest in the treatment of waste industrial waters are given. These products have unique properties: the required dose is smaller by a factor of 10 to 50 as compared to the dose requirement for other polymeric materials and they are used in aqueous solutions in a concentration of one or two magnitude orders smaller than the conventional inorganic flocculants. The acrylamide polymers technologies was first developed at semi-industrial scale with IETI 10000 gamma rays source and then transferred to the ALIN-10 electron linear accelerator. The operation of the ALIN-10 built in the Accelerator Laboratory from the Institute of Atomic Physics is presented. An original feature of this accelerator, using an electron gun of the diode type is its capability to obtain programmed beam single shots and pulse trains. It is particularly useful for the automatic control of irradiation processing in order to provide the maximum efficiency of the electron beam application. The preliminary results obtained by ALIN-10 lead to the assumption that the low output power high energy linacs are economically attractive for the commercial production of acrylamide type polymers. (Author) 7 Figs. 2 Tabs., 10 Refs

  20. Disabling CNT Electronic Devices by Use of Electron Beams

    Science.gov (United States)

    Petkov, Mihail

    2008-01-01

    Bombardment with tightly focused electron beams has been suggested as a means of electrically disabling selected individual carbon-nanotubes (CNTs) in electronic devices. Evidence in support of the suggestion was obtained in an experiment in which a CNT field-effect transistor was disabled (see figure) by focusing a 1-keV electron beam on a CNT that served as the active channel of a field-effect transistor (FET). Such bombardment could be useful in the manufacture of nonvolatile-memory circuits containing CNT FETs. Ultimately, in order to obtain the best electronic performances in CNT FETs and other electronic devices, it will be necessary to fabricate the devices such that each one contains only a single CNT as an active element. At present, this is difficult because there is no way to grow a single CNT at a specific location and with a specific orientation. Instead, the common practice is to build CNTs into electronic devices by relying on spatial distribution to bridge contacts. This practice results in some devices containing no CNTs and some devices containing more than one CNT. Thus, CNT FETs have statistically distributed electronic characteristics (including switching voltages, gains, and mixtures of metallic and semiconducting CNTs). According to the suggestion, by using a 1-keV electron beam (e.g., a beam from a scanning electron microscope), a particular nanotube could be rendered electrically dysfunctional. This procedure could be repeated as many times as necessary on different CNTs in a device until all of the excess CNTs in the device had been disabled, leaving only one CNT as an active element (e.g., as FET channel). The physical mechanism through which a CNT becomes electrically disabled is not yet understood. On one hand, data in the literature show that electron kinetic energy >86 keV is needed to cause displacement damage in a CNT. On the other hand, inasmuch as a 1-keV beam focused on a small spot (typically a few tens of nanometers wide

  1. Two-beam detuned-cavity electron accelerator structure

    International Nuclear Information System (INIS)

    Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.

  2. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G. [Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Singh, P. [Bhabha Atomic Research Centre, Mumbai (India)

    2013-12-15

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  3. Progress with Tevatron Electron Lens Head-On Beam-Beam Compensation

    International Nuclear Information System (INIS)

    Tevatron electron lenses have been successfully used to mitigate bunch-to-bunch differences caused by longrange beam-beam interactions. For this purpose, the electron beam with uniform transverse density distribution was used. Another planned application of the electron lens is the suppression of tune spread due to head-on beam-beam collisions. For this purpose, the transverse distribution of the E- beam must be matched to that of the antiproton beam. In 2009, the Gaussian profile electron gun was installed in one of the Tevatron electron lenses. We report on the first experiments with non-linear beam-beam compensation. Discussed topics include measurement and control of the betatron tune spread, importance of the beam alignment and stability, and effect of electron lens on the antiproton beam lifetime.

  4. Electron beam dynamics and design of electron beam ion-charge breeding source

    International Nuclear Information System (INIS)

    There is a requirement to develop an electron beam ion-charge breeding source (EBIBS) to produce a highly charged and highly pure ion beam of common elements as well as rare isotopes. The EBIBS consists of an electron gun chamber, the main solenoid and ionization chamber and an electron collector chamber for attaining highly charged and pure ion beam of species. Some studies have been performed to reach appropriate design of the proposed source, The report explains certain design choices and constraints involved in developing the EBIBS. Trajectory simulation of electron beams in >5A range current has been done to determine the configuration of electrodes and magnet coils appropriate to obtain high current density electron pencil beam at the ionization region in high magnetic field of the superconducting solenoid. The electron beam starts from the high pervious electron gun and dumped on the water cooled electron collector. The background pressure in the trap region should be low enough that one does not produce a significant number of ions from the background gas. An impurity value of the order of ∼5% can be tolerated, so an acceptable range of vacuum in EBIBS, 10-10 - 10-12 mbar, is assumed. Physics design of high perveance electron gun, superconducting solenoid ionization region and the electron collector has been done and is under further study to achieve superior design of the source, The mechanical design of various components and the source bench has been started also. All these developments will be presented in the conference. (author)

  5. Large area electron beam diode development

    International Nuclear Information System (INIS)

    A large area annular electron beam diode has been tested at Physics International Co. on the multi-terawatt PITHON generator. A twelve element post hole convolute converted the coaxial MITL into a triaxial arrangement of anode current return structures both inside and outside the cathode structure. The presence of both inner and outer current return paths provide magnetic pressure balance for the beam, as determined by diode current measurements. X-ray pinhole photographs indicated uniform emission with intensity maxima between the post positions. Current losses in the post hole region were negligible, as evidenced by the absence of damage to the aluminum hardware. Radial electron flow near the cathode ring however did damage the inner anode cylinder between the post positions. Cutting away these regions prevented further damage of the transmission lines

  6. Quality of electron beam irradiated strawberries

    International Nuclear Information System (INIS)

    Fresh 'Tristar' strawberries were treated by electron beam irradiation to determine the effects on postharvest quality attributes and shelf life. The intensity of red color rated by sensory panelists decreased as irradiation dosage increased from 0- to 2 kGy. Hunter 'L' values were higher for fruit treated with 2 kGy than for 0 and 0.5 kGy. Instron firmness values were lower for all irradiated fruit than for control fruit. Panelists rated irradiated fruit less firm than nonirradiated fruit stored 1, 2 and 4 days. An increase in off-flavor was noted among all treatments stored 6 and 8 days. Irradiation suppressed fungi on stored berries. Irradiation doses of 1 and 2 kGy extended shelf life 2 and 4 days, respectively. Electron beam irradiation technology has excellent potential for extension of shelf life of fresh strawberry fruits

  7. NOx reduction by compact electron beam processing

    International Nuclear Information System (INIS)

    Among the new methods being investigated for the post-combustion removal of nitrogen oxides (NOx) are based on non-thermal plasmas. These plasmas can be produced by electrical discharge methods or electron beam irradiation. The application of electron beam irradiation for NOx removal in power plant flue gases has been investigated since the early 1970's in both laboratory- and pilot-scale experiments. Electrical discharge methods are relatively new entrants in the field of flue gas cleanup. Pulsed corona and dielectric-barrier discharge techniques are two of the more commonly used electrical discharge methods for producing nonthermal plasmas at atmospheric pressure. There are basically two types of reactions responsible for the depletion of NO by non-thermal plasmas: oxidation and reduction

  8. Characterization of electron beam cured epoxy acrylate

    International Nuclear Information System (INIS)

    Epoxy resin has wide application in various industrial fields because of their good mechanical strength, superiority adhesion and low shrinkage etc. And the typical curing method for epoxy resins is thermal and press compaction. However, a curing method was used electron beam process in this study. Epoxy acrylate was fabricated from mixture of epoxy, acrylic acid, tetraphenylporphyrin (TPP) and hydroquinone monomethyl ether (MEHQ) with mole ratios. Then electron beam irradiation effect on the curing of the epoxy acrylate resin was investigated various absorption dose in nitrogen atmospheres at room temperature. The dynamic mechanical and thermal properties of the irradiated epoxy acrylate resins were characterized using dynamic mechanical analysis (DMA) and thermogravimetric analyzer (TGA). And the tensile and flexural strength were measured by an universal tensile machine (UTM)

  9. Compact two-beam push-pull free electron laser

    Science.gov (United States)

    Hutton, Andrew

    2009-03-03

    An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

  10. Multiple Electron Stripping of Heavy Ion Beams

    International Nuclear Information System (INIS)

    One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters

  11. Femtosecond Transversal Deflection of Electron Beams with the Help of Laser Beams and Its Possible Applications

    OpenAIRE

    Ispirian, K. A.; Ispiryan, M. K.

    2003-01-01

    It is shown that the interaction of an electron beam with polarized electromagnetic wave of laser photons propagating in the same direction in a short interaction region results in significant transversal deflection of the electrons which can be used for production of femtosecond electron and synchrotron radiation beams, for chopping the electron beams and construction of laser oscilloscopes measuring femtosecond processes.

  12. Electron beam therapy of mycosis fungoides

    International Nuclear Information System (INIS)

    Sixteen patients with mycosis fungoides were treated with a 3.3 MeV skin electron beam to a dose of 30 Gy over 40 days. Nine patients achieved a complete remission which was generally short. Only two patients remained free of disease one year following treatment. All patients received palliative benefit from treatment, but no significant increase in survival can be anticipated. (Auth.)

  13. Polarization in electron and proton beams

    International Nuclear Information System (INIS)

    One first introduces the concept of polarization for spin 1/2 particle beams and discusses properties of spin kinetics in a stationary magnetic field. Then the acceleration of polarized protons in synchrotrons is studied with emphasis on depolarization when resonances are crossed and on the cures for reducing it. Finally, transverse polarization of electrons in storage rings is discussed as an equilibrium between polarizing and depolarizing effects of synchrotron radiation. Means for obtaining longitudinal polarization are also treated

  14. Irradiation of Gemstones using Electron Beam

    International Nuclear Information System (INIS)

    Gemstone irradiation treatment using radiation is one of the studies conducted in the ALURTRON. The purpose of radiation is to study the effects of radiation on the gems. Through studies conducted on freshwater pearls and stones such as Topaz, Kunzite, TOURMALINE, Aquamarine, Quartz and so on, electron beam irradiation method can highlight the jewel colors but also to reduce the effects of haze on gemstones. The dose of radiation used is 25 kGy to 200 kGy. (author)

  15. Qualification of electron beam welding procedure

    International Nuclear Information System (INIS)

    In electron beam welding, the problem of the procedure qualification is quite special. The main results obtained are presented namely: the influence of the welding equipment used, the finding of significant testing to be taken into consideration for the process qualification. The experiments have been made using two different welding machines. Two materials have been selected (austenitic stainless steel and ferritic steel) and two welding positions (flat position and horizontal-vertical position) investigated

  16. Helical relativistic electron beam and THz radiation

    CERN Document Server

    Son, S

    2011-01-01

    A THz laser generation utilizing a helical relativistic electron beam propagating through a strong magnetic field is discussed. The initial amplification rate in this scheme is much stronger than that in the conventional free electron laser. A magnetic field of the order of Tesla can yield a radiation in the range of 0.5 to 3 THz, corresponding to the total energy of mJ and the duration of tens of pico-second, or the temporal power of the order of GW.

  17. Electron Beam Welding of Gear Wheels by Splitted Beam

    Science.gov (United States)

    Dřímal, Daniel

    2014-06-01

    This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max.. In case of common welding procedure, cracks were formed in the weld, initiated by spiking in the weld root. Crack formation was prevented by the use of an interlocking joint with a rounded recess and suitable welding parameters, eliminating crack initiation by spiking in the weld root. Minimisation of the welding distortions was achieved by the application of tack welding with simultaneous splitting of one beam into two parts in the opposite sections of circumferential face weld attained on the principle of a new system of controlled deflection with digital scanning of the beam. This welding procedure assured that the weldment temperature after welding would not be higher than 400 °C. Thus, this procedure allowed achieving the final run-outs in the critical point of gearwheels within the maximum range up to 0.04 mm, which is acceptable for the given application. Accurate optical measurements did not reveal any changes in the teeth dimensions.

  18. Stern-Gerlach Effect for Electron Beams

    International Nuclear Information System (INIS)

    The conflict between Bohr close-quote s assertion that the magnetic moment of the electron cannot be measured with experiments based on the concept of classical trajectories, and the measurement of the magnetic moment of electrons in a modified Penning trap by Dehmelt et al.has led us to reevaluate other implications of Bohr close-quote s assertion. We show that, contrary to the analysis of Bohr and Pauli, the assumption of classical trajectories in a Stern-Gerlach endash like device can result in a high degree of spin separation for an electron beam. This effect may persist within a fully quantum-mechanical analysis. The magnetic fields considered are such that a tabletop Stern-Gerlach electron spin filter is feasible. copyright 1997 The American Physical Society

  19. Transverse profile imager for ultrabright electron beams

    Science.gov (United States)

    Ischebeck, Rasmus; Prat, Eduard; Thominet, Vincent; Ozkan Loch, Cigdem

    2015-08-01

    A transverse profile imager for ultrabright electron beams is presented, which overcomes resolution issues in present designs by observing the Scheimpflug imaging condition as well as the Snell-Descartes law of refraction in the scintillating crystal. Coherent optical transition radiation emitted by highly compressed electron bunches on the surface of the crystal is directed away from the camera, allowing to use the monitor for profile measurements of electron bunches suitable for X-ray free electron lasers. The optical design has been verified by ray tracing simulations, and the angular dependency of the resolution has been verified experimentally. An instrument according to the presented design principles has been used in the SwissFEL Injector Test Facility, and different scintillator materials have been tested. Measurements in conjunction with a transverse deflecting radiofrequency structure and an array of quadrupole magnets demonstrate a normalized slice emittance of 25 nm in the core of a 30 fC electron beam at a pulse length of 10 ps and a particle energy of 230 MeV.

  20. Electron beam welding of austenitic stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel is used for liquid metal-cooled fast breeder reactors with operating temperature of about 550 deg C, because its elevated temperature properties are excellent and the results of use are abundant. The welded joints in LMFBRs require high degree of safety, and the application of electron beam welding is studied to make welding joints of high quality. When the inelastic deformation in a certain limit is allowed as prescribed in the ASME Code, Case 1592, the elevated temperature properties of the welded joints of structures are particularly important. The materials tested were 10 mm thick plates of SUS 304, SUS 316 and SUS 321 steels, and 150 kV - 40 mA electron beam welder was employed. The method of welding was one side, one pass Uranami welding, and first, the appropriate welding conditions were decided. Elevated temperature tensile test was carried out on the parent materials and welded joints by electron beam welding and coated arc welding. Creep rupture test and elevated temperature fatigue test were also carried out. In EB-welded austenitic stainless steel, delta ferrite is scattered finely in austenite, and its quantity is very small and less than 1.5%. The tensile strength and 0.2% proof stress of EB-welded joints are almost same as those of parent materials. The creep rupture and fatigue properties of the joints are also close to those of parent materials. (Kako, I.)

  1. Exhaust gas treatment by electron beam irradiation

    International Nuclear Information System (INIS)

    Among global environmental problems, atmospheric pollution has been discussed since relatively old days, and various countermeasures have been taken, but recently in connection with acid rain, the efficient and economical treatment technology is demanded. As the denitration and desulfurization technology for the exhaust gas from the combustion of fossil fuel, the incineration of city trash and internal combustion engines, three is the treatment method by electron beam irradiation. By irradiating electron beam to exhaust gas, nitrogen oxides and sulfur oxides are oxidized to nitric acid and sulfuric acid, and by promoting the neutralization of these acids with injected alkali, harmless salts are recovered. This method has the merit that nitrogen oxides and surfur oxides can be removed efficiently with a single system. In this report, as for the exhaust gas treatment by electron beam irradiation, its principle, features, and the present status of research and development are described, and in particular, the research on the recent exhaust gas treatment in city trash incineration is introduced. This treatment method is a dry process, accordingly, waste water disposal is unnecessary. The reaction products are utilized as fertilizer, and waste is not produced. (K.I.)

  2. Measuring the orbital angular momentum of electron beams

    OpenAIRE

    Giulio Guzzinati; Laura Clark; Armand B\\xe9ch\\xe9; Jo Verbeeck

    2014-01-01

    Abstract: The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, and diffraction from a knife ed...

  3. Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; /Fermilab; Alexahin, Yu.; Bishofberger, Kip; Kamerdzhiev, V.; Parkhomchuk, V.; Reva, V.; Solyak, N.; Wildman, D.; Zhang, X.-L.; Zimmermann, F.; /Fermilab /Los Alamos /Novosibirsk, IYF /CERN

    2008-02-01

    Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with 'electron lenses', novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position; we explore the effects of electron-beam imperfections and noises; and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses.

  4. Electron beam technology for details strengthening for steel industry

    International Nuclear Information System (INIS)

    The present paper is focused on the advanced deposition technologies, such as electron-beam surfacing in vacuum. Modern electron beam surfacing equipment «LUNa-10» has been developed for iron and steel industry. The present paper contains investigation of properties of composite coatings for different part of metallurgy equipment. Key words: electron-beam surfacing in vacuum, composite coatings, metallurgical

  5. Effects of electron beam irradiation on tin dioxide gas sensors

    Indian Academy of Sciences (India)

    Zheng Jiao; Xiaojuan Wan; Bing Zhao; Huijiao Guo; Tiebing Liu; Minghong Wu

    2008-02-01

    In this paper, the effects of electron beam irradiation on the gas sensing performance of tin dioxide thin films toward H2 are studied. The tin dioxide thin films were prepared by ultrasonic spray pyrolysis. The results show that the sensitivity increased after electron beam irradiation. The electron beam irradiation effects on tin dioxide thin films were simulated and the mechanism was discussed.

  6. Coherent Radiation from Relativistic Electron Beams.

    Science.gov (United States)

    Chen, Kuan-Ren

    Two new laser concepts, the Ion-Ripple Laser (IRL) and the Ion-Channel Laser (ICL), are proposed. A unified theory for coherent radiation from relativistic electron beams devices is developed; the theory not only links the physics of Cyclotron Masers (CMs) and Free Electron Lasers (FELs) but covers the physics of the IRLs and the ICLs. We have also invented a new numerical method, the Neo-Finite -Difference (NFD) method, for electromagnetic plasma simulations and applied it to studies of these lasers. The unified amplification theory compares the growth mechanisms. Two bunching mechanisms (both axial and azimuthal) exist, not only for the noncollective single electron resonance regime, but also in the collective gain regime. Competition or reinforcement between the two bunching mechanisms is determined by the q value (a parameter that determines how the electron oscillation frequency depends on energy), the electron axial velocity, and the wave phase velocity. The unified theory concludes that, for wave amplification, the sign of the electron mismatch frequency is required to be the same as the sign of a bunching parameter that is determined by the total bunching. In an IRL, a relativistic electron beam propagates obliquely through an ion ripple in a plasma. The radiation frequency depends on the beam energy, the ripple wave number, and the angle: omega ~ 2gamma ^{2}k_{ir}ccos theta. By proper choice of device parameters, sources of microwaves, optical, and perhaps even X-rays can be made. The dispersion relation for wave coupling is derived and used to calculate the radiation frequency and linear growth rate. The nonlinear saturation mechanism is explored. Computer simulation is used to verify the ideas, scaling laws and nonlinear mechanisms. In an ICL, the ion focusing force causes the electrons to oscillate about the channel axis and plays a similar role to the magnetic field in a CM. This electron motion is nonlinear and is studied. Simulations were performed

  7. First test of BNL electron beam ion source with high current density electron beam

    International Nuclear Information System (INIS)

    A new electron gun with electrostatic compression has been installed at the Electron Beam Ion Source (EBIS) Test Stand at BNL. This is a collaborative effort by BNL and CERN teams with a common goal to study an EBIS with electron beam current up to 10 A, current density up to 10,000 A/cm2 and energy more than 50 keV. Intensive and pure beams of heavy highly charged ions with mass-to-charge ratio < 4.5 are requested by many heavy ion research facilities including NASA Space Radiation Laboratory (NSRL) at BNL and HIE-ISOLDE at CERN. With a multiampere electron gun, the EBIS should be capable of delivering highly charged ions for both RHIC facility applications at BNL and for ISOLDE experiments at CERN. Details of the electron gun simulations and design, and the Test EBIS electrostatic and magnetostatic structures with the new electron gun are presented. The experimental results of the electron beam transmission are given

  8. Experimental demonstration of colliding beam lifetime improvement by electron lenses

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir; Alexahin, Yuri; Kamerdzhiev, Vsevolod; Kuznetsov, Gennady; Zhang, Xiao-Long; /Fermilab; Bishofberger, Kip; /Los Alamos

    2007-10-01

    We report successful application of space-charge forces of a low-energy electron beam for improvement of particle lifetime determined by beam-beam interaction in high-energy collider. In our experiments, an electron lens, a novel instrument developed for the beam-beam compensation, was set on a 980-GeV proton bunch in the Tevatron proton-antiproton collider. The proton bunch losses due to its interaction with antiproton beam were reduced by a factor of 2 when the electron lens was operating. We describe the principle of electron lens operation and present experimental results.

  9. Development of beam diagnostic devices for characterizing electron guns

    International Nuclear Information System (INIS)

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

  10. Ion accumulation and space charge neutralization in intensive electron beams for ion sources and electron cooling

    International Nuclear Information System (INIS)

    The Electron Beam Ion Sources (EBIS), Electron Beam Ion Traps (EBIT) and electron beams for electron cooling application have the beam parameters in the same ranges of magnitudes. EBIS and EBIT produce and accumulate ions in the beam due to electron impact ionization. The cooling electron beam accumulates positive ions from the residual gas in the accelerator chamber during the cooling cycle. The space charge neutralization of cooling beam is also used to reduce the electron energy spread and enhance the cooling ability. The advanced results of experimental investigations and theoretical models of the EBIS electron beams are applied to analyze the problem of beam neutralization in the electron cooling techniques. The report presents the analysis of the most important processes connected with ion production, accumulation and losses in the intensive electron beams of ion sources and electron cooling systems for proton and ion colliders. The inelastic and elastic collision processes of charged particles in the electron beams are considered. The inelastic processes such as ionization, charge exchange and recombination change the charge states of ions and neutral atoms in the beam. The elastic Coulomb collisions change the energy of particles and cause the energy redistribution among components in the electron-ion beams. The characteristic times and specific features of ionization, beam neutralization, ion heating and loss in the ion sources and electron cooling beams are determined. The dependence of negative potential in the beam cross section on neutralization factor is studied. 17 refs., 5 figs., 1 tab

  11. Coherent radiation by short bunch electron beam

    International Nuclear Information System (INIS)

    The electron beam which is accelerated with a linear accelerator forms the bunch of which the length in advancing direction is several millimeter. The radiation in far infrared region and transition radiation emitted from it are the coherent radiation, in which the phase of the radiation components from many electrons are uniform. Consequently, the intensity increases remarkably. By using this, the research on the properties of transition radiation of long wavelength and Cherenkov radiation which were unknown so far because those are weak was carried out. The radiation like this is not only powerful light source, but also it can be utilized to measure the shape of the bunch of accelerated particles. The coherent effect and the intensity of coherent radiation are explained. The spectra and the intensity distribution, the interference of coherent light, the properties of transition radiation, the formation layer of Cherenkov radiation from finite tracks and so on are reported. The measurement of the shape of bunch was carried out, and line-shaped beam and laterally extended beam are explained. The application as light source is reported. (K.I.)

  12. Environmental applications of electron-beam technology

    International Nuclear Information System (INIS)

    The main directions of modern environmental applications of electron-beam technology are the following: 1) treatment of polluted natural and drinking water, municipal and industrial wastewater, other liquid wastes; 2) purification of gases; 3) treatment of sewage sludges; 4) treatment of solid wastes (medical wastes, contaminated soil and so on). In some cases, the results of respective researches and developments found a large-scale application. For example, recently several industrial plants for electron-beam purification of flue gases of thermal power plants from SO2 and NOx were created in China, Poland and Japan. In the report, a brief summary of the most important results obtained in the mentioned directions will be presented. A special attention will be paid to the data in the first direction. In particular, the recent results on radiation treatment of some liquid systems obtained in the laboratory under author's leadership will be considered. One of them is water polluted with petroleum products (motor oil, diesel fuel, residual fuel oil). The pollutants were present in water in dissolved form and as a separate phase. It was found that irradiation (dose 25-40 kGy) decomposes and removes the pollutants as a precipitate. The second system is natural oil gas consisting of gaseous and low-boiling hydrocarbons, water and so on. Laboratory- and pilot-scale (with electron accelerator of 0.7 MeV and 30 kW) studies have shown that electron-beam treatment (in a recycling regime with continuous sampling the liquid phase) of this gas leads to the formation of a mixture of liquid branched hydrocarbons, alcohols, ethers and so on, i.e., there is a radiation-induced liquefaction of the natural oil gas. The mechanism of radiolytic conversions occurring in the mentioned systems will be discussed

  13. Electron beam disinfection of sewage sludge

    International Nuclear Information System (INIS)

    Electron beam treatment of dehydrated sewage sludge for safe reutilization was performed. Ranges of total bacterial counts and total coliforms in the sludge were from 1.5 x 108 to 1.6 x 109 and from 2.2 x 107 to 1.5 x 108 per wet gram, respectively. Total bacterial counts decreased about 5 log cycles after irradiating 5 kGy and irradiation with 2 kGy was enough to kill all coliforms in sewage sludge. The survival curves of total bacteria, obtained by irradiation in oxygen atmosphere, approached to that in nitrogen atmosphere with the increase of sludge thickness. No effects of dose rate and electron energy were found when the sludge layers were thin enough. Continuous disinfection of sewage sludge cake, with the maximum feed rate of 300 kg-sludge/hr, was successfully performed with a Cockcroft-Walton type electron accelerator, a sludge pump and a flat nozzle. (J.P.N.)

  14. Electron Beam Diagnostic at the ELBE Free Electron Laser

    OpenAIRE

    Evtushenko, Pavel

    2004-01-01

    The radiation source ELBE is a scientific user facility able to generate electromagnetic radiation as well as beams of secondary particles. The figure below shows the layout of the facility. ELBE is based on a superconducting electron linac. The linac consists of two accelerating modules and uses TESLA type nine-cell niobium cavities, two cavities in each module. The cavities were developed at DESY in the framework of the TESLA linear collider project and the X-ray free electron laser (FEL) p...

  15. Implementation to spanish protocol of quality control of accelerators to daily control of electron beams

    International Nuclear Information System (INIS)

    A revised procedure for daily control of the electron beams to make measurements more meaningful physically, having a better reproducibility and more in line with the recommendations of the Spanish Protocol for Quality Control in Electron Linear Accelerators Clinical Use. The daily quality control beams of high energy electrons that had been done so far was the finding that the record of a series of measures (symmetry, uniformity, stability, energy, beam central dose) were within tolerance values established. The amendment is to check the beam quality by directly measuring changes in absorption depth at which the dose is reduced to half its maximum value, R50.

  16. The principle and applications of an iso-energetic intensity modulation method for therapeutic electron beams

    International Nuclear Information System (INIS)

    Purpose/Objective: Many clinical situations indicate that an electron beam with a modified dose profile, i.e., tilted, concave or other shape is useful for the treatment with a curved, oblique or other non-flat skin surface. The well known difficulty in electron beam dose profile modification is the energy degradation while using absorbers with different thickness, such as wedge shape filter, similar to photon wedges. In this presentation, we describe the principle and applications of an iso-energetic electron beam intensity modulation method, a general technique which can be used to modified the intensity of a static electron field with virtually no alteration of the original beam energy. Materials and Methods: Due to the Coulomb multiple-scattering effect in air medium, Gaussian spread in air of the electron beam broadens with increasing distance from the source. Two narrow parallel electron beams with limited separation will join together as one composite distribution at certain distance from the source. Based on this physical principle, the intensity distribution of a broad electron beam can be modulated into different shapes by dividing the broad beam into a plurality of narrow slit electron beams with different spatial separation. With an adequate distance, these narrow electron beams merge to form a profile with desired shape and smoothness. Since an intensity modulated electron beam results from the plurality of narrow electron beams which have the same energy characteristics, the modulated beam will have the same energy as the original open beam. The applications of this new technique include the constructions of iso-energetic electron beam 'wedge' filters, concave filters (for dome shape skin surface such as skull), flattening filters for total skin treatment at an extended SSD, linac internal electron beam scattering/flattening filter, and other general electron beam compensating filters for irregular skin surface. Results: Several iso-energetic electron

  17. Use of beam deflection to control an electron beam wire deposition process

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hofmeister, William H. (Inventor); Hafley, Robert A. (Inventor)

    2013-01-01

    A method for controlling an electron beam process wherein a wire is melted and deposited on a substrate as a molten pool comprises generating the electron beam with a complex raster pattern, and directing the beam onto an outer surface of the wire to thereby control a location of the wire with respect to the molten pool. Directing the beam selectively heats the outer surface of the wire and maintains the position of the wire with respect to the molten pool. An apparatus for controlling an electron beam process includes a beam gun adapted for generating the electron beam, and a controller adapted for providing the electron beam with a complex raster pattern and for directing the electron beam onto an outer surface of the wire to control a location of the wire with respect to the molten pool.

  18. Research on Brightness Measurement of Intense Electron Beam

    CERN Document Server

    Wang, Yuan; Zhang, Huang; Yang, GuoJun; Li, YiDing; Li, Jin

    2015-01-01

    The mostly research fasten on high emission density of injector to study electron beam's brightness in LIA. Using the injector(2MeV) was built to research brightness of multi-pulsed high current(KA) electron beam, and researchs three measurement method (the pepper-pot method, beam collimator without magnetic field, beam collimator with magnetic field method) to detect beam's brightness with time-resolved measurement system.

  19. Electron beam application in gas waste treatment in China

    International Nuclear Information System (INIS)

    In the most recent decade, electron beam waste treatment technology attracted serious attention from environment policymaker and industrial leaders in power industry in China. Starting in middle of 1980's, Chinese research institute began experiment of electron beam treatment on flue gas. By the end of 2000, two 10,000 cubic meters per hour small scale electron beam gas purifying station were established in Sichuang province and Beijing. Several electron beam gas purifying demonstration projects are under construction. With robust economy and strong energy demand, needless to say, in near future, electron beam gas purifying technology will have a bright prospect in China. (author)

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

    Science.gov (United States)

    Retsky, Michael W.

    2007-10-16

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

  1. The CMS Beam Halo Monitor Electronics

    CERN Document Server

    Tosi, Nicolo

    2015-01-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes. The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few ns resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is readout by IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, provid...

  2. Electron beam processing - status and prospects

    International Nuclear Information System (INIS)

    A variety of commercial products now on the market are being produced by electron beam processing, which involves the treatment of materials with high-energy electrons to obtain beneficial effects. Ongoing applications include the high-speed curing of printing inks, clear and pigmented coatings, release coatings and adhesive films, the crosslinking of plastic film, foam, tubing, pipe, molded parts, electrical wire and cable, the cold vulcanization of rubber sheets for automobile tires and factory roofing as well as the sterilization of medical devices and packaging materials, and the preservation of food. Continuing growth is being driven by some inherent advantages of electron beam processing over alternative chemical and thermal treatment processes, such as enhanced product quality and lower unit costs that result from higher production rates, dynamic process control, quicker process start-up and shutdown, and reductions in scrap loss, energy consumption, floor space requirements, and toxic residues. Other potential applications that have not yet reached commercial fruition are focused on environmental protection and the reclamation of waste materials. These include the disinfection of potable water supplies, municipal waste water, sewage sludge, and the infectious wastes from hospitals and airports, the modification of toxic chemicals, the degradation of cellulosic materials, the cracking of crude oil and residual tars from refineries, and the extraction of sulfur and nitrogen oxides from combustion gases to reduce the effects of acid rain

  3. Estimation of the Processing Parameters in Electron Beam Thermal Treatments

    OpenAIRE

    Dulau, Mircea

    2014-01-01

    Electron beam have many special properties which make them particularly well suited for use in materials handling through melting, welding, surface treatment, etc., taking into account that this manufacturing is performed in vacuum. The use of electron beam for surface limited heat treatment of workpiece has brought about a noticeable extension of the beam technologies. Some theoretical aspects and simulation results are presented in this paper, considering a high power electron beam processi...

  4. Purification of iridium by electron beam melting

    International Nuclear Information System (INIS)

    The purification of iridium metal by electron beam melting has been characterized for 48 impurity elements. Chemical analysis was performed by glow discharge mass spectrographic (GDMS) analysis for all elements except carbon, which was analyzed by combustion. The average levels of individual elemental impurities in the starting powder varied from 37 μg/g to 0.02 μg/g. The impurity elements Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb, and Bi were not detectable following the purification. No significant change in the concentration of the elements Ti, V, Zr, Nb, Mo, and Re was found following melting. The elements B, C, Al, Si, Cr, Fe, Ru, Rh, and Pt were partially removed by vaporization during electron beam melting. Langmuir's equation for ideal vaporization into a vacuum was used to calculate for each impurity element the expected ratio of impurity content after melting to that before melting. Equilibrium vapor pressures were calculated using Henry's law, with activity coefficients obtained from published data for the elements Fe, Ti, and Pt. Activity coefficients were estimated from enthalpy data for Al, Si, V, Cr, Mn, Co, Ni, Zr, Nb, Mo, and Hf and an ideal solution model was used for the remaining elements. The melt temperature was estimated from measured iridium weight loss and impurity measurements. Good agreement, either quantitative or qualitative, was found between measured and calculated impurity ratios for all impurity elements. The results are consistent with some localized heating of the melt pool due to rastering of the electron beam, with an average vaporization temperature of 3100 K as compared to a temperature of 2965 K calculated for uniform heating of the melt pool. The results are also consistent with ideal mixing in the melt pool

  5. Electron acoustic solitons in the presence of an electron beam and superthermal electrons

    Directory of Open Access Journals (Sweden)

    S. Devanandhan

    2011-09-01

    Full Text Available Arbitrary amplitude electron acoustic solitons are studied in an unmagnetized plasma having cold electrons and ions, superthermal hot electrons and an electron beam. Using the Sagdeev pseudo potential method, theoretical analysis is carried out by assuming superthermal hot electrons having kappa distribution. The results show that inclusion of an electron beam alters the minimum value of spectral index, κ, of the superthermal electron distribution and Mach number for which electron-acoustic solitons can exist and also changes their width and electric field amplitude. For the auroral region parameters, the maximum electric field amplitudes and soliton widths are found in the range ~(30–524 mV m−1 and ~(329–729 m, respectively, for fixed Mach number M = 1.1 and for electron beam speed of (660–1990 km s−1.

  6. Polymeric materials obtained by electron beam irradiation

    International Nuclear Information System (INIS)

    Research activities in the field of electron beam irradiation of monomer aqueous solution to produce polymeric materials used for waste waters treatment, agriculture and medicine are presented. The technologies and special features of these polymeric materials are also described. The influence of the chemical composition of the solution to ba irradiated, absorbed dose level and absorbed dose rate level are discussed. Two kinds of polyelectrolytes, PA and PV types and three kinds of hydrogels, pAAm, pAAmNa and pNaAc types, the production of which was first developed with IETI-10000 Co-60 source and then adapted to the linacs built in Accelerator Laboratory, are described. (author)

  7. Limits to Electron Beam Emittance from Stochastic Coulomb Interactions

    International Nuclear Information System (INIS)

    Dense electron beams can now be generated on an ultrafast timescale using laser driven photo-cathodes and these are used for a range of applications from ultrafast electron defraction to free electron lasers. Here we determine a lower bound to the emittance of an electron beam limited by fundamental stochastic Coulomb interactions.

  8. Limits to Electron Beam Emittance from Stochastic Coulomb Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Coleman-Smith, Christopher; Padmore, Howard A.; Wan, Weishi

    2008-08-22

    Dense electron beams can now be generated on an ultrafast timescale using laser driven photo-cathodes and these are used for a range of applications from ultrafast electron defraction to free electron lasers. Here we determine a lower bound to the emittance of an electron beam limited by fundamental stochastic Coulomb interactions.

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

    Science.gov (United States)

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

    1996-02-01

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

  10. Beam characterisation of the KIRAMS electron microbeam system

    International Nuclear Information System (INIS)

    An electron microbeam system has been installed at the Korea Inst. of Radiological and Medical Sciences (KIRAMS) for use in radiation biology studies. The electron beam is produced from a commercial electron gun, and the beam size is defined by a 5 μm diameter pinhole. Beam energy can be varied in the range of 1-100 keV, covering a range of linear energy transfer from 0.4 to 12.1 keV μm-1. The micrometer-sized electron beam selectively irradiates cells cultured in a Mylar-bottomed dish. The positioning of target cells one by one onto the beam exit is automated, as is beam shooting. The electron beam entering the target cells has been calibrated using a Passivated Implanted Planar Silicon (PIPS) detector. This paper describes the KIRAMS microbeam cell irradiation system and its beam characteristics. (authors)

  11. Study on nanosecond pulsed electron beam generation

    Science.gov (United States)

    Ponomarev, D.; Kholodnaya, G.; Remnev, G.; Kaikanov, M.; Sazonov, R.

    2014-11-01

    The paper presents the findings of an investigation on volt-ampere characteristics of the diode with explosive emission cathodes of different constructions (blade metal-dielectric (MD-cathode) and solid graphite cathodes) under the change of the anode-cathode gap in wide ranges. The investigations were carried out using the TEA-500 pulsed electron accelerator. The total current of the electron beam was measured using the Faraday cup (FC). A 0.5-mm foiled glass fiber laminate was used as an emitting edge of the cathode in the experimental study with the explosive emission blade MD-cathode. Based on the obtained results, the conclusion was made that the graphite cathode has the most effective efficiency factor.

  12. Study on nanosecond pulsed electron beam generation

    International Nuclear Information System (INIS)

    The paper presents the findings of an investigation on volt-ampere characteristics of the diode with explosive emission cathodes of different constructions (blade metal-dielectric (MD-cathode) and solid graphite cathodes) under the change of the anode-cathode gap in wide ranges. The investigations were carried out using the TEA-500 pulsed electron accelerator. The total current of the electron beam was measured using the Faraday cup (FC). A 0.5-mm foiled glass fiber laminate was used as an emitting edge of the cathode in the experimental study with the explosive emission blade MD-cathode. Based on the obtained results, the conclusion was made that the graphite cathode has the most effective efficiency factor

  13. The electron beam instability and turbulence theories

    Science.gov (United States)

    Dum, C. T.

    1990-01-01

    Extensions and practical applications of recent observations of electron beam-plasma interactions are investigated for the range of turbulence theories, extending from quasi-linear to strong turbulence theory, which have been developed on the basis of the Langmuir-wave excitation model. Electron foreshock observations have indicated that linear instability theory must encompass the excitation of waves whose frequencies are substantially different from those of the plasma frequency; the point of departure for such extensions should be a quantitative test of existing theories, and particle simulations conducive to such testing are presented. A step-by-step addition of physical considerations is used in such simulation studies to differentiate among nonlinear turbulence effects.

  14. Electron beam welding of heat exchangers

    International Nuclear Information System (INIS)

    For a long time neither qualitative, nor quantitative criteria have been available that would have allowed choosing the most suitable welding techniques from the three stated below: 1) electron gun rotates relative to stationary tube; 2) electron beam is magnetically deviated relative to stationary tube; 3) permanent deviation magnet is rotated mechanically relative to stationary tube and gun. To our experience, the 2nd technique is most promising when welding 16x1.5 diameter stainless tubes. The e-b welds are vulnerable to root defects. With welding done in a movable manner, the root defect area will be found to locate in the tube plate body and, hence, the weldment, as a whole, will not be impaired

  15. Study of electron beam production by a plasma focus

    International Nuclear Information System (INIS)

    A preliminary investigation of the electron beam produced by a plasma focus device using a current charged transmission line is described. Electron beam currents as high as 10 kA were measured. Interaction of the extracted beam and the filling gas was studied using open shutter photography

  16. Generation and application of bessel beams in electron microscopy.

    Science.gov (United States)

    Grillo, Vincenzo; Harris, Jérémie; Gazzadi, Gian Carlo; Balboni, Roberto; Mafakheri, Erfan; Dennis, Mark R; Frabboni, Stefano; Boyd, Robert W; Karimi, Ebrahim

    2016-07-01

    We report a systematic treatment of the holographic generation of electron Bessel beams, with a view to applications in electron microscopy. We describe in detail the theory underlying hologram patterning, as well as the actual electron-optical configuration used experimentally. We show that by optimizing our nanofabrication recipe, electron Bessel beams can be generated with relative efficiencies reaching 37±3%. We also demonstrate by tuning various hologram parameters that electron Bessel beams can be produced with many visible rings, making them ideal for interferometric applications, or in more highly localized forms with fewer rings, more suitable for imaging. We describe the settings required to tune beam localization in this way, and explore beam and hologram configurations that allow the convergences and topological charges of electron Bessel beams to be controlled. We also characterize the phase structure of the Bessel beams generated with our technique, using a simulation procedure that accounts for imperfections in the hologram manufacturing process. PMID:27203186

  17. Polarization of a stored electron beam

    International Nuclear Information System (INIS)

    Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given

  18. Electron beam irradiation technology for environmental conservation

    International Nuclear Information System (INIS)

    This paper reviews research and development of application of electron beam (EB) irradiation technology for treatment of flue gas and waste water, and for disinfection of sewage sludge. Feasibility studies on EB purification of flue gases have been performed with pilot-scale experiments in Japan, the USA and Germany, and is being carried out in Poland for flue gases from iron-sintering furnaces or coal burning boilers. Based on results obtained by experiments using simulated flue gas, pilot scale test for treatment of flue gas of low-sulfur containing coal combustion has recently started in Japan. Organic pollutants in waste water and ground water have been found to be decomposed by EB irradiation. Synergetic effect of EB irradiation and ozone addition was found to improve the decomposition efficiency. Electron beam irradiation technology for disinfection of water effluent from water treatment plants was found to avoid formation of chlorinated organic compounds which are formed in using chlorine. Efficient process for composting of sewage sludge disinfected by EB irradiation has been developed by small scale and pilot scale experiments. In the new process, disinfection by EB irradiation and composing can be done separately and optimum temperature for composting can be, therefore, selected to minimize period of composting. (author)

  19. Industrial wastewater treatment with electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bumsoo; Ko, Jaein; Kim, Jinkyu; Kim, Yuri; Chung, Wooho [Central Research Institute of Samsung Heavy Industries Co., Taejon (Korea)

    2001-03-01

    Global withdrawals of water to satisfy human demands have grown dramatically in this century. Between 1900 and 1945, water consumption increased by over six times, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industrial uses, and the increasing use per capita for domestic purposes. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. In the Central Research Institute of Samsung Heavy Industries (SHI), many industrial wastewater including leachate from landfill area, wastewater from papermill, dyeing complex, petrochemical processes, etc. are under investigation with electron beam irradiation. For the study of treating dyeing wastewater combined with conventional facilities, an electron beam pilot plant for treating 1,000m{sup 3}/day of wastewater from 80,000m{sup 3}/day of total dyeing wastewater has constructed and operated in Taegu Dyeing Industrial Complex. A commercial plant for re-circulation of wastewater from Papermill Company is also designed for S-paper Co. in Cheongwon City, and after the successful installation, up to 80% of wastewater could be re-used in paper producing process. (author)

  20. Electron beam melting of sponge titanium

    International Nuclear Information System (INIS)

    Fundamental investigations were done on electron beam (EB) melting of sponge titanium by using 80 kW EB melting furnace. Results obtained are as follows: (1) To increase the melting yield of titanium in EB melting of sponge titanium, it is important to recover splashed metal by installation of water-cooled copper wall around the hearth and to decrease evaporation loss of titanium by keeping the surface temperature of molten metal just above the melting temperature of titanium without local heating. (2) Specific power consumption of drip melting of pressed sponge titanium bar and hearth melting of sponge titanium are approximately 0.9 kWh/kg-Ti and 0.5-0.7 kWh/kg-Ti, respectively. (3) Ratios of the heat conducted to water-cooled mould in the drip melting and to water-cooled hearth in the hearth melting to the electron beam input power are 50-65% and 60-65%, respectively. (4) Surface defects of EB-melted ingots include rap which occurs when the EB output is excessively great, and transverse cracks when the EB output is excessively small. To prevent surface defects, the up-down withdrawal method is effective. (author)

  1. Polarization of a stored electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chao, A.W.

    1981-07-01

    Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given.

  2. Contact lens surface by electron beam

    International Nuclear Information System (INIS)

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility

  3. Contact lens surface by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hyuck [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin [Dongshin Univ., Naju (Korea, Republic of)

    2011-07-01

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility.

  4. Industrial wastewater treatment with electron beam

    International Nuclear Information System (INIS)

    Global withdrawals of water to satisfy human demands have grown dramatically in this century. Between 1900 and 1945, water consumption increased by over six times, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industrial uses, and the increasing use per capita for domestic purposes. Given the seriousness of the situation and future risk of crises, there is an urgent need to develop the water-efficient technologies including economical treatment methods of wastewater and polluted water. In the Central Research Institute of Samsung Heavy Industries (SHI), many industrial wastewater including leachate from landfill area, wastewater from papermill, dyeing complex, petrochemical processes, etc. are under investigation with electron beam irradiation. For the study of treating dyeing wastewater combined with conventional facilities, an electron beam pilot plant for treating 1,000m3/day of wastewater from 80,000m3/day of total dyeing wastewater has constructed and operated in Taegu Dyeing Industrial Complex. A commercial plant for re-circulation of wastewater from Papermill Company is also designed for S-paper Co. in Cheongwon City, and after the successful installation, up to 80% of wastewater could be re-used in paper producing process. (author)

  5. Electron Beam Welding of Thick Copper Material

    Energy Technology Data Exchange (ETDEWEB)

    Broemssen, Bernt von [IVF Industriforskning och utveckling AB, Stockholm (Sweden)

    2002-08-01

    The purpose of this study was to review the two variants of the Electron Beam Welding (EBW) processes developed (or used) by 1- SKB, Sweden with assistance from TWI, England and 2 - POSIVA, Finland with assistance from Outokumpu, Finland. The aim was also to explain the principle properties of the EBW method: how it works, the parameters controlling the welding result but also giving rise to benefits, and differences between the EBW variants. The main conclusions are that both SKB and POSIVA will within a few years succeed to qualify their respective EBW method for welding of copper canisters. The Reduced Pressure EBW that SKB use today seems to be very promising in order to avoid root defects. If POSIVA does not succeed to avoid root defects with the high vacuum method and the beam oscillation technique it should be possible for POSIVA to incorporate the Reduced Pressure technique albeit with significant changes to the EBW equipment. POSIVA has possibly an advantage over SKB with the beam oscillation technique used, which gives an extra degree of freedom to affect the weld quality. The beam oscillation could be of importance for closing of the keyhole. Before EBW of lids, the material certification showing the alloy content (specifying min and max impurity percentages) and the mechanical properties should be checked. The welded material needs also to be tested for mechanical properties. If possible the weld should have a toughness level equal to that of the unwelded parent material. Specifically some conclusions are reported regarding the SKB equipment. Suggestions for further development are also given in the conclusion chapter.

  6. Electron Beam Welding of Thick Copper Material

    International Nuclear Information System (INIS)

    The purpose of this study was to review the two variants of the Electron Beam Welding (EBW) processes developed (or used) by 1- SKB, Sweden with assistance from TWI, England and 2 - POSIVA, Finland with assistance from Outokumpu, Finland. The aim was also to explain the principle properties of the EBW method: how it works, the parameters controlling the welding result but also giving rise to benefits, and differences between the EBW variants. The main conclusions are that both SKB and POSIVA will within a few years succeed to qualify their respective EBW method for welding of copper canisters. The Reduced Pressure EBW that SKB use today seems to be very promising in order to avoid root defects. If POSIVA does not succeed to avoid root defects with the high vacuum method and the beam oscillation technique it should be possible for POSIVA to incorporate the Reduced Pressure technique albeit with significant changes to the EBW equipment. POSIVA has possibly an advantage over SKB with the beam oscillation technique used, which gives an extra degree of freedom to affect the weld quality. The beam oscillation could be of importance for closing of the keyhole. Before EBW of lids, the material certification showing the alloy content (specifying min and max impurity percentages) and the mechanical properties should be checked. The welded material needs also to be tested for mechanical properties. If possible the weld should have a toughness level equal to that of the unwelded parent material. Specifically some conclusions are reported regarding the SKB equipment. Suggestions for further development are also given in the conclusion chapter

  7. Electron Beam Ion Trap and its Applications

    Science.gov (United States)

    Zou, Yaming

    2013-03-01

    Electron Beam Ion Traps (EBIT), initially developed at LLNL, are sophisticated devices capable of acting both as highly charged ion (HCI) light sources and ion sources. As a HCI light source, they can basically provide light from emission states of any charge state of any element in the periodic table, hence almost unique for spectroscopic research. Furthermore, the emitting ions are almost at rest compared to those produced by heavy ion accelerators or storage rings, much less bothered with Doppler shifts and line broadening. Because of its flexibility in producing various ions, it is very good for studies along iso-electronic sequences, and along iso-nuclear charge sequences to reveal physical properties behind experimental phenomenon. In an EBIT, a thin plasma can be formed with basically any elements, and more important with almost mono-energy electrons. On top of this, the electron energy can be tuned in the range of few hundreds eV to above one hundred keV. This property made it possible to use an EBIT for detail studies of processes in hot plasmas, so as to make disentangling studies of hot plasmas and to assist plasma diagnostics for temperature, density, electromagnetic field, as well as ion moving...

  8. Application of electron beam irradiation. 4. Treatment of pollutants by electron beam irradiation

    International Nuclear Information System (INIS)

    Electron beam irradiation is capable of dissolving and removing pollutants, such as sulfur oxides, nitrogen oxides, and organic compounds, by easy production of OH radicals in flue gas and water. This paper deals with current status in the search for techniques for treating flue gas and waste water, using electron beam irradiation. Pilot tests have been conducted during the period 1991-1994 for the treatment of flue gas caused by coal and garbage burning and road tunnels. Firstly, techniques for cleaning flue gas with electron beams are outlined, with special reference to their characteristics and process of research development. Secondly, the application of electron beam irradiation in the treatment of waste water is described in terms of the following: (1) disinfection of sewage, (2) cleaning of water polluted with toxic organic compounds, (3) treatment for eliminating sewage sludge, (4) promotion of sewage sludge sedimentation, (5) disinfection and composting of sewage sludge, and (6) regeneration of activated carbon used for the treatment of waste water. (N.K.)

  9. High-power, electron beam-induced switching in diamond

    International Nuclear Information System (INIS)

    The authors are developing a high-voltage, high-average-power, electron beam-controlled diamond switch that could significantly impact high power solid-state electronics in industrial and defense applications. An electron beam-controlled, thin film diamond could switch, with high efficiency, well over 100 kW average power at MHz frequencies greater than 5kV. This performance is due to the excellent thermal and electronic properties of diamond, the high efficiency achieved with electron beam control, and the demonstrated effectiveness of microchannel cooling. The authors' electron beam penetration-depth measurements agree with their Monte Carlo calculations. They have not observed electron beam damage in diamond for beam energies up to 150 keV. This report describes their experimental and calculational results and research objectives

  10. Physical aspects of electron-beam arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khan, F.M.; Fullerton, G.D.; Lee, J.M.F.; Moore, V.C.; Levitt, S.H.

    1977-08-01

    The effect of different parameters on dose distribution in electron-beam arc therapy was studied in order to develop a technique for routine clinical use. A special diaphragm was designed to facilitate telecentric rotation. Dosimetry was performed with an ion chamber, film, and LiF powder in cylindrical polystyrene phantoms and an Alderson Rando phantom. Dose distributions were evaluated with regard to dose homogeneity, and a method of sharpening the dose fall-off near the ends of the arc was proposed. Criteria for selection of isocenter depth and field size were developed. Methods of dose calculation, calibration, and treatment planning are discussed.

  11. High current precision long pulse electron beam position monitor

    CERN Document Server

    Nelson, S D; Fessenden, T J; Holmes, C

    2000-01-01

    Precision high current long pulse electron beam position monitoring has typically experienced problems with high Q sensors, sensors damped to the point of lack of precision, or sensors that interact substantially with any beam halo thus obscuring the desired signal. As part of the effort to develop a multi-axis electron beam transport system using transverse electromagnetic stripline kicker technology, it is necessary to precisely determine the position and extent of long high energy beams for accurate beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs beam pulse, sub millimeter beam position accuracy.) The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (< 20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt position measurements.

  12. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    CERN Document Server

    Stancari, Giulio

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compens...

  13. Analysis of transmission efficiency of SSRF electron beam transfer lines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this article, the main factors which influence transmission efficiency of the SSRF electron beam transfer lines are described, including physical requirements for magnet system, vacuum system, beam diagnostic system,trajectory correction system, etc. The dynamic simulation calculation and transmission efficiency analysis of the SSRF electron beam transfer lines are presented, and the studies show that the design purpose of efficient beam transmission and injection will be achieved.

  14. Electron beam time-of-flight plasma potential diagnostic

    International Nuclear Information System (INIS)

    A time-of-flight method for measuring electrostatic potentials in plasmas using a modulated electron beam has been developed. The beam is injected along the magnetic field in a cylindrical plasma geometry. The phase of the electron beam modulation is detected using a Rogowski loop which encircles the beam and plasma, and the phase information is in turn related to the electrostatic potential. Measurements in vacuum and in plasma have been performed

  15. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    CERN Document Server

    Tang, J F; Chen, L; Zhao, G Q; Tan, C M

    2016-01-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool in the understanding of FEBs as well as the solar plasma environment in which they are propagating along solar magnetic fields. In particular, the evolutions of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field when propagating can significantly influence the efficiency and property of their emissions. In this paper, we discuss some possible evolutions of the energy spectrum and velocity distribution of FEBs due to the energy loss processes and the pitch-angle effect caused by the magnetic field inhomogeneity, and analyze the effects of these evolutions on electron cyclotron maser (ECM) emission, which is one of the most important mechanisms of producing solar radio bursts by FEBs. The results show that the growth rates all decrease with the energy loss factor $Q$, but increase with the magnetic mirror ratio $\\sigma$ as well ...

  16. Marking of welded pieces using continuous or pulse electron beam

    Czech Academy of Sciences Publication Activity Database

    Zobač, Martin

    Varna: Institute of Electronic s BAS, 2003, s. 191 - 197. [EBT 2003. Varna (BG), 01.06.2003-06.06.2003] R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : continuous electron beam * pulse electron beam * material surface Subject RIV: BM - Solid Matter Physics ; Magnetism

  17. ANTENNA ARRAY WITH ELECTRONIC BEAM STEERING FOR TELECOMMUNICATION APPLICATIONS

    OpenAIRE

    Ali Akbarian, Hadi; Volskiy, Vladimir; Vandenbosch, Guy

    2010-01-01

    Electronically controlled beam steering array antennas highly increase the performance of telecommunication links by improving the link budget. Moreover, digital (baseband) beam steering includes the possibility of having multiple beams simultaneously and of communicating with more than one user at the same time. The basics of digital beam forming are explained in this paper. A 1x2 prototype array with digital beam steering is introduced and measurement results are shown.

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

    International Nuclear Information System (INIS)

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

  19. Electron beam accelerator energy control system

    International Nuclear Information System (INIS)

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

  20. Prediction of electron beam welding spiking tendency

    International Nuclear Information System (INIS)

    On the basis of measured temperature distributions in electron beam welding cavities it is shown that the vapor pressure force dominates in the lower region and the surface tension in the upper region. The region where these two forces are approximately equal is unstable and the surface tension force causes inward flow of liquid metal which tends to form a projection. For a specific material this projection location was found to depend on cavity depth. By postulating that the formation of liquid metal projections at this location results in cavity instabilities, a physical model for predicting when spiking would occur was purposed. A procedure then developed for determining the spiking tendency for a specified material and set of weld parameters is described

  1. Radiation sterilization of gelatin with electron beam

    International Nuclear Information System (INIS)

    The radiation sterilization of gelatin contaminated with 4 x 103 to 4 x 106 bacteria per gram was investigated with electron beam from a JJ-2 accelerator. After treatment with the doses of 3-4 kGy, the initial microbial counts in the gelatin could be approximately reduced by two orders of magnitude and the coliforms were substantively killed at the same time. The viscosities, transparencies and major gelatin compositions of the irradiated gelatin (with doses of 1.5-10 kGy) and the control sample were determined. The results show that the viscosity of the gelatin solution decreases gradually with the increase of the irradiation doses, the irradiation degradation of the gelatin molecules can not be decreased under the condition of nitrogen atomosphere of lower irradiation temperature, and the amino acid contents of the gelatin irradiated do not undergo any marked changes in comparison with the control sample except for cystine

  2. A compact and high efficient electron beam accelerator

    International Nuclear Information System (INIS)

    To obtain short duration time high-current electron beam for KrF laser, a compact high-efficient electron beam accelerator has been constructed based on a co-axial Marx generator. The generator can be connected directly with a vacuum diode without additional pulse forming line because of low inductance. The energy conversion efficiency from the Marx generator to the electron beam reached to 61 % at an optimum condition. (author)

  3. Highly efficient electron vortex beams generated by nanofabricated phase holograms

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, Vincenzo, E-mail: vincenzo.grillo@nano.cnr.it [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM Parco Area delle Scienze 37/A, I-43124 Parma (Italy); Carlo Gazzadi, Gian [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Karimi, Ebrahim [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Mafakheri, Erfan [Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy); Boyd, Robert W. [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Frabboni, Stefano [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); Dipartimento di Fisica Informatica e Matematica, Università di Modena e Reggio Emilia, via G Campi 213/a, I-41125 Modena (Italy)

    2014-01-27

    We propose an improved type of holographic-plate suitable for the shaping of electron beams. The plate is fabricated by a focused ion beam on a silicon nitride membrane and introduces a controllable phase shift to the electron wavefunction. We adopted the optimal blazed-profile design for the phase hologram, which results in the generation of highly efficient (25%) electron vortex beams. This approach paves the route towards applications in nano-scale imaging and materials science.

  4. Ion beam steering with a high intensity electron beam

    International Nuclear Information System (INIS)

    In conventional theory, steering or bending an ion beam of high energy and high current requires very intense magnetic fields, which are both uneconomical and bulky. This problem is even more severe for a singly charged ion beam with very high atomic number, which requires large magnetic field energy both to bend and also to focus the beam against its self electric field. In this paper we present a new and simple technique, which will substantially alleviate these problems

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-05

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

  6. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; Assmann, R.; Kabantsev, A.

    2010-01-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams

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

    International Nuclear Information System (INIS)

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

  8. Measuring the Orbital Angular Momentum of Electron Beams

    CERN Document Server

    Guzzinati, Giulio; Béché, Armand; Verbeeck, Jo

    2014-01-01

    The recent demonstration of electron vortex beams has opened up the new possibility of studying orbital angular momentum (OAM) in the interaction between electron beams and matter. To this aim, methods to analyze the OAM of an electron beam are fundamentally important and a necessary next step. We demonstrate the measurement of electron beam OAM through a variety of techniques. The use of forked holographic masks, diffraction from geometric apertures, diffraction from a knife-edge and the application of an astigmatic lens are all experimentally demonstrated. The viability and limitations of each are discussed with supporting numerical simulations.

  9. High yields from the Stockholm electron beam ion source CRYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R.; Bjoerkhage, M.; Carle, P.; Engstroem, Aa.; Liljeby, L.; Rouleau, G.; Wenander, F. [Manne Siegbahn Lab., Stockholm (Sweden)

    1997-04-01

    CRYSIS is an electron beam ion source (EBIS) with a superconducting solenoid. Highly charged ions are delivered to the acceleration and storage ring CRYRING, SMILETRAP and to low energy atomic and surface physics experiments. Stable electron beam currents up to 700 mA are obtained, in order to enhance the ion yield out of the EBIS. Measurements of the total charge per pulse at different working conditions and electron beam current density measurements were done. At electron beam currents of 600 mA yields up to 2.5 x 10{sup 10} charges per pulse could be measured. (orig.). 8 refs.

  10. Hollow Electron Beam Collimator: R&D Status Report

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Valishev, A; Kabantsev, A; Vorobiev, L

    2012-01-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  11. Development of hollow electron beams for proton and ion collimation

    CERN Document Server

    Stancari, G; Kuznetsov, G; Shiltsev, V; Still, D A; Valishev, A; Vorobiev, L G; Assmann, R; Kabantsev, A

    2012-01-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  12. Development of hollow electron beams for proton and ion collimation

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; /Fermilab; Assmann, R.; /CERN; Kabantsev, A.; /UC, San Diego

    2010-06-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  13. Unveiling orbital angular momentum and acceleration of light beams and electron beams

    Science.gov (United States)

    Arie, Ady

    Special beams, such as the vortex beams that carry orbital angular momentum (OAM) and the Airy beam that preserves its shape while propagating along parabolic trajectory, have drawn significant attention recently both in light optics and in electron optics experiments. In order to utilize these beams, simple methods are needed that enable to easily quantify their defining properties, namely the OAM for the vortex beams and the nodal trajectory acceleration coefficient for the Airy beam. Here we demonstrate a straightforward method to determine these quantities by astigmatic Fourier transform of the beam. For electron beams in a transmission electron microscope, this transformation is easily realized using the condenser and objective stigmators, whereas for light beam this can be achieved using a cylindrical lens. In the case of Laguerre-Gauss vortex beams, it is already well known that applying the astigmatic Fourier transformation converts them to Hermite-Gauss beams. The topological charge (and hence the OAM) can be determined by simply counting the number of dark stripes of the Hermite-Gauss beam. We generated a series of electron vortex beams and managed to determine the topological charge up to a value of 10. The same concept of astigmatic transformation was then used to unveil the acceleration of an electron Airy beam. The shape of astigmatic-transformed depends only on the astigmatic measure and on the acceleration coefficient. This method was experimentally verified by generating electron Airy beams with different known acceleration parameters, enabling direct comparison to the deduced values from the astigmatic transformation measurements. The method can be extended to other types of waves. Specifically, we have recently used it to determine the acceleration of an optical Airy beams and the topological charge of so-called Airy-vortex light beam, i.e. an Airy light beam with an embedded vortex. This work was supported by DIP and the Israel Science

  14. Crosslinking of wire and cables with electron beam

    International Nuclear Information System (INIS)

    Since the first electron beam accelerator was established in a wire and cable manufacturer in Japan, about 25 years have elapsed. First, the wires for electronic appliances insulated with cross-linked polyvinyl chloride, cross-linked polyethylene and cross-linked flame retardant polyethylene were produced with electron beam machines. Nowadays, large quantities of electron beam cross-linked materials such a PVC, PE, FRPE and flame retardant polyolefine are used for the insulation and jacket of electronic wires and cables. In this paper, the reason why the electron beam cross-linking production in wire and cable industry has increased year by year is discussed. 38 electron beam accelerator machines are used by 13 wire and cable manufacturers. The market share and the sales of wire and cable manufacturers are shown. The advantageous properties brought about by cross-linking are solder resistance, heat resistance and good mechanical properties. The results of main tests are reported. Electron beam cross-linked products are listed, most of which were approved by UL and CSA. The electron beam processing system for wires and cables, the technical and economical comparison of electron beam process with other competitive processes and radiation control are reported. (K.I.)

  15. Electron beam processing of carbon fibre reinforced braided composites beams

    International Nuclear Information System (INIS)

    Complete text of publication follows. In this paper the possibility of producing a new type carbon fiber reinforced composite is examined by applying braiding, a well-known process of textile technology. The appearance of the new Hungarian carbon fiber with excellent mechanical properties in the market enables the development of newer type carbon fiber reinforced composites in the continuously widening range of engineering applications. Advanced hollow profiles, pipes and other composite products can be manufactured in continuous operation. A new way of composite production of this kind is the manufacturing of reinforcing structure by braiding technology producing a composite with sufficient mechanical properties from this cross directional fabric-like textile structure by impregnation. This manufacturing process can complete the variety of hollow products serving the same purpose as pultrusion or filament winding. This way a profile type framework element with a hollow cross section is manufactured having favorable mechanical properties. Owing to its small mass and high specific strength this product can be applied in dynamically loaded structures e.g. in the automotive industry. For crosslinking of the matrix the method of high-speed electron beam curing has been examined in order to reach continuous operation. The field of use and application of carbon fiber braided structures has a great chance especially in machine engineering and in the automotive industry. The main reason for this is that braiding processes are capable of producing structures having good mechanical properties at a low processing price. The mass of the composite load-bearing structure produced this way is one fifth of the steel product having similar geometry, and its specific mechanical properties are nearly as good as that of the most commonly applied semiproduct and structural component, the welded steel profile

  16. Electron-beam-induced conduction in polyethylene

    International Nuclear Information System (INIS)

    The electrical conduction in polyethylene induced by the irradiation of the short-pulsed-electron-beam (100 nsec time width) consists of the fast and the slow components. The former is attributed to the carrier transport in the crystalline part and the latter to that in the amorphous part. Logarithmic plot (Scher-Montroll plot) of the slow part of the induced current vs. time gives a knee at time T sub(r), which is thought to be the transit time of the carrier front between electrodes. Simple calculation by the formula μ = L/T sub(r) E gives the apparent slow carrier mobility μ of 5.6 x 10-7 cm2/V.sec and 3.2 x 10-7 cm2/V.sec for the electron and the hole respectively at 343 K under the field E of 1.2 MV/cm for the sample thickness L of 12 μm. These apparent slow carrier mobilities are dependent on both the thickness and the field strength. These behavior are discussed in terms of Scher-Montroll theory on the transport in amorphous substances. The activation energy of the mobility is in good agreement with the apparent trap depth obtained from the TSC measurement. (author)

  17. Electron beam diagnostic system using computed tomography and an annular sensor

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, John W.; Teruya, Alan T.

    2015-08-11

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  18. Electron beam diagnostic system using computed tomography and an annular sensor

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  19. Problem of obliquely incident beams in electron-beam treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, K.E.; Dixon, R.L.

    1982-03-01

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beams, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths.

  20. Planar Heating Element Adjusted by Electron Beam Micromachining

    Czech Academy of Sciences Publication Activity Database

    Dupák, Libor; Dupák, Jan

    2009-01-01

    Roč. 44, 5-6 (2009), s. 82-84. ISSN 0861-4717 Institutional research plan: CEZ:AV0Z20650511 Keywords : electron beam machining * heating element Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  1. 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.

  2. High throughput defect detection with multiple parallel electron beams

    NARCIS (Netherlands)

    Himbergen, H.M.P. van; Nijkerk, M.D.; Jager, P.W.H. de; Hosman, T.C.; Kruit, P.

    2007-01-01

    A new concept for high throughput defect detection with multiple parallel electron beams is described. As many as 30 000 beams can be placed on a footprint of a in.2, each beam having its own microcolumn and detection system without cross-talk. Based on the International Technology Roadmap for Semic

  3. Focusing and guiding intense electron beams by a superconductor tube

    International Nuclear Information System (INIS)

    An intense electron beam travelling axially through the opening of a superconductor tube was studied. Model calculations showed that the beam is focused by the superconductor tube when the space-charge effect of the beam electrons is compensated. The tube functions as a lens for electrons injected parallel to the tube axis and also for electrons having a small initial radial velocity component. The electron trajectories were computed, and the focal length of the superconductor tube was estimated. (author). 2 figs., 6 refs

  4. Measurement of electron beam polarization at the SLC

    International Nuclear Information System (INIS)

    The polarimeters needed to monitor and measure electron beam polarization at the Stanford Linear Collider are discussed. Two types of polarimeters, are to be used. The first is based on the spin dependent elastic scattering of photons from high energy electrons. The second utilizes the spin dependence of elastic electron-electron scattering. The plans of the SLC polarization group to measure and monitor electron beam polarization are discussed. A brief discussion of the physics and the demands it imposes on beam polarization measurements is presented. The Compton polarimeter and the essential characteristics of two Moeller polarimeters are presented

  5. Measurement of electron beam polarization at the SLC

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, H.

    1987-03-01

    The polarimeters needed to monitor and measure electron beam polarization at the Stanford Linear Collider are discussed. Two types of polarimeters, are to be used. The first is based on the spin dependent elastic scattering of photons from high energy electrons. The second utilizes the spin dependence of elastic electron-electron scattering. The plans of the SLC polarization group to measure and monitor electron beam polarization are discussed. A brief discussion of the physics and the demands it imposes on beam polarization measurements is presented. The Compton polarimeter and the essential characteristics of two Moeller polarimeters are presented. (LEW)

  6. Storage-ring Electron Cooler for Relativistic Ion Beams

    OpenAIRE

    Lin, F; Derbenev, Y. S.; Douglas, D.; Guo, J.; Johnson, R P.; Krafft, G.; Morozov, V. S.; Zhang, Y.

    2016-01-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring elect...

  7. Automatic tracking of laser and electron beam intersection

    International Nuclear Information System (INIS)

    For the Compton Polarimeter experiment at the Stanford Linear Accelerator the crossing point of a laser beam across the path of an electron beam must be kept accurate and stable. This paper describes an electronic system for automatic tracking and correction of the beam crossing. A remote CCD camera, relatively insensitive to electromagnetic disturbance, records small displacements of the pulsed laser beam. Video signals are analyzed at a remote station, the amount of drift from the selected reference point determined and the appropriate correction command sent to the motorized mirror deflecting the laser beam. A description of the system, its performance and the test results are presented

  8. Double-decker electron beam accelerator and pulse radiolysis

    International Nuclear Information System (INIS)

    A new concept of double-decker electron beam accelerator is proposed to study the ultra-fast electron-induced reactions in materials by pulse radiolysis. The double-decker electron beams are generated and accelerated in an S-band linear accelerator with different positions in vertical direction and a time delay. One of them is used as a pump electron source and another is converted to light as a probe light source. The time jitter between the pump electron beam and the probe light is thus reduced. The time resolution of pulse radiolysis is expected to be improved. The double-decker electron beam has been generated successfully by injected two laser beam into the photocathode RF gun, which is generated by splitting an Nd:YLF picosecond laser beam. The double-decker electron beams were accelerated up to 31 MeV by an S-band booster linear accelerator and compressed into femtosecond by a magnetic bunch compressor. The profiles of the double-decker electron beams were measured at the exits of the RF gun, the linac and the bunch compressor. The normalized transverse emittance was obtained to be 3.3 mm-mrad for the upper beam and 6.4 mm-mrad for the lower beam at bunch charge of 2nC. The relative energy spread was obtained to be 0.1-0.2% for both beams. The Cherenkov light generated in a suprasil plate and OTR produced on a mirror from the electron beam were also measured. (author)

  9. Post-Disruptive Runaway Electron Beam in COMPASS Tokamak

    OpenAIRE

    Vlainic, Milos; Mlynar, Jan; Cavalier, Jordan; Weinzettl, Vladimir; Paprok, Richard; Imrisek, Martin; Ficker, Ondrej; Noterdaeme, Jean-Marie; Team, the COMPASS

    2015-01-01

    For ITER-relevant runaway electron studies, such as suppression, mitigation, termination and/or control of runaway beam, obtaining the runaway electrons after the disruption is important. In this paper we report on the first achieved discharges with post-disruptive runaway electron beam, entitled "runaway plateau", in the COMPASS tokamak. The runaway plateau is produced by massive gas injection of argon. Almost all of the disruptions with runaway electron plateaus occurred during the plasma c...

  10. Limitations of silicon diodes for clinical electron dosimetry

    International Nuclear Information System (INIS)

    This work investigates the relevance of several factors affecting the response of silicon diode dosemeters in depth-dose scans of electron beams. These factors are electron energy, instantaneous dose rate, dose per pulse, photon/electron dose ratio and electron scattering angle (directional response). Data from the literature and our own experiments indicate that the impact of these factors may be up to ±15%. Thus, the different factors would have to cancel out perfectly at all depths in order to produce true depth-dose curves. There are reports of good agreement between depth-doses measured with diodes and ionisation chambers. However, our measurements with a Scantronix electron field detector (EFD) diode and with a plane-parallel ionisation chamber show discrepancies both in the build-up and in the low-dose regions, with a ratio up to 1.4. Moreover, the absolute sensitivity of two diodes of the same EFD model was found to differ by a factor of 3, and this ratio was not constant but changed with depth between 5 and 15% in the low-dose regions of some clinical electron beams. Owing to these inhomogeneities among diodes even of the same model, corrections for each factor would have to be diode-specific and beam-specific. All these corrections would have to be determined using parallel plane chambers, as recommended by AAPM TG-25, which would be unrealistic in clinical practice. Our conclusion is that in general diodes are not reliable in the measurement of depth-dose curves of clinical electron beams. (authors)

  11. How to calibrate Grenz-beams in clinical practice?

    Energy Technology Data Exchange (ETDEWEB)

    Schaeken, B. [Algemeen Ziekenhius Middelheim, Antwerp (Belgium); Bressers, E. [Virga jesse Ziekenhius, Hasselt (Belgium)

    1995-12-01

    In recent years, considerable efforts have been spent improving the precision and consistency in the whole process of calibration of high energy photon and electron beams (national protocols, primary calibration facilities ....). The reading in air of 5 different ionisation chambers (NE2532, NE2536, NE2571, PTWM23342, Markus) in an X-ray beam (RT50, HVL=0.35 mm Al) has been compared. Ali NE chambers were provided with a calibration factor Nk, the PTW chamber was directly calibrated in dose water ND,W. The polarisation and recombination effects were measured. In our reference field (ssd=4cm, field diameter 40 mm), the readings in air for the dedicated plan parallel chambers deviated by not more than 8%. The measurements with the NE2571 chamber did not correspond very well with the other measurements. For the equipment in our hospital, the dose rate in air for the reference field was measured from 1971 on and found to be very stable: 17.36 Gy/min (0.48) (1sd). An attempt was made to measure the BSF for the field defining cones used in clinical practice using a Markus plane parallel chamber, but the resulting BSF did not correspond to those reported in BJR/suppl. 17. Special attention has been be paid to the calibration of beams with field size comparable to the dimension of the chamber window- chamber body.

  12. Transport of a relativistic electron beam through hydrogen gas

    International Nuclear Information System (INIS)

    In this thesis the author describes the transport properties of an electron beam through vacuum and through hydrogen gas with pressure ranging from 25 to 1000 Pa. Maximum beam energy and current are 0.8 MeV and 6 kA, respectively. The pulse length is around 150 ns. A description is given of the experimental device. Also the diagnostics for probing the beam and the plasma, produced by the beam, are discussed, as well as the data acquisition system. The interaction between the beam and hydrogen gas with a pressure around 200 Pa is considered. A plasma with density around 1019 m-3 is produced within a few nanoseconds. Measurements yield the atomic hydrogen temperature, electron density, beam energy loss, and induced plasma current and these are compared with the results of a model combining gas ionization and dissociation, and turbulent plasma heating. The angular distribution of the beam electrons about the magnetic field axis is discussed. (Auth.)

  13. Effect of electron beam on in vitro cultured orchid organs

    International Nuclear Information System (INIS)

    Ionizing radiations have been effective mutagen sources to overcome the limitation of the useful genetic resources in natural environment. The study was conducted to investigate an effect of electron beam on organogenesis, growth patterns and genetic variation in the irradiated orchid organs. The in utero cultured rhizomes of orchids were irradiated with the electron beam in the dose range of 15Gy to 2240Gy under the condition of various beam energy and beam current. Significant decreases in survival, growth and organogenesis were observed by increase of intensity of electron beam irradiation. The irradiation intensity of lethal dose 50 of the in utero cultured orchid was estimated as approximately 500Gy to 1000Gy under 10MeV/n, and 1000Gy was optimal for growth and organogenesis of the cultures under 10MeV/n with 0.05mA treatment, and 15Gy ∼ 48Gy under 2MeV/n and 0.5mA electron beam condition. RAPD and ISSR analyses for the electron beam irradiated organs were performed to analyze genetic variation under the electron beam condition. Both of RAPD and ISSR analyses showed higher polymorphic rate in the electron-beam irradiated C. gangrene and C. Kaner

  14. Storage-ring Electron Cooler for Relativistic Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Guo, Jiquan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Johnson, Rolland P. [Muons Inc., Batavia, IL (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the electron beam. The necessary energy difference is provided by an energy recovering SRF structure. A prototype linear optics of such storage-ring cooler is presented.

  15. Toroidal equilibrium of plasma with concentrated relativistic electron beam

    International Nuclear Information System (INIS)

    A simplified model has been given for toroidal equilibrium of a tokamak-type plasma with high-current concentrated electron beam. The plasma has a thermal pressure, and the electron beam has effective inertial pressure. Strong deformations of tokamak equilibria have been simulated by numerical calculations. Toroidal equilibria with relatively large vertical field are obtained when we consider high-energy intense electron beam. The beam orbit, which is shifted outward from the magnetic axis of the plasma, is closed by the sum of the externally applied relatively large vertical field and the poloidal magnetic field of the plasma. (author)

  16. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    International Nuclear Information System (INIS)

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper

  17. Estimation of the Processing Parameters in Electron Beam Thermal Treatments

    Directory of Open Access Journals (Sweden)

    DULAU Mircea

    2014-05-01

    Full Text Available Electron beam have many special properties which make them particularly well suited for use in materials handling through melting, welding, surface treatment, etc., taking into account that this manufacturing is performed in vacuum. The use of electron beam for surface limited heat treatment of workpiece has brought about a noticeable extension of the beam technologies. Some theoretical aspects and simulation results are presented in this paper, considering a high power electron beam processing system and Matlab facilities. This paper can be used in power engineering and electro-technologies fields as a guideline, in order to simulate and analyse the process parameters.

  18. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Wenjie; Guan, Xiaotong; Yan, Yang [THz Research Center, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2016-01-15

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper.

  19. Measurements on wave propagation characteristics of spiraling electron beams

    Science.gov (United States)

    Singh, A.; Getty, W. D.

    1976-01-01

    Dispersion characteristics of cyclotron-harmonic waves propagating on a neutralized spiraling electron beam immersed in a uniform axial magnetic field are studied experimentally. The experimental setup consisted of a vacuum system, an electron-gun corkscrew assembly which produces a 110-eV beam with the desired delta-function velocity distribution, a measurement region where a microwave signal is injected onto the beam to measure wavelengths, and a velocity analyzer for measuring the axial electron velocity. Results of wavelength measurements made at beam currents of 0.15, 1.0, and 2.0 mA are compared with calculated values, and undesirable effects produced by increasing the beam current are discussed. It is concluded that a suitable electron beam for studies of cyclotron-harmonic waves can be generated by the corkscrew device.

  20. Electronic health records improve clinical note quality

    OpenAIRE

    Burke, Harry B; SESSUMS, LAURA L; Hoang, Albert; Becher, Dorothy A; Fontelo, Paul; Liu, Fang; Stephens, Mark; Pangaro, Louis N; O'Malley, Patrick G; Baxi, Nancy S; Bunt, Christopher W; Capaldi, Vincent F; Chen, Julie M; Cooper, Barbara A; Djuric, David A

    2014-01-01

    Background and objective The clinical note documents the clinician's information collection, problem assessment, clinical management, and its used for administrative purposes. Electronic health records (EHRs) are being implemented in clinical practices throughout the USA yet it is not known whether they improve the quality of clinical notes. The goal in this study was to determine if EHRs improve the quality of outpatient clinical notes. Materials and methods A five and a half year longitudin...

  1. Preliminary test experiment for electron beam injection to JSR

    International Nuclear Information System (INIS)

    A preliminary test experiment has been carried out to investigate the property of electron beam from the JAERI linac which will be used as an injector for the JSR(JAERI Storage Ring). The electron beam was obtained within the energy resolution of 1.55 % and the peak current of 38 mA at 150 MeV. (author)

  2. NOx reduction by electron beam-produced nitrogen atom injection

    Science.gov (United States)

    Penetrante, Bernardino M.

    2002-01-01

    Deactivated atomic nitrogen generated by an electron beam from a gas stream containing more than 99% N.sub.2 is injected at low temperatures into an engine exhaust to reduce NOx emissions. High NOx reduction efficiency is achieved with compact electron beam devices without use of a catalyst.

  3. Electron-beam-fusion progress report, January--June 1976

    International Nuclear Information System (INIS)

    Research progress is reported for the following areas: (1) Proto I, (2) Proto II, (3) EBFA, (4) power flow, (5) contract progress reports, (6) progress in the Sandia program, (7) repetitively operated pulse generator development, (8) electron beam power from inductive storage, (9) fusion target design, (10) beam physics research, (11) power flow, (12) heavy ion fusion, (13) particle beam source development, (14) beam target interaction and target response studies, (15) diagnostic development, and (16) hybrid systems

  4. Ribbon Reduces Spiking in Electron-Beam Welding

    Science.gov (United States)

    Olson, R. E.

    1984-01-01

    Spiking in electron-beam welding reduced by placing high-vapor-pressure substance along path of electron beam. Strip of metal having vapor pressure higher than base metal at same temperature placed in slot machined along weld line. Strip vaporizes as beam strikes it, and vapor pressure keeps surface tension from closing off top of channel. Technique used successfully on nickel alloys and aluminum alloys and effective on steel and titanium.

  5. Electron-beam-sustained discharge revisited - light emission from combined electron beam and microwave excited argon at atmospheric pressure

    CERN Document Server

    Dandl, T; Neumeier, A; Wieser, J; Ulrich, A

    2015-01-01

    A novel kind of electron beam sustained discharge is presented in which a 12keV electron beam is combined with a 2.45GHz microwave power to excite argon gas at atmospheric pressure in a continuous mode of operation. Optical emission spectroscopy is performed over a wide wavelength range from the vacuum ultraviolet (VUV) to the near infrared (NIR). Several effects which modify the emission spectra compared to sole electron beam excitation are observed and interpreted by the changing plasma parameters such as electron density, electron temperature and gas temperature.

  6. Radiation produced by the modulated electron beam of a free electron laser

    OpenAIRE

    Neighbours, John Robert; Maruyama, Xavier K.; Buskirk, Fred Ramon

    1986-01-01

    The electron beam in a free electron laser (FEL) becomes axially modulated at the optical wave length of the FEL radiation. This electron beam passed through a gas may produce intense Cerenkov radiation. The effects of the radial and axial dimension of the electron bunches on the radiation are explored

  7. Innovative energy efficient low-voltage electron beam emitters

    International Nuclear Information System (INIS)

    Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates

  8. Effects of modulated electron beams and cavities on reditrons

    International Nuclear Information System (INIS)

    The reditron has been shown to be an efficient, high-power, single-mode, monochromatic microwave generator in a virtual cathode configuration. The authors studied the use of premodulated electron beams and cavities in a reditron to enhance the efficiency of microwave production and electromagnetic mode selectivity, respectively. They found that electron beam current modulation of only 15% can significantly increase the generation of microwaves by the oscillating virtual cathode. Their 2-D particle-in-cell simulations show that modulation of the electron beam at the oscillating frequency of the virtual cathode in a reditron can increase the microwave power by 40%. Further, it can also provide frequency fine tuning when the electron beam is modulated at a slightly off-resonant frequency. They demonstrated in computer simulations that a 2.0 MeV electron beam can be modulated at a 15% level in a 15-cm long cavity when the appropriate cavity mode is excited

  9. Spin-polarizing interferometric beam splitter for free electrons

    CERN Document Server

    Dellweg, Matthias M

    2016-01-01

    A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam into two portions, with electron spin and momentum being entangled. Afterwards, the partial beams are coherently superposed in an interferometric setup formed by standing laser waves. As a result, the outgoing electron beam is separated into its spin components along the laser magnetic field, which is shown by both analytical and numerical solutions of Pauli's equation. The proposed laser field configuration thus exerts the same effect on free electrons like an ordinary Stern-Gerlach magnet does on atoms.

  10. Heat shrinkage of electron beam modified EVA

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S.K.; Chaki, T.K.; Bhowmick, A.K. [Indian Institute of Technology, Kharagpur (India). Rubber Technology Center; Tikku, V.K.; Pradhan, N.K. [NICCO Corporation Ltd., (Cable Div.), Calcutta (India)

    1997-10-01

    Heat shrinkage of electron beam modified ethylene vinyl acetate copolymer (EVA) has been investigated over a range of times, temperatures, stretching, irradiation doses and trimethylolpropane trimethacrylate (TMPTMA) levels. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) and stretched (100% elongation) sample shrinks to a maximum level when kept at 453K temperature for 60 s. The heat shrinkage of samples irradiated with radiation doses of 20, 50, 100 and 150 kGy increases sharply with increasing stretching in the initial stage. Amnesia rating decreases with increasing radiation dose and TMPTMA level as well as gel content. The high radiation dose and TMPTMA level lower the heat shrinkage due to the chain scission. The effect of temperature at which extension is carried out on heat shrinkage is marginal. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) EVA tubes of different dimensions expanded in a laboratory grade tube expander show similar behaviour at 453K and 60 s. The X-ray and DSC studies reveal that the crystallinity increases on stretching due to orientation of chains and it decreases to a considerable extent on heat shrinking. The theoretical and experimental values of heat shrinkage for tubes and rectangular strips are in good accord, when the radiation dose is 50 kGy and TMPTMA level 1%. (author).

  11. Electron beam induced modification of grafted polyamides

    International Nuclear Information System (INIS)

    It is well known that irradiation, when applied on its own or in combination with other physical and chemical treatments, can manifest in radiation damage to materials. Radiation processing technology focuses upon producing favourable modification of materials through use of relatively high dose and dose rates. Current interest is in modifying the thermal and electrical properties of textured polymers in an effort to improve safety and wear comfort of clothing. No less important is the production of textiles which are safe to use, both in homes and offices. Present investigations provide additional data in support of findings which show that polyamides, a particular class of textured polymer, are amenable to radiation processing. Accelerated electron beam irradiation of sheets of polyamide fibre results in induced grafting of acrylic and methacrylic acids. The degree of grafting is critically dependent upon irradiation dose and the extent of monomers dilution. Of particular importance is the high correlation which is found between degree of grafting and a decrease in the softening rate of the modified polyamide. A systematic modification of electrical conductivity is also observed. (author)

  12. Electron beam curing of intaglio inks

    International Nuclear Information System (INIS)

    Press trials conducted by the U.S. Bureau of Engraving and Printing at the National Bank of Denmark clearly indicated the feasibility of Electron Beam (E.B.) curing for web intaglio printing . These trials, some at continuous press runs of up to six hours, gave positive results for virtually all our requirements including: print quality, press speeds, ability to print both sides of the web on one pass through a press, acceptable ink curing at one megarad or less, and minimum substrate deterioration or loss of moisture. In addition, these trials demonstrated many advantages over thermal curing which is the only other alternative to two sided printing in one pass through the press. These advantages can be found in product quality, a cleaner environment, and in economics. This development program is still in progress with efforts now directed towards adapting E.B. ink technology to the latest developments in intaglio printing, i.e. aqueous cylinder wiping which requires E.B. inks to be water dispersable. Also the stability of materials in contact with E.B. inks is being investigated. (author)

  13. Electron Beam curing of intaglio inks

    International Nuclear Information System (INIS)

    Press trials conducted by the US Bureau of Engraving and Printing at the National Bank of Denmark in September 8-21, 1982, clearly indicated the feasibility of Electron Beam (EB) curing for web intaglio printing. These trials, some at continuous press runs of up to six hours, gave positive results for virtually all our requirements including: print quality, press speeds, ability to print both sides of the web on one pass through a press, acceptable ink curing at one megarad or less, and minimum substrate deterioration or loss of moisture. In addition, these trials demonstrated many advantages over thermal curing which is the only other alternative to two sided printing in one pass through the press. These advantages can be found in product quality, a cleaner environment, and in economics. This development program is still in progress with efforts now directed towards adapting EB ink technology to the latest developments in intaglio printing, i.e. aqueous cylinder wiping which requires EB inks to be water dispersable. Also the stability of materials in contact with EB inks is being investigated

  14. Heat shrinkage of electron beam modified EVA

    International Nuclear Information System (INIS)

    Heat shrinkage of electron beam modified ethylene vinyl acetate copolymer (EVA) has been investigated over a range of times, temperatures, stretching, irradiation doses and trimethylolpropane trimethacrylate (TMPTMA) levels. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) and stretched (100% elongation) sample shrinks to a maximum level when kept at 453K temperature for 60 s. The heat shrinkage of samples irradiated with radiation doses of 20, 50, 100 and 150 kGy increases sharply with increasing stretching in the initial stage. Amnesia rating decreases with increasing radiation dose and TMPTMA level as well as gel content. The high radiation dose and TMPTMA level lower the heat shrinkage due to the chain scission. The effect of temperature at which extension is carried out on heat shrinkage is marginal. The irradiated (radiation dose 50 kGy and TMPTMA level 1%) EVA tubes of different dimensions expanded in a laboratory grade tube expander show similar behaviour at 453K and 60 s. The X-ray and DSC studies reveal that the crystallinity increases on stretching due to orientation of chains and it decreases to a considerable extent on heat shrinking. The theoretical and experimental values of heat shrinkage for tubes and rectangular strips are in good accord, when the radiation dose is 50 kGy and TMPTMA level 1%. (author)

  15. Applications of electron beam in nanotechnology

    International Nuclear Information System (INIS)

    The use of radiation technique to process nanostructured materials or to produce nanostructured materials have been shown technically superior as alternative and viable techniques for further commercial exploitation. Research on radiation processing of nanocomposites have been initiated at the Radiation Processing Technology Division of MINT in the past three years. The main focus of this research is to utilize indigenous natural polymer for production of nanocomposites material. Natural rubber/clay composites and thermoplastic natural rubber/clay composites are the important materials that under studied. The natural rubber used in this work is of grade SMRL (Standard Malaysian Rubber) and the clay used was sodium montmorillonite modified with various types of cationic surfactants in order to make the galleries hydrophobic and thus more compatible with the elastomer. The natural rubber/clay nanocomposites were prepared by melt mixing. The compound was then irradiated using electron beam at optimum dose of 250 kGy. X-ray diffraction results indicated intercalation of the natural rubber into silicate interlayer. Upon irradiation at 250 kGy, the tensile strength of the NR/Na-MMT nanocomposites constantly reduced slightly with increasing clay loading, whereas the tensile strengths of NR/DDA-MMT and NR/ODA-MMT increases to optimum levels, 12.1 MPa and 9.5 MPa respectively at 3 phr clay contents. On the other hand, the elongation of NR/DDA-MMT nanocomposites is less affected with increasing clay content up to 3 phr. (author)

  16. Electron beam welding of structural aircraft components

    International Nuclear Information System (INIS)

    Illustrations of how electron beam (EB) welding is currently being used in the manufacture of large complex aircraft structures are reviewed. Starting with a general description of the process, its advantages and limitations and then tracing the evolution of the equipment from the sizes being used as recently as 1969 having vacuum chamber capacities of approximately 64 cubic feet to those presently in production having chamber capacities over 2500 cubic feet. A parallel growth is outlined in the application of the process to larger structures, beginning with the basic data on mechanical properties obtained with small element testing, through the testing of sub and full scale structures. Welding parameters for some typical joints are presented together with the mechanical properties being achieved, including tensile, fatigue, and fracture toughness properties. Pre and post weld processing are described which are being used to optimize these properties. Several examples are reviewed including the Grumman F-14 wing center section and wing outer panels, Boeing Vertol UTTAS Helicopter swashplates, Messerschmitt-Bolkow- Blohm, Multi-Role Combat Aircraft wing center section and the Dassault Mirage G8A wing panel. The final portion describes general guidelines in designing structures for EB welding, with particular emphasis on accessibility for visual, x-ray, ultrasonic, and dye penetrant inspection

  17. Modification of Biodegradable Polyesters Using Electron Beam

    International Nuclear Information System (INIS)

    Poly(4-Hydroxybutyrate) P4HB, Poly(butylene succinate-co-adipate) PBSA and Poly(ε-caprolactone) PCL were electron beam (EB)-irradiated. Poly(4-Hydroxybutyrate) was irradiated without any polyfunctional monomers (PFM). While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC), Polyethyleneglycol dimethacrylate (2G, 4G), Trimethylolpropane trimethacrylate (TMPT) and Tetramethylolmethane tetraacrylate (A-TMMT) at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel) was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields. (author)

  18. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    Science.gov (United States)

    Tang, J. F.; Wu, D. J.; Chen, L.; Zhao, G. Q.; Tan, C. M.

    2016-05-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool for understanding FEBs and the solar plasma environment in which they propagate along solar magnetic fields. In particular, the evolution of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field during propagation can significantly influence the efficiency and properties of their emissions. In this paper, we discuss the possible evolution of the energy spectrum and velocity distribution of FEBs due to energy loss processes and the pitch-angle effect caused by magnetic field inhomogeneity, and we analyze the effects of the evolution on electron-cyclotron maser (ECM) emission, which is one of the most important mechanisms for producing solar radio bursts by FEBs. Our results show that the growth rates all decrease with the energy loss factor Q, but increase with the magnetic mirror ratio σ as well as with the steepness index δ. Moreover, the evolution of FEBs can also significantly influence the fastest growing mode and the fastest growing phase angle. This leads to the change of the polarization sense of the ECM emission. In particular, our results also reveal that an FEB that undergoes different evolution processes will generate different types of ECM emission. We believe the present results to be very helpful for a more comprehensive understanding of the dynamic spectra of solar radio bursts.

  19. Simulating Electron Cloud Effects in Heavy-Ion Beams

    International Nuclear Information System (INIS)

    Stray electrons can be introduced in heavy ion fusion accelerators as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We summarize here results from several studies of electron-cloud accumulation and effects: (1) Calculation of the electron cloud produced by electron desorption from computed beam ion loss; the importance of ion scattering is shown; (2) Simulation of the effect of specified electron cloud distributions on ion beam dynamics. We find electron cloud variations that are resonant with the breathing mode of the beam have the biggest impact on the beam (larger than other resonant and random variations), and that the ion beam is surprisingly robust, with an electron density several percent of the beam density required to produce significant beam degradation in a 200-quadrupole system. We identify a possible instability associated with desorption and resonance with the breathing mode. (3) Preliminary investigations of a long-timestep algorithm for electron dynamics in arbitrary magnetic fields

  20. Injection line of 1+ ion beam for electron beam ion-charge breeding source and related beam elements

    International Nuclear Information System (INIS)

    Main purpose of the electron beam ion-charge breeding source (EBIBS) is to produce highly pure and highly charged ion beam from single charge ion of stable or radioactive species. It can accept low emittance ion beam from either online or offline ECR ion sources (ECRIS). The emittance of the extracted beam is low at lower RF frequencies and magnetic field of the ECRIS. The beam at the position of extraction is approximately reproduced at the entrance of the electron collector of the EBIBS. The beam moves forward under the influence of the negative potential deep of the electron beam and enters the ionization region in solenoid field of the EBIBS. The injection line starts at the extraction region of the ECRIS. The assumed parameters of the extracted beam of 20 keV energy and 0.0732 GeV/c momentum for injection are 10 mm diameter and 30 mrad beam divergence cone. As mass number of the ions decreases the energy decreases for constant momentum of the ion beam. The value of the momentum or the beam rigidity is judiciously chosen to encompass the most of the isotopes of various elements. The beam is focused by a quadrupole doublet and passes the beam through a 90° bending magnet. The beam is analyzed also by the dipole magnet to remove the contaminants and the selected ion beam is focused by a quadrupole doublet magnet to pass through an electrostatic 90° bending elements. The beam approaches the opening of 16 mm diameter of the electron collector. A round beam of 12 mm diameter is achieved here with the help of a quadrupole triplet through point-to-point imaging from start to the end. The transport matrices for the electrostatic bending elements were calculated and incorporated into the TRANSPORT code. (author)

  1. Optimization of combined electron and photon beams for breast cancer

    International Nuclear Information System (INIS)

    Recently, intensity-modulated radiation therapy and modulated electron radiotherapy have gathered a growing interest for the treatment of breast and head and neck tumours. In this work, we carried out a study to combine electron and photon beams to achieve differential dose distributions for multiple target volumes simultaneously. A Monte Carlo based treatment planning system was investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We compared breast treatment plans generated using this home-grown optimization and dose calculation software for different treatment techniques. Five different planning techniques have been developed for this study based on a standard photon beam whole breast treatment and an electron beam tumour bed cone down. Technique 1 includes two 6 MV tangential wedged photon beams followed by an anterior boost electron field. Technique 2 includes two 6 MV tangential intensity-modulated photon beams and the same boost electron field. Technique 3 optimizes two intensity-modulated photon beams based on a boost electron field. Technique 4 optimizes two intensity-modulated photon beams and the weight of the boost electron field. Technique 5 combines two intensity-modulated photon beams with an intensity-modulated electron field. Our results show that technique 2 can reduce hot spots both in the breast and the tumour bed compared to technique 1 (dose inhomogeneity is reduced from 34% to 28% for the target). Techniques 3, 4 and 5 can deliver a more homogeneous dose distribution to the target (with dose inhomogeneities for the target of 22%, 20% and 9%, respectively). In many cases techniques 3, 4 and 5 can reduce the dose to the lung and heart. It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost

  2. Elastic Scattering of Electron Vortex Beams in Magnetic Matter

    Science.gov (United States)

    Edström, Alexander; Lubk, Axel; Rusz, Ján

    2016-03-01

    Elastic scattering of electron vortex beams on magnetic materials leads to a weak magnetic contrast due to Zeeman interaction of orbital angular momentum of the beam with magnetic fields in the sample. The magnetic signal manifests itself as a redistribution of intensity in diffraction patterns due to a change of sign of the orbital angular momentum of the electron vortex beam. While in the atomic resolution regime the magnetic signal is most likely under the detection limits of present transmission electron microscopes, for electron probes with high orbital angular momenta, and correspondingly larger spatial extent, its detection is predicted to be feasible.

  3. Problem of obliquely incident beams in electron-beam treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Ekstrand, K.E.; Dixon, R.L.

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beans, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths.

  4. Problem of obliquely incident beams in electron-beam treatment planning

    International Nuclear Information System (INIS)

    Oblique incidence of an electron beam can alter the central axis depth dose. The incident beam can be considered to be an integration of many pencil beams or slit beams. Depending on the depth in the phantom, neighboring pencil beams may have a greater or lesser contribution to the dose at a point on the central axis compared to the contribution under normal incidence. The effect has been studied experimentally and theoretically. For 6- and 9-MeV electron beans, oblique incidence is found to produce an increased dose at shallow depths and a decreased dose at normal treatment depths

  5. First beam test of ΔΦ-A initial beam loading compensation for electron linacs

    International Nuclear Information System (INIS)

    The initial-beam-loading effect may cause serious beam loss in the electron linac of the Super SOR light source. Because of the large energy spread, it is difficult to compensate the beam loading with ordinary methods, such as the adjustment of injection timing and ECS (Energy Compensation System). A phase-amplitude (ΔΦ-A) modulation system has already been developed and tested. First beam test using this system was carried out at the 125 MeV electron linac of Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University. Its result shows that our system well corrects the energy spread due to initial beam loading effect. In this paper, we report the results of first beam test. (author)

  6. Focused electron beam induced deposition as a tool to create electron vortices.

    Science.gov (United States)

    Béché, A; Winkler, R; Plank, H; Hofer, F; Verbeeck, J

    2016-01-01

    Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be ∼0.8ℏ per electron with almost 60% of the beam ending up in the ℓ=1 state. PMID:26432987

  7. Electron beam generation in high voltage glow discharges

    International Nuclear Information System (INIS)

    The generation of intense CW and pulsed electron beams in glow discharges in reviewed. Glow discharge electron guns operate at a pressure of the order of 1 Torr and often have an advantage in applications that require a broad area electron beam in a gaseous atmosphere, such as laser excitation and some aspects of materials processing. Aspects of electron gun design are covered. Diagnostics of the high voltage glow discharges including the electric field distribution mapped by Doppler free laser spectroscopy, and plasma density and electron temperature measurements of the electron yield of different cathode materials under glow discharge conditions are presented

  8. Electron Beam Energy Compensation by Controlling RF Pulse Shape

    CERN Document Server

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

    2005-01-01

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

  9. High-current runaway electron beam in a tokamak plasma

    International Nuclear Information System (INIS)

    An equilibrium of toroidal plasma with a large electron-beam current has been realized using the runaway effect in a tokamak. Reproducible runaway-mode discharges are obtained with pure hydrogen gas by the help of intense titanium flashing which results in a low electron density. The beam current is estimated to be more than a half of the total toroidal current. The equilibrium of this discharge is maintained by a strong vertical field because the beam pressure gives rise to an additional increase in Shafranov Λ. The beam pressure is estimated to be more than 80% of the total pressure. The kinetic energy and the spatial distributions of beam electrons are studied by seeing X-ray emission from a tungsten wire inserted into the plasma. The increase of Shafranov Λ due to beam pressure is enhanced by puffing gas into the discharge. (author)

  10. Plasma Charge Current for Controlling and Monitoring Electron Beam Welding with Beam Oscillation

    Science.gov (United States)

    Trushnikov, Dmitriy; Belenkiy, Vladimir; Shchavlev, Valeriy; Piskunov, Anatoliy; Abdullin, Aleksandr; Mladenov, Georgy

    2012-01-01

    Electron beam welding (EBW) shows certain problems with the control of focus regime. The electron beam focus can be controlled in electron-beam welding based on the parameters of a secondary signal. In this case, the parameters like secondary emissions and focus coil current have extreme relationships. There are two values of focus coil current which provide equal value signal parameters. Therefore, adaptive systems of electron beam focus control use low-frequency scanning of focus, which substantially limits the operation speed of these systems and has a negative effect on weld joint quality. The purpose of this study is to develop a method for operational control of the electron beam focus during welding in the deep penetration mode. The method uses the plasma charge current signal as an additional informational parameter. This parameter allows identification of the electron beam focus regime in electron-beam welding without application of additional low-frequency scanning of focus. It can be used for working out operational electron beam control methods focusing exactly on the welding. In addition, use of this parameter allows one to observe the shape of the keyhole during the welding process. PMID:23242276

  11. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    International Nuclear Information System (INIS)

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device

  12. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, J.A.; Vroom, D.A.

    1978-07-01

    An electron-beam heater and associated power supply have been developed for use in formation of metal vapors for neutral beam studies. The device is small with relatively low power (250 W). It is easily constructed and designed such that the target surface is normal to the direction of propagation of the neutral beam. Beams of tantalum atoms and carbon particles have been formed using the device.

  13. Exact suppression of depolarisation by beam-beam interaction in an electron ring

    International Nuclear Information System (INIS)

    It is shown that depolarisation due to beam-beam interaction can be exactly suppressed in an electron storage ring. The necessary ''spin matching'' conditions to be fulfilled are derived for a planar ring. They depend on the ring optics, assumed linear, but not on the features of the beam-beam force, like intensity and non-linearity. Extension to a ring equipped with 900 spin rotators is straightorward

  14. Tuning of Graphene Properties via Controlled Exposure to Electron Beams

    OpenAIRE

    Liu, G; Teweldebrhan, D.; Balandin, A. A.

    2010-01-01

    Controlled modification of graphene properties is essential for its proposed electronic applications. Here we describe a possibility of tuning electrical properties of graphene via electron beam irradiation. We show that by controlling the irradiation dose one can change the carrier mobility and increase the resistance at the minimum conduction point in the single layer graphene. The bilayer graphene is less susceptible to the electron beam irradiation. The modification of graphene properties...

  15. Intraoperative electron-beam radiotherapy and ureteral obstruction

    International Nuclear Information System (INIS)

    Purpose: To quantify the risk of ureteral obstruction (UO) after intraoperative electron-beam radiotherapy (IOERT). Methods and Materials: One hundred forty-six patients received IOERT of 7.5 to 30 Gy to 168 ureters; 132 patients received external radiotherapy. Results: Follow-up ranged from 0.01 to 19.1 years (median, 2.1 years). The rates of clinically apparent type 1 UO (UO from any cause) after IOERT at 2, 5, and 10 years were 47%, 63%, and 79%, respectively. The rates of clinically apparent type 2 UO (UO occurring at least 1 month after IOERT, excluding UO caused by tumor or abscess and patients with stents) at 2, 5, and 10 years were 27%, 47%, and 70%, respectively. Multivariate analysis revealed that the presence of UO before IOERT (p < 0.001) was associated with an increased risk of clinically apparent type 1 UO. Increasing IOERT dose (p < 0.04) was associated with an increased risk of clinically apparent type 2 UO. UO rates in ureters not receiving IOERT at 2, 5, and 10 years were 19%, 19%, and 51%, respectively. Conclusions: Risk of UO after IOERT increases with dose. However, UO risk for ureters not receiving IOERT was also high, which suggests an underlying risk of ureteral injury from other causes

  16. Limiting current of intense electron beams in a decelerating gap

    Science.gov (United States)

    Nusinovich, G. S.; Beaudoin, B. L.; Thompson, C.; Karakkad, J. A.; Antonsen, T. M.

    2016-02-01

    For numerous applications, it is desirable to develop electron beam driven efficient sources of electromagnetic radiation that are capable of producing the required power at beam voltages as low as possible. This trend is limited by space charge effects that cause the reduction of electron kinetic energy and can lead to electron reflection. So far, this effect was analyzed for intense beams propagating in uniform metallic pipes. In the present study, the limiting currents of intense electron beams are analyzed for the case of beam propagation in the tubes with gaps. A general treatment is illustrated by an example evaluating the limiting current in a high-power, tunable 1-10 MHz inductive output tube (IOT), which is currently under development for ionospheric modification. Results of the analytical theory are compared to results of numerical simulations. The results obtained allow one to estimate the interaction efficiency of IOTs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten

    2010-09-15

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

  18. Electronic Health Records Should Support Clinical Research

    OpenAIRE

    Powell, John; Buchan, Iain

    2005-01-01

    One aspect of electronic care records which has received little attention is the potential benefit to clinical research. Electronic records could facilitate new interfaces between care and research environments, leading to great improvements in the scope and efficiency of research. Benefits range from systematically generating hypotheses for research to undertaking entire studies based only on electronic record data. Researchers and research managers must engage with electronic record initiat...

  19. Storage-ring Electron Cooler for Relativistic Ion Beams

    CERN Document Server

    Lin, F; Douglas, D; Guo, J; Johnson, R P; Krafft, G; Morozov, V S; Zhang, Y

    2016-01-01

    Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the...

  20. Examination Of Nanostructures By Electron Beam

    Czech Academy of Sciences Publication Activity Database

    Hrnčiřík, Petr; Müllerová, Ilona

    Bled: European Microbeam Analysis Society, 2004, s. 139. [EMAS 2004 /6./ Electron Probe Analysis Today - Practical Aspects. Bled (SI), 08.05.2004-11.05.2004] R&D Projects: GA AV ČR KJB2065405 Keywords : scanning electron microscope * scanning Auger electron microscopy * very slow electrons Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  1. Unveiling the orbital angular momentum and acceleration of electron beams.

    Science.gov (United States)

    Shiloh, Roy; Tsur, Yuval; Remez, Roei; Lereah, Yossi; Malomed, Boris A; Shvedov, Vladlen; Hnatovsky, Cyril; Krolikowski, Wieslaw; Arie, Ady

    2015-03-01

    New forms of electron beams have been intensively investigated recently, including vortex beams carrying orbital angular momentum, as well as Airy beams propagating along a parabolic trajectory. Their traits may be harnessed for applications in materials science, electron microscopy, and interferometry, and so it is important to measure their properties with ease. Here, we show how one may immediately quantify these beams' parameters without need for additional fabrication or nonstandard microscopic tools. Our experimental results are backed by numerical simulations and analytic derivation. PMID:25793830

  2. Unveiling the orbital angular momentum and acceleration of electron beams

    CERN Document Server

    Shiloh, Roy; Lereah, Yossi; Malomed, Boris A; Shvedov, Vladlen; Hnatovsky, Cyril; Krolikowski, Wieslaw; Arie, Ady

    2014-01-01

    New forms of electron beams have been intensively investigated recently, including vortex beams carrying orbital angular momentum, as well as Airy beams propagating along a parabolic trajectory. Their traits may be harnessed for applications in materials science, electron microscopy and interferometry, and so it is important to measure their properties with ease. Here we show how one may immediately quantify these beams' parameters without need for additional fabrication or non-standard microscopic tools. Our experimental results are backed by numerical simulations and analytic derivation.

  3. Measurement of accelerated electron beam current at the Erevan synchrotron

    International Nuclear Information System (INIS)

    A system which ensures high accuracy of accelerated electro n beam current measurement at the synchrotron is described. The expected limits for the frequency characteristic of the measured magnitude, i.e. current of accelerated electron beam, are analyzed. A structure of measurement devices ensuring a necessary frecuency range for measured signals is chosen. A magnetoinduction feedback converter operating in aperiodic mode is taken as a primary beam current monitor. The parameters of the converter with a coincidence amplifier were calculated with a computer. Oscillograms of accelerated electron beam current corresponding to different operational modes of the synchrotron are presented

  4. Application of optical beams to electrons in graphene

    Science.gov (United States)

    Matulis, A.; Masir, M. Ramezani; Peeters, F. M.

    2011-03-01

    The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed.

  5. Design and Construction of Solenoid Magnetic Lens for Focusing Electron Beam from Thermionic Electron Gun

    International Nuclear Information System (INIS)

    Electron gun is an important part of an electron accelerator for producing electron beam to be irradiated on material. The electron gun of electron accelerator constructed at P3TM BATAN, is a thermionic electron gun, A solenoid magnetic lens had been designed and constructed for focusing electron beam extracted from the electron gun in such away that all of the electron beam enter the accelerating tube. Technical specification of the solenoid magnetic lens is given in this paper. Measurement of magnetic field generated by solenoid coil shows that the largest magnetic field is in the middle of the solenoid coil. The test using the thermionic electron gun shows the focusing effect on electron beam by the solenoid magnetic lens. The focus strength is maximum after the coil current reaches 9 A. (author)

  6. Development of modulated electron beam for intensity modulated radiation therapy (IMRT) on a photocathode electron gun

    International Nuclear Information System (INIS)

    Radiation therapy of cancer is developing to un-uniform irradiation, for concentrating dose to a cancer tumor and reducing dose to normal tissue. As a step toward the Intensity modulated radiation therapy, we examined dynamic optical modulation of electron beam produced by a photocathode electron gun. Images on photo-masks were transferred onto a photocathode by relay imaging. Electron beam could be controlled by a remote mirror. Modulated electron beam maintained its shape on acceleration, had a fine spatial resolution, and could be moved dynamically by optical methods. As a second step, optical modulation of electron beam and dynamic control succeeded by a digital micro mirror device (DMD). (author)

  7. A microwave plasma cathode electron gun for ion beam neutralization

    Science.gov (United States)

    Fusellier, C.; Wartski, L.; Aubert, J.; Schwebel, C.; Coste, Ph.; Chabrier, A.

    1998-02-01

    It is well known that there exist two distinct types of ion beam neutralization, viz., charge and current neutralization. We have designed and studied a versatile and compact microwave plasma (MP) cathode electron gun dedicated to charge as well as current neutralization. Unlike the conventional hot cathode neutralizer, this MP cathode allows operation of the electron gun in a reactive gaseous environment when it is eventually associated with an electron cyclotron resonance (ECR) ion gun. Charge neutralization can be easily carried out by extracting from the MP cathode through a 1 mm diameter hole, a 35 mA electron beam under a 20 V voltage; the MP cathode being fed with a 75 W microwave power at 2.45 GHz. Higher beam intensities could be obtained using a multiaperture thin plate. Electron beam intensities as high as 300 mA and energies of 2 keV needed for current neutralization, e.g., when an ion beam impinges onto a thick dielectric surface, are obtained via a two-stage arrangement including an anodic chamber associated with a set of three monoaperture plates for the electron beam extraction. Transport of 200-2000 eV electron beams is ensured using focusing optics composed of three aligned tubes 6 cm in diameter and unsymmetrically polarized.

  8. Feasibility test to control algal bloom using electron beam irradiation

    International Nuclear Information System (INIS)

    Efforts were made to assess the feasibility to control algal growth using electron beam irradiation. Fresh water algae (e.g. Chlorella sp., Scenedesmus sp., Microcystis sp., Anabaena sp., Oscillatoria sp.) and sea water red algae (e.g. Procentrium minimum, Lingulodinium polyedra, Cochlodinium polykrikoides, Scrippsiella trochoidea, Procentrium micans) were cultured in laboratory and irradiated at different dose of 1.0-10kGy by ELV-4 model electron beam accelerator. The results indicated that in spite of low dose, electron beam irradiation have a great effect on the algal photosynthetic activity; especially for sea water red algae, approximately 40% reduction in chlorophyll-a concentration was observed right after electron beam irradiation at 1.0kGy. Decrease in photosynthetic activity of sea water red algae was more pronounced than that of fresh water algae. With regard to fresh water algae, blue green algae(e.g. Microcystis sp., Oscillatoria sp.) was more vulnerable to electron beam exposure than green algae(e.g. Chlorella sp., Scenedesmus sp.). It is interesting to observe that complete bioflocculation marked by cell aggregation and rapid settling of fresh water algae occurred within 2 days after electron beam irradiation. Continuous mixing was one of the important factors to induce algal bioflocculation. Algal removal and settleable matter production were found to be proportional to irradiation dose and mixing intensity. It is likely that electron beam irradiation damages cell contents including chlorophyll-a, releasing extracellular biopolymer that can be used for inducing bioflocculation. (author)

  9. Charged particle acceleration by electron beam in corrugated plasma waveguide

    International Nuclear Information System (INIS)

    A two-beam charged particle acceleration scheme in a plasma waveguide with corrugated conducting walls is considered. The guiding heavy-current relativistic electron beam is in synchronism with the first plasma wave space harmonics and the accelerated beam is synchronism with a quicker plasma wave. In this case under weak corrugation of the wall the accelerating resonance field effecting the accelerated particles notably increases the field braking the guiding beam. The process of plasma wave excitation with regard to the guiding beam space charge and the relativistic particle acceleration dynamics are investigated by numeric methods. Optimal acceleration modes are found. 19 refs.; 12 figs

  10. Stimulated electromagnetic interactions in spatiotemporally gyrating relativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J.A.; Chen, C.

    1999-07-01

    One possible method to significantly widen the band-widths of present gyroklystron amplifiers is to utilize extended interaction structures in the input sections, the buncher sections and the output sections, in conjunction with stagger tuning. Through extended interactions, however, electron beams can undergo stimulated electromagnetic interactions, causing multimode excitations. In this paper, the authors investigate stimulated electromagnetic interactions in relativistic electron beams gyrating in an externally applied uniform magnetic field. The electron gyrophases are assumed to have strong spatiotemporal correlations. By applying Vlassor-Maxwell equations together with Lorentz transformations, they obtain the general dispersion relation for electromagnetic and electrostatic wave perturbations on the electron beam for this system. The dispersion relation is used to analyze a variety of stimulated electromagnetic interactions on such electron beams. Results of these analyses are discussed.

  11. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    International Nuclear Information System (INIS)

    We discuss the design and current status of experiments to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

  12. Measurement of electron beam bunch phase length by rectangular cavities

    International Nuclear Information System (INIS)

    An analysis of a phase length of electron bunches with the help of crossed rectangular resonators with the Hsub(102) oscillation type has been made. It has been shown that the electron coordinates after the duplex resonator are described by an ellipse equation for a non-modulated beam. An influence of the initial energy spread upon the electron motion has been studied. It has been ascertained that energy modulation of the electron beam results in displacement of each electron with respect to the ellipse which is proportional to modulation energy, i.e. an error in determination of the phase length of an electron bunch is proportional to the beam energy spread. Relations have been obtained which enable to find genuine values of phases of the analyzed electrons with an accuracy up to linear multipliers

  13. Beam induced electron cloud resonances in dipole magnetic fields

    Science.gov (United States)

    Calvey, J. R.; Hartung, W.; Makita, J.; Venturini, M.

    2016-07-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple of bunch spacing. Both resonances have been studied directly in dipole fields using retarding field analyzers installed in the Cornell Electron Storage Ring. These measurements are supported by both analytical models and computer simulations.

  14. Color coating on tin plate by electron beam curing

    International Nuclear Information System (INIS)

    The characteristics of thin films of color paints cured by electron beam radiation were examined for the purpose of appling electron beams to the color printing of can exteriors. The mixtures of various kinds of acrylic oligomers, monomers, and pigments were used as color paints. The color paints were coated on tin plate and the plates were irradiated in an atmosphere of nitrogen with low energy electron beams of 200 kV. The pencil hardness, adhesion, cracking, and hue of cured coating were measured. From the results of these tests, several color paints seem to be appropriate for the processing of can exterious. (author)

  15. Patterned electrochemical deposition of copper using an electron beam

    Directory of Open Access Journals (Sweden)

    Mark den Heijer

    2014-02-01

    Full Text Available We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we control nucleation to form patterns of deposited copper. We discuss the mechanism for this effect in terms of electron beam-induced reactions with copper chloride, and consider possible applications.

  16. Prospects for using electron beam welding in domestic power engineering

    International Nuclear Information System (INIS)

    Brief information on commercial use of electron beam welding in home power engineering is given. Perfect weldability of the 15GS, 10GN2MFA, 15Kh2NMFA and 15Kh1M1F perlitic steels with the manganese content lower limit 0.6% is pointed out. The absence of hot cracks in austenitic stainless steels is guaranteed provided the Ni/Cr ratio is below 1. Some technological practices of electron beam welding contributing to the improvement of formation are described. Substitution of electron beam welding for electroslag welding is shown to be promising in manufacturing reactor vessels and tube-tube plate joints in steam generators

  17. High energy gain electron beam acceleration by 100TW laser

    International Nuclear Information System (INIS)

    A laser wakefield acceleration experiment using a 100TW laser is planed at JAERI-Kansai. High quality and short pulse electron beams are necessary to accelerate the electron beam by the laser. Electron beam - laser synchronization is also necessary. A microtron with a photocathode rf-gun was prepared as a high quality electron injector. The quantum efficiency (QE) of the photocathode of 2x10-5 was obtained. A charge of 100pC from the microtron was measured. The emittance and pulse width of the electron beam was 6π mm-mrad and 10ps, respectively. In order to produce a short pulse electron beam, and to synchronize between the electron beam and the laser pulse, an inverse free electron laser (IFEL) is planned. One of problems of LWFA is the short acceleration length. In order to overcome the problem, a Z-pinch plasma waveguide will be prepared as a laser wakefield acceleration tube for 1 GeV acceleration. (author)

  18. The use of electron beams for pasteurization of meats

    International Nuclear Information System (INIS)

    Electron beam accelerators can be used for electronic pasteurization of meat products by: (1) using the electrons directly impacting the products, or (2) optimizing the conversion of electron energy to x-rays and treating the product with these x-rays. The choice of process depends on the configuration of the product when it is treated. For electron treatment, ten million electron volt (MeV) kinetic energy is the maximum allowed by international agreement. The depth of penetration of electrons with that energy into a product with density of meat is about five centimeters (cm). Two-sided treatment can be done on products up to 10 cm thick with a two-to-one ratio between minimum and maximum dose. Ground beef patties are about 1.25 cm (0.5 inch thick). Beams with 2.5 MeV electron energy could be used to treat these products. Our calculations show that maximum to minimum dose ratios less than 1.2 can be achieved with this energy if the transverse beam energy is small. If the product thickness is greater than 10 cm, x-rays can provide the needed dose uniformity. Uniform doses can be supplied for pallets with dimensions greater than 1.2 m on each side using x-rays from a 5 MeV electron beam. The efficiency of converting the electron beam to x-rays and configurations to achieve dose uniformity are discussed

  19. Monte Carlo simulation of electron beam air plasma characteristics

    Institute of Scientific and Technical Information of China (English)

    Deng Yong-Feng; Han Xian-Wei; Tan Chang

    2009-01-01

    A high-energy electron beam generator is used to generate a plasma in atmosphere. Based on a Monte Carlo toolkit named GEANT4,a model including complete physics processes is established to simulate the passage of the electron beam in air. Based on the model,the characteristics of the electron beam air plasma are calculated. The energy distribution of beam electrons (BEs) indicates that high-energy electrons almost reside in the centre region of the beam,but low-energy electrons always live in the fringe area. The energy deposition is calculated in two cases,i.e.,with and without secondary electrons (SEs). Analysis indicates that the energy deposition of Ses accounts for a large part of the total energy deposition. The results of the energy spectrum show that the electrons in the inlet layer of the low-pressure chamber (LPC) are monoenergetic,but the energy spectrum of the electrons in the outlet layer is not pure. The SEs are largely generated at the outlet of the LPC. Moreover,both the energy distribution of Bes and the magnitude of the density of SEs are closely related to the pressure of LPC. Thus,a conclusion is drawn that a low magnitude of LPC pressure is helpful for reducing the energy loss in the LPC and also useful for greatly increasing the secondary electron density in dense air.

  20. Profiling of back-scattered electrons in opposed magnetic field of a Twin Electron Beam Gun

    International Nuclear Information System (INIS)

    Electron gun is extensively used in material processing, physical vapour deposition and atomic vapour based laser processes. In these processes where the electron beam is incident on the substrate, a significant fraction of electron beam gets back-scattered from the target surface. The trajectory of this back scattered electron beam depends on the magnetic field in the vicinity. The fraction of back-scattered depends on the atomic number of the target metal and can be as high as ∼40% of the incident beam current. These back-scattered electrons can cause undesired hot spots and also affect the overall process. Hence, the study of the trajectory of these back-scattered electrons is important. This paper provides the details of experimentally mapped back-scattered electrons of a 2×20kW Twin Electron Beam Gun (TEBG) in opposed magnetic field i.e. with these guns placed at 180° to each other.

  1. Electron gun for a multiple beam klystron with magnetic compression of the electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Ives, R. Lawrence; Tran, Hien T; Bui, Thuc; Attarian, Adam; Tallis, William; David, John; Forstall, Virginia; Andujar, Cynthia; Blach, Noah T; Brown, David B; Gadson, Sean E; Kiley, Erin M; Read, Michael

    2013-10-01

    A multi-beam electron gun provides a plurality N of cathode assemblies comprising a cathode, anode, and focus electrode, each cathode assembly having a local cathode axis and also a central cathode point defined by the intersection of the local cathode axis with the emitting surface of the cathode. Each cathode is arranged with its central point positioned in a plane orthogonal to a device central axis, with each cathode central point an equal distance from the device axis and with an included angle of 360/N between each cathode central point. The local axis of each cathode has a cathode divergence angle with respect to the central axis which is set such that the diverging magnetic field from a solenoidal coil is less than 5 degrees with respect to the projection of the local cathode axis onto a cathode reference plane formed by the device axis and the central cathode point, and the local axis of each cathode is also set such that the angle formed between the cathode reference plane and the local cathode axis results in minimum spiraling in the path of the electron beams in a homogenous magnetic field region of the solenoidal field generator.

  2. Large Dynamic Range Beam Profile Measurements with Low Current Electron Beams

    International Nuclear Information System (INIS)

    Large dynamic range [Peak/Noise > 105] beam profile measurements are routinely performed in the Hall-B beamline at Jefferson Lab. These measurements are made with a 1 to 10nA electron beam current with energies between 1 to 6 GeV. The electron beam scatters off of a thin [25 mu-m] W or Fe wire and the scattered particle/shower is detected via scintillation or Cerenkov light several meters downstream of the wire. This light is converted to an electrical pulse via photomultiplier tubes [PMT]. The PMT readout and wire motion are controlled and synchronized by VME electronics. This report describes results on increasing the dynamic range by using multiple wires of varying diameters. Profile measurements with this large dynamic range can be of use for machines with very large beam currents (ERL) where any FR-actional beam loss represents a significant amount of beam power [1,2

  3. Beam-beam compensation studies in the Tevatron with electron lenses

    CERN Document Server

    Stancari, Giulio

    2013-01-01

    At the Fermilab Tevatron collider, we studied the feasibility of suppressing the antiproton head-on beam-beam tune spread using a magnetically confined 5-keV electron beam with Gaussian transverse profile overlapping with the circulating beam. When electron cooling of antiprotons was applied in regular Tevatron operations, the nonlinear head-on beam-beam effect on antiprotons was small. Therefore, we first focused on the operational aspects, such as beam alignment and stability, and on fundamental observations of tune shifts, tune spreads, lifetimes, and emittances. We also attempted two special collider stores with only 3 proton bunches colliding with 3 antiproton bunches, to suppress long-range forces and enhance head-on effects. We present here the results of this study and a comparison between numerical simulations and observations. These results contributed to the application of this compensation concept to RHIC at Brookhaven.

  4. Direct measurement of electron beam quality conversion factors using water calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, James, E-mail: james.renaud@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada); Sarfehnia, Arman [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3E2 (Canada); Marchant, Kristin [Allan Blair Cancer Centre, Saskatchewan Cancer Agency, Regina, Saskatchewan S4T 7T1, Canada and Department of Oncology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A1 (Canada); McEwen, Malcolm; Ross, Carl [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

    2015-11-15

    Purpose: In this work, the authors describe an electron sealed water calorimeter (ESWcal) designed to directly measure absorbed dose to water in clinical electron beams and its use to derive electron beam quality conversion factors for two ionization chamber types. Methods: A functioning calorimeter prototype was constructed in-house and used to obtain reproducible measurements in clinical accelerator-based 6, 9, 12, 16, and 20 MeV electron beams. Corrections for the radiation field perturbation due to the presence of the glass calorimeter vessel were calculated using Monte Carlo (MC) simulations. The conductive heat transfer due to dose gradients and nonwater materials was also accounted for using a commercial finite element method software package. Results: The relative combined standard uncertainty on the ESWcal dose was estimated to be 0.50% for the 9–20 MeV beams and 1.00% for the 6 MeV beam, demonstrating that the development of a water calorimeter-based standard for electron beams over such a wide range of clinically relevant energies is feasible. The largest contributor to the uncertainty was the positioning (Type A, 0.10%–0.40%) and its influence on the perturbation correction (Type B, 0.10%–0.60%). As a preliminary validation, measurements performed with the ESWcal in a 6 MV photon beam were directly compared to results derived from the National Research Council of Canada (NRC) photon beam standard water calorimeter. These two independent devices were shown to agree well within the 0.43% combined relative uncertainty of the ESWcal for this beam type and quality. Absorbed dose electron beam quality conversion factors were measured using the ESWcal for the Exradin A12 and PTW Roos ionization chambers. The photon-electron conversion factor, k{sub ecal}, for the A12 was also experimentally determined. Nonstatistically significant differences of up to 0.7% were found when compared to the calculation-based factors listed in the AAPM’s TG-51 protocol

  5. Direct measurement of electron beam quality conversion factors using water calorimetry

    International Nuclear Information System (INIS)

    Purpose: In this work, the authors describe an electron sealed water calorimeter (ESWcal) designed to directly measure absorbed dose to water in clinical electron beams and its use to derive electron beam quality conversion factors for two ionization chamber types. Methods: A functioning calorimeter prototype was constructed in-house and used to obtain reproducible measurements in clinical accelerator-based 6, 9, 12, 16, and 20 MeV electron beams. Corrections for the radiation field perturbation due to the presence of the glass calorimeter vessel were calculated using Monte Carlo (MC) simulations. The conductive heat transfer due to dose gradients and nonwater materials was also accounted for using a commercial finite element method software package. Results: The relative combined standard uncertainty on the ESWcal dose was estimated to be 0.50% for the 9–20 MeV beams and 1.00% for the 6 MeV beam, demonstrating that the development of a water calorimeter-based standard for electron beams over such a wide range of clinically relevant energies is feasible. The largest contributor to the uncertainty was the positioning (Type A, 0.10%–0.40%) and its influence on the perturbation correction (Type B, 0.10%–0.60%). As a preliminary validation, measurements performed with the ESWcal in a 6 MV photon beam were directly compared to results derived from the National Research Council of Canada (NRC) photon beam standard water calorimeter. These two independent devices were shown to agree well within the 0.43% combined relative uncertainty of the ESWcal for this beam type and quality. Absorbed dose electron beam quality conversion factors were measured using the ESWcal for the Exradin A12 and PTW Roos ionization chambers. The photon-electron conversion factor, kecal, for the A12 was also experimentally determined. Nonstatistically significant differences of up to 0.7% were found when compared to the calculation-based factors listed in the AAPM’s TG-51 protocol. General

  6. Electronic beam steering of semiconductor injection lasers

    Science.gov (United States)

    Katz, J.

    1982-01-01

    A theoretical analysis of the problem of beam steering is presented. The required modifications of the dielectric constant profile of the laser structure were derived. A practical method for implementing the needed modifications is outlined.

  7. Electron beam characteristics in the hollow beam diode and cusped magnetic field of the Maryland ERA

    International Nuclear Information System (INIS)

    The University of Maryland electron ring accelerator (ERA) concept calls for the formation of an electron ring current by transmission of a hollow relativistic electron beam through a static, azimuthally symmetric, cusped magnetic field. Electron motion is approximately paraxial in the diode and pre-cusp drift region and is axis-encircling in the post-cusp region. Experiments show the electron flow in the diode to be approximately pressureless. The radial thickness of the drifting Brillouin hollow beam is derived from a radial force balance equation. Time-resolved measurements of the beam current and energy are made by measuring the extrapolated range of the beam in aluminum targets. These measurements are analyzed with a model of the diode as a terminating impedance driven by a transmission line. Beam motion in the cusped field region is analyzed. Beam dynamics in the post-cusp region are studied by examining the interaction of a hollow rotating beam with its self-induced potentials in a cylindrical box with conducting walls and ends. The energy of the self-induced electric and magnetic potentials is much less than the kinetic energy of the beam electrons for cases approximating experimental conditions

  8. Transmission of Megawatt Relativistic Electron Beams Through Millimeter Apertures

    CERN Document Server

    Alarcon, R; Benson, S V; Bertozzi, W; Boyce, J R; Cowan, R; Douglas, D; Evtushenko, P; Fisher, P; Ihloff, E; Kalantarians, N; Kelleher, A; Legg, R; Milner, R G; Neil, G R; Ou, L; Schmookler, B; Tennant, C; Tschalaer, C; Williams, G P; Zhang, S

    2013-01-01

    High power, relativistic electron beams from energy recovery linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration for this new generation of experimental capabilities is the understanding of the halo associated with these bright, intense beams. In this Letter, we report on measurements performed using the 100 MeV, 430 kWatt CW electron beam from the energy recovery linac at the Jefferson Laboratory's Free Electron Laser facility as it traversed a set of small apertures in a 127 mm long aluminum block. Thermal measurements of the block together with neutron measurements near the beam-target interaction point yielded a consistent understanding of the beam losses. These were determined to be 3 ppm through a 2 mm diameter aperture and were maintained during a 7 hour continuous run.

  9. Electron Beam Size Measurements in a Cooling Solenoid

    CERN Document Server

    Kroc, Thomas K; Burov, Alexey; Seletsky, Sergey; Shemyakin, Alexander V

    2005-01-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide effective cooling of the antiprotons in the Recycler. A measurement system was developed using movable appertures and steering bumps to measure the beam size in a 20 m long, nearly continuous, solenoid. This paper discusses the required beam parameters, the implimentation of the measurement system and results for our application.

  10. Beam spill control with frequency modulation in electron synchrotron

    International Nuclear Information System (INIS)

    The new method has been applied to the beam spill control of the INS electron synchrotron. In this method, the RF operating frequency is slowly increased at the final stage of the accelerating period. Then the equilibrium orbit shrinks and the beam hits the radiator gradually, staying in the stable phase. The new method gives the uniform beam spill in the energy region below 700 MeV where the old method has not been successful enough. (author)

  11. Electron beam optics for the FEL experiment and IFEL experiment

    International Nuclear Information System (INIS)

    Electron beam transport system parameters for the FEL experiment and for the FEL experiment are given. The perturbation of the ''interaction region'' optics due to wiggler focussing is taken into account and a range of solutions are provided for relevant Twiss parameters in the FEL or IFEL region. Modifications of the transport optics in specific sections of the overall beam transport lines, for reasons of enhanced diagnostic capability or enhanced beam momentum analysis resolution, is also presented

  12. Radiation sterilization by 10 MeV electron beams

    International Nuclear Information System (INIS)

    Gamma-ray sterilization by 60Co source has been already popular in Japan. Many Kinds of medical plastic devices such as catheters, disposable syringes, dializers etc, has been irradiated at 60Co irradiation facilities instead of the conventional ethylene oxide fumigation method. On the other hand, improvement of the quality of electron accelerators has made it easier to take advantage of relatively high energy electrons which are profitable for radiation sterilization because of their high dose rate saving process hours and easiness of source handling and radiation control. So electron-beam sterilization is now under investigation in Japan and, partly, it will be practiced in the near future. Yet few data are available in the present situation. Especially for high energy electron beams near 10 MeV, more data are necessary for practical application of electron-beam sterilization. Therefore, in this study, sensitivity of Bacillus pumilus E601, the biological standard of radiation sterilization, was examined using 10 MeV electron beams from linear accelerator and sterility of the beams was also checked at each depth of plastic boards in order to get basic information for determination of sterility dose. Endospores from B. pumilus were dried on filter papers (Toyo No.1) and irradiated by 10 MeV electron beams of 60Co gamma-rays. The survival curves were shown in Fig. 1. The D values were obtained as 1.9 kGy ± 0.2 for electron beams and 1.7 kGy ± 0.1 for 60Co gamma-rays, both of which were similar. Electron beams could sterilize the endospores nearly uniformly till 3 cm depth of plastic boards at 10 MeV (Fig. 2,3). This indicates a possibility to sterilize relatively bulky products such as dializers etc. (author)

  13. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    Science.gov (United States)

    Scisciò, M.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Papaphilippou, Y.; Antici, P.

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  14. New fast beam profile monitor for electron-positron colliders.

    Science.gov (United States)

    Bogomyagkov, A V; Gurko, V F; Zhuravlev, A N; Zubarev, P V; Kiselev, V A; Meshkov, O I; Muchnoi, N Yu; Selivanov, A N; Smaluk, V V; Khilchenko, A D

    2007-04-01

    A new fast beam profile monitor has been developed at the Budker Institute of Nuclear Physics. This monitor is based on the Hamamatsu multianode photomultiplier with 16 anode strips and provides turn-by-turn measurement of the transverse beam profile. The device is equipped with an internal memory, which has enough capacity to store 131,072 samples of the beam profile. The dynamic range of the beam profile monitor allows us to study turn-by-turn beam dynamics within the bunch charge range from 1 pC up to 10 nC. Using this instrument, we have investigated at the VEPP-4M electron-positron collider a number of beam dynamics effects which cannot be observed by other beam diagnostics tools. PMID:17477653

  15. Relativistic Electron Vortex Beams in a Laser Field.

    Science.gov (United States)

    Bandyopadhyay, Pratul; Basu, Banasri; Chowdhury, Debashree

    2015-11-01

    The orbital angular momentum Hall effect and the spin Hall effect of electron vortex beams (EVBs) have been studied for the EVBs interacting with a laser field. In the scenario of a paraxial beam, the cumulative effect of the orbit-orbit interaction of EVBs and laser fields drives the orbital Hall effect, which in turn produces a shift of the center of the beam from that of the field-free case towards the polarization axis of the photons. In addition, for nonparaxial beams one can also perceive a similar shift of the center of the beam owing to the spin Hall effect involving spin-orbit interaction. Our analysis suggests that the shift in the paraxial beams will always be larger than that in the nonparaxial beams. PMID:26588389

  16. Multipass electron beam narrow-gap welding using filler wire

    International Nuclear Information System (INIS)

    The use of a filler wire in electron beam welding offers the possibility of a multipass narrow-gap welding up to 100 mm plate thickness with a beam power of 6 kW. Describing the major principles of this method, the report considers the mechanical and metallurgical properties of multipass weldments, and the spiking phenomenon is also discussed. (orig./IHOE)

  17. Telemetry signal damping during rocket electron beam injections

    International Nuclear Information System (INIS)

    We present here a preliminary analysis of telemetry signal damping associated with the injection of intense energetic electron beams in the ionosphere during the Zarnitza 2 and Araks experiments. It is suggested that the damping of the signal is due to an enhancement of density fluctuations generated by the beam

  18. Lens and deflection unit arrangement for electron beam columns

    International Nuclear Information System (INIS)

    An improved electron beam tube system is described wherein the electron beam magnetic deflection yoke is physically located inside the lens pole piece of the final or projection magnetic lens of the beam tube. The electron beam tube system includes a focussing and deflection unit which comprises means for producing a magnetic lens in the path of the electron beam for focussing the beam onto a target and a magnetic deflection yoke including sinusoidally distributed windings for producing a dynamic magnetic field. The magnetic lens producing means includes a field generating coil and two pole pieces forming an air gap. This arrangement produces static magnetic field lines which form a rotationally symmetrical field distribution with a field maximum in the gap to focus the beam. The yoke is located inside longitudinal magnetic field lines of the gap at the maximum of the symmetrical field distribution to superimpose the dynamic magnetic field and the static magnetic field to deflect the beam onto the target. (author)

  19. Vortex stabilized electron beam compressed fusion grade plasma

    International Nuclear Information System (INIS)

    Most inertial confinement fusion schemes are comprised of highly compressed dense plasmas. Those schemes involve short, extremely high power, short pulses of beams (lasers, particles) applied to lower density plasmas or solid pellets. An alternative approach could be to shoot an intense electron beam through very dense, atmospheric pressure, vortex stabilized plasma.

  20. A Gridded Electron Gun for a Sheet Beam Klystron

    Energy Technology Data Exchange (ETDEWEB)

    Read, M.E.; Miram, G.; Ives, R.L.; /Calabazas Creek Res., Saratoga; Ivanov, V.; Krasnykh, A.; /SLAC

    2008-04-25

    This paper describes the development of an electron gun for a sheet beam klystron. Initially intended for accelerator applications, the gun can operate at a higher perveance than one with a cylindrically symmetric beam. Results of 2D and 3D simulations are discussed.

  1. Study on surface treatment by pulsed electron beams

    International Nuclear Information System (INIS)

    We developed a pulsed electron beam system for surface treatment use. It features high peak power density and broad area beams, which result in the possibility of the advanced surface treatment. We experimentally demonstrated surface hardening, amorphizing and alloying with this system. A description of the performance of the system and results of surface treatment experiments are presented. (author)

  2. Two cavity autoacceleration of an intense relativistic electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, P.D.; Lockner, T.R.

    1985-01-01

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-..cap omega.. cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs.

  3. Two cavity autoacceleration of an intense relativistic electron beam

    International Nuclear Information System (INIS)

    Two autoacceleration cavities have been used to accelerate an 11-kA electron beam from 2 MeV to approx. =2.8 MeV. The two 40-Ω cavities each accelerated the beam by approx. =400 kV with no observable interaction between the two cavities over several cavity transmit times. 6 figs

  4. RADLAC II high current electron beam propagation experiment

    International Nuclear Information System (INIS)

    The resistive hose instability of an electron beam was observed to be convective in recent RADLAC II experiments for higher current shots. The effects of air scattering for these shots were minimal. These experiments and theory suggest low-frequency hose motion which does not appear convective may be due to rapid expansion and subsequent drifting of the beam nose

  5. Beam dynamics analysis in pulse compression using electron beam compact simulator for Heavy Ion Fusion

    Directory of Open Access Journals (Sweden)

    Kikuchi Takashi

    2013-11-01

    Full Text Available In a final stage of an accelerator system for heavy ion inertial fusion (HIF, pulse shaping and beam current increase by bunch compression are required for effective pellet implosion. A compact simulator with an electron beam was constructed to understand the beam dynamics. In this study, we investigate theoretically and numerically the beam dynamics for the extreme bunch compression in the final stage of HIF accelerator complex. The theoretical and numerical results implied that the compact experimental device simulates the beam dynamics around the stagnation point for initial low temperature condition.

  6. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hristu, Radu; Stanciu, Stefan G.; Tranca, Denis E.; Stanciu, George A., E-mail: stanciu@physics.pub.ro

    2015-08-15

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed.

  7. Electron beam influence on the carbon contamination of electron irradiated hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Highlights: • Carbon contamination mechanisms of electron-beam-irradiated hydroxyapatite. • Atomic force microscopy phase imaging used to detect carbon contamination. • Carbon contamination dependence on electron energy, irradiation time, beam current. • Simulation of backscattered electrons confirms the experimental results. - Abstract: Electron beam irradiation which is considered a reliable method for tailoring the surface charge of hydroxyapatite is hindered by carbon contamination. Separating the effects of the carbon contamination from those of irradiation-induced trapped charge is important for a wide range of biological applications. In this work we focus on the understanding of the electron-beam-induced carbon contamination with special emphasis on the influence of the electron irradiation parameters on this phenomenon. Phase imaging in atomic force microscopy is used to evaluate the influence of electron energy, beam current and irradiation time on the shape and size of the resulted contamination patterns. Different processes involved in the carbon contamination of hydroxyapatite are discussed

  8. Advances in Defocused-Beam Electron-Probe Microanalysis

    Science.gov (United States)

    Carpenter, P. K.; Zeigler, R. A.; Jolliff, B. L.

    2010-03-01

    Advances in defocused-beam electron-probe microanalysis are presented, with an Excel VBA algorithm which uses a polynomial alpha factor correction algorithm coupled with a catanorm procedure to correct DBA data.

  9. Brushless dc motor uses electron beam switching tube as commutator

    Science.gov (United States)

    Studer, P.

    1965-01-01

    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  10. Phenomena related to electron beams in solar flares

    International Nuclear Information System (INIS)

    The physical processes of solar flares are briefly described, starting from the basic observation characteristics. The role of electron beams in flare scenarios is highlighted. The observational manifestations of electron beams are described, e.g. type III and U radio bursts. The results of numerical modelling of such processes are given. In addition to the magnetic field-line reconnection process which is considered to be a primary flare process, attention is paid to the evolution of electron beams in flare loops, interpretation of U bursts, electron beam bombardment of deep and dense layers of the solar atmosphere, and accompanying phenomena such as the evaporation process and the asymmetry of optical chromospheric lines. 11 figs., 10 refs

  11. Self-shielding Electron Beam Installation for Sterilization

    Institute of Scientific and Technical Information of China (English)

    Linac; Laboratory

    2002-01-01

    China Institute of Atomic Energy (CIAE) has developed a self-shielding electron beam installationfor sterilization as handling letters with anthrax germ or spores which has the least volume and the least

  12. Inductive voltage adder (IVA) for submillimeter radius electron beam

    International Nuclear Information System (INIS)

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway

  13. Electron beam generation in the fore-vacuum pressure range

    CERN Document Server

    Burachevskij, Y A; Kuzemchenko, M N; Mytnikov, A V; Oks, E M

    2001-01-01

    One presents the results of investigations to generate electron beams within 0.01-0.1 Torr gas pressure range. To generate a beam one used a plasma source based on a hollow cathode discharge in combination with a plane accelerating gap. Peculiar features of electron emission and acceleration within the mentioned pressure range are associated with high probability of gas ionization in an accelerating gap and with generation of ion flow meeting electron beam. It results in reduction of discharge combustion intensification, as well as, in plasma concentration range. The developed design of an electron source enables to generate cylindrical beams with up to 1 A current and with up to 10 keV energy

  14. Microorganisms inactivation by electron beam irradiation and microwave heating

    International Nuclear Information System (INIS)

    The comparative results obtained by applying separate beam irradiation, separate microwave heating and combined electron beam irradiation and microwave heating (successive and simultaneous) to reduction of viable cells of Staphylococcus intermedius and Pseudomaonas aeruginosa are presented. Simultaneous irradiation results in a more dramatic reduction of microorganisms than by either microwave or electron beam irradiation alone. The tests demonstrated that irradiation time and the upper limit of required absorbed dose which ensures a complete sterilization effect of the studied microorganisms could be reduced of about six times by additional use of microwave energy to electron beam irradiation. Experiments were carried out using an electron linear accelerator ALIN-10 of 6 MeV and 180 W maximum output power and 2.45 GHz microwave source of controlled power up to 0.85 kW. (authors)

  15. Optical emitter and amplifier by utilizing traveling electron beam

    OpenAIRE

    Yamada, Minoru; Kuwamura, Yuji

    2008-01-01

    Optical emission and amplification by a travelling electron beam adjacent to a high refractive index waveguide in vacuum was theoretically predicted and experimentally confirmed. Experimentally observed characteristics were compared with theoretical examinations. ©2008 IEEE.

  16. A study on beam profile at an industrial electron beam accelerator

    International Nuclear Information System (INIS)

    An industrial type electron beam accelerator located at BARC-BRIT complex, Vashi, Navi Mumbai is operational for development of applications and technology demonstration to the Indian industry in the field of polymer modifications and for processing of various other products. Recently the accelerator has been upgraded from 2 MeV to 5 MeV to process thick polymers, packaged products and for waste water treatment. This accelerator is capable of delivering powered electron beams up to 15 kW average beam power in the energy range 3 to 5 MeV. In the facility, product is irradiated either in static or conveyor mode of operation under the scanning- type beam. In the present work, we have performed beam profile measurement at different distances from the beam extraction window under conveyor and static mode of operation. We have used cellulose triacetate (CTA) strip dosimeters for the beam profile measurement. Dose profile measured along the scan direction (beam width) in conveyor mode and beam length profile in static mode of operation at different distances below accelerator beam exit window is shown. In the conveyor mode of operation, as the distance increases from the beam window the uniformity of the dose distribution improves but dose decreases linearly with distance. For a scanned beam, the beam width defines the dimension of the beam sweep. For static mode of operation, the dose from the exit window of the accelerator follows inverse relation with distance (i.e. l/r). This shows that the system is a line-type directional radiation source. Beam length is critical for processes where product is stationary under the beam and also for setting speed of the conveyor depending on pulse frequency in conveyor mode of operation. The present paper describes optimization of operational parameters to maximize the efficiency of the irradiation process based on these measurements. (author)

  17. Production of a sub-10 fs electron beam with 107 electrons

    Science.gov (United States)

    Han, Jang-Hui

    2011-05-01

    We study the possibility to produce a 1.6 pC electron beam (107 electrons) with a bunch length of less than 10 fs and a beam energy of a few MeV. Such a short, relativistic beam will be useful for an electron diffraction experiment with a 10 fs time resolution. An electron beam with 107 electrons will allow a single-shot experiment with a laser pulse pump and an electron beam probe. In this design, an S-band photocathode gun is used for generating and accelerating a beam and a buncher consisting of two S-band four-cell cavities is used for temporally compressing the beam. Focusing solenoids control the beam transverse divergence and size at the sample. Numerical optimization is carried out to achieve a beam with a 4 fs full-width-at-half-maximum length, a 26 microradian root-mean-square divergence, and a 2 nm transverse coherence length at a 3.24 MeV beam energy. When state-of-the-art rf stability is considered, beam arrival time jitter at the sample is calculated to be about 10 fs.

  18. Laser cooling of electron beams at linear colliders

    OpenAIRE

    Telnov, Valery

    2000-01-01

    A method of electron beam cooling is considered which can be used for linear colliders. The electron beam is cooled during collision with focused powerful laser pulse. The ultimate transverse emittances are much below those achievable by other methods. This method is especially useful for high energy gamma-gamma colliders. In this paper we review and analyse limitations in this method, also discuss a new method of obtaining very high laser powers required for the laser cooling, radiation cond...

  19. New data on electron-beam purification of wastewater

    International Nuclear Information System (INIS)

    Recent environmental applications of radiation technology, developed in the author's laboratory, are presented in this paper. They are electron-beam and coagulation purification of molasses distillery slops from distillery-produced ethyl alcohol by fermentation of plant materials, electron-beam purification of wastewater from carboxylic acids (for example, formic acid) and removal of petroleum products (diesel fuel, motor oil and residual fuel oil) from water by γ-irradiation

  20. Patterned electrochemical deposition of copper using an electron beam

    OpenAIRE

    Mark den Heijer; Ingrid Shao; Alex Radisic; Reuter, Mark C.; Ross, Frances M.

    2014-01-01

    We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we contro...

  1. Electron Beam Collimation for the Next Generation Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

    2013-05-20

    The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

  2. Relativistic electron beam interaction with a thin target

    International Nuclear Information System (INIS)

    This study is concerned with the increasing possibilities of electron energy deposition in thin targets. The thesis theoretical part studies the relativistic electron beam-plasma instability; the Buneman-Pierce instability in limited medium is also studied. In the experimental part, several questions are tentatively answered: - what is the spatial and temporal evolution of the anode material, in temperature and in density. - What sort of interaction is the beam-target interaction; more particularly questions about focusing and energy deposition are studied

  3. Measurement of power density distribution and beam waist simulation for electron beam

    International Nuclear Information System (INIS)

    The study aims to measure the power density distribution of the electron beam (EB) for further estimating its characteristics. A compact device combining deflection signal controller and current signal acquisition circuit of the EB was built. A software modelling framework was developed to investigate structural parameters of the electron beam. With an iterative algorithm, the functional relationship between the electron beam power and its power density was solved and the corresponding contour map of power density distribution was plotted through isoline tracking approach. The power density distribution of various layers of cross-section beam was reconstructed for beam volume by direct volume rendering technique. The further simulation of beam waist with all-known marching cubes algorithm reveals the evolution of spatial appearance and geometry measurement principle was explained in detail. The study provides an evaluation of promising to replace the traditional idea of EB spatial characteristics. - Highlights: ► We build a framework for measuring power density distribution for electron beam. ► We capture actual electron and build transient spatial power distribution for EB. ► Tracing algorithm of power density contour for cross-section was designed. ► The volume and waist of the beam are reconstructed in 4D mode. ► Geometry measurement is finished which is befit for designing of process welding.

  4. Absolute dose determinations in electron beams - Intercomparison of methodologies

    International Nuclear Information System (INIS)

    The use of plane parallel ionization chambers for the dosimetry of electron beams has been extensively recognized in national and international recommendations and codes of practice. The construction details of different chambers and their influence on the measure, which should be converted in suitable perturbation factors, have also been published. Updated information, new data, refined investigations have recently been gathered in IAEA TRS 398 where the major efforts of Primary Standard Dosimetry Laboratories (PSDLs) in providing calibration factors in terms of absorbed dose to water at a reference quality is reflected. From the users point of view, and specially concerning electron beams, one can probably get confused with different methodologies and procedures in order to accurately determine absorbed dose to water. The aim of this work is to explore the different methodologies and procedures concerning absolute dose determinations, in a hospital and using different chambers, in order to appreciate the relative deviations in absolute dose values. Despite the fact that Markus chamber does not meet all the minimum requirements namely concerning scattering perturbation effects due to the geometry and dimensions of the guard electrode, it is still a quite used chamber type in current clinical practice. So we have included dose determinations with this plane parallel chamber (PTW 23343) and also with a Roos chamber (PTW 34001). Markus chamber is provided with a standard calibration certificate in terms of absorbed dose to water (NW) and also in terms of absorbed dose to air (NA), referred to a high energy electron beam whereas Roos chamber has a calibration factor in terms of absorbed dose to water referred to 60Co. Starting from these materials different methodologies have been applied: i) Using NA of Markus chamber according to the users instruction manual which refers DGMP Report No.6 Praktische Dosimetrie von Elektronenstrahlung und ultraharter Rontgenstrahlung

  5. Electron beam sterilization of the Agaroze gel used for electrophoresis

    International Nuclear Information System (INIS)

    Electron beam sterilization is based on its ability to kill pathogenic microorganisms. It is applied to a broad range of disposable medical products such as syringes, needles, surgical sutures, transplant kits, inhalation and dialysis equipment, blood-handling equipment, wound and burn dressings, gloves, masks, gowns, Petri dishes and pipettes. By this work we intend to extend the EB irradiation to the sterilization of the agarose gel put on plastic plates. Electrophoresis of serum proteins on agarose gel is an important investigation method of variety disproteinemia types, used in clinical laboratory. By this method are separated six proteic fractions: Albumin; Alpha 1 globulin consisting of α1 lipoproteins and α1 antitrypsin; Alpha 2 globulin consisting of α2 macroglobulin and haptoglobin; Beta 1 globulin consisting of transferrin and β lipoprotein; Beta 2 globulin consisting of complement C3; Gamma globulin consisting of immunoglobulins and fibrogen. Agarose is a natural colloid extracted from seaweed. It is very fragile and easily destroyed by handling. Agarose gel can be processed faster than polyacrylamide gels, but the agarose gel is a favorable medium for the microorganisms' development, which is the cause for the degradation of the gel and of the results. Thus, the sterilization of the plates with agarose gels becomes important. A disadvantage is that ionizing radiation degrades some plastic gels above a certain absorbed dose level. In view of this important aspects the sterilization of the agarose gel, which is put on plastic plates, by electron beam irradiation has been studied. Also, the effects of the electron beam irradiation upon the agarose gel and on the process of the proteic fraction separation have been investigated. In the experimental studies are used the plastic plates with 1% agarose gel in Tris-barbital tampon, supplied by DDS DIAGNOSTIC-Romania. The used migration solution is Tris-barbital tampon pH 8.6. In order to establish the

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

    International Nuclear Information System (INIS)

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

  7. Generation of intense pulsed electron beams by the pseudospark discharge

    International Nuclear Information System (INIS)

    A low-pressure gas discharge is presented as a source of intense pulsed electron beams. The so-called pseudospark discharge emits a short-duration pinched electron beam during the breakdown phase. At voltages of typically 20 kV, approximately 10 to 20 percent of the total discharge current appears as the electron beam current of typically 20 ns induration. According to the breakdown voltage in the beam, a power density of the order of 109 W/cm2 is reached. Thus, this electron beam turns out to be a good tool for material processing, comparable to pulsed high-power lasers. Besides the drilling of holes into metals and insulators, an interesting application is the production of high-temperature superconducting thin YBa2Cu3O7-x films. The electron beam is used to evaporate material from a stoichiometric 1-2-3 target. Experimental results concerning the propagation behavior in neutral gas, the electron energy distribution, and the interaction with matter are reported

  8. Beam size measurement of the stored electron beam at the APS storage ring using pinhole optics

    International Nuclear Information System (INIS)

    Beam sizes of the stored electron beam at the APS storage ring were measured using pinhole optics and bending magnet x-rays in single-bunch and low-current mode. A pinhole of 25 μm and a fast x-ray imaging system were located 23.8 m and 35.4 m from the source, respectively. The x-ray imaging system consists of a CdWO4 scintillation crystal 60 μm thick, an optical imaging system, and a CCD detector. A measurement time of a few tenths of a second was obtained on a photon beam of E>30 keV produced in a bending magnet from a 7-GeV electron beam of 2mA current. The measured vertical and horizontal sizes of the electron beam were in reasonable agreement with the expected values

  9. Production of GW electron and ion beams by focused discharges

    International Nuclear Information System (INIS)

    This chapter attempts to determine how magnetized plasma structure and current distribution must vary with time in the pinch region to have a consistent picture. A method is presented to evaluate the total charge of a beam from a single discharge. Discusses the experimental system; an optimized mode of operation; ion beams; electron beams; the beam source; and plasmoid imaging by nuclear tracks in solids. The data support the existence of a fibrous structure for all stages of evolution of the current sheath (CS), from propagation in the interelectrodegap to axial-pinch collapse and at a later time when CS is fragmented

  10. Beam Dump Experiment at Future Electron-Positron Colliders

    OpenAIRE

    Shinya Kanemura; Takeo Moroi; Tomohiko Tanabe

    2015-01-01

    We propose a new beam dump experiment at future colliders with electron ($e^-$) and positron ($e^+$) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of $e^\\pm$ beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at $e^+e^-$ linear collider...

  11. Beam dump experiment at future electron-positron colliders

    Science.gov (United States)

    Kanemura, Shinya; Moroi, Takeo; Tanabe, Tomohiko

    2015-12-01

    We propose a new beam dump experiment at future colliders with electron (e-) and positron (e+) beams, BDee, which will provide a new possibility to search for hidden particles, like hidden photon. If a particle detector is installed behind the beam dump, it can detect the signal of in-flight decay of the hidden particles produced by the scatterings of e± beams off materials for dumping. We show that, compared to past experiments, BDee (in particular BDee at e+e- linear collider) significantly enlarges the parameter region where the signal of the hidden particle can be discovered.

  12. The use of intensity-modulated radiation therapy photon beams for improving the dose uniformity of electron beams shaped with MLC

    International Nuclear Information System (INIS)

    Electrons are ideal for treating shallow tumors and sparing adjacent normal tissue. Conventionally, electron beams are collimated by cut-outs that are time-consuming to make and difficult to adapt to tumor shape throughout the course of treatment. We propose that electron cut-outs can be replaced using photon multileaf collimator (MLC). Two major problems of this approach are that the scattering of electrons causes penumbra widening because of a large air gap, and available commercial treatment planning systems (TPSs) do not support MLC-collimated electron beams. In this study, these difficulties were overcome by (1) modeling electron beams collimated by photon MLC for a commercial TPS, and (2) developing a technique to reduce electron beam penumbra by adding low-energy intensity-modulated radiation therapy (IMRT) photons (4 MV). We used blocks to simulate MLC shielding in the TPS. Inverse planning was used to optimize boost photon beams. This technique was applied to a parotid and a central nervous system (CNS) clinical case. Combined photon and electron plans were compared with conventional plans and verified using ion chamber, film, and a 2D diode array. Our studies showed that the beam penumbra for mixed beams with 90 cm source to surface distance (SSD) is comparable with electron applicators and cut-outs at 100 cm SSD. Our mixed-beam technique yielded more uniform dose to the planning target volume and lower doses to various organs at risk for both parotid and CNS clinical cases. The plans were verified with measurements, with more than 95% points passing the gamma criteria of 5% in dose difference and 5 mm for distance to agreement. In conclusion, the study has demonstrated the feasibility and potential advantage of using photon MLC to collimate electron beams with boost photon IMRT fields.

  13. Anomalous broadening of energy distributions in photoemitted electron beams

    Science.gov (United States)

    Guidi, Vincenzo

    1996-06-01

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

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

    International Nuclear Information System (INIS)

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

  15. Electron temperature effects for an ion beam source

    International Nuclear Information System (INIS)

    A hydrogen high temperature plasma up to 200 eV is produced by acceleration of electrons in a hot hollow cathode discharge and is used as an ion beam source. Then, two characteristics are observed: A rate of the atomic ion (H+) number increases above 70%. A perveance of the ion beam increases above 30 times compared with that of a cold plasma, while a floating potential of an ion acceleration electrode approaches an ion acceleration potential (- 500 V) according as an increment of the electron temperature. Moreover, a neutralized ion beam can be produced by only the negative floating electrode without an external power supply. (author)

  16. Molecule-by-Molecule Writing Using a Focused Electron Beam

    DEFF Research Database (Denmark)

    Van Dorp, Willem F.; Zhang, Xiaoyan; Feringa, Ben L.; Hansen, Thomas Willum; Wagner, Jakob Birkedal; De Hosson, Jeff Th. M.

    2012-01-01

    The resolution of lithography techniques needs to be extended beyond their current limits to continue the trend of miniaturization and enable new applications. But what is the ultimate spatial resolution? It is known that single atoms can be imaged with a highly focused electron beam. Can single...... atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor on...... graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated...

  17. Water equivalence study of some phantoms based on effective photon energy, effective atomic numbers and electron densities for clinical MV X-ray and Co-60 γ-ray beams

    Science.gov (United States)

    Kurudirek, Murat

    2013-02-01

    A previously proposed procedure has been applied to some water equivalent phantoms namely PMMA, Polystyrene, Solid Water (WT1), RW3 and ABS for the first time to compute effective photon energy (Eeff), effective atomic numbers (Zeff) and electron densities (neeff) for different MV X-ray beams and Co-60 gamma beam which are heterogeneous in energy. For the purpose of the present investigation, effective atomic cross-sections of the given materials have been determined first to obtain effective photon energies which were further used for calculation of Zeff and neeff. Similar procedure was adopted for Co-60 γ-rays to check the validity of the present method. Results were found to be quite satisfactory. When it comes to the water equivalence, the Eeff results showed that the RW3 and ABS phantoms are more effective for 6 MV beam whereas RW3 and Polystyrene are more effective for 15 MV and Co-60 beams, respectively. The ABS and WT1 phantoms have better water equivalences than the others according to the Zeff and neeff results, respectively.

  18. Angular-momentum-dominated electron beams and flat-beam generation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yin-e

    2005-06-01

    In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 {+-} 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to

  19. Low Starting Electron Beam Current in Degenerate Band Edge Oscillators

    CERN Document Server

    Othman, Mohamed A K; Figotin, Alexander; Capolino, Filippo

    2016-01-01

    We propose a new principle of operation in vacuum electron-beam-based oscillators that leads to a low beam current for starting oscillations. The principle is based on super synchronous operation of an electron beam interacting with four degenerate electromagnetic modes in a slow-wave structure (SWS). The four mode super synchronous regime is associated with a very special degeneracy condition in the dispersion diagram of a cold periodic SWS called degenerate band edge (DBE). This regime features a giant group delay in the finitelength SWS and low starting-oscillation beam current. The starting beam current is at least an order of magnitude smaller compared to a conventional backward wave oscillator (BWO) of the same length. As a representative example we consider a SWS conceived by a periodically-loaded metallic waveguide supporting a DBE, and investigate starting-oscillation conditions using Pierce theory generalized to coupled transmission lines (CTL). The proposed super synchronism regime can be straightf...

  20. Superconducting nanowires by electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Shamashis, E-mail: shamashis.sengupta@u-psud.fr [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Li, Chuan; Guéron, S.; Bouchiat, H. [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Baumier, Cedric; Fortuna, F. [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); Kasumov, Alik [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Institute of Microelectronics Technology and High Purity Materials, RAS, ac. Ossipyan, 6, Chernogolovka, Moscow Region 142432 (Russian Federation)

    2015-01-26

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column.

  1. Superconducting nanowires by electron-beam-induced deposition

    International Nuclear Information System (INIS)

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column

  2. Electron-beam induced synthesis of nanostructures: a review

    Science.gov (United States)

    Gonzalez-Martinez, I. G.; Bachmatiuk, A.; Bezugly, V.; Kunstmann, J.; Gemming, T.; Liu, Z.; Cuniberti, G.; Rümmeli, M. H.

    2016-06-01

    As the success of nanostructures grows in modern society so does the importance of our ability to control their synthesis in precise manners, often with atomic precision as this can directly affect the final properties of the nanostructures. Hence it is crucial to have both deep insight, ideally with real-time temporal resolution, and precise control during the fabrication of nanomaterials. Transmission electron microscopy offers these attributes potentially providing atomic resolution with near real time temporal resolution. In addition, one can fabricate nanostructures in situ in a TEM. This can be achieved with the use of environmental electron microscopes and/or specialized specimen holders. A rather simpler and rapidly growing approach is to take advantage of the imaging electron beam as a tool for in situ reactions. This is possible because there is a wealth of electron specimen interactions, which, when implemented under controlled conditions, enable different approaches to fabricate nanostructures. Moreover, when using the electron beam to drive reactions no specialized specimen holders or peripheral equipment is required. This review is dedicated to explore the body of work available on electron-beam induced synthesis techniques with in situ capabilities. Particular emphasis is placed on the electron beam-induced synthesis of nanostructures conducted inside a TEM, viz. the e-beam is the sole (or primary) agent triggering and driving the synthesis process.

  3. Sources of Helicity-correlated Electron Beam Asymmetries

    International Nuclear Information System (INIS)

    The availability of high current, high polarization electron beams from laser-driven GaAs photocathodes has enabled a broad program studying parity violation in electron scattering. Precision measurements of the tiny (<1 part per million) parity-violating beam-helicity asymmetry are used to study the structure of nuclei or to test the Standard Model of electroweak interactions. As these experiments grow ever more precise, asymmetric beam properties between the two beam helicity states threaten to become the leading source of experimental uncertainty.These helicity-correlated beam asymmetries are predominantly created in the conversion of circularly polarized laser light to a polarized electron beam. In recent experiments at Jefferson Lab, improved techniques for configuring the laser optics of the polarized source have been used to control beam asymmetries to such a level as to be a negligible source of systematic uncertainty. This successful result serves as a promising start for the next generation of parity-violating electron-nuclear scattering measurements, which strive to improve precision by a factor of twenty.

  4. A beam position monitor system for electron cooler in HIRFL-CSR

    International Nuclear Information System (INIS)

    The efficient electron cooling requires that the ion beam and electron beam are parallel and overlapped. In order to measure the positions of ion beam and electron beam simultaneously, a beam position monitor system is developed for the HIRFL-CSR electron cooler device, which probe consists of four capacitive cylinder linear-cut poles. One can get the both beam positions from the picking up signals of four poles by using Fourier transform (FFT) method. The measurement results show that the beam position monitor system is accurate. This system is suitable for investigating the relation between electron cooling processing and the angle of ion beam and electron beam. (authors)

  5. An Electron Beam Profile Instrument Based on FBGs

    Directory of Open Access Journals (Sweden)

    Dan Sporea

    2014-08-01

    Full Text Available Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application.

  6. Compact electron-beam source for formation of neutral beams of very low vapor pressure materials

    Science.gov (United States)

    Rutherford, J. A.; Vroom, D. A.

    1978-01-01

    In order to form metal vapors for neutral beam studies, an electron-beam heater and a power supply have been designed. The source, which measures about 30 x 50 x 70 mm, consists of a filament, accelerating plate (defined by pole pieces), and a supported target. The electrons from the filament are focused by the field penetration through a 2 mm slit in the high-voltage cage. They are then accelerated to about 5 kV to a ground plate. The electrons then follow a path in the magnetic field and strike the sample to be heated on its front surface. The assembly is attached to a water-cooled base plate. The electron beam source has produced beams of Ta and C particles with densities of about 10 to the 8th power/cu cm.

  7. Electron beam heating of a semi-infinite solid

    International Nuclear Information System (INIS)

    Techniques are described for calculating the temperature rise in a semi-infinite solid caused by any cylindrically symmetric electron beam incident on its surface. The temperature rise at any point and time can be expressed as two dimensional integral, but this cannot be evaluated conveniently by numerical methods because of singularities. A mixed numerical plus analytical method has therefore been developed. For the special case of a 'hollow' electron beam consisting of a line of Gaussian sources uniformly distributed along a circle further simplification is possible, to a one dimensional integral which can be evaluated by simple numerical methods. Results are presented for this 'hollow' electron beam and for a beam with uniform current density. (author)

  8. Safety Aspects of EPS-3000 Electron Beam Machine

    International Nuclear Information System (INIS)

    The EPS-3000 electron beam machine was installed and commission in 1991 at the Alurtron Electron Beam Irradiation Centre. It is utilized as a tool to enhance finished products through electron beam irradiation. The machine and its auxiliary systems were built with highest safety in mind due to the possible dangers that it can cause during the irradiation activities. Automatic stops may be activated via various interlocks to protect the integrity of the machine. This type of interlocks are controlled by the set upper and lower limits, mostly related to the machine high voltage (and beam) generation and cooling systems. Radiation safety is also taken care of by provision of shielding and area monitoring. Other potential hazards include ozone poisoning and electromagnetic field (EMF) could be generated by the high voltage. This paper describes the safety and security systems installed within the facility as measures to protect the workers and general public from radiation and other physical threats. (author)

  9. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    Energy Technology Data Exchange (ETDEWEB)

    Adeyemi, Adeleke H. [Hampton Univ., Hampton, VA (United States); et al.

    2015-09-01

    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁻/e⁺ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high-energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

  10. Electromagnetic instability in an electron beam-ion channel system

    Science.gov (United States)

    Su, D.; Tang, C. J.

    2009-05-01

    The transverse electromagnetic instability in the electron beam-ion channel system is investigated using kinetic theory. The equilibrium distribution function of a relativistic electron beam, which takes into account a strong ion channel effect, is obtained. The linearized Vlasov equation is solved and the dispersion relation of the system is derived by perturbing the equilibrium with a high frequency electromagnetic wave (EMW). Analysis of the dispersion relation shows that the coupling of the electron beam with the transverse high frequency EMW is achieved through the deflection of the beam electrons due to the synergistic effects of the transverse high frequency EMW and transverse betatron oscillation. The numerical calculation finds that a branch of slow wave instability (SWI) with a wide frequency band is excited. The attenuation index of the SWI increases and its frequency band broadens as the normalized beam radii increases. Besides, the SWI will be suppressed as the longitudinal velocity of the electron beam increases to a certain value; meanwhile, a bunch of fast wave instability (FWI) is excited, which is equal to the increase of the relativistic factor. Also both the SWI and the FWI reach maximum when the EMW frequency meets a resonance condition.

  11. Electromagnetic instability in an electron beam-ion channel system

    International Nuclear Information System (INIS)

    The transverse electromagnetic instability in the electron beam-ion channel system is investigated using kinetic theory. The equilibrium distribution function of a relativistic electron beam, which takes into account a strong ion channel effect, is obtained. The linearized Vlasov equation is solved and the dispersion relation of the system is derived by perturbing the equilibrium with a high frequency electromagnetic wave (EMW). Analysis of the dispersion relation shows that the coupling of the electron beam with the transverse high frequency EMW is achieved through the deflection of the beam electrons due to the synergistic effects of the transverse high frequency EMW and transverse betatron oscillation. The numerical calculation finds that a branch of slow wave instability (SWI) with a wide frequency band is excited. The attenuation index of the SWI increases and its frequency band broadens as the normalized beam radii increases. Besides, the SWI will be suppressed as the longitudinal velocity of the electron beam increases to a certain value; meanwhile, a bunch of fast wave instability (FWI) is excited, which is equal to the increase of the relativistic factor. Also both the SWI and the FWI reach maximum when the EMW frequency meets a resonance condition.

  12. Electron beam hardening type copper plate printing ink

    International Nuclear Information System (INIS)

    Copper plate printing is the printing method of filling ink in the parts of concave printing elements on a type area, and transferring the ink to a base, and it is the feature that the ink in the printing element parts of a print rises. Copper plate prints show profound feeling, in addition, its effect of preventing forgery is high. This method is generally called engraving printing, and is used frequently for printing various bills and artistic prints. The electron beam irradiation apparatus installed in the laboratory of the Printing Bureau, Ministry of Finance, is an experimental machine of area beam type, and is so constructed as to do batch conveyance and web conveyance. As the ink in printing element parts rises, the offset at the delivery part of a printing machine becomes a problem. Electron beam is superior in its transparency, and can dry instantaneously to the inside of opaque ink. At 200 kV of acceleration voltage, the ink of copper plate prints can be hardened by electron beam irradiation. The dilution monomers as the vehicle for ink were tested for their dilution capability and the effect of electron beam hardening. The problem in the utilization of electron beam is the deterioration of papers, and the counter-measures were tested. (K.I.)

  13. Improved resonator stability and performance of oscillator free-electron lasers using a hollow electron beam

    International Nuclear Information System (INIS)

    We consider the performance of free-electron lasers (FELs) in the oscillator configuration, using a hollow or annular electron beam, instead of the usual Gaussian. Using the three-dimensional, time- dependent FEL code GENESIS, we show that for FEL oscillators use of an annular beam extends the region of resonator stability over that of a Gaussian beam, arising out of reduced mode competition. We also find a three-fold increase in the saturated out-coupled power, with the optical mode still remaining the fundamental TEM00 mode. Thus, it may be preferable to operate an FEL oscillator with a hollow electron beam. (author)

  14. MO-G-BRF-07: Optical Characterization of Novel Terbium-Doped Nanophosphors Excited by Clinical Electron and Photon Beams for Potential Use in Molecular Imaging Or Photodynamic Therapy

    International Nuclear Information System (INIS)

    Purpose: Optical properties of terbium (Tb3+)-doped gadolinium trifluoride (GdF3) nanoplates irradiated by electron and photon beams were investigated for their potential as optical probes. The contribution of induced Cerenkov radiation in exciting the nanophosphors was investigated as well. Methods: The emission spectra of Terbium-doped GdF3 dispersed in hexane, embedded in tissue mimicking phantoms were collected by an optical fiber connected to a CCD-coupled spectrograph, while the samples were irradiated by a medical linear accelerator with electron beams of energies 6, 9, 12, 16, and 20 MeV or X-ray beams of energies of 6, and 15 MV. The contribution of induced Cerenkov radiation in exciting the nanophosphores was investigated in a dedicated experimental apparatus through optical isolation of the samples and also by using 125 kVp X-ray beams whose energy is below the threshold for generating Cerenkov radiation in that medium. Results: Terbium-doped GdF3 nanoplates show characteristic cathodoluminescence emission peaks at 488, 543, 586, and 619 nm, which are responsible for the characteristic f-f transition of terbium ion. In a series of experiments, the contribution of Cerenkov radiation in the luminescence of such nanophosphors was ruled out. Conclusion: We have characterized the optical properties of Terbium-doped GdF3 nanoplates. Such nanocrystals with emission tunability and high surface area that facilitates attachment with targeting reagents are promising in situ light source candidates for molecular imaging or exciting a photosensitizer for ultralow fluence photodynamic therapy. This work is supported by the Department of Radiation Oncology at the University of Pennsylvania, the American Cancer Society through IRG-78-002-28, and the University of Pennsylvania's Nano/Bio Interface Center through NSEC DMR08-32802

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

  16. Propagation properties of a relativistic prebunched electron beam in free electron laser

    International Nuclear Information System (INIS)

    The propagation properties of a prebunched electron beam in free electron lasers is investigated. Results show that: As the beam propagates downstream, the amplitude of the fundamental modulation current is enhanced and its phase keeps unchanged, while both the amplitude and phase of the high harmonic modulation current remain unchanged

  17. Electron beam instrumentation techniques using coherent radiation

    International Nuclear Information System (INIS)

    Much progress has been made on coherent radiation research since coherent synchrotron radiation was first observed in 1989. The use of coherent radiation as a bunch length diagnostic tool has been studied by several groups. In this paper, brief introductions to coherent radiation and far-infrared measurement are given, the progress and status of their beam diagnostic application are reviewed, different techniques are described, and their advantages and limitations are discussed

  18. Quantum rings as electron spin beam splitters

    OpenAIRE

    Foldi, Peter; Kalman, Orsolya; Benedict, Mihaly G.; Peeters, F. M

    2005-01-01

    Quantum interference and spin-orbit interaction in a one-dimensional mesoscopic semiconductor ring with one input and two output leads can act as a spin beam splitter. Different polarization can be achieved in the two output channels from an originally totally unpolarized incoming spin state, very much like in a Stern-Gerlach apparatus. We determine the relevant parameters such that the device has unit efficiency.

  19. Recent progress in applications of electron vortex beams

    Czech Academy of Sciences Publication Activity Database

    Řiháček, Tomáš; Müllerová, Ilona

    Praha: Československá mikroskopická společnost, 2015. s. 79-80. [Mikroskopie 2015. 12.05.2015-13.05.2015, Lednice] R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:68081731 Keywords : electron vortex beam Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  20. Temperature Controlled Cathode Heating in Electron Beam Welding Machine

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav; Dupák, Jan

    2001-01-01

    Roč. 62, 2-3 (2001), s. 165-169. ISSN 0042-207X R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : Electron beam welding machine * cathode heating * temperature control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.541, year: 2001

  1. Simulation of Laser-Compton Cooling of Electron Beams

    OpenAIRE

    Ohgaki, T.

    2000-01-01

    We study a method of laser-Compton cooling of electron beams. Using a Monte Carlo code, we evaluate the effects of the laser-electron interaction for transverse cooling. The optics with and without chromatic correction for the cooling are examined. The laser-Compton cooling for JLC/NLC at E_0=2 GeV is considered.

  2. Solid gold nanostructures fabricated by electron beam deposition

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Rasmussen, A.M.;

    2003-01-01

    Direct writing with gold by electron beam deposition is a method for rapid fabrication of electrically conducting nanostructures. An environmental scanning electron microscope (ESEM) equipped with a source of the precursor gas dimethylacetylacetonate gold(Ill) was used to fabricate nanoscale tips...

  3. Recent applications of low energy electron beam processing

    International Nuclear Information System (INIS)

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

  4. Preliminary investigations on high energy electron beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Baertling, Yves; Hoppe, Dietrich; Hampel, Uwe

    2010-12-15

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

  5. Particle Simulations for Electron Beam-Plasma Interactions

    Science.gov (United States)

    Zhou, Guo-cheng; G, Zhou C.; Li, Yang; Cao, Jin-bin; J, Cao B.; Wang, Xue-yi; X, Wang Y.

    1998-12-01

    The computer simulations of high-frequency instabilities excited by the high density electron beam and their nonlinear effect are presented. One-dimensional electromagnetic particle simulations are performed with different values of the electron beam-to-plasma density ratio. The results show that for the high electron beam-to-background plasma density ratio, all the Langmuir waves and two electromagnetic waves with left-hand and right-hand circular polarizations (i.e., the "L-O mode" and the "R-X mode") propagating parallel to the magnetic field can be generated and the maximum values of wave electric fields are nearly the same. The electron beam and background plasma are diffused and a part of energetic background electrons are obviously accelerated by the wave-particle interactions. The heating of the beam and background plasma is mainly due to the electrostatic (Langmuir) wave-particle interactions, but the accelerations of a part of energetic background electrons may be mainly due to the electromagnetic wave-particle interactions.

  6. Hydrophobicity of electron beam modified surface of hydroxyapatite films

    Energy Technology Data Exchange (ETDEWEB)

    Gregor, M., E-mail: gregor@fmph.uniba.sk [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Plecenik, T. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Tofail, S.A.M. [Materials & Surface Science Institute, University of Limerick, Limerick (Ireland); Zahoran, M.; Truchly, M. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia); Vargova, M. [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 84215 Bratislava (Slovakia); Laffir, F. [Materials & Surface Science Institute, University of Limerick, Limerick (Ireland); Plesch, G. [Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, 84215 Bratislava (Slovakia); Kus, P.; Plecenik, A. [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava (Slovakia)

    2015-05-15

    Highlights: • Surface potential of hydroxyapatite films were modified by focused electron beam. • Micron-sized domains of modified surface potential were created. • Wettability and surface free energy of the irradiated areas was studied. • Possible mechanisms of increased surface hydrophobicity are discussed. - Abstract: Arrays of micron-sized domains of modified surface potential were created on hydroxyapatite films by mid-energy (20 keV) electron beam irradiation available in a laboratory scanning electron microscope. The dosage of electron beam was varied between 10{sup −3} and 10{sup 3} μC/cm{sup 2} to inject charge into the film surface. Contrary to the conventional electrowetting theory, the dosage of injected charge used in creating such microdomains caused a gradual increase of the water contact angle from 57° to 93° due to the elimination of the polar component of the surface free energy. Surface contamination by carbonaceous species can be held only partially responsible for such behavior at lower dosage of electron beam. A transfer of free surface charge to water and an electron beam induced disruption of polar orientation of OH ions have been attributed to be influencial factors in the overall dewetting behavior.

  7. Buildup of electrons with hot electron beam injection into a homogeneous magnetic field

    International Nuclear Information System (INIS)

    The injection of the monoenergetic beam of electrons into the vacuum drift channel under the conditions when the beam current exceeds a certain threshold value involves a virtual cathode creation. The process of virtual cathode creation leads to an exchange of one-fluid movement of beam particles to three-fluid one corresponding to incident, reflected and passed through anticathode beam particles. For the monoenergetic beam case when the velocity spread Δvdr (vdr is the beam drift velocity), the beam instability was predicted in theory and was observed in experiment. Meanwhile, the injection in the drift space of the 'hot' beam having finite spread in velocities may be accompanied not only by the reflection of particles if their velocity v1/2 (where φ is the electrostatic potential dip value, e and m are the electron charge and mass, respectively), but also the mutual Coulomb scattering of incident and reflected electrons. The scattering process leads in its turn to appearance of viscosity forces and to trapping of a part of beam electrons into the effective potential well formed by electrostatic potential dip and the viscous force potential. The interaction of travelling and trapped particles may occur even at the stage preceding the virtual electrode formation and it may influence the process of its appearance and also the current flow through the drift space. In this report there are described the experimental results on accumulation of electrons when electron beam propagates in vacuum and has a large spread in particle velocities Δvdr in the homogeneous longitudinal magnetic field when ωpeHe where ωpe is the electron Langmuir frequency of beam electrons, ωHe is the electron cyclotron frequency. (author) 6 refs., 2 figs

  8. Design of the AGS Booster Beam Position Monitor electronics

    International Nuclear Information System (INIS)

    The operational requirements of the AGS Booster Beam Position Monitor system necessitate the use of electronics with wide dynamic range and broad instantaneous bandwidth. Bunch synchronization is provided by a remote timing sequencer coupled to the local ring electronics via digital fiber-optic links. The Sequencer and local ring circuitry work together to provide single turn trajectory or average orbit and intensity information, integrated over 1 to 225 bunches. Test capabilities are built in for the purpose of enhancing BPM system accuracy. This paper describes the design of the Booster Beam Position Monitor electronics, and presents performance details of the front end processing, acquisition and timing circuitry

  9. An RF excited plasma cathode electron beam gun design

    OpenAIRE

    Del Pozo, S.; Ribton, C; Smith, DR

    2014-01-01

    A plasma cathode electron beam (EB) gun is presented in this work. A radio frequency (RF) excited plasma at 84 MHz was used as the electron source to produce a beam power of up to 3.2 kW at -60 kV accelerating voltage. The pressure in the plasma chamber is approximately 1 mbar. The electrons are extracted from the plasma chamber to the vacuum chamber (at 10-5 mbar) through a diaphragm with a 0.5 mm diameter nozzle. Advantages over thermionic cathode guns were demonstrated empirically. Mainten...

  10. Polystyrene calorimeter for electron beam dose measurements

    DEFF Research Database (Denmark)

    Miller, A.

    Calorimeters from polystrene have been constructed for dose measurement at 4-10 MeV electron accelerators. These calorimeters have been used successfully for a few years, and polystyrene calorimeters for use at energies down to 1 MeV and being tested. Advantage of polystyrene as the absorbing...... material are the radiation stability of this material and the fact that identical phantoms can be made for irradiation of other dosimeters for calibration. This provides a precise tool for establishing traceability of dose measurements at industrial electron electron accelerators....

  11. Electromagnetic forces on plasmonic nanoparticles induced by fast electron beams

    International Nuclear Information System (INIS)

    The total momentum transfer from fast electron beams, like those employed in scanning transmission electron microscopy (STEM), to plasmonic nanoparticles is calculated. The momentum transfer is obtained by integrating the electromagnetic forces acting on the particles over time. Numerical results for single and dimer metallic nanoparticles are presented, for sizes ranging between 2 and 80 nm. We analyze the momentum transfer in the case of metallic dimers where the different relevant parameters such as particle size, interparticle distance, and electron beam impact parameter are modified. It is shown that depending on the specific values of the parameters, the total momentum transfer yields a force that can be either attractive or repulsive. The time-average forces calculated for electron beams commonly employed in STEM are on the order of piconewtons, comparable in magnitude to optical forces and are thus capable of producing movement in the nanoparticles. This effect can be exploited in mechanical control of nanoparticle induced motion.

  12. Pulsed electron beam propagation in argon and nitrogen gas mixture

    International Nuclear Information System (INIS)

    The paper presents the results of current measurements for the electron beam, propagating inside a drift tube filled in with a gas mixture (Ar and N2). The experiments were performed using the TEA-500 pulsed electron accelerator. The main characteristics of electron beam were as follows: 60 ns pulse duration, up to 200 J energy, and 5 cm diameter. The electron beam propagated inside the drift tube assembled of three sections. Gas pressures inside the drift tube were 760 ± 3, 300 ± 3, and 50 ± 1 Torr. The studies were performed in argon, nitrogen, and their mixtures of 33%, 50%, and 66% volume concentrations, respectively

  13. Electron beam curing of coatings, and other applications

    International Nuclear Information System (INIS)

    The authors explain why accelerated electrons have the effects desired, and compare the electron beam curing method with other methods applicable for the same purposes. The structure and reactions of materials which can be treated by radiation in order to achieve hardening or other surface finishing effects are explained, as well as other applications of electron beams, e.g. in offset printing, or for ornamental or protective coating. The practical conditions are discussed in detail (substrates, application methods, safety, costs). The book is intended for professionals and process engineers in the wood and paper manufacturing industry, in the processing and packaging industry, and the automobile and supporting industry, presenting reliable information on advantages and drawbacks of the electron beam curing methods. Newcomers in this field will find a concise and complete survey, and experienced engineers and chemists will appreciate the book as a source of information for comparison and new approaches to production problems. (orig./HP)

  14. Generation of anomalously energetic suprathermal electrons by an electron beam interacting with a nonuniform plasma

    International Nuclear Information System (INIS)

    Generation of anomalously energetic suprathermal electrons was observed in simulation of a high-voltage dc discharge with electron emission from the cathode. An electron beam produced by the emission interacts with the nonuniform plasma in the discharge via a two-stream instability. The energy transfer from the beam to the plasma electrons is ensured by the plasma nonuniformity. The electron beam excites plasma waves whose wavelength and phase speed gradually decrease towards anode. The waves with short wavelength near the anode accelerate plasma bulk electrons to suprathermal energies. The sheath near the anode reflects some of the accelerated electrons back into the plasma. These electrons travel through the plasma, reflect near the cathode, and enter the accelerating area again but with a higher energy than before. Such particles are accelerated to energies much higher than after the first acceleration. This mechanism plays a role in explaining earlier experimental observations of energetic suprathermal electrons in similar discharges

  15. Generation of anomalously energetic suprathermal electrons by an electron beam interacting with a nonuniform plasma

    CERN Document Server

    Sydorenko, D; Chen, L; Ventzek, P L G

    2015-01-01

    Generation of anomalously energetic suprathermal electrons was observed in simulation of a high- voltage dc discharge with electron emission from the cathode. An electron beam produced by the emission interacts with the nonuniform plasma in the discharge via a two-stream instability. Efficient energy transfer from the beam to the plasma electrons is ensured by the plasma nonuniformity. The electron beam excites plasma waves whose wavelength and phase speed gradually decrease towards anode. The short waves near the anode accelerate plasma bulk electrons to suprathermal energies. The sheath near the anode reflects some of the accelerated electrons back into the plasma. These electrons travel through the plasma, reflect near the cathode, and enter the accelerating area again but with a higher energy than before. Such particles are accelerated to energies much higher than after the first acceleration. This mechanism plays a role in explaining earlier experimental observations of energetic suprathermal electrons i...

  16. Dynamics of a high-current relativistic electron beam

    International Nuclear Information System (INIS)

    The dynamics of a high-current relativistic electron beam is studied experimentally and by numerical simulation. The beam is formed in a magnetically insulated diode with a transverse-blade explosive-emission cathode. It is found experimentally that the radius of a 500-keV beam with a current of 2 kA and duration of 500 ns decreases with time during the beam current pulse. The same effect was observed in numerical simulations. This effect is explained by a change in the shape of the cathode plasma during the current pulse, which, according to calculations, leads to a change in the beam parameters, such as the electron pitch angle and the spread over the longitudinal electron momentum. These parameters are hard to measure experimentally; however, the time evolution of the radial profile of the beam current density, which can be measured reliably, coincides with the simulation results. This allows one to expect that the behavior of the other beam parameters also agrees with numerical simulations

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

    International Nuclear Information System (INIS)

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

  18. Cellulose membrane as a biomaterial: from hydrolysis to depolymerization with electron beam.

    Science.gov (United States)

    Eo, Mi Young; Fan, Huan; Cho, Yun Ju; Kim, Soung Min; Lee, Suk Keun

    2016-01-01

    The cellulose membrane (CM) is a major component of plant cell walls and is both a chemically and mechanically stable synthetic polymer with many applications for use in tissue engineering. However, due to its dissolution difficulty, there are no known physiologically relevant or pharmaceutically clinical applications for this polymer. Thus, research is underway on controlled and adjusted forms of cellulose depolymerization. To advance the study of applying CM for tissue engineering, we have suggested new possibilities for electron beam (E-beam) treatment of CM. Treatment of CM with an E-beam can modify physical, chemical, molecular and biological properties, so it can be studied continuously to improve its usefulness and to enhance value. We review clinical applications of CM, cellulose binding domains, cellulose crosslinking proteins, conventional hydrolysis of cellulose, and depolymerization with radiation and focus our experiences with depolymerization of E-beam irradiated CM in this article. PMID:27418974

  19. Return Current Electron Beams and Their Generation of "Raman" Scattering

    Science.gov (United States)

    Simon, A.

    1998-11-01

    For some years, we(A. Simon and R. W. Short, Phys. Rev. Lett. 53), 1912 (1984). have proposed that the only reasonable explanation for many of the observations of "Raman" scattering is the presence of an electron beam in the plasma. (The beam creates a bump-on-tail instability.) Two major objections to this picture have been observation of Raman when no n_c/4 surface was present, with no likely source for the electron beam, and the necessity for the initially outward directed beam to bounce once to create the proper waves. Now new observations on LLE's OMEGA(R. Petrasso et al), this conference. and at LULI(C. Labaune et al)., Phys. Plasma 5, 234 (1998). have suggested a new origin for the electron beam. This new scenario answers the previous objections, maintains electron beams as the explanation of the older experiments, and may clear up puzzling observations that have remained unexplained. The new scenario is based on two assumptions: (1) High positive potentials develop in target plasmas during their creation. (2) A high-intensity laser beam initiates spark discharges from nearby surfaces to the target plasma. The resulting return current of electrons should be much more delta-like, is initially inwardly directed, and no longer requires the continued presence of a n_c/4 surface. Scattering of the interaction beam from the BOT waves yields the observed Raman signal. Experimental observations that support this picture will be cited. ``Pulsation'' of the scattering and broadband ``flashes'' are a natural part of this scenario. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

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

    International Nuclear Information System (INIS)

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

  1. Electron beam diodes using ferroelectric cathodes

    International Nuclear Information System (INIS)

    A new high current density electron source is investigated. The source consists of a polarized ceramic disk with aluminum electrodes coated on both faces. The front electrode is etched in a periodic grid to expose the ceramic beneath. A rapid change in the polarization state of the ceramic results in the emission of a high density electron cloud into a 1 to 10mm diode gap. The anode potential is maintained by a charged transmission line. Some of the emitted electrons traverse the gap and an electron current flows. The emitted electron current has been measured as a function of the gap spacing and the anode potential. Current densities in excess of 70 A/cm2 have been measured. The current is found to vary linearly with the anode voltage for gaps < 10 mm, and exceeds the Child-Langmuir current by at least two orders of magnitude. The experimental data will be compared with predictions from a model based on the emission of a cloud of electrons from the ferroelectric which in turn reflex in the diode gap

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

    Institute of Scientific and Technical Information of China (English)

    李泉凤; 吴频; 高建江; 吴刚

    2004-01-01

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

  3. TRISTAN, electron-positron colliding beam project

    International Nuclear Information System (INIS)

    In this report e+e- colliding beam program which is now referred to as TRISTAN Project will be described. A brief chronology and outline of TRISTAN Project is given in Chapter 1. Chapter 2 of this article gives a discussion of physics objectives at TRISTAN. Chapter 3 treats the overall description of the accelerators. Chapter 4 describes design of each of the accelerator systems. In Chapter 5, detector facilities are discussed in some detail. A description of accelerator tunnels, experimental areas, and utilities are given in Chapter 6. In the Appendix, the publications on the TRISTAN Project are listed. (author)

  4. Applied dosimetry to ionization techniques by electron beams

    International Nuclear Information System (INIS)

    After a general introduction about electron beam dosimetry, the second part is about the determination of treatment parameter for an electron ionization: are treated the problems of electron path determination, treatment depth of a product and finally, the radiation dose heterogeneities in all the volume of a treated product. The third part describes a process that greatly reduces radiation dose heterogeneity and then industrial interest is analyzed. The fourth part describes 2 applications of diffusion screen utilization. 66 figs

  5. Effect of beam oscillation on borated stainless steel electron beam welds

    International Nuclear Information System (INIS)

    Borated stainless steels are used in nuclear power plants to control neutron criticality in reactors as control rods, shielding material, spent fuel storage racks and transportation casks. In this study, bead on plate welds were made using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Electron beam welds made using beam oscillation technique exhibited higher tensile strength values compared to that of GTA welds. Electron beam welds were found to show fine dendritic microstructure while GTA welds exhibited larger dendrites. While both processes produced defect free welds, GTA welds are marked by partially melted zone (PMZ) where the hardness is low. EBW obviate the PMZ failure due to low heat input and in case of high heat input GTA welding process failure occurs in the PMZ.

  6. Review of clinical experience with ion beam radiotherapy

    OpenAIRE

    Jensen, A D; Münter, M W; Debus, J.

    2011-01-01

    The article describes both the early development of oncology as a core discipline at the University of Heidelberg Hospital and the first steps towards ion beam treatment, from the pilot project carried out in co-operation with the Gesellschaft für Schwerionenforschung Darmstadt to the initial start-up of clinical service at the Heidelberg Heavy Ion Centre (HIT). We present an overview, based on data published in the literature, of the available clinical evidence relating the use of ion beam t...

  7. Fiber-Matrix Interface Studies on Electron Beam Cured Composites

    Energy Technology Data Exchange (ETDEWEB)

    Drazel, L.T.; Janke, C.J.; Yarborough, K.D.

    1999-05-23

    The recently completed Department of Energy (DOE) and industry sponsored Cooperative Research and Development Agreement (CRADA) entitled, ''Electron Beam Curing of Polymer Matrix Composites,'' determined that the interlaminar shear strength properties of the best electron beam cured IM7/epoxy composites were 19-28% lower than autoclave cured IM7/epoxy composites (i.e. IM7/977-2 and IM7/977-3). Low interlaminar shear strength is widely acknowledged as the key barrier to the successful acceptance and implementation of electron beam cured composites in the aircraft/aerospace industry. The objective of this work was to improve the interlaminar shear strength properties of electron beam cured composites by formulating and evaluating several different fiber sizings or coating materials. The researchers have recently achieved some promising results by having discovered that the application of epoxy-based, electron beam compatible sizings or coatings onto surface-treated, unsized IM7 carbon fibers improved the composite interlaminar shear strength properties by as much as 55% versus composites fabricated from surface-treated, unsized IM7 fibers. In addition, by applying these same epoxy-based sizings or coatings onto surface-treated, unsized IM7 fibers it was possible to achieve an 11% increase in the composite interlaminar shear strength compared to composites made from surface-treated, GP-sized IM7 fibers. Work is continuing in this area of research to further improve these properties.

  8. Gamma-ray generation using laser-accelerated electron beam

    Science.gov (United States)

    Park, Seong Hee; Lee, Ho-Hyung; Lee, Kitae; Cha, Yong-Ho; Lee, Ji-Young; Kim, Kyung-Nam; Jeong, Young Uk

    2011-06-01

    A compact gamma-ray source using laser-accelerated electron beam is being under development at KAERI for nuclear applications, such as, radiography, nuclear activation, photonuclear reaction, and so on. One of two different schemes, Bremsstrahlung radiation and Compton backscattering, may be selected depending on the required specification of photons and/or the energy of electron beams. Compton backscattered gamma-ray source is tunable and quasimonochromatic and requires electron beams with its energy of higher than 100 MeV to produced MeV photons. Bremsstrahlung radiation can generate high energy photons with 20 - 30 MeV electron beams, but its spectrum is continuous. As we know, laser accelerators are good for compact size due to localized shielding at the expense of low average flux, while linear RF accelerators are good for high average flux. We present the design issues for a compact gamma-ray source at KAERI, via either Bremsstrahlung radiation or Compton backscattering, using laser accelerated electron beams for the potential nuclear applications.

  9. Detoxification of the veterinary antibiotic chloramphenicol using electron beam irradiation.

    Science.gov (United States)

    Cho, Jae Young; Chung, Byung Yeoup; Hwang, Seon Ah

    2015-07-01

    Electron beam irradiation has shown potential as an alternative process for the treatment of industrial effluents that contain toxic organic chemicals. This study investigated the effectiveness of electron beam in degrading chloramphenicol (CAP) in aqueous solution. The degradation efficiency was 32.4% at 1 kGy, 86.9% at 5 kGy, and 100% at 10 kGy. The total organic carbon (TOC) of CAP in aqueous solution declined 4.6% at 1 kGy, 12.1% at 5 kGy, and 17.1% at 10 kGy of irradiation with electron beam. The CAP degradation products after irradiation were CAP1 ([M + H] m/z 307.1), CAP2 ([M + H] m/z 291.1), and CAP3 ([M + H] m/z 321.1). The degradation products were tested for microbial toxicity against Escherichia coli, Pseudomonas putida, and Bacillus subtilis and did not show any toxic antimicrobial effects caused by the CAP degradation products after irradiation with electron beam. The results of this study suggest that electron beam irradiation is the best technology for the comprehensive treatment of veterinary antibiotics at wastewater treatment plants. PMID:25616384

  10. Effect of secondary ions on the electron beam optics in the Recycler Electron Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A.; Prost, L.; Saewert, G.; /Fermilab

    2010-05-01

    Antiprotons in Fermilab's Recycler ring are cooled by a 4.3 MeV, 0.1-0.5 A DC electron beam (as well as by a stochastic cooling system). The unique combination of the relativistic energy ({gamma} = 9.49), an Ampere-range DC beam, and a relatively weak focusing makes the cooling efficiency particularly sensitive to ion neutralization. A capability to clear ions was recently implemented by way of interrupting the electron beam for 1-30 {micro}s with a repetition rate of up to 40 Hz. The cooling properties of the electron beam were analyzed with drag rate measurements and showed that accumulated ions significantly affect the beam optics. For a beam current of 0.3 A, the longitudinal cooling rate was increased by factor of {approx}2 when ions were removed.

  11. Improvement of SACLA electron beam performance

    International Nuclear Information System (INIS)

    In March 2012, SACLA is open as a public user facility. While the first lasing was achieved at 10 keV after several months of machine commissioning, the pulse energy was about 30 μJ, which is lower than the design value. In the autumn of 2011, we intensively worked on the reduction of a projected emittance, then 120 μJ was finally obtained at 10 keV. After the cathode replacement in the winter shutdown, we re-tuned the accelerator and further increased the pulse energy to 250 μJ by increasing the beam energy and the undulator K-value. Currently the pulse energy more than 100 μJ are routinely available to user experiments at photon energies ranging from 5 to 15 keV. During the user time, the user can freely change the undulator gap to finely adjust the photon energy. Since the floor of the SACLA undulator hall still moves by 50 μm in 2 months, the beam orbit at the undulator section is re-aligned every 2 weeks to maintain the FEL performance. In this presentation, we will report the recent progress of the SACLA laser performance and operation. (author)

  12. Calculations of Intensive Electron Source for Electron Beam Welding

    Czech Academy of Sciences Publication Activity Database

    Jánský, Pavel; Lencová, Bohumila; Zlámal, J.

    2003-01-01

    Roč. 9, Sup. 3 (2003), s. 22 - 23. ISSN 1431-9276. [MC 2003. Dresden, 07.09.2003-12.09.2003] R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : electron optics * space charge effects * electron gun s Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.648, year: 2003

  13. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    The computer simulations based on Monte Carlo (MC) method and the ModeCEB software were carried out in connection with electron beam (EB) radiation set-up for crosslinking of electric wire and cable insulation. The theoretical predictions for absorbed dose distribution in irradiated electric insulation induced by scanned EB were compared to the experimental results of irradiation that was carried out in the experimental set-up based on ILU 6 electron accelerator with electron energy 0.5–2.0 MeV. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for various process parameters, namely electric wire and cable geometry (thickness of insulation layers and copper wire diameter), type of polymer insulation, electron energy, energy spread and geometry of electron beam, electric wire and cable layout in irradiation zone. The geometry of electron beam distribution in the irradiation zone was measured using CTA and PVC foil dosimeters for available electron energy range. The temperature rise of the irradiated electric wire and irradiation homogeneity were evaluated for different experimental conditions to optimize technological process parameters. The results of computer simulation are consistent with the experimental data of dose distribution evaluated by gel-fraction measurements. Such conformity indicates that ModeCEB computer simulation is reliable and sufficient for optimization absorbed dose distribution in the multi-layer circular objects irradiated with scanned electron beams. - Highlights: ► We model wire and cables irradiation process by Monte Carlo simulations. ► We optimize irradiation configuration for various process parameters. ► Temperature rise and irradiation homogeneity were evaluated. ► Calculation (dose) and experimental (gel-fraction) results were compared. ► Computer simulation was found reliable and sufficient for process optimization.

  14. Electrical measurement techniques for pulsed high current electron beams

    International Nuclear Information System (INIS)

    The advent of high current (1 to 100 kA), moderate energy (>10 MeV), short pulse (1 to 100 ns) electron accelerators used for charged particle beam research has motivated a need to complement standard diagnostics with development of new diagnostic techniques to measure electron beam parameters. A brief survey is given of the diagnostics for measuring beam current, position, size, energy, and emittance. While a broad scope of diagnostics will be discussed, this survey will emphasize diagnostics used on the Experimental Test Accelerator (ETA) and Advanced Test Accelerator (ATA). Focus is placed on diagnostics measuring beam current, position and size. Among the diagnostics discussed are resistive wall current monitors, B/sub theta/ loops, Rogowski coils, Faraday cups, and x-ray wire diagnostics. Operation at higher current levels also increases radiation and electromagnetic pulse interference. These difficulties and methods for circumventing them are also discussed

  15. Collective process in microsecond relativistic electron beam: regularities and mechanism

    International Nuclear Information System (INIS)

    The collective processes in the spatial charge of the microsecond relativistic electron beams with magnetic isolation are studied. The spatial-time characteristics of the low-frequency and high-frequency branches of oscillations are determined. The effect of the beams magnetic compression on the above oscillations near the cathode is studied. The basic source of the low-frequency oscillations - the collective motions of the spatial charge, developing in the crossed electric and magnetic fields near the cathode, is identified. It is established that the basic cause of the high-frequency oscillations consists in the development of the two-phase instability in the beam. The possibility of suppressing the low-frequency and high-frequency oscillations through the relativistic electron beams compression near the cathode is identified

  16. Electron beam-assisted healing of nanopores in magnesium alloys

    Science.gov (United States)

    Zheng, He; Liu, Yu; Cao, Fan; Wu, Shujing; Jia, Shuangfeng; Cao, Ajing; Zhao, Dongshan; Wang, Jianbo

    2013-01-01

    Nanopore-based sensing has emerged as a promising candidate for affordable and powerful DNA sequencing technologies. Herein, we demonstrate that nanopores can be successfully fabricated in Mg alloys via focused electron beam (e-beam) technology. Employing in situ high-resolution transmission electron microscopy techniques, we obtained unambiguous evidence that layer-by-layer growth of atomic planes at the nanopore periphery occurs when the e-beam is spread out, leading to the shrinkage and eventual disappearance of nanopores. The proposed healing process was attributed to the e-beam-induced anisotropic diffusion of Mg atoms in the vicinity of nanopore edges. A plausible diffusion mechanism that describes the observed phenomena is discussed. Our results constitute the first experimental investigation of nanopores in Mg alloys. Direct evidence of the healing process has advanced our fundamental understanding of surface science, which is of great practical importance for many technological applications, including thin film deposition and surface nanopatterning. PMID:23719630

  17. Time-resolved tomographic images of a relativistic electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, H.A.; Jacoby, B.A.; Nelson, M.

    1984-07-01

    We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0/sup 0/, 61/sup 0/, and 117/sup 0/. The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse.

  18. Optical beam diagnostics at the Electron Stretcher Accelerator ELSA

    International Nuclear Information System (INIS)

    At the ELectron Stretcher Accelerator ELSA, a resonant excitation of the horizontal particle oscillations is used to extract the electrons to the experiments. This so-called resonance extraction influences the properties of the extracted beam. The emittance, as a number of the beam quality, was determined by using synchrotron light monitors. To enable broad investigations of the emittance a system of synchrotron light monitors was set up. This system was used to measure the influence of the extraction method on the emittance. Time resolved measurements were conducted to investigate the development of the emittance during an accelerator cycle. To improve the optical beam diagnostics a new beamline to an external laboratory was constructed. There, a new high resolution synchrotron light monitor was commissioned. In addition, a streak camera has been installed to enable longitudinal diagnostics of the beam profiles. First measurements of the longitudinal charge distribution with a time resolution in the range of a few picoseconds were conducted successfully.

  19. Research on multi-pulsed intensive electron beam sources

    International Nuclear Information System (INIS)

    This paper is involved in multi-pulsed emission characteristics of some cathodes while generating intensive relativistic electron beams. Research results indicate that the velvet, the carbon fiber and the dispenser cathode all have the ability to generate a few kilo-ampere multi-pulsed beams with brightness better than 3 x 107 A/(m·rad)2. And some new cathodes such as carbon nano-tubes and nano-diamond film also can generate a few kilo-ampere multi-pulsed electron beams. Because of the cold field emission, the beams generated by the carbon nano-tubes and the nano-diamond film are expected to be higher brightness. Some experimental results of above cathodes are present and some suggestion for farther work is also proposed. (authors)

  20. Image processing system for electron linac beam diagnosis

    International Nuclear Information System (INIS)

    For diagnosis of electron linac beams, image signals from a TV camera viewing a ceramic screen monitor were processed and analyzed using a waveform digitizer and a personal computer. The black-and-white TV camera used has a zoom lens with a remote-controllable iris; the automatic gain control circuit was switched off to obtain tolerable linearity of the output video signal against the brightness of the beam spot on the screen. The video signals are taken by the waveform digitizer with a sampling rate of 4 MHz; the digitized picture is transmitted to the personal computer via the GPIB and is analyzed to derive spatial intensity distribution of the beam. The sync signal of the TV camera is externally synchronized with the electron linac beam timing