mev photoinjector system: Topics by WorldWideScience.org

Sample records for mev photoinjector system

Operation of the APEX photoinjector accelerator at 40 MeV

International Nuclear Information System (INIS)

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

1992-01-01

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-30

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

Energy Technology Data Exchange (ETDEWEB)

Musumeci, P. [UCLA Department of Physics and Astronomy, 475 Portola Plaza, Los Angeles, CA 90095-1547 (United States)], E-mail: musumeci@physics.ucla.edu; Moody, J.T.; Scoby, C.M. [UCLA Department of Physics and Astronomy, 475 Portola Plaza, Los Angeles, CA 90095-1547 (United States)

2008-10-15

Electron diffraction holds the promise to yield real-time resolution of atomic motion in an easily accessible environment like a university laboratory at a fraction of the cost of fourth-generation X-ray sources. Currently the limit in time-resolution for conventional electron diffraction is set by how short an electron pulse can be made. A very promising solution to maintain the highest possible beam intensity without excessive pulse broadening from space charge effects is to increase the electron energy to the MeV level where relativistic effects significantly reduce the space charge forces. Rf photoinjectors can in principle deliver up to 10{sup 7}-10{sup 8} electrons packed in bunches of {approx}100-fs length, allowing an unprecedented time resolution and enabling the study of irreversible phenomena by single-shot diffraction patterns. The use of rf photoinjectors as sources for ultrafast electron diffraction has been recently at the center of various theoretical and experimental studies. The UCLA Pegasus laboratory, commissioned in early 2007 as an advanced photoinjector facility, is the only operating system in the country, which has recently demonstrated electron diffraction using a relativistic beam from an rf photoinjector. Due to the use of a state-of-the-art ultrashort photoinjector driver laser system, the beam has been measured to be sub-100-fs long, at least a factor of 5 better than what measured in previous relativistic electron diffraction setups. Moreover, diffraction patterns from various metal targets (titanium and aluminum) have been obtained using the Pegasus beam. One of the main laboratory goals in the near future is to fully develop the rf photoinjector-based ultrafast electron diffraction technique with particular attention to the optimization of the working point of the photoinjector in a low-charge ultrashort pulse regime, and to the development of suitable beam diagnostics.
Relativistic electron diffraction at the UCLA Pegasus photoinjector laboratory

International Nuclear Information System (INIS)

Musumeci, P.; Moody, J.T.; Scoby, C.M.

2008-01-01

Electron diffraction holds the promise to yield real-time resolution of atomic motion in an easily accessible environment like a university laboratory at a fraction of the cost of fourth-generation X-ray sources. Currently the limit in time-resolution for conventional electron diffraction is set by how short an electron pulse can be made. A very promising solution to maintain the highest possible beam intensity without excessive pulse broadening from space charge effects is to increase the electron energy to the MeV level where relativistic effects significantly reduce the space charge forces. Rf photoinjectors can in principle deliver up to 10 7 -10 8 electrons packed in bunches of ∼100-fs length, allowing an unprecedented time resolution and enabling the study of irreversible phenomena by single-shot diffraction patterns. The use of rf photoinjectors as sources for ultrafast electron diffraction has been recently at the center of various theoretical and experimental studies. The UCLA Pegasus laboratory, commissioned in early 2007 as an advanced photoinjector facility, is the only operating system in the country, which has recently demonstrated electron diffraction using a relativistic beam from an rf photoinjector. Due to the use of a state-of-the-art ultrashort photoinjector driver laser system, the beam has been measured to be sub-100-fs long, at least a factor of 5 better than what measured in previous relativistic electron diffraction setups. Moreover, diffraction patterns from various metal targets (titanium and aluminum) have been obtained using the Pegasus beam. One of the main laboratory goals in the near future is to fully develop the rf photoinjector-based ultrafast electron diffraction technique with particular attention to the optimization of the working point of the photoinjector in a low-charge ultrashort pulse regime, and to the development of suitable beam diagnostics
Relativistic electron diffraction at the UCLA Pegasus photoinjector laboratory.

Science.gov (United States)

Musumeci, P; Moody, J T; Scoby, C M

2008-10-01

Electron diffraction holds the promise to yield real-time resolution of atomic motion in an easily accessible environment like a university laboratory at a fraction of the cost of fourth-generation X-ray sources. Currently the limit in time-resolution for conventional electron diffraction is set by how short an electron pulse can be made. A very promising solution to maintain the highest possible beam intensity without excessive pulse broadening from space charge effects is to increase the electron energy to the MeV level where relativistic effects significantly reduce the space charge forces. Rf photoinjectors can in principle deliver up to 10(7)-10(8) electrons packed in bunches of approximately 100-fs length, allowing an unprecedented time resolution and enabling the study of irreversible phenomena by single-shot diffraction patterns. The use of rf photoinjectors as sources for ultrafast electron diffraction has been recently at the center of various theoretical and experimental studies. The UCLA Pegasus laboratory, commissioned in early 2007 as an advanced photoinjector facility, is the only operating system in the country, which has recently demonstrated electron diffraction using a relativistic beam from an rf photoinjector. Due to the use of a state-of-the-art ultrashort photoinjector driver laser system, the beam has been measured to be sub-100-fs long, at least a factor of 5 better than what measured in previous relativistic electron diffraction setups. Moreover, diffraction patterns from various metal targets (titanium and aluminum) have been obtained using the Pegasus beam. One of the main laboratory goals in the near future is to fully develop the rf photoinjector-based ultrafast electron diffraction technique with particular attention to the optimization of the working point of the photoinjector in a low-charge ultrashort pulse regime, and to the development of suitable beam diagnostics.
The Los Alamos high-brightness photoinjector

Energy Technology Data Exchange (ETDEWEB)

O' Shea, P.G.

1991-01-01

For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven photocathode is placed directly in a high-gradient RF accelerating cavity. A photocathode allows unsurpassed control over the current, and the spatial and temporal profile of the beam. In addition the electrodeless emission'' avoids many of the difficulties associated with multi-electrode guns, i.e. the electrons are accelerated very rapidly to relativistic energies, and there are no electrodes to distort the accelerating fields. For the past two years we have been integrating a photocathode into our existing FEL facility by replacing our thermionic gun and subharmonic bunchers with a high-gradient 1.3 GHz photoinjector. The photoinjector, which is approximately 0.6 m in length, produces 6 MeV, 300 A, 15 ps linac, and accelerated to a final energy of 40 MeV. We have recently begun lasing at wavelengths near 3 {mu}m. 16 refs., 2 figs., 5 tabs.
DC-SC Photoinjector with Low Emittance at Peking University

CERN Document Server

Xiang Rong; Hao, J; Huang, Senlin; Lu Xiang Yang; Quan, Shengwen; Zhang, Baocheng; Zhao, Kui

2005-01-01

High average power Free Electron Lasers require the high quality electron beams with the low emittance and the sub-picosecond bunches. The design of DC-SC photoinjector, directly combining a DC photoinjector with an SRF cavity, can produce high average current beam with moderate bunch charge and high duty factor. Because of the DC gun, the emittance increases quickly at the beginning, so a carefully design is needed to control that. In this paper, the simulation of an upgraded design has been done to lower the normalized emittance below 1.5mm·mrad. The photoinjector consists of a DC gap and a 2+1/2-cell SRF cavity, and it is designed to produce 4.2 MeV electron beams at 100pC bunch charge and 81.25MHz repetition rate (8 mA average current).
Primary beam-loading tests on DC-SC photoinjector at Peking University

International Nuclear Information System (INIS)

Hao Jiankui; Lu Xiangyang; Ding, Yuantao; Quan Shengwen; Huang Senlin; Zhao Kui; Zhang Baocheng; Wang Lifang; Lin Lin; Jiao Fei; Wang Guimei; Xie Datao; Zhu Feng; Xiao Binping; Xiang Rong; Chen Jia'er

2006-01-01

The DC-SC photoinjector is a compact electron gun integrating a DC pierce gun with a 1.3 GHz 1+1/2 cell superconducting cavity. A test facility of the DC-SC photoinjector had been installed in Peking University and beam-loading tests at 4.4 K have been finished. To date the gradient of 6 MV/m has been achieved. The maximum energy gain is 1.1 MeV at 4.4 K. With average beam current of 270 μA, the measured rms emittance is about 5 mm mrad at the beam energy of 500 keV. In this paper some of the experimental results are summarized
Status of the C-band RF System for the SPARC-LAB high brightness photo-injector

CERN Document Server

Boni, R.; Bellaveglia, M.; Di Pirro, G.; Ferrario, M.; Gallo, A.; Spataro, B.; Mostacci, A.; Palumbo, L.

2013-01-01

The high brightness photo-injector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy so improving the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.
Low emittance photoinjectors

International Nuclear Information System (INIS)

Ferrario, Massimo

2001-01-01

Photon colliders require high charge polarized electron beams with very low normalized emittances, possibly lower than the actual damping rings design goals. Recent analytical and numerical efforts in understanding beam dynamics in RF photoinjectors have raised again the question as to whether the performances of an RF electron gun based injector could be competitive with respect to a damping ring. As a matter of discussion we report in this paper the most recent results concerning low emittance photoinjector designs: the production of polarized electron beams by DC and/or RF guns is illustrated together with space charge compensation techniques and thermal emittance effects. New ideas concerning multi-gun injection system and generation of flat beams by RF gun are also discussed
Emittances Studies at the Fermilab/NICADD Photoinjector Laboratory

CERN Document Server

Tikhoplav, Rodion; Melissinos, A C; Regis-Guy Piot, Philippe

2005-01-01

The Fermilab/NICADD photoinjector incorporates an L-band rf-gun capable of generating 1-10 nC bunches. The bunches are then accelerated to 16 MeV with a TESLA superconducting cavity. In the present paper we present parametric studies of transverse emittances and energy spread for a various operating points of the electron source (RF-gun E-field, laser length and spot size, and solenoid settings). We especially study the impact, on transverse emittance, of Gaussian and Plateau temporal distribution of the photocathode drive-laser.
Overview of Photoinjectors

International Nuclear Information System (INIS)

Power, J. G.

2010-01-01

High-brightness electron beam sources play a crucial role in many advanced acceleration schemes as well as linac-based light sources such as Energy Recovery Linac (ERL) based light sources and FELs. Three varieties electron sources (photo, thermionic, and field emission) the photoinjector is especially attractive due to its innate ability to control the time structure of intense electron bunches with low transverse and longitudinal emittance. In all cases, the quality of the bunch begins with the intrinsic emittance and time response of the photocathode, and we discuss the trade-offs involved between the various material choices. A variety of longitudinal laser pulse-shaping techniques are currently being developed to linearize space charge forces or create trains of ultra-short bunches. The emittance compensation technique mitigates the growth of the projected emittance due to the linear space charge force while the bunch is accelerated and compressed in an injector. While the normal conducting rf photoinjector is the workhorse of this field, the dc photoinjector is being pushed to its high-voltage limits, and the year 2010 promises to be a critical year for the superconducting rf photoinjector. Parallel to the development of the hardware, rapid progress has also been made with modeling codes, theory, and bench marking of diagnostics. We attempt to give both a tutorial of photoinjectors and a review of the current state of the art in this rapidly developing field.
Process of DC-SC photoinjector

International Nuclear Information System (INIS)

Xiang Rong; Zhao Kui; Quan Shengwen; Ding Yuantao; Zhang Baocheng; Lu Xiangyang; Lin Lin; Wang Lifang; Chen Jiaer

2004-01-01

The DC-SC photoinjector at Beijing University is designed to provide an electron beam of average current 1 mA with the energy of 2-3 MeV and normalized rms transverse emittance of 3πmm-mrad at an 81.25 MHz repetition rate. The test facility has been completely installed in our lab. In this paper some of the ongoing experimental activities are summarized. First results from the cold test of superconducting cavity have been presented. According to the results, authors have improved the main coupler to repress the multipacting. The beam test of 100 μA on the DC gun has been done, photocathode preparation chamber can produce Cs 2 Te cathodes, and the laser system can provide laser pulse with 266 nm wavelength. The time synchronization between laser and RF power has been achieved by a timing stabilizer. A new method using 'due image pattern' of Cherenkov radiation will be commissioned to measure beam emittance. The next step is under way, to prepare all the equipment for the beam tests. (authors)
Recent progress in photo-injectors

International Nuclear Information System (INIS)

Ben-Zvi, I.

1996-10-01

In photoinjector electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense RF fields in a resonant cavity. Photoinjectors are very versatile tools. Normally we think of them in terms of the production of high electron density in 6-D phase space, for reasons such as injection to laser accelerators, generation of x-rays by Compton scattering and short wavelength FELs. Another example for the use of photo-injectors is the production of a high charge in a short time, for wake- field acceleration, two-beam accelerators and high-power, long-wavelength FELs. There are other potential uses, such as the generation of polarized electrons, compact accelerators for industrial applications and more. Photoinjectors are in operation in many electron accelerator facilities and a large number of new guns are under construction. The purpose of this work is to present some trend setting recent results that have been obtained in some of these laboratories. In particular the subjects of high density in 6-D phase space, new diagnostic tools, photocathode advances and high-charge production will be discussed
A 90 GHz photoinjector

International Nuclear Information System (INIS)

Palmer, D.T.; Hogan, M.J.; Ferrario, M.; Serafini, L.

1999-01-01

Photocathode rf guns depend on mode locked laser systems to produce an electron beam at a given phase of the rf. In general, the laser pulse is less than σ 2 = 10'' of rf phase in length and the required stability is on the order of Δφ = 1 At 90 GHz (W-band), these requirements correspond to σ 2 = 333 fsec and Δφ = 33 fsec. Laser system with pulse lengths in the fsec regime are commercially available, the timing stability is a major concern. It is proposed a multi-cell W-band photoinjector that does not require a mode locked laser system. Thereby eliminating the stability requirements at W-band. The laser pulse is allowed to be many rf periods long. In principle, the photoinjector can now be considered as a thermionic rf gun. Instead of using an alpha magnet to compress the electron bunch, which would have a detrimental effect on the transverse hase space quality due to longitudinal phase space mixing, it is here proposed to use long pulse laser system and a pair of undulators to produce a low emittance, high current, ultra-short electron bunch for beam dynamics experiments in the 90 GHz regime
VELOCIRAPTOR: An X-band photoinjector and linear accelerator for the production of Mono-Energetic {gamma}-rays

Energy Technology Data Exchange (ETDEWEB)

Anderson, S.G., E-mail: anderson131@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94551 (United States); Albert, F.; Bayramian, A.J.; Beer, G.; Bonanno, R.E.; Cross, R.R.; Deis, G.; Ebbers, C.A.; Gibson, D.J.; Hartemann, F.V.; Houck, T.L.; Marsh, R.A.; McNabb, D.P.; Messerly, M.J.; Scarpetti, R.D.; Shverdin, M.Y.; Siders, C.W.; Wu, S.S.; Barty, C.P.J. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94551 (United States); Adolphsen, C.E. [SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025 (United States); and others

2011-11-21

The rf photoinjector and linear accelerator in the Mono-Energetic Gamma-ray (MEGa-ray) facility at LLNL is presented. This machine uses 11.4 GHz rf technology to accelerate a high-brightness electron beam up to 250 MeV to produce MeV {gamma}-rays through Compton scattering with a Joule-class laser pulse. Compton scattering-based generation of high flux, narrow bandwidth {gamma}-rays places stringent requirements on the performance of the accelerator. The component parts of the accelerator are presented and their requirements described. Simulations of expected electron beam parameters and the resulting light source properties are presented.
Progress in photoinjectors for linacs

International Nuclear Information System (INIS)

Sheffield, R.L.

1990-01-01

Several programs have started which are based on the photoinjector as the electron source. Some reasons for using a laser to produce an electron beam are improved beam brightness, high-charge single-bunch pulses (>50 nC), and several high-current pulses closely spaced in time. This presentation will cover present and planned activities in photoinjector development. Topics will include materials, gun designs, and present experimental results. 21 refs
Transverse emittance and phase space program developed for use at the Fermilab A0 Photoinjector

International Nuclear Information System (INIS)

Thurman-Keup, R.; Johnson, A.S.; Lumpkin, A.H.; Ruan, J.

2011-01-01

The Fermilab A0 Photoinjector is a 16 MeV high intensity, high brightness electron linac developed for advanced accelerator R and D. One of the key parameters for the electron beam is the transverse beam emittance. Here we report on a newly developed MATLAB based GUI program used for transverse emittance measurements using the multi-slit technique. This program combines the image acquisition and post-processing tools for determining the transverse phase space parameters with uncertainties. An integral part of accelerator research is a measurement of the beam phase space. Measurements of the transverse phase space can be accomplished by a variety of methods including multiple screens separated by drift spaces, or by sampling phase space via pepper pots or slits. In any case, the measurement of the phase space parameters, in particular the emittance, can be drastically simplified and sped up by automating the measurement in an intuitive fashion utilizing a graphical interface. At the A0 Photoinjector (A0PI), the control system is DOOCS, which originated at DESY. In addition, there is a library for interfacing to MATLAB, a graphically capable numerical analysis package sold by The Mathworks. It is this graphical package which was chosen as the basis for a graphical phase space measurement system due to its combination of analysis and display capabilities.
Design and Results of a Time Resolved Spectrometer for the 5 MeV Photo-Injector Phin

CERN Document Server

Dabrowski, A; Egger, D; Mete, O; Lefevre, T

2010-01-01

The CLIC Test Facility 3 (CTF3) drive beam injector should provide high intensity and high quality electron beams. The present installation relies on a thermionic gun followed by a complex RF bunching system. As an upgrade to improve the beam emittance and the energy spread and to minimize the beam losses, a photo-injector is being developed and tested at CERN. One of the major challenges is to provide a 3.5A beam with a stable (0.1%) beam energy over 1.2 μs and a relative energy spread smaller than 1%. A 90◦ spectrometer line consisting of a segmented dump and an Optical Transition Radiation screen has been built in order to study these issues. The following paper describes its design and shows performances during the beam commissioning.
Optical transition radiation interferometry for A0 photoinjector

International Nuclear Information System (INIS)

Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Lebedev, V.; Nagaitsev, S.; Santucci, J.; Thurman-Keup, R.; Fermilab; Piot, P.; Fermilab; Northern Illinois U.; Li, J.; Tikhoplav, R.; UCLA

2007-01-01

A charged particle passing through the boundary of two medias with different permittivity values generates Transition Radiation (TR), [1]. The TR is caused by a variation of the particle electric field with variation of the permittivity. The TR for relativistic particles has a wide spectrum with a significant portion in the optical range. The Optical Transition Radiation (OTR) is widely used for a beam profile monitoring and measurements of a beam size. Moreover, OTR can be used to characterize the energy, energy spread and transverse angles in the beam by employing the interference of the OTR from two thin films [2] inserted in the beam trajectory. This method has been applied in number of works [3-5] demonstrating high results and good coincidence in measurements and calculations. In this paper we present and discuss in details a simulation of the interference pattern in several experimental setups. We consider the main optical effects, for diagnostics for the beam properties at A0 Photoinjector and the ILC module test area (NML) in a wide range of electron beam energy. In this paper, we first derive the OTR intensity formula for a single film at 90 degrees to the beam, then for two films at normal incidence, and finally with films at 45 degree incidence to the beam. The last section illustrates application with beam parameters like those at the A0 Photoinjector (electron energy 15 MeV)

High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector

Energy Technology Data Exchange (ETDEWEB)

Musumeci, P.; Moody, J. T.; Scoby, C. M.; Gutierrez, M. S. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States); Bender, H. A.; Wilcox, N. S. [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)

2010-01-15

Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.
High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector.

Science.gov (United States)

Musumeci, P; Moody, J T; Scoby, C M; Gutierrez, M S; Bender, H A; Wilcox, N S

2010-01-01

Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.
High quality single shot diffraction patterns using ultrashort megaelectron volt electron beams from a radio frequency photoinjector

International Nuclear Information System (INIS)

Musumeci, P.; Moody, J. T.; Scoby, C. M.; Gutierrez, M. S.; Bender, H. A.; Wilcox, N. S.

2010-01-01

Single shot diffraction patterns using a 250-fs-long electron beam have been obtained at the UCLA Pegasus laboratory. High quality images with spatial resolution sufficient to distinguish closely spaced peaks in the Debye-Scherrer ring pattern have been recorded by scattering the 1.6 pC 3.5 MeV electron beam generated in the rf photoinjector off a 100-nm-thick Au foil. Dark current and high emittance particles are removed from the beam before sending it onto the diffraction target using a 1 mm diameter collimating hole. These results open the door to the study of irreversible phase transformations by single shot MeV electron diffraction.
A 700 MHZ, 1 MW CW RF System for a FEL 100mA RF Photoinjector

CERN Document Server

Roybal, William; Reass, William; Rees, Daniel; Tallerico, Paul J; Torrez, Phillip A

2005-01-01

This paper describes a 700 MHz, 1 Megawatt CW, high efficiency klystron RF system utilized for a Free Electron Laser (FEL) high-brightness electron photoinjector (PI). The E2V klystron is mod-anode tube that operates with a beam voltage of 95 kV. This tube, operating with a 65% efficiency, requires ~96 watts of input power to produce in excess of 1 MW of output power. This output drives the 3rd cell of a 2½-cell, p-mode PI cavity through a pair of planar waveguide windows. Coupling is via a ridge-loaded tapered waveguide section and "dog-bone" iris. This paper will present the design of the RF, RF transport, coupling, and monitoring/protection systems that are required to support CW operations of the 100 mA cesiated, semi-porous SiC photoinjector.
An introduction to photo-injector design

International Nuclear Information System (INIS)

Travier, C.

1993-07-01

A quick overview is given of the RF gun basic theory for photo-injectors and of the presently achievable technical parameters thus providing some guidelines to help the designer in his choices. Simple scaling laws and formulas for both beam dynamics and technical parameters are proposed and compared to corresponding values for existing photo-injectors. Various sophisticated schemes used to improve the performances beyond those given by a straightforward approach are reviewed. (author) 65 refs., 11 figs., 3 tabs
Investigation into diode pumped modelocked Nd based laser oscillators for the CLIC-3 photoinjector system

NARCIS (Netherlands)

Valentine, G.J.; Burns, D.; Bente, E.A.J.M.; Berghmans, F.; Thienpont, H.; Danckaert, J.; Desmet, L.

2001-01-01

The photo-injector system envisaged for the proposed CLIC linear e+-e- accelerator at CERN has a demanding set of specifications on output pulse structure, power and timing stability. This paper reports on results obtained with quasi-CW diode pumped laser oscillators with output stabilisation. A
Photoinjector optimization using a derivative-free, model-based trust-region algorithm for the Argonne Wakefield Accelerator

Science.gov (United States)

Neveu, N.; Larson, J.; Power, J. G.; Spentzouris, L.

2017-07-01

Model-based, derivative-free, trust-region algorithms are increasingly popular for optimizing computationally expensive numerical simulations. A strength of such methods is their efficient use of function evaluations. In this paper, we use one such algorithm to optimize the beam dynamics in two cases of interest at the Argonne Wakefield Accelerator (AWA) facility. First, we minimize the emittance of a 1 nC electron bunch produced by the AWA rf photocathode gun by adjusting three parameters: rf gun phase, solenoid strength, and laser radius. The algorithm converges to a set of parameters that yield an emittance of 1.08 μm. Second, we expand the number of optimization parameters to model the complete AWA rf photoinjector (the gun and six accelerating cavities) at 40 nC. The optimization algorithm is used in a Pareto study that compares the trade-off between emittance and bunch length for the AWA 70MeV photoinjector.
Feasibility Study for the CERN "CLIC" Photo-Injector Laser System

CERN Document Server

Ross, I N

2000-01-01

This study is designed to contribute to the development of the Cern Linear Collider (CLIC). One route to the generation of the required electron injection into this system is through the use of photo-cathodes illuminated with a suitably designed laser system. The requirements of the accelerator and photo-cathodes have led to a specification for the laser system given in Table 1. Because CLIC will not be built directly but in stages, notably via CLIC Test Facilities (CTF), this table also includes the specification for a photo-injector laser system for CTF3 which will be required before the final system for CLIC. Although there are significant differences between these two specifications it will be necessary to design the CTF3 system such that it can be easily upgraded to the system for CLIC and will be able to check all the critical issues necessary for CLIC.
Simulation study of the high intensity S-Band photoinjector

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiongwei; Nakajima, Kazuhisa [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2001-10-01

In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 {pi} mm mrad can be outputted at the exit of photoinjector. (author)
Simulation study of the high intensity S-Band photoinjector

International Nuclear Information System (INIS)

Zhu, Xiongwei; Nakajima, Kazuhisa

2001-01-01

In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 π mm mrad can be outputted at the exit of photoinjector. (author)
Technological Challenges for High-Brightness Photo-Injectors

CERN Multimedia

Suberlucq, Guy

2004-01-01

Many applications, from linear colliders to free-electron lasers, passing through light sources and many other electron sources, require high brightness electron beams, usually produced by photo-injectors. Because certain parameters of these applications differ by several orders of magnitude, various solutions were implemented for the design and construction of the three main parts of the photo-injectors: lasers, photocathodes and guns. This paper summarizes the different requirements, how they lead to technological challenges and how R&D programs try to overcome these challenges. Some examples of state-of-the-art parts are presented.
Overview on superconducting photoinjectors

CERN Document Server

Arnold, A

2011-01-01

The success of most of the proposed energy recovery linac (ERL) based electron accelerator projects for future storage ring replacements (SRR) and high power IR–free-electron lasers (FELs) largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J.W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004)] electron beams with an unprecedented combination of high brightness, low emittance (0.1 µmrad), and high average current (hundreds of mA) are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun). SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University). Substantial progress was achieved in recent years and the first long term ...
Generation of angular-momentum-dominated electron beams from a photoinjector

International Nuclear Information System (INIS)

Sun, Yin-E.; Piot, Philippe; Kim, Kwang-Je; Barov, Nikolas; Lidia, Steven; Santucci, James; Tikhoplav, Rodion; Wennerberg, Jason

2004-01-01

Various projects under study require an angular-momentum-dominated electron beam generated by a photoinjector. Some of the proposals directly use the angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while others require the beam to be transformed into a flat beam (e.g. possible electron injectors for light sources and linear colliders). In this paper, we report our experimental study of an angular-momentum-dominated beam produced in a photoinjector, addressing the dependencies of angular momentum on initial conditions. We also briefly discuss the removal of angular momentum. The results of the experiment, carried out at the Fermilab/NICADD Photoinjector Laboratory, are found to be in good agreement with theoretical and numerical models
Optical transition radiation interferometry for the A0 photoinjector

International Nuclear Information System (INIS)

Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Nagaitsev, S.; Ruan, J.; Thurman-Keup, R.; Fermilab

2008-01-01

Optical Transition Radiation Interferometry (OTRI) is a promising diagnostic technique and has been successfully developed and used for investigation of relativistic beams. For mid-energy accelerators the technique is traditionally based on thin polymer films (the first one is being transparent for visible light), which causes beam multiple scattering of about 1 mrad. A disadvantage of those films is unacceptable vacuum properties for photoinjectors and accelerators using superconducting cavities. We have studied the application of thin mica sheets for the OTRI diagnostics at the A0 Photoinjector in comparison with 2.5 (micro)m thick Mylar films. This diagnostic is also applicable for the ILCTA-NML accelerator test facility that is planned at Fermilab. This report discusses the experimental setups of the OTR interferometer for the A0 Photoinjector and presents comparisons of simulations and measurements obtained using Mylar and mica-based interferometers
Emittance compensation of CW DC-gun photoinjector

International Nuclear Information System (INIS)

Li Peng; Wu Dai; Xu Zhou; Li Ming; Yang Xingfan

2011-01-01

Emittance growth induced by space charge effect is very important, especially for CW DC-gun photoinjector. In this work, the linear space charge force and its effect on electron beam transverse emittance are studied, and the principle and properties of emittance compensation by solenoid are analyzed. The CAEP DC-gun photoinjector with a solenoid is also simulated by code Parmela. Simulated results indicate that the normalized transverse emittance of an 80 pC bunch at the 350 keV DC-gun ex-it is 5.14 mm · mrad. And after compensated by a solenoid, it becomes 1.27 mm · mrad. The emittance of beam is well compensated. (authors)
Development and Measurement of Strain Free RF Photoinjector Vacuum Windows

CERN Document Server

Biedron, Sandra G

2004-01-01

RF photoinjectors produce the highest brightness electron bunches only under nearly ideal illumination by a drive laser. The vacuum window used to introduce the laser beam is an essential element that may potentially degrade any distribution, making it difficult or impossible to know the actual uniformity achieved at the cathode. Because of the necessity to obtain ultrahigh vacuum near the photoinjector, some restrictions are imposed on the fabrication technology available to manufacture distortion-free windows. At the UV wavelengths commonly used for photoinjectors, it is challenging to measure and eliminate degradation caused by vacuum windows. Here, we discuss the initial laser-based measurements of a strain-free, coated, UHV window manufactured by Insulator Seal in collaboration with members of Brookhaven and Argonne National Laboratories.
The transverse and longitudinal beam characteristics of the PHIN photo-injector at CERN

CERN Document Server

Mete, Ö; Dabrowski, A; Divall, M; Döbert, S; Egger, D; Elsener, K; Fedosseev, V; Lefèvre, T; Petrarca, M

2010-01-01

A new photo-injector, capable to deliver a long pulse train with a high charge per bunch for CTF3, has been designed and installed by a collaboration between LAL, CCLRC and CERN within the framework of the second Joint Research Activity PHIN of the European CARE program. The demonstration of the high charge and the stability along the pulse train are the important goals for CTF3 and the CLIC drive beam. The nominal beam for CTF3 has an average current of 3.5 A, a 1.5 GHz bunch repetation frequency and a pulse length of 1.27 μs (1908 bunches). The existing CTF3 injector consists of a thermionic gun and a subharmonic bunching system. The PHIN photo-injector is being tested in a dedicated test-stand at CERN to replace the existing CTF3 injector that is producing unwanted satellite bunches during the bunching process. A phase-coding scheme is planned to be implemented to the PHIN laser system providing the required beam temporal structure by CTF3. RF photo-injectors are high-brightness, low-emittance electron so...
Modified SRF Photoinjector for the ELBE at HZDR

CERN Document Server

Murcek, P; Buettig, H; Michel, P; Teichert, J; Xiang, R; Kneisel, P

2012-01-01

The superconducting radio frequency photoinjector (SRF photoinjector) with Cs2Te cathode has been successfully operated under the collaboration of HZB, DESY, HZDR, and MBI.[1] In order to improve the gradient of the gun cavity and the beam quality, a new modified SRF gun (SRF-gun 2008) has been designed. The main updates of the new cavity design for the new photoinjector were publisched before. (ID THPPO022 on the SRF09 Berlin.) This cavity is being fabricated in Jefferson Lab. In this paper the new ideas of the further parts of the SRF-gun 2008 will be presented. The most important issue is the special design of half-cell and choke filter. The cathode cooler is also slightly changed, which simplifies the installation of the cathode cooler in the cavity. The next update is the separation of input and output of the liquid nitrogen supply, for the purpose of the stability of the nitrogen pressure as well as the better possibility of temperature measurement. Another key point is the implementation of the superco...
State-Of High Brightness RF Photo-Injector Design

Science.gov (United States)

Ferrario, Massimo; Clendenin, Jym; Palmer, Dennis; Rosenzweig, James; Serafini, Luca

2000-04-01

The art of designing optimized high brightness electron RF Photo-Injectors has moved in the last decade from a cut and try procedure, guided by experimental experience and time consuming particle tracking simulations, up to a fast parameter space scanning, guided by recent analytical results and a fast running semi-analytical code, so to reach the optimum operating point which corresponds to maximum beam brightness. Scaling laws and the theory of invariant envelope provide to the designers excellent tools for a first parameters choice and the code HOMDYN, based on a multi-slice envelope description of the beam dynamics, is tailored to describe the space charge dominated dynamics of laminar beams in presence of time dependent space charge forces, giving rise to a very fast modeling capability for photo-injectors design. We report in this talk the results of a recent beam dynamics study, motivated by the need to redesign the LCLS photoinjector. During this work a new effective working point for a split RF photoinjector has been discovered by means of the previous mentioned approach. By a proper choice of rf gun and solenoid parameters, the emittance evolution shows a double minimum behavior in the drifting region. If the booster is located where the relative emittance maximum and the envelope waist occur, the second emittance minimum can be shifted at the booster exit and frozen at a very low level (0.3 mm-mrad for a 1 nC flat top bunch), to the extent that the invariant envelope matching conditions are satisfied.
Alternate Tunings for the Linac Coherent Light Source Photoinjector

CERN Document Server

Limborg-Deprey, Cecile

2005-01-01

The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser (FEL) project based on the SLAC linac. The LCLS Photoinjector beamline has been designed to deliver 10 ps long electron bunches of 1nC with a normalized transverse emittance of less than 1 mm.mrad for 80% of the slices constituting the core of the bunch at 135 MeV. Tolerances and regulation requirements are tight for this tuning. The main contribution to emittance is the "cathode emittance which counts for 0.72 mm.mrad for the nominal tuning. As the "cathode emittance" scales linearly with laser spot radius, the emittance will be dramatically reduced for smaller radius, but this is only possible at lower charge. In particular, for a 0.2nC, we believe we can achieve an emittance closer to 0.4 mm.mrad. This working point will be easier to tune and the beam quality should be much easier to maintain than for the nominal one. In this paper, we also discuss how emittance could be further reduced by using the appropriate laser pulse shaping.

Characterization of Cs-Sb cathodes for high charge RF photoinjectors

CERN Document Server

AUTHOR|(CDS)2082505; Beghi, Marco

Future accelerators such as CLIC (Compact LInear Collider), require high brightness electron beams that could be produced with a photoinjector (laser-driven electron source). Cs2Te photocathodes in combination with ultra-violet (UV) laser beams are currently used in many photoinjector facilities, but requirements to the electron sources for future accelerators like CLIC are more demanding. The main challenge for the CLIC drive beam photoinjector is to achieve high bunch charges (8.4 nC), high bunch repetition rates (500 MHz) within long trains (140 s) and with suciently long cathode lifetimes. In particular the laser pulse energy in UV, for such long pulse trains, is currently limited due to a degradation of the beam quality during the 4th harmonic frequency conversion process. Using the 2nd harmonic (green laser beam), provided it is matched with a low photoemission threshold photocathode material, would overcome this limitation. Cesium antimonide (Cs3Sb), being a photoemissive material in the visible range,...
Experimental Study of Coherent Synchrotron Radiation in the Emittance Exchange Line at the A0-Photoinjector

Science.gov (United States)

Thangaraj, Jayakar C. T.; Thurman-Keup, R.; Johnson, A.; Lumpkin, A. H.; Edwards, H.; Ruan, J.; Santucci, J.; Sun, Y. E.; Church, M.; Piot, P.

2010-11-01

Next generation accelerators will require a high current, low emittance beam with a low energy spread. Such accelerators will employ advanced beam conditioning systems such as emittance exchangers to manipulate high brightness beams. One of the goals of the Fermilab A0 photoinjector is to investigate the transverse to longitudinal emittance exchange principle. Coherent synchrotron radiation could limit high current operation of the emittance exchanger. In this paper, we report on the preliminary experimental and simulation study of the coherent synchroton radiation (CSR) in the emittance exchange line at the A0 photoinjector.
50 MeV Run of the IOTA / FAST Electron Accelerator

Energy Technology Data Exchange (ETDEWEB)

Edstrom Jr., D.; et al.

2017-02-02

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

International Nuclear Information System (INIS)

Marhauser, F.

2006-01-01

This paper details electromagnetical, thermal and structural 3D Finite Element Analyses (FEA) for normal conducting RF photoinjector gun cavities. The simulation methods are described extensively. Achieved results are presented. (orig.)
Finite element analyses for RF photoinjector gun cavities

Energy Technology Data Exchange (ETDEWEB)

Marhauser, F. [Berliner Elektronenspeicherring-Gesellschaft fuer Synchrotronstrahlung mbH (BESSY), Berlin (Germany)

2006-07-01

This paper details electromagnetical, thermal and structural 3D Finite Element Analyses (FEA) for normal conducting RF photoinjector gun cavities. The simulation methods are described extensively. Achieved results are presented. (orig.)
The Next Generation Photoinjector

Energy Technology Data Exchange (ETDEWEB)

Palmer, Dennis Thomas; /Stanford U., Appl. Phys. Dept.

2005-09-12

This dissertation will elucidate the design, construction, theory, and operation of the Next Generation Photoinjector (NGP). This photoinjector is comprised of the BNL/SLAC/UCLA 1.6 cell symmetrized S-band photocathode radio frequency (rf) electron gun and a single emittance-compensation solenoidal magnet. This photoinjector is a prototype for the Linear Coherent Light Source X-ray Free Electron Laser operating in the 1.5 {angstrom} range. Simulations indicate that this photoinjector is capable of producing a 1nC electron bunch with transverse normalized emittance less than 1 {pi} mm mrad were the cathode is illuminated with a 10 psec longitudinal flat top pulse. Using a Gaussian longitudinal laser profile with a full width half maximum (FWHM) of 10 psec, simulation indicates that the NGP is capable of producing a normalized rms emittance of 2.50 {pi} mm mrad at 1 nC. Using the removable cathode plate we have studied the quantum efficiency (QE) of both copper and magnesium photo-cathodes. The Cu QE was found to be 4.5 x 10{sup -5} with a 25% variation in the QE across the emitting surface of the cathode, while supporting a field gradient of 125 MV/m. At low charge, the transverse normalized rms emittance, {epsilon}{sub n,rms}, produced by the NGP is {epsilon}{sub n,rms} = 1.2 {pi} mm mrad for Q{sub T} = 0.3 nC. The 95% electron beam bunch length was measured to 10.9 psec. The emittance due to the finite magnetic field at the cathode has been studied. The scaling of this magnetic emittance term as a function of cathode magnetic field was found to be 0.01 {pi} mm mrad per Gauss. The 1.6 cell rf gun has been designed to reduce the dipole field asymmetry of the longitudinal accelerating field. Low level rf measurements show that this has in fact been accomplished, with an order of magnitude decrease in the dipole field. High power beam studies also show that the dipole field has been decreased. An upper limit of the intrinsic non-reducible thermal emittance of a
A phase stabilized and pulse shaped Ti:Sapphire oscillator-amplifier laser system for the LCLS rf photoinjector

International Nuclear Information System (INIS)

Kotseroglou, T.; Alley, R.; Clendenin, J.; Fisher, A.; Frisch, J.

1998-04-01

The authors have designed a laser system for the Linac Coherent Light Source rf photoinjector consisting of a Ti:Sapphire oscillator and 2 amplifiers using Chirped Pulse Amplification. The output after tripling will be 0.5 mJ tunable UV pulses at 120 Hz, with wavelength around 260 nm, pulsewidth of 10 ps FWHM and 200 fs rise and fall times. Amplitude stability is expected to be 1% rms in the UV and timing jitter better than 500 fs rms
Design of a low emittance and high repetition rate S-band photoinjector

Science.gov (United States)

Han, Jang-Hui

2014-09-01

As an electron beam injector of X-ray free-electron lasers (FELs), photoinjectors have been developed for the past few decades. Such an injector starting with a photocathode RF gun provides high brightness beams and therefore it is being adopted as an injector of X-ray FELs. In this paper we show how to improve photoinjector performance in terms of emittance and repetition rates by means of injector components optimization, especially with the gun. Transverse emittance at the end of an injector is reduced by optimizing the gun design, gun solenoid position, and accelerating section position. The repetition rate of an injector mainly depends on the gun. It is discussed that a repetition rate of 1 kHz at a normal-conducting S-band photoinjector is feasible by adopting a coaxial RF coupler and improving cooling-water channels surrounding the gun.
Emittance control and RF bunch compression in the NSRRC photoinjector

International Nuclear Information System (INIS)

Lau, W.K.; Hung, S.B.; Lee, A.P.; Chou, C.S.; Huang, N.Y.

2011-01-01

The high-brightness photoinjector being constructed at the National Synchrotron Radiation Research Center is for testing new accelerator and light-source concepts. It is the so-called split photoinjector configuration in which a short solenoid magnet is used for emittance compensation. The UV-drive laser pulses are also shaped to produce uniform cylindrical bunches for further reduction of beam emittance. However, limited by the available power from our microwave power system, the nominal accelerating gradient in the S-band booster linac is set at 18 MV/m. A simulation study with PARMELA shows that the linac operating at this gradient fails to freeze the electron beam emittance at low value. A background solenoid magnetic field is applied for beam emittance control in the linac during acceleration. A satisfactory result that meets our preliminary goal has been achieved with the solenoid magnetic field strength at 0.1 T. RF bunch compression as a means to achieve the required beam brightness for high-gain free-electron laser experiments is also examined. The reduction of bunch length to a few hundred femtoseconds can be obtained.
Overview on superconducting photoinjectors

Directory of Open Access Journals (Sweden)

A. Arnold

2011-02-01

Full Text Available The success of most of the proposed energy recovery linac (ERL based electron accelerator projects for future storage ring replacements (SRR and high power IR–free-electron lasers (FELs largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J. W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004PSISDG0277-786X10.1117/12.557378] electron beams with an unprecedented combination of high brightness, low emittance (0.1 μmrad, and high average current (hundreds of mA are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun. SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University. Substantial progress was achieved in recent years and the first long term operation was demonstrated at FZD [R. Xiang et al., in Proceedings of the 31st International Free Electron Laser Conference (FEL 09, Liverpool, UK (STFC Daresbury Laboratory, Warrington, 2009, p. 488]. In the near future SRF guns are expected to play an important role for linac-driven FEL facilities. In this paper we will review the concepts, the design parameters, and the status of the major SRF gun projects.
rf traveling-wave electron gun for photoinjectors

Science.gov (United States)

Schaer, Mattia; Citterio, Alessandro; Craievich, Paolo; Reiche, Sven; Stingelin, Lukas; Zennaro, Riccardo

2016-07-01

The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL) machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least) double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.
Modeling and design of an X-band rf photoinjector

Directory of Open Access Journals (Sweden)

R. A. Marsh

2012-10-01

Full Text Available A design for an X-band rf photoinjector that was developed jointly by SLAC National Accelerator Laboratory (SLAC and Lawrence Livermore National Laboratory (LLNL is presented. The photoinjector is based around a 5.59 cell rf gun that has state-of-the-art features including: elliptical contoured irises; improved mode separation; an optimized initial half cell length; a racetrack input coupler; and coupling that balances pulsed heating with cavity fill time. Radio-frequency and beam dynamics modeling have been done using a combination of codes including PARMELA, HFSS, IMPACT-T, ASTRA, and the ACE3P suite of codes developed at SLAC. The impact of lower gradient operation, magnet misalignment, solenoid multipole errors, beam offset, mode beating, wakefields, and beam line symmetry have been analyzed and are described. Fabrication and testing plans at both LLNL and SLAC are discussed.
rf traveling-wave electron gun for photoinjectors

Directory of Open Access Journals (Sweden)

Mattia Schaer

2016-07-01

Full Text Available The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.
A Masked Photocathode in a Photoinjector

OpenAIRE

Qiang, Ji

2011-01-01

In this paper, we propose a masked photocathode inside a photoinjector for generating high brightness electron beam. Instead of mounting the photocathode onto an electrode, an electrode with small hole is used as a mask to shield the photocathode from the accelerating vacuum chamber. Using such a masked photocathode will make the replacement of photocathode material easy by rotating the photocathode behind the electrode into the hole. Furthermore, this helps reduce the dark current or seconda...
An L-Band Polarized Electron PWT Photoinjector for the International Linear Collider (ILC)

CERN Document Server

Yu, David; Chen Ping; Lundquist, Martin; Luo, Yan; Smirnov, Alexei Yu

2005-01-01

A multi-cell, standing-wave, L-band, p-mode, plane-wave-transformer (PWT) photoinjector with an integrated photocathode in a novel linac structure is proposed by DULY Research Inc. as a polarized electron source. The PWT photoinjector is capable of operation in ultra high vacuum and moderate field gradient. Expected performance of an L-band polarized electron PWT injector operating under the parameters for the International Linear Collider is presented. The projected normalized transverse rms emittance is an order of magnitude lower than that produced with a polarized electron dc gun followed by subharmonic bunchers.
Advanced photoinjector experiment photogun commissioning results

Science.gov (United States)

Sannibale, F.; Filippetto, D.; Papadopoulos, C. F.; Staples, J.; Wells, R.; Bailey, B.; Baptiste, K.; Corlett, J.; Cork, C.; De Santis, S.; Dimaggio, S.; Doolittle, L.; Doyle, J.; Feng, J.; Garcia Quintas, D.; Huang, G.; Huang, H.; Kramasz, T.; Kwiatkowski, S.; Lellinger, R.; Moroz, V.; Norum, W. E.; Padmore, H.; Pappas, C.; Portmann, G.; Vecchione, T.; Vinco, M.; Zolotorev, M.; Zucca, F.

2012-10-01

The Advanced Photoinjector Experiment (APEX) at the Lawrence Berkeley National Laboratory is dedicated to the development of a high-brightness high-repetition rate (MHz-class) electron injector for x-ray free-electron laser (FEL) and other applications where high repetition rates and high brightness are simultaneously required. The injector is based on a new concept rf gun utilizing a normal-conducting (NC) cavity resonating in the VHF band at 186 MHz, and operating in continuous wave (cw) mode in conjunction with high quantum efficiency photocathodes capable of delivering the required charge at MHz repetition rates with available laser technology. The APEX activities are staged in three phases. In phase 0, the NC cw gun is built and tested to demonstrate the major milestones to validate the gun design and performance. Also, starting in phase 0 and continuing in phase I, different photocathodes are tested at the gun energy and at full repetition rate for validating candidate materials to operate in a high-repetition rate FEL. In phase II, a room-temperature pulsed linac is added for accelerating the beam at several tens of MeV to reduce space charge effects and allow the measurement of the brightness of the beam from the gun when integrated in an injector scheme. The installation of the phase 0 beam line and the commissioning of the VHF gun are completed, phase I components are under fabrication, and initial design and specification of components and layout for phase II are under way. This paper presents the phase 0 commissioning results with emphasis on the experimental milestones that have successfully demonstrated the APEX gun capability of operating at the required performance.
Lifetime Studies of Cs2Te Cathodes at the Phin RF Photoinjector at CERN

CERN Document Server

Hessler, C; Divall Csatari, M; Doebert, S; Fedosseev, V

2012-01-01

The PHIN photoinjector has been developed to study the feasibility of a photoinjector option for the CLIC (Compact LInear Collider) drive beam as an alternative to the baseline design, using a thermionic gun. The CLIC drive beam requires a high charge of 8.4 nC per bunch in 0.14 ms long trains, with 2 ns bunch spacing and 50 Hz macro pulse repetition rate, which corresponds to a total charge per macro pulse of 0.59 mC. This means unusually high peak and average currents for photoinjectors and is challenging concerning the cathode lifetime. In this paper detailed studies of the lifetime of Cs2Te cathodes, produced by the co-evaporation technique, are presented with respect to bunch charge, train length and vacuum level. Furthermore, the impact of the train length and bunch charge on the vacuum level will be discussed and steps to extend the lifetime will be outlined.
Improvement in the laser system for the A0 TTF photoinjector

International Nuclear Information System (INIS)

Yang, Xi

2003-01-01

The production of high charge and high brightness electron beams places increasingly challenging demands on the drive laser used at the A0 photoinjector in the Fermilab. The IR and UV laser pulse lengths need to be optimized for such purpose. We have experimentally investigated two different ways to change the UV laser pulse length on the cathode; either by changing the bandwidth of the oscillator or by changing the distance between two compression gratings, the UV laser pulse length can be varied in the range of 3ps to 30ps. Also the strong correlation between the UV laser energy and the IR laser pulse length has been studied, and the result is applied to achieve the UV laser energy of 18 (micro)J/pulse
Electron beam and rf characterization of a low-emittance X-band photoinjector

Directory of Open Access Journals (Sweden)

D. J. Gibson

2001-09-01

Full Text Available Detailed experimental studies of the first operation of an X-band (8.547 GHz rf photoinjector are reported. The rf characteristics of the device are first described, as well as the tuning technique used to ensure operation of the 11/2-cell rf gun in the balanced π-mode. The characterization of the photoelectron beam produced by the rf gun includes: measurements of the bunch charge as a function of the laser injection phase, yielding information about the quantum efficiency of the Cu photocathode ( 2×10^{-5} for a surface field of 100 MV/m; measurements of the beam energy (1.5–2 MeV and relative energy spread ( Δγ/γ_{0}=1.8±0.2% using a magnetic spectrometer; measurements of the beam 90% normalized emittance, which is found to be ɛ_{n}=1.65π mm mrad for a charge of 25 pC; and measurements of the bunch duration ( <2 ps. Coherent synchrotron radiation experiments at Ku-band and Ka-band confirm the extremely short duration of the photoelectron bunch and a peak power scaling quadratically with the bunch charge.
Masked Photocathode for Photoinjector

International Nuclear Information System (INIS)

Qiang, Ji

2010-01-01

In this research note, we propose a scheme to insert a photocathode inside a photoinjector for generating high brightness electron beam. Instead of mounting the photocathode onto the electrode, a masked electrode with small hole is used to shield the photocathode from the accelerating vacuum chamber. Using such a masked photocathode will make the replacement of photocathode material very simple by rotating the photocathode behind the mask into the hole. This will significantly increase the usage lifetime of a photocathode. Furthermore, this also helps reduce the dark current or secondary electron emission from the photocathode. The hole on the mask also provides a transverse cut-off to the Gaussian laser profile which can be beneficial from the beam dynamics point of view.

Advanced photoinjector experiment photogun commissioning results

Directory of Open Access Journals (Sweden)

F. Sannibale

2012-10-01

Full Text Available The Advanced Photoinjector Experiment (APEX at the Lawrence Berkeley National Laboratory is dedicated to the development of a high-brightness high-repetition rate (MHz-class electron injector for x-ray free-electron laser (FEL and other applications where high repetition rates and high brightness are simultaneously required. The injector is based on a new concept rf gun utilizing a normal-conducting (NC cavity resonating in the VHF band at 186 MHz, and operating in continuous wave (cw mode in conjunction with high quantum efficiency photocathodes capable of delivering the required charge at MHz repetition rates with available laser technology. The APEX activities are staged in three phases. In phase 0, the NC cw gun is built and tested to demonstrate the major milestones to validate the gun design and performance. Also, starting in phase 0 and continuing in phase I, different photocathodes are tested at the gun energy and at full repetition rate for validating candidate materials to operate in a high-repetition rate FEL. In phase II, a room-temperature pulsed linac is added for accelerating the beam at several tens of MeV to reduce space charge effects and allow the measurement of the brightness of the beam from the gun when integrated in an injector scheme. The installation of the phase 0 beam line and the commissioning of the VHF gun are completed, phase I components are under fabrication, and initial design and specification of components and layout for phase II are under way. This paper presents the phase 0 commissioning results with emphasis on the experimental milestones that have successfully demonstrated the APEX gun capability of operating at the required performance.
Operational experience with nanocoulomb bunch charges in the Cornell photoinjector

Directory of Open Access Journals (Sweden)

Adam Bartnik

2015-08-01

Full Text Available Characterization of 9–9.5 MeV electron beams produced in the dc-gun based Cornell photoinjector is given for bunch charges ranging from 20 pC to 2 nC. Comparison of the measured emittances and longitudinal current profiles to optimized 3D space charge simulations yields excellent agreement for bunch charges up to 1 nC when the measured laser distribution is used to generate initial particle distributions in simulation. Analysis of the scaling of the measured emittance with bunch charge shows that the emittance scales roughly as the square root of the bunch charge up to 300 pC, above which the trend becomes linear. These measurements demonstrate that the Cornell photoinjector can produce cathode emittance dominated beams meeting the emittance and peak current specifications for next generation free electron lasers operating at high repetition rate. In addition, the 1 and 2 nC results are relevant to the electron ion collider community.
Numerical and experimental study of the beam dynamics of CANDELA photo-injector and associated instrumentation

International Nuclear Information System (INIS)

Devanz, Guillaume

1999-01-01

Laser triggered radiofrequency guns are the most luminous electron sources allowing to reach the performances requested by highly demanding applications like the e + /e - linear colliders and the short wave free electron lasers. CANDELA is a band S photo-injector triggered by a sub-picosecond laser. It allows reaching peak currents of hundred of amperes at average energies higher than 2 MeV. The original concept of two accelerating cavities aims at minimizing the transverse and longitudinal emittances following the Gao's principles. From practical reasons the operating parameters, particularly the laser pulse duration, do not correspond to those considered in the design. Hence, numerical simulations were performed to evaluate the gun's performances in experimental environment. The study of a stabile injector operation resulted in evolutions with consequences in the phase control systems implying the laser and the HF (Hyper Frequency) source. The beam transverse and longitudinal characteristics have been measured as a function of the main parameters i.e., the beam charge and the phase shift between the laser and the HF wave. Measurements of the transverse emittance energy dispersion and wave packed duration are presented for several injector configurations. The systems of existing beam measurements have been studied to determine the resolution and the experimental conditions to fulfill, in order to suggest improvements for the CANDELA beam. The experiments with the beam have been compared with numerical simulations. Agreement was obtained within wide ranges of parameters for most of the characteristic beam quantities
Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC photo-injector energy upgrade

CERN Document Server

Alesini, D.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.; Higo, T.; Kakihara, K.; Matsumoto, S.; Campogiani, G.; Mostacci, A.; Palumbo, L.; Persichelli, S.; Spizzo, V.; Verdú-Andrés, S.

2011-01-01

The energy upgrade of the SPARC photo-injector from 160 to more than 260 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.4m high gradient C-band structures. The structures are travelling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates (10^6 bpp/m) at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.
The PHIN photoinjector for the CTF3 Drive beam

CERN Document Server

Losito, R; Braun, H; Champault, N; Chevallay, E; Divall, M; Fedosseev, V; Hirst, G; Kumar, A; Kurdi, G; Martin, W; Masi, A; Mercier, B; Musgrave, I; Prevost, C; Ross, I; Roux, R; Springate, E; Suberlucq, Guy

2006-01-01

A new photoinjector for the CTF3 drive beam has been designed and is now being constructed by a collaboration among LAL, CCLRC and CERN within PHIN, the second Joint Research Activity of CARE. The photoinjector will provide a train of 2332 pulses at 1.5 GHz with a complex timing structure (sub-trains of 212 pulses spaced from one another by 333 ps or 999 ps) to allow the frequency multiplication scheme, which is one of the features of CLIC, to be tested in CTF3. Each pulse of 2.33 nC will be emitted by a Cs2Te photocathode deposited by a co-evaporation process to allow high quantum efficiency in operation (>3% for a minimum of 40 h). The 3 GHz, 2 1/2 cell RF gun has a 2 port coupler to minimize emittance growth due to asymmetric fields, racetrack profile of the irises and two solenoids to keep the emittance at the output below 20 p.mm.mrad. The laser has to survive very high average powers both within the pulse train (15 kW) and overall (200 W before pulse slicing). Challenging targets are also for amplitude ...
Characterization of the transverse phase space at the photo-injector test facility in DESY, Zeuthen site

International Nuclear Information System (INIS)

Staykov, Lazar

2012-10-01

High brightness electron beams with charge of 1 nC and low transverse emittance are necessary for the functioning of advanced light sources such as the Free-electron Laser in Hamburg (FLASH) and the European X-ray FEL (XFEL). The photo-injector test facility at DESY, Zeuthen site (PITZ) is dedicated to the optimization of such electron beams. At PITZ the electrons are produced using an RF gun cavity operated at accelerating gradients of up to 60 MV/m. The gun is equipped with a pair of solenoids for the compensation of the emittance growth due to linear space charge forces. This solenoid compensation scheme is enhanced with a properly matched TESLA type normal conducting booster cavity. The main tool for the characterization of the transverse phase space of the electron beam at PITZ is the emittance measurement system (EMSY). It employs the single slit method for the measurement of the transverse phase space distribution of the electron beam. In this thesis, the performance of the EMSY was optimized for measurement of low emittances in a wide range of photo-injector parameters including such that result in electron beams close to the XFEL specifications. First results on the characterization of the PITZ photo-injector with a gun operated at maximum accelerating gradient of 60 MV/m are presented. This includes scans of the solenoid focusing strength, the initial beam size and the booster gradient. A comparison between results obtained at lower accelerating gradients is made with emphasize on the benefit of higher accelerating gradient.
Characterization of the transverse phase space at the photo-injector test facility in DESY, Zeuthen site

Energy Technology Data Exchange (ETDEWEB)

Staykov, Lazar

2012-10-15

High brightness electron beams with charge of 1 nC and low transverse emittance are necessary for the functioning of advanced light sources such as the Free-electron Laser in Hamburg (FLASH) and the European X-ray FEL (XFEL). The photo-injector test facility at DESY, Zeuthen site (PITZ) is dedicated to the optimization of such electron beams. At PITZ the electrons are produced using an RF gun cavity operated at accelerating gradients of up to 60 MV/m. The gun is equipped with a pair of solenoids for the compensation of the emittance growth due to linear space charge forces. This solenoid compensation scheme is enhanced with a properly matched TESLA type normal conducting booster cavity. The main tool for the characterization of the transverse phase space of the electron beam at PITZ is the emittance measurement system (EMSY). It employs the single slit method for the measurement of the transverse phase space distribution of the electron beam. In this thesis, the performance of the EMSY was optimized for measurement of low emittances in a wide range of photo-injector parameters including such that result in electron beams close to the XFEL specifications. First results on the characterization of the PITZ photo-injector with a gun operated at maximum accelerating gradient of 60 MV/m are presented. This includes scans of the solenoid focusing strength, the initial beam size and the booster gradient. A comparison between results obtained at lower accelerating gradients is made with emphasize on the benefit of higher accelerating gradient.
Study of the Powerful Nd:YLF Laser Amplifiers for the CTF3 Photoinjectors

CERN Document Server

Petrarca, M; Luchinin, G; Divall, M

2011-01-01

A high-power neodymium-doped yttrium lithium fluoride (Nd:YLF) mode-locked 1.5-GHz laser currently used to drive the two photoinjectors of the Compact Linear Collider Test Facility project at the European Organization for Nuclear Research is described. A phenomenological characterization of the two powerful Nd:YLF amplifiers is presented and compared with the measurements. The laser system operates in a saturated steady-state mode. This mode provides good shot-to-shot stability with pulse train mean power in the 10 kW range.
Extraction of High Charge Electron Bunch from the ELSA RF Injector Comparison Between Simulation and Experiment

CERN Document Server

Lemaire, J; Binet, A; Lagniel, J M; Le Flanchec, V; Pichoff, N

2004-01-01

A new scheme based on a photoinjector and a RF linear accelerator operating at 352 MHz has been recently proposed as a versatile radiographic facility. Beam pulses of 60 ns duration contain 20 succesive electron bunches which will be extracted at 2.5 MeV from a photoinjector then accelerated through the next structure to the final energy of 51 MeV. Bunches carrying 100 nC are required for this purpose. As a first demonstrating step, 50 nC electron bunches have been produced and accelerated to 2.5 MeV with the 144 MHz ELSA photoinjector at Bruyères le Chatel. For this experiment, we compare the results and the numerical simulations made with PARMELA, MAGIC and MAFIA codes.
Hamiltonian analysis of transverse dynamics in axisymmetric rf photoinjectors

International Nuclear Information System (INIS)

Wang, C.-x.

2006-01-01

A general Hamiltonian that governs the beam dynamics in an rf photoinjector is derived from first principles. With proper choice of coordinates, the resulting Hamiltonian has a simple and familiar form, while taking into account the rapid acceleration, rf focusing, magnetic focusing, and space-charge forces. From the linear Hamiltonian, beam-envelope evolution is readily obtained, which better illuminates the theory of emittance compensation. Preliminary results on the third-order nonlinear Hamiltonian will be given as well.
Laser System for Photoelectron and X-Ray Production in the PLEIADES Compton Light Source

CERN Document Server

Gibson, David J; Betts, S; Crane, John; Jovanovic, Igor

2005-01-01

The PLEIADES (Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures) facility provides tunable short x-ray pulses with energies of 30-140 keV and pulse durations of 0.3 - 5 ps by scattering an intense, ultrashort laser pulse off a 35-75 MeV electron beam. Synchronization of the laser and electron beam is obtained by using a photoinjector gun, and using the same laser system to generate the electrons and the scattering laser. The Ti:Sapphire, chirped pulse amplification based 500 mJ, 50 fs, 810 nm scattering laser and the similar 300 μJ, 5 ps, 266 nm photoinjector laser systems are detailed. Additionally, an optical parametric chirped pulse amplification (OPCPA) system is studied as a replacement for part of the scattering laser front end. Such a change would significantly simplify the set-up the laser system by removing the need for active switching optics, as well as increase the pre-pulse contrast ratio which will be important when part of the scattering laser is used as a...
Multipacting Analysis of a Quarter Wave Choke Joint used for Insertion of a Demountable Cathode into a SRF Photoinjector

International Nuclear Information System (INIS)

A. Burrill; I. Ben-Zvi; M. D. Cole; J. Rathke; P. Kneisel; R. Manus; R. A. Rimmer

2007-01-01

The multipacting phenomena in accelerating structures and coaxial lines are well documented and methods of mitigating or suppressing it are understood. The multipacting that occurs in a quarter wave choke joint designed to mount a cathode insertion stalk into a superconducting RF photoinjector has been analyzed via calculations and experimental measurements and the effect of introducing multipacting suppression grooves into the structure is analyzed. Several alternative choke joint designs are analyzed and suggestions made regarding future choke joint development. Furthermore, the problems encountered in cleaning the choke joint surfaces, factors important in changes to the secondary electron yield, are discussed and evaluated. This design is being implemented on the BNL 1.3 GHz photoinjector, previously used for measurement of the quantum efficiency of bare Nb, to allow for the introduction of other cathode materials for study, and to verify the design functions properly prior to constructing our 703 MHz photoinjector with a similar choke joint design
On the possibility of a normal conducting photo-injector for Tesla

International Nuclear Information System (INIS)

Travier, C.

1992-12-01

The possibility of using a normal conducting photo-injector for the TESLA linear collider is investigated. It is shown that the 8 nC,3 ps bunch can be produced with a normalized emittance less than 100 Π mm mrad. The generation of the train depends on the feasibility of the laser which has to be looked at more carefully
NSRL 200 MeV linac beam energy stabilization system

International Nuclear Information System (INIS)

Huang Guirong; Pei Yuanji; Dong Sai

2001-01-01

By using the computer image processing technology and RF phase auto-shifting system, the ESS (Energy Stabilization System) was applied to 200 MeV Linac. the ESS adjusts beam energy automatically in a range of +-4 MeV. After adjustment beam energy stability is improved to +-6%
Measurement of self-shaped ellipsoidal bunches from a photoinjector with postacceleration

Directory of Open Access Journals (Sweden)

Brendan O’Shea

2011-01-01

Full Text Available Recent work has shown the possibility of generating self-shaped ellipsoidal beams with properties commensurate with the requirements of future light sources such as free-electron lasers and inverse Compton sources. In this so-termed “blowout” regime, short laser bunches are transformed via photoemission into short electron bunches which then self-consistently evolve into nearly uniform-density ellipsoids under space-charge forces. We report here on the first blowout studies conducted in collaboration between the UCLA Particle Beam Physics Lab and the Photo Injector Test Facility, Zeuthen (PITZ. The measurements conducted at the PITZ photoinjector facility examine the evolution of 750 pC, 2.7 ps FWHM electron bunches born in an L-band photoinjector and subsequently accelerated through a nine-cell L-band booster for a resulting energy of 12 MeV. These measurements represent the first observations of self-shaped ellipsoid evolution under postinjector acceleration, a key step in demonstrating the utility of such self-shaped beams at higher energy, where the advantages in both transverse and longitudinal and transverse phase space may be exploited in creating very high brightness beams.
Three-dimensional laser pulse intensity diagnostic for photoinjectors

Directory of Open Access Journals (Sweden)

Heng Li

2011-11-01

Full Text Available Minimizing the electron-beam emittance of photoinjectors is an important task for maximizing the brightness of the next-generation x-ray facilities, such as free-electron lasers and energy recovery linacs. Optimally shaped laser pulses can significantly reduce emittance. A reliable diagnostic for the laser pulse intensity is required for this purpose. We demonstrate measurement of three-dimensional spatiotemporal intensity profiles, with spatial resolution of 20 μm and temporal resolution of 130 fs. The capability is illustrated by measurements of stacked soliton pulses and pulses from a dissipative-soliton laser.
Ultra-Short Electron Beam Compression and Phase Locking Using an Inverse Free Electron Laser Interaction in the THz Regime

International Nuclear Information System (INIS)

Moody, J. T.; Musumeci, P.; Scoby, C. M.; To, H.; Marcoux, C.

2010-01-01

The concept of a THz-based IFEL compressor at the UCLA Pegasus photoinjector laboratory is explored. A 3.5 MeV sub-picosecond electron beam generated in the photoinjector blowout regime can be compressed to femtosecond timescales by a THz IFEL interaction.
The drive laser for the APS LEUTL FEL Rf photoinjector

International Nuclear Information System (INIS)

Arnold, N.; Koldenhoven, R.; Travish, G.

1999-01-01

The APS LEUTL free-electron laser (FEL) is a high-gain, short-wavelength device requiring a high-current, low-emittance beam. An rf photoinjector driven by a laser is used to provide the requisite beam. The drive laser consists of a diode-pumped Nd:Glass oscillator and a chirped pulse amplification (CPA) system consisting of a grating stretcher, a flashlamp-pumped Nd:Glass regenerative amplifier, and a grating compressor. The system generates 4-mj pulses in the R with a pulse length as short as 2 ps FWHM and a repetition rate of 6 Hz. Nonlinear doubling crystals are used to generate fourth-harmonic output of ∼500 microJ in the UV (263 nm), which is required to exceed the work function of the copper cathode in the gun. This paper describes the drive laser as well as the extensive controls implemented to allow for remote operation and monitoring. Performance measurements as well as the operating experience are presented
Radial bunch compression : path-length compensation in an rf photoinjector with a curved cathode

NARCIS (Netherlands)

Loos, de M.J.; Geer, van der S.B.; Saveliev, Y.M.; Pavlov, V.M.; Reitsma, A.J.W.; Wiggins, S.M.; Rodier, J.; Garvey, T.; Jaroszynski, D.A.

2006-01-01

Electron bunch lengthening due to space-charge forces in state-of-the-art rf photoinjectors limits the minimum bunch length attainable to several hundreds of femtoseconds. Although this can be alleviated by increasing the transverse dimension of the electron bunch, a larger initial radius causes
Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector

Energy Technology Data Exchange (ETDEWEB)

Gulliford, Colwyn, E-mail: cg248@cornell.edu; Bartnik, Adam, E-mail: acb20@cornell.edu; Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca [CLASSE, Cornell University, 161 Synchrotron Drive Ithaca, New York 14853-8001 (United States)

2015-03-02

We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (≥100 pC) beams produced in the DC gun-based Cornell energy recovery linac photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittances measured at 9–9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs and Free Electron Lasers.

Criteria for emittance compensation in high-brightness photoinjectors

Directory of Open Access Journals (Sweden)

Chun-xi Wang

2007-10-01

Full Text Available A critical process in high-brightness photoinjectors is emittance compensation, which brings under control the correlated transverse emittance growth due to the linear space-charge force. Although emittance compensation has been used and studied for almost two decades, the exact criteria to achieve emittance compensation is not as clear as it should be. In this paper, a perturbative analysis of slice envelopes and emittance evolution close to any reference envelope is developed, via which space-charge and chromatic effects are investigated. A new criterion for emittance compensation is found, which is complementary to the well-known matching condition for the invariant envelope and agrees very well with simulations.
TREDI simulations for high-brilliance photoinjectors and magnetic chicanes

Directory of Open Access Journals (Sweden)

L. Giannessi

2003-12-01

Full Text Available The TREDI Monte Carlo program is briefly described, devoting some emphasis to the Lienard-Wiechert potentials approach followed to account for self-field effects and the covariant technique devised to achieve regularization of electromagnetic fields. Some guidelines to the choice of the correct parameters to be used in the simulation are also sketched. The predictions obtained for the reference work point of the space-charge compensated SPARC photoinjector and a benchmark chicane designed to study coherent synchrotron radiation effects in a magnetic compressor are compared to those of other well-established simulation codes.
Characterization of a superconducting Pb photocathode in a superconducting rf photoinjector cavity

CERN Document Server

Barday, R; Jankowiak, A; Kamps, T; Knobloch, J; Kugeler, O; Matveenko, A; Neumann, A; Schmeißer, M; Volker, J; Kneisel, P; Nietubyc, R; Schubert S; Smedley J; Sekutowicz, J; Will, I

2014-01-01

Photocathodes are a limiting factor for the next generation of ultrahigh brightness photoinjectors. We studied the behavior of a superconducting Pb cathode in the cryogenic environment of a superconducting rf gun cavity to measure the quantum efficiency, its spatial distribution, and the work function. We will also discuss how the cathode surface contaminants modify the performance of the photocathode as well as the gun cavity and we discuss the possibilities to remove these contaminants.
A sub-picosecond pulsed 5 MeV electron beam system

International Nuclear Information System (INIS)

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

2001-01-01

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

Science.gov (United States)

Filippetto, D.; Bellaveglia, M.; Musumeci, P.; Ronsivalle, C.

2009-07-01

The SPARC photo-injector is an R&D facility dedicated to the production of high brightness electron beams for radiation generation via FEL or Thomson scattering processes. It is the prototype injector for the recently approved SPARX project, aiming at the construction in the Frascati/University of Rome Tor Vergata area of a new high brightness electron linac for the generation of SASE-FEL radiation in the 1-10 nm wavelength range. The first phase of the SPARC project has been dedicated to the e-beam source characterization; the beam transverse and longitudinal parameters at the exit of the gun have been measured, and the photo-injector settings optimized to achieve best performance. Several beam dynamics topics have been experimentally studied in this first phase of operation, as, for example, the effect of photocathode driver laser beam shaping and the evolution of the beam transverse emittance. These studies have been made possible by the use of a novel diagnostic tool, the " emittance-meter" which enables the measurement of the transverse beam parameters at different positions along the propagation axis in the very interesting region at the exit of the RF gun. The new idea of extending the e-meter capabilities came out more recently. Information on the beam longitudinal phase space and correlations with the transverse planes can be retrieved by the slicing technique. In this paper, we illustrate the basic concept of the measurement together with simulations that theoretically validate the methodology. Some preliminary results are discussed and explained with the aid of code simulations.
The drive system of 100 MeV electron linear accelerator

International Nuclear Information System (INIS)

Sun Yuzhen; Su Guoping; Wang Xiulong; Tianlu

1988-06-01

The principle, structure, measurement results and technical performances of microwave drive system for 100MeV electron linear accelerator are presented. In this system the peak power of 15 kW is produced by the S bank middle power klystron. The output power of the klystron is divided into six subdrive lines that drive six high power klystrons respectively. The results show the system with simple structure and good characteristics completely meets the requirements of 100 MeV Linac
Synchronization and Characterization of an Ultra-Short Laser for Photoemission and Electron-Beam Diagnostics Studies at a Radio Frequency Photoinjector

Energy Technology Data Exchange (ETDEWEB)

Maxwell, Timothy; Ruan, Jinhao; Piot, Philippe; Lumpkin, Alex

2012-03-01

A commercially-available titanium-sapphire laser system has recently been installed at the Fermilab A0 photoinjector laboratory in support of photoemission and electron beam diagnostics studies. The laser system is synchronized to both the 1.3-GHz master oscillator and a 1-Hz signal use to trigger the radiofrequency system and instrumentation acquisition. The synchronization scheme and performance are detailed. Long-term temporal and intensity drifts are identified and actively suppressed to within 1 ps and 1.5%, respectively. Measurement and optimization of the laser's temporal profile are accomplished using frequency-resolved optical gating.
Particle-In-Cell/Monte Carlo Simulation of Ion Back Bombardment in Photoinjectors

International Nuclear Information System (INIS)

Qiang, Ji; Corlett, John; Staples, John

2009-01-01

In this paper, we report on studies of ion back bombardment in high average current dc and rf photoinjectors using a particle-in-cell/Monte Carlo method. Using H 2 ion as an example, we observed that the ion density and energy deposition on the photocathode in rf guns are order of magnitude lower than that in a dc gun. A higher rf frequency helps mitigate the ion back bombardment of the cathode in rf guns
Detection and clearing of trapped ions in the high current Cornell photoinjector

Directory of Open Access Journals (Sweden)

S. Full

2016-03-01

Full Text Available We have recently performed experiments to test the effectiveness of three ion-clearing strategies in the Cornell high intensity photoinjector: DC clearing electrodes, bunch gaps, and beam shaking. The photoinjector reaches a new regime of linac beam parameters where high continuous wave beam currents lead to ion trapping. Therefore ion mitigation strategies must be evaluated for this machine and other similar future high current linacs. We have developed several techniques to directly measure the residual trapped ions. Our two primary indicators of successful clearing are the amount of ion current removed by a DC clearing electrode, and the absence of bremsstrahlung radiation generated by beam-ion interactions. Measurements were taken for an electron beam with an energy of 5 MeV and continuous wave beam currents in the range of 1–20 mA. Several theoretical models have been developed to explain our data. Using them, we are able to estimate the clearing electrode voltage required for maximum ion clearing, the creation and clearing rates of the ions while employing bunch gaps, and the sinusoidal shaking frequency necessary for clearing via beam shaking. In all cases, we achieve a maximum ion clearing of at least 70% or higher, and in some cases our data is consistent with full ion clearing.
Technical Design and Optimization Study for the FERMI at Elettra FEL Photoinjector

International Nuclear Information System (INIS)

Lidia, Steven M.; Penco, Giuseppe; Trovo', Mauro

2006-01-01

The FERMI (at) Elettra FEL project will provide a novel, x-ray free electron laser user facility at Sincrotrone Trieste based on seeded and cascade FEL techniques. The electron beam source and injector systems play a crucial role in the success of the facility by providing the highest quality electron beams to the linac and FEL undulators. This Technical Note examines the critical technology components that make up the injector system, and demonstrates optimum beam dynamics solutions to achieve the required high quality electron beams. Section 2 provides an overview of the various systems and subsystems that comprise the photoinjector. The different operating modes of the injector are described as they pertain to the different linac configurations driven by the FEL and experimental design. For each mode, the required electron beam parameters are given. Sections 3 and 4 describe the critical beamline elements in the injector complex: the photocathode and drive laser, and the RF gun. The required drive laser parameters are given at the end of Section 3. Additional details on the design of the photoinjector drive laser systems are presented in a separate Technical Note. Design considerations for the RF gun are extensively presented in Section 4. There, we describe the variation of the cavity geometry to optimize the efficiency of the energy transfer to the electron beam. A study of the power coupling into the various cavity modes that interact within the bandwidth of the RF drive pulse is presented, followed by a study of the transient cavity response under several models and, finally, the effects on extracted beam quality. Section 5 describes the initial design for the low energy, off-axis diagnostic beamline. Beam dynamics simulations using ASTRA, elegant, and MAD are presented. Section 6 presents the optimization studies for the beam dynamics in the various operating modes. The optimized baseline configurations for the beamline and incident drive laser pulse are
Remote Operation of the Fermilab/NICADD Photoinjector

International Nuclear Information System (INIS)

Barov, Nikolai

2002-01-01

The recognition that a new major HEP facility must receive international support and that its execution would benefit from worldwide interaction from design through operation has given rise to the term Global Accelerator Network (GAN). A welcome consequence has been a more permissive attitude toward remote operation of existing facilities.For roughly thirty years, the computer has been the principal operator interface to the beam,and, through the development of the Internet, the operator can be literally anywhere. In this note, the authors describe their approach to enabling a sufficient degree of operation of the photoinjector from afar in order to carry out investigations in beam physics. The goal was to do so on a time scale of a few months and at minimal cost. At this writing, remote shifts are routinely scheduled involving DESY and LBL, limited in frequency only by the requests of the collaborators and by the need for time to interpret the data
Etude Experimentale du Photo-Injecteur de Fermilab

Energy Technology Data Exchange (ETDEWEB)

Carneiro, Jean-Paul [Orsay

2001-01-01

TESLA (TeV Superconducting Linear Accelerator) is an international collaboration which is studying the feasibility of an $e^+e^-$ collider of energy 0.8 TeV in the center of mass. One of the first goals of this collaboration was to construct a prototype linear accelerator at the DESY Laboratory in Hamburg, the TESLA Test Facility (TTF), in order to establish the technical basis for the collider. Two injectors were developed for TTF: a thermionic injector (developed by LAL-Orsay, IPN-Orsay, and CEA-Saclay) and a photo-injector (developed by Fermilab). The thermionic injector was used from February 1997 to October 1998, and then it was replaced by the photo-injector, which was first operated in December 1998. Another photo-injector, identical to the one delivered to TTF, was installed at Fermilab in the $A{\\emptyset}$ Building. The first beam from the latter was produced on 3 March 1999. The photo-injector consists of an RF gun, followed by a superconducting cavity. The RF gun is a 1.625-cell copper cavity with a resonant frequency of 1.3 GHz. The gun contains a cesium telluride ($C_{s_2}$Te) photo-cathode, which is illuminated by UV pulses from a Nd:YLF laser. The system can produce trains of 800 bunches of photo-electrons of charge 8 nC per bunch with spacing between bunches of 1$\\mu$s and 10 Hz repetition rate. Upon emerging from the RF gun, the beam energy is 4 to 5 MeV; the beam is then rapidly accelerated by the superconducting cavity to an energy of 17 to 20 MeV. Finally, a magnetic chicane, consisting of 4 dipoles, produces longitudinal compression of the electron bunches. This thesis describes the installation of the photo-injector at Fermilab and presents the experimentally-measured characteristics of the injector. The principal measurements were quantum eciency, dark current, transverse emittance, and bunch length. The conclusion from these studies is that the quality of the photo-injector beam fullls the design goals. The photo-injector at Fermilab is
Charge measurement system at 100 MeV linac

International Nuclear Information System (INIS)

Li Dongmei; Chinese Academy of Sciences, Beijing; Yin Chongxian; Ye Kairong

2005-01-01

A charge measurement system of 100 Mev linac is introduced in this paper. After describing the characteristics and functions of the system's components, the authors analyze the methods of data processing and systematic error in detail. Basing on these, the authors get system resolution in the lab. The actual measurement results are presented at last. (authors)
Software of the System Protection for the PEFP 20MeV Proton Linac

International Nuclear Information System (INIS)

Song, Young-Gi; Hong, In-Seok; Cho, Yong-Sub

2007-01-01

A 20 MeV proton linear accelerator (linac) has been developed at Proton Engineering Frontier Project (PEFP). A 20 MeV linac consists of 50 keV proton injector, 3 MeV radio frequency quadrupole (RFQ), and 20 MeV drift tube linac (DTL). PEFP control system is developed with several sub-systems (e.g. machine control, diagnostic control, timing control, and interlock systems). These systems have each EPICS based control system which provides a network-based real time distributed control. For stable and harmonic operation, we had developed sequential logic by using state notation language (SNL) and database records with alarm fields for warning signal. The various control system can drop a transmission rate of the control network traffic. We need to manage control signals by a control network gateway and protect values of control servers by security management. In this paper, the stabilization methods of the control signals are described and the results of the stabilized signals are presented
Longitudinal phase space characterization of the blow-out regime of rf photoinjector operation

OpenAIRE

J. T. Moody; P. Musumeci; M. S. Gutierrez; J. B. Rosenzweig; C. M. Scoby

2009-01-01

Using an experimental scheme based on a vertically deflecting rf deflector and a horizontally dispersing dipole, we characterize the longitudinal phase space of the beam in the blow-out regime at the UCLA Pegasus rf photoinjector. Because of the achievement of unprecedented resolution both in time (50 fs) and energy (1.0 keV), we are able to demonstrate some important properties of the beams created in this regime such as extremely low longitudinal emittance, large temporal energy chirp, and ...
Investigation of fundamental limits to beam brightness available from photoinjectors

International Nuclear Information System (INIS)

Bazarov, Ivan

2015-01-01

The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.
Investigation of fundamental limits to beam brightness available from photoinjectors

Energy Technology Data Exchange (ETDEWEB)

Bazarov, Ivan [Cornell Univ., Ithaca, NY (United States)

2015-07-09

The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.
Nanometer emittance ultralow charge beams from rf photoinjectors

Directory of Open Access Journals (Sweden)

R. K. Li

2012-09-01

Full Text Available In this paper we discuss the generation of a new class of high brightness relativistic electron beams, characterized by ultralow charge (0.1–1 pC and ultralow normalized emittance (<50 nm. These beams are created in rf photoinjectors when the laser is focused on the cathode to very small transverse sizes (<30 μm rms. In this regime, the charge density at the cathode approaches the limit set by the extraction electric field. By shaping the laser pulse to have a cigarlike aspect ratio (the longitudinal dimension much larger than the transverse dimension and a parabolic temporal profile, the resulting space charge dominated dynamics creates a uniformly filled ellipsoidal distribution and the emittance can be nearly preserved to its thermal value. We also present a new method, based on a variation of the pepper-pot technique, for single shot measurements of the ultralow emittances for this new class of beams.
Production of Transverse Controllable Laser Density Distribution in Fermilab/NICADD Photoinjector

CERN Document Server

Li, Jianliang; Tikhoplav, Rodion

2005-01-01

The Fermilab/NICADD photoinjector laboratory consist of a photoemission electron source based on an L band rf-gun. The CsTe photocathode is illuminated by an ultrashort UV laser. The transport line from the laser to the photocathode was recently upgraded to allow imaging of an object plane located ~20 m from the photocathode. This upgrade allows the generation of transverse laser distributions with controlled nonuniformity, yielding the production of an electron beam with various transverse densities patterns. Measuring the evolution of the artificial pattern on the electron bunch provides information that can be used to benchmark numerical simulations and investigate the impact of space charge. Preliminary data on these investigations are presented in the present paper.
The RF system for the 70 MeV linac injector

International Nuclear Information System (INIS)

Planner, C.W.

1975-12-01

The Radio Frequency System for the 70 MeV Linac Injector for Nimrod is required to power the four Accelerating Cavities and the Buncher and Debuncher Cavities. The frequency of operation is 202.5 MHz and is determined by the use of existing equipment from the redundant 50 MeV Proton Linac for the second and third accelerating cavities and the buncher and de-buncher cavities. The subject is discussed under the following headings: low power drive chain; RF feed lines; cavity field level stabilisation. Circuit diagrams are presented. (U.K.)

70 MeV injector auto tuning system handbook

International Nuclear Information System (INIS)

Ellis, J.E.; Munn, R.W.; Sandels, E.G.

1976-06-01

The handbook is in three sections: (1) description and location; (2) operating instructions; and (3) design notes on the tank and debuncher auto tuning systems for the 70 MeV injector. The purpose of the auto tuning system is to maintain the 'tune' of the four tanks and debuncher to within a few Hz, stabilizing against changes of temperature and other physical factors affecting the resonant frequency of the tanks. (U.K.)
7.5 MeV High Average Power Linear Accelerator System for Food Irradiation Applications

International Nuclear Information System (INIS)

Eichenberger, Carl; Palmer, Dennis; Wong, Sik-Lam; Robison, Greg; Miller, Bruce; Shimer, Daniel

2005-09-01

In December 2004 the US Food and Drug Administration (FDA) approved the use of 7.5 MeV X-rays for irradiation of food products. The increased efficiency for treatment at 7.5 MeV (versus the previous maximum allowable X-ray energy of 5 MeV) will have a significant impact on processing rates and, therefore, reduce the per-package cost of irradiation using X-rays. Titan Pulse Sciences Division is developing a new food irradiation system based on this ruling. The irradiation system incorporates a 7.5 MeV electron linear accelerator (linac) that is capable of 100 kW average power. A tantalum converter is positioned close to the exit window of the scan horn. The linac is an RF standing waveguide structure based on a 5 MeV accelerator that is used for X-ray processing of food products. The linac is powered by a 1300 MHz (L-Band) klystron tube. The electrical drive for the klystron is a solid state modulator that uses inductive energy store and solid-state opening switches. The system is designed to operate 7000 hours per year. Keywords: Rf Accelerator, Solid state modulator, X-ray processing
Ultra-High Density Electron Beams for Beam Radiation and Beam Plasma Interaction

CERN Document Server

Anderson, Scott; Frigola, Pedro; Gibson, David J; Hartemann, Fred V; Jacob, Jeremy S; Lim, Jae; Musumeci, Pietro; Rosenzweig, James E; Travish, Gil; Tremaine, Aaron M

2005-01-01

Current and future applications of high brightness electron beams, which include advanced accelerators such as the plasma wake-field accelerator (PWFA) and beam-radiation interactions such as inverse-Compton scattering (ICS), require both transverse and longitudinal beam sizes on the order of tens of microns. Ultra-high density beams may be produced at moderate energy (50 MeV) by compression and subsequent strong focusing of low emittance, photoinjector sources. We describe the implementation of this method used at LLNL's PLEIADES ICS x-ray source in which the photoinjector-generated beam has been compressed to 300 fsec duration using the velocity bunching technique and focused to 20 μm rms size using an extremely high gradient, permanent magnet quadrupole (PMQ) focusing system.
Experimental investigation of the longitudinal beam dynamics in a photoinjector using a two-macroparticle bunch

Directory of Open Access Journals (Sweden)

P. Piot

2006-05-01

Full Text Available We have developed a two-macroparticle bunch to explore the longitudinal beam dynamics through various components of the Fermilab/NICADD photoinjector. Such a two-macroparticle bunch is generated by splitting the ultraviolet pulse from the photocathode drive laser. The presented method allows the exploration of radio-frequency-induced compression in the 1.625 cell radio frequency gun and the booster cavity. It also allows a direct measurement of the momentum compaction of the magnetic bunch compressor. The measurements are compared with analytical and numerical models.
Development of an MeV ion beam lithography system in Jyvaeskylae

Energy Technology Data Exchange (ETDEWEB)

Gorelick, Sergey [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland)]. E-mail: Sergey.Gorelick@phys.jyu.fi; Ylimaeki, Tommi [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland); Sajavaara, Timo [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland); Laitinen, Mikko [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland); Sagari, A.R.A. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland); Whitlow, Harry J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FIN-40014 (Finland)

2007-07-15

A lithographic facility for writing patterns with ion beams from cyclotron beams is under development for the Jyvaeskylae cyclotron. Instead of focusing and deflecting the beam with electrostatic and magnetic fields a different approach is used. Here a small rectangular beam spot is defined by the shadow of a computer-controlled variable aperture in close proximity to the sample. This allows parallel exposure of rectangular pattern elements of 5-500 {mu}m side with protons up to 6 MeV and heavy ions ({sup 20}Ne, {sup 85}Kr) up to few 100 MeV. Here we present a short overview of the system under construction and development of the aperture design, which is a critical aspect for all ion beam lithography systems.
Longitudinal phase space characterization of the blow-out regime of rf photoinjector operation

Directory of Open Access Journals (Sweden)

J. T. Moody

2009-07-01

Full Text Available Using an experimental scheme based on a vertically deflecting rf deflector and a horizontally dispersing dipole, we characterize the longitudinal phase space of the beam in the blow-out regime at the UCLA Pegasus rf photoinjector. Because of the achievement of unprecedented resolution both in time (50 fs and energy (1.0 keV, we are able to demonstrate some important properties of the beams created in this regime such as extremely low longitudinal emittance, large temporal energy chirp, and the degrading effects of the cathode image charge in the longitudinal phase space which eventually leads to poorer beam quality. All of these results have been found in good agreement with simulations.
Status of PPI (Pohang Photo-Injector) for PAL XFEL

CERN Document Server

Park, Sung-Ju; Oh, Jong-Seok; Park, Chong-Do; Park Jang Ho; Soo Ko In; Wang, Xijie; Woon Parc, Yong

2005-01-01

A X-Ray Free Electron Laser (XFEL) project based on the Self-Amplified Spontaneous Emission (SASE) is under progress at the Pohang Accelerator Laboratory (PAL). One of the critical R&D for the PAL XFEL* is to develop the Pohang Photo-Injector (PPI) which is required to deliver electron beams with normalized emittance < 1.5 mm-mrad. In order to achieve the required beam quality with high stability and reliability, we will use photocathode with quantum efficiency > 0.1 % and long lifetime. This will greatly lessen the laser energy requirement for producing flat-top UV pulses, and open the possibility of using only regenerative amplifiers (RGAs) to drive the photocathode RF gun. The RGAs can produce mJs output with much better stability than multi-pass amplifiers. Both the Cs2Te and Mg are under consideration for the possible photo-cathode. To demonstrate the suitability of the Mg and Cs2Te for the future 4th generation light source application, an improved BNL-type S-band RF gun with a high-pe...
Design of W-Band photoinjector

International Nuclear Information System (INIS)

Zhu, Xiongwei; Nakajima, Kazuhisa

2000-01-01

We present a design study on W-Band photocathode RF gun which is capable of generating and accelerating 300 pC electron bunch. The design system is made up of 91.392 GHz photocathode RF gun and 91.392 GHz travelling wave linac cells. Based on the numerical simulation using SUPERFISH and PARMELA and the conventional RF linac scaling law, the design will produce 300 pC at 1.74 MeV with bunch length 0.72 ps and normalized tranverse emittance 0.5 mm mrad. We study the beam dynamics in high frequency and high gradient; due to the high gradient, the pondermotive effect plays an important role in beam dynamics; we found the pondermotive effect still exist with only the fundamental space harmonics (synchrotron mode) due to the coupling of the transverse and longitudinal motion. (author)
Conceptual design of 30 MeV magnet system used for BNCT epithermal neutron source

International Nuclear Information System (INIS)

Slamet Santosa; Taufik

2015-01-01

Conceptual design of 30 MeV Magnet System Used for BNCT Epithermal Neutron Source has been done based on methods of empirical model of basic equation, experiences of 13 MeV cyclotron magnet design and personal communications. In the field of health, cyclotron can be used as an epithermal neutron source for Boron Neutron Capture Therapy (BNCT). The development of cyclotron producing epithermal neutrons for BNCT has been performed at Kyoto University, of which it produces a proton beam current of 1.1 mA with energy of 30 MeV. With some experiences on 13 MeV cyclotron magnet design, to support BNCT research and development we performed the design studies of 30 MeV cyclotron magnet system, which is one of the main components of the cyclotron for deflecting proton beam into circular trajectory and serves as beam focusing. Results of this study are expected to define the parameters of particular cyclotron magnet. The scope of this study includes the study of the parameters component of the 30 MeV cyclotron and magnet initial parameters. The empirical method of basic equation model is then corroborated by a simulation using Superfish software. Based on the results, a 30 MeV cyclotron magnet for BNCT neutron source enables to be realized with the parameters of B 0 = 1.06 T, frequency RF = 64.733938 ≈ 65 MHz, the external radius of 0.73 m, the radius of the polar = 0.85 m, BH = 1.95 T and a gap hill of 4 cm. Because proton beam current that be needed for BNCT application is very large, then in the calculation it is chosen a great focusing axial νz = 0.630361 which can generate B V = 0.44 T. (author)
Numerical and experimental study of the beam dynamics of CANDELA photo-injector and associated instrumentation; Etude numerique et experimentale de la dynamique du faisceau du photo-injecteur CANDELA et instrumentation associee

Energy Technology Data Exchange (ETDEWEB)

Devanz, Guillaume [Paris-6 Univ., 95 Paris (France)

1999-03-04

Laser triggered radiofrequency guns are the most luminous electron sources allowing to reach the performances requested by highly demanding applications like the e{sup +}/e{sup -}linear colliders and the short wave free electron lasers. CANDELA is a band S photo-injector triggered by a sub-picosecond laser. It allows reaching peak currents of hundred of amperes at average energies higher than 2 MeV. The original concept of two accelerating cavities aims at minimizing the transverse and longitudinal emittances following the Gao's principles. From practical reasons the operating parameters, particularly the laser pulse duration, do not correspond to those considered in the design. Hence, numerical simulations were performed to evaluate the gun's performances in experimental environment. The study of a stabile injector operation resulted in evolutions with consequences in the phase control systems implying the laser and the HF (Hyper Frequency) source. The beam transverse and longitudinal characteristics have been measured as a function of the main parameters i.e., the beam charge and the phase shift between the laser and the HF wave. Measurements of the transverse emittance energy dispersion and wave packed duration are presented for several injector configurations. The systems of existing beam measurements have been studied to determine the resolution and the experimental conditions to fulfill, in order to suggest improvements for the CANDELA beam. The experiments with the beam have been compared with numerical simulations. Agreement was obtained within wide ranges of parameters for most of the characteristic beam quantities.
Gamma and X-rays Production for Experiments at ELSA Facility

CERN Document Server

Lemaire, J

2004-01-01

The ELSA facility is a high brightness 18 MeV electron source dedicated to electron radiation, gamma-rays and picosecond hard and soft X-rays. It consists of a 144 MHz RF photoinjector producing short bunches which are further accelerated to a final energy varying from 2 to 18 MeV thanks to three 433 MHz RF cavities. Former beam compression design used a half turn magnet compressor system. It has been recently replaced by a double alpha magnet compressor. Electron beams are now delivered to a new experimental room. We present the new panel of interests offered by this facility in term of gamma-ray and X-ray production.
Measurements of pp→π+d between 398 MeV and 572 MeV

International Nuclear Information System (INIS)

Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.-C.; Rapin, D.; Werren, D.W.

1976-01-01

The reaction pp→π + d was studied at incident proton energies of 398, 455, 497, 530 and 572 MeV. Measurements of dsigma/dΩ at 455 and 572 MeV show the presence of pion d-waves in the pion-deuteron system. Asymmetry measurements yield similar conclusions. Total cross-section measurements agree with recent fits to earlier data. (Auth.)
Kelvin probe studies of cesium telluride photocathode for AWA photoinjector

Energy Technology Data Exchange (ETDEWEB)

Wisniewski, Eric E., E-mail: ewisniew@anl.gov [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Velazquez, Daniel [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Yusof, Zikri, E-mail: zyusof@hawk.iit.edu [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Spentzouris, Linda; Terry, Jeff [Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Sarkar, Tapash J. [Rice University, 6100 Main, Houston, TX 77005 (United States); Harkay, Katherine [Accelerator Science Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States)

2013-05-21

Cesium telluride is an important photocathode as an electron source for particle accelerators. It has a relatively high quantum efficiency (>1%), is sufficiently robust in a photoinjector, and has a long lifetime. This photocathode is grown in-house for a new Argonne Wakefield Accelerator (AWA) beamline to produce high charge per bunch (≈50nC) in a long bunch train. Here, we present a study of the work function of cesium telluride photocathode using the Kelvin probe technique. The study includes an investigation of the correlation between the quantum efficiency and the work function, the effect of photocathode aging, the effect of UV exposure on the work function, and the evolution of the work function during and after photocathode rejuvenation via heating. -- Highlights: ► The correlation between Quantum Efficiency (QE) and work function. ► How QE and work function evolve together. ► Rejuvenation of the photocathode via heating and the effect on work function. ► The effects on the work function due to exposure to UV light.
Experimental studies on coherent synchrotron radiaiton in the emittance exchange line at the Fermilab A0 Photoinjector

International Nuclear Information System (INIS)

Thangaraj, J.C.T.; Keup, R.; Johnson, A.; Ruan, J.; Piot, P.; Church, M.; Edwards, H.; Lumpkin, A.; Sun, Y.-E.; Santucci, J.

2011-01-01

Future accelerators will employ advanced beam conditioning systems such as emittance exchangers to manipulate high brightness beams. Coherent synchrotron radiation (CSR) in the dipoles could limit the performance of the emittance exchanger. In this paper, we report the experimental studies on measuring CSR and its effects on the beam at the A0 photoinjector in the emittance exchange line. After reporting the CSR power measurements, we report on the diagnostic scheme based on a weak skew quad in the emittance exchange line to study the CSR effects on the beam and other beam dynamics. In this work, we have reported on CSR measurements and the effect of skew quad on the dogleg line with the 5-cell turned on and off. We plan to study CSR effects on the bunch with the 5-cell on at larger chirp. This is will not only increase the CSR self-effect but also reduce the beamsize at the screen for convenient beamsize measurements.
Pulse compression system for the ANL 20 MeV linac

International Nuclear Information System (INIS)

Mavrogenes, G.; Norem, J.; Simpson, J.

1986-01-01

This paper describes the pulse compression system being built on the Argonne 20 MeV electron linac. The system is designed to rotate the bunch from the present measured pulse length of 38 psec FWHM, to pulse lengths of 5 to 6 ps with the large instantaneous currents (1 to 4 kA) possible instantaneous current. This system was necessary to extend the study of reactive fragments of molecules to the time scale of a few picoseconds, in particular to examine the chemistry of electrons and ions before and during relaxation of the surrounding media. These experiments are not sensitive to the beam energy spread, High Energy Physics experiments studying wake fields have also been proposed using the short bunches and the facility was designed so that the wake field experiment could share the beam bunching system. The 20 MeV electron linac uses a double gap, 12th subharmonic prebuncher together with a one wavelength 1.3 Ghz prebuncher to produce a single pulse of 38 ps from one occupied rf bucket. Beam emittances of 15.7 mmmr have been measured for 40 nC of accelerated charge and 8 mmmr at 10 nC. The energy spread of dE/E = 1% (FWHM) has been measured at 40 nC. Thus the accelerated beam has excellent time structure, high current, and good emittance
Radial bunch compression: Path-length compensation in an rf photoinjector with a curved cathode

Directory of Open Access Journals (Sweden)

M. J. de Loos

2006-08-01

Full Text Available Electron bunch lengthening due to space-charge forces in state-of-the-art rf photoinjectors limits the minimum bunch length attainable to several hundreds of femtoseconds. Although this can be alleviated by increasing the transverse dimension of the electron bunch, a larger initial radius causes path-length differences in both the rf cavity and in downstream focusing elements. In this paper we show that a curved cathode virtually eliminates these undesired effects. Detailed numerical simulations confirm that significantly shorter bunches are produced by an rf photogun with a curved cathode compared to a flat cathode device. The proposed novel method will be used to provide 100 fs duration electron bunches for injection into a laser-driven plasma wakefield accelerator.
A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

CERN Document Server

Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

2005-01-01

American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.
Time dependent formulation of the energy loss by an accelerated intense electron beam just emitted by the cathode of RF-FEL photoinjector

Energy Technology Data Exchange (ETDEWEB)

Salah, Wa' el [Physics Department, Hashemite University, Zarqa 13115 (Jordan)]. E-mail: wael_salahh@hotmail.com; Coacolo, J.-L. [Institut de Physique Nucleaire d' Orsay, 91406 Orsay Cedex (France); Hallak, A.B. [Physics Department, Hashemite University, Zarqa 13115 (Jordan); Al-Obaid, M. [Physics Department, Hashemite University, Zarqa 13115 (Jordan)

2006-08-01

The energy loss by an accelerated electron bunch of a conical shape propagating in the laser-driven RF-photoinjector is expressed in terms of an expansion of the vector and scalar potentials into a series of eigenfunctions of the empty unit 'pill-box' cavity. A versatile and simple analytical formula which can be easily applied to a bunch of any shape is obtained.
Status of the SPARC Project

CERN Document Server

Serafini, Luca; Alessandria, Franco; Bacci, Alberto; Bellaveglia, Marco; Bertolucci, Sergio; Biagini, Maria; Boni, Roberto; Boscolo, Ilario; Boscolo, Manuela; Broggi, Francesco; Castellano, Michele; Catani, Luciano; Chiadroni, Enrica; Cialdi, Simone; Cianchi, Alessandro; Ciocci, Franco; Clozza, Alberto; Dattoli, Giuseppe; De Martinis, Carlo; Di Pirro, Giampiero; Dipace, Antonio; Doria, Andrea; Dowell, David; Drago, Alessandro; Emma, Paul; Esposito, Adolfo; Ferrario, Massimo; Ficcadenti, L; Filippetto, Daniele; Flora, F; Fusco, Valeria; Gabrielli, E; Gallerano, Gian P; Gallo, Alessandro; Gatti, Giancarlo; Ghigo, Andrea; Giannessi, Luca; Giove, Dario; Giovenale, Emilio; Guiducci, Susanna; Incurvati, Maurizio; Levi, Decio; Ligi, Carlo; Limborg-Deprey, Cecile; Marcellini, Fabio; Maroli, Cesare; Mattioli, Mario; Mauri, Marco; Medici, G; Messina, Giovanni; Migliorati, Mauro; Mostacci, Andrea; Musumeci, Pietro; Nisoli, Mauro; Ottaviani, P L; Pagnutti, Simonetta; Palumbo, Luigi; Parisi, Giovanni; Pellegrino, Luigi; Pelliccia, Daniele; Petrarca, Massimo; Petrillo, Vittoria; Picardi, Luigi; Preger, Miro; Quattromini, Marcello; Renieri, Alberto; Ricci, Ruggero; Rome, Massimiliano; Ronci, G; Ronsivalle, Concetta; Rosenzweig, James E; Rosetti, Maurizio; Sabia, Elio; Sanelli, Claudio; Sassi, Mauro; Serio, Mario; Sgamma, Francesco; Spataro, Bruno; Stagira, Salvatore; Stecchi, Alessandro; Stella, Angelo; Tazzari, Sergio; Tazzioli, Franco; Thomas Palmer, Dennis; Torre, A; Vaccarezza, Cristina; Vescovi, Mario; Vicario, Carlo; Zucchini, Alberto; de Silvestri, Sandro

2005-01-01

The SPARC project has entered its installation phase at INFN-LNF: its main goal is the promotion of an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments. The design of the 150 MeV photoinjector has been completed and the construction of its main components is in progress, as well as the design of the 12 m undulator. In this paper we will report on the installation and test of some major components, like the Ti:Sa laser system to drive the photo-cathode, the RF gun, the RF power system, as well as some test results on the RF deflector and 4th harmonic X-band cavity prototypes. Advancements in the control and beam diagnostics systems will also be reported, in particular on the emittance-meter device for beam emittance measurements in the drift space downstream the RF gun. Recent results on laser pulse shaping, obtained with two alternative techniques (DAZZLER and Liquid Crystal Mask), show the feasibility of producing 10 ps flat-top laser pulses in the...
Observation and simulation of space-charge effects in a radio-frequency photoinjector using a transverse multibeamlet distribution

Directory of Open Access Journals (Sweden)

M. Rihaoui

2009-12-01

Full Text Available We report on an experimental study of space-charge effects in a radio-frequency (rf photoinjector. A 5 MeV electron bunch, consisting of a number of beamlets separated transversely, was generated in an rf photocathode gun and propagated in the succeeding drift space. The collective interaction of these beamlets was studied for different experimental conditions. The experiment allowed the exploration of space-charge effects and its comparison with 3D particle-in-cell simulations. Our observations also suggest the possible use of a multibeam configuration to tailor the transverse distribution of an electron beam.

Control system for 10 MeV irradiation electron linac

International Nuclear Information System (INIS)

Zeng Ziqiang; Zhang Lifeng; Lu Weixing; Gao Zhenjiang; Zhang Yan; Han Guangwen; Wang Shuxian

2005-01-01

Control system of the 10 MeV electron linac using Distributed Control System (DCS) was studied. The hardware of control system consists of four SIEMENS PLCs and monitor computer, the software bases on STEP 7, Labwindows/CVI and SQL Server. The bus between the monitor computer and the main PLC is 100 M industrial networks, between PLCs is MPI bus, between PLC and remote partner is PROFIBUS, between PLC and terminals is RS485/422. The software of control system can provide a friendly human machine interface to operate the machine, protect the human and equipment from risk, and storage the status of the accelerator real time to the database. The monitor and maintenance of the linac can been carried out not only on local computer or local network, but also in internet. (author)
Electron Cooling of RHIC

CERN Document Server

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

2005-01-01

We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...
Instrumentation and control system for PLS-IM-T 60 MeV LINAC

International Nuclear Information System (INIS)

Liu, D.K.; Yei, K.R.; Cheng, H.J.

1992-01-01

The PLSIMT is a 60 MeV LINAC as a preinjector for 2 GeV LINAC of PLS project. The instrumentation and control system have been designed under the institutional collaboration between the IHEP (Beijing, China) and POSTECH (Pohang, Korea). So far, the I and C system are being set up nowadays at the POSTECH of Pohang. This paper describes its major characteristics and present status. (author)
Development of quasi-monochromatic p-7Li neutron generating system for 80-210 MeV

International Nuclear Information System (INIS)

Nakao, Noriaki; Shibata, Tokushi; Nakamura, Takashi; Uwamino, Yoshitomo; Nakanishi, Noriyoshi; Kurosawa, Tadahiro; Kim, Unju.

1996-01-01

Recently the requirements for the experimental data on the response characteristics of neutron detector and the cross section for neutron generation by charged particles have been increasing for shield designing. Here, a system for quasi-monochromatic neutron generation was developed in the facility of ring-cyclotron in Institute of Physical and Chemical Sciences. In this study, H 2 + accelerated to an energy range of 80-135 MeV/n and P + to 150-210 MeV was irradiated to E4 beam course and NE102A plastic scintillator was used for monitoring the neutron flux. The amount of neutrons generated was estimated from the radioactivity of 7 Be produced in 7 Li-target. The neutron spectres thus estimated as an energy range of 80-210 MeV were presented and the lower limit of these spectres was about 20 MeV. The peaks in the range of 150 and 210 MeV were comparatively wide because of the inferiority of energy resolving power at a higher energy level. (M.N.)
Human machine interface based on labview for vacuum system operation of cyclotron proton DECY-13 MeV

International Nuclear Information System (INIS)

Fajar Sidik Permana; Saminto; Kurnia Wibowo; Vika Arwida Fanita Sari

2016-01-01

Center of Accelerator Science and Technology (CAST), BATAN is designing DECY-13 MeV Proton Cyclotron. So far, this operation system has been conducted conventionally. In this research, an Human Machine Interface system has been successfully built for simplifying operation and monitoring pressure inside vacuum chamber of cyclotron DECY-13 MeV. HMI system is built with LabVIEW software and integrated with Programmable Logic Controller FX-2424 series and NI cRIO (NI-9025 and NI-9870) module. HMI system consist of turning on/of pumps (rotary and diffusion), opening/ closing valve automatically, and retrieving of data from sensor in real time. (author)
The ORION Facility

International Nuclear Information System (INIS)

Noble, Robert

2003-01-01

ORION will be a user-oriented research facility for understanding the physics and developing the technology for future high-energy particle accelerators, as well as for research in related fields. The facility has as its centerpiece the Next Linear Collider Test Accelerator (NLCTA) at the Stanford Linear Accelerator Center (SLAC). The NLCTA will be modified with the addition of a new, high-brightness photoinjector, its drive laser, an S-band rf power system, a user laser room, a low-energy experimental hall supplied with electron beams up to 60 MeV in energy, and a high-energy hall supplied with beams up to 350 MeV. The facility design and parameters are described here along with highlights from the 2nd ORION Workshop held in February 2003
An Observation of a Transverse to Longitudinal Emittance Exchange at the Fermilab A0 Photoinjector

Energy Technology Data Exchange (ETDEWEB)

Koeth, Timothy W [State Univ. of New Jersey, New Brunswick, NJ (United States)

2009-05-01

An experimental program to perform a proof of principle of transverse to longitudinal emittance exchange (ϵ_{x_in} ↔ ϵ_{z_out} and ϵ_{x_in} ↔ ϵ_{z_out}) has been developed at the Fermilab A0 Photoinjector. A new beamline, including two magnetic dogleg channels and a TM₁₁₀ deflecting mode radio frequency cavity, were constructed for the emittance exchange experiment. The first priority was a measurement of the Emittance Exchange beamline transport matrix. The method of difference orbits was used to measure the transport matrix. Through varying individual beam input vector elements, such as x_in, x'_in, y_in, y'_in, z_in, or δ_in, and measuring the changes in all of the beam output vector's elements, x_out, x'_out, y_out, y'_out, z_out, δ_out, the full 6 x 6 transport matrix was measured. The measured emittance exchange transport matrix was in overall good agreement with our calculated transport matrix. A direct observation of an emittance exchange was performed by measuring the electron beam's characteristics before and after the emittance exchange beamline. Operating with a 14.3 MeV, 250pC electron bunch, ϵ_{z_in} of 21.1 ± 1.5 mm • mrad was observed to be exchanged with ϵ_{x_out} of 20.8 ± 2.00 mm • mrad. Diagnostic limitations in the ϵ_{z_out} measurement did not account for an energy-time correlation, thus potentially returning values larger than the actual longitudinal emittance. The ϵ_{x_in} of 4.67 ± 0.22 mm • mrad was observed to be exchanged with ϵ_{z_out} of 7.06 ± 0.43 mm • mrad. The apparent ϵ_{z_out}growth is consistent with calculated values in which the correlation term is neglected.
Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

International Nuclear Information System (INIS)

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

1996-07-01

The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm 3 thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm 3 active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response
Hot composite systems with a > 200 and T > 6 MeV

International Nuclear Information System (INIS)

Crema, E.; Bresson, S.; Doubre, H.; Galin, J.; Guerreau, D.; Morjean, M.; Piasecki, E.; Pouthas, J.; Saint-Laurent, F.; Sokolov, A.; Wang, X.M.; Gatty, B.; Jacquet, D.; Piasecki, E.; Crema, E.; Wang, X.M.

1990-01-01

Neutron multiplicities have been measured in coincidence with the light charged particles evaporated in the backward direction for the reaction 84 Kr+ 197 Au at 32 MeV/u. A method is presented which makes possible an evaluation of the recoil velocity, excitation energy and temperature of hot and thermalized heavy composite systems formed for different impact parameters. Temperatures larger than 6 MeV are found for the most dissipative collisions
Development of Compton gamma-ray sources at LLNL

Energy Technology Data Exchange (ETDEWEB)

Albert, F.; Anderson, S. G.; Ebbers, C. A.; Gibson, D. J.; Hartemann, F. V.; Marsh, R. A.; Messerly, M. J.; Prantil, M. A.; Wu, S.; Barty, C. P. J. [Lawrence Livermore National Laboratory, NIF and Photon Science, 7000 East avenue, Livermore, CA 94550 (United States)

2012-12-21

Compact Compton scattering gamma-ray sources offer the potential of studying nuclear photonics with new tools. The optimization of such sources depends on the final application, but generally requires maximizing the spectral density (photons/eV) of the gamma-ray beam while simultaneously reducing the overall bandwidth on target to minimize noise. We have developed an advanced design for one such system, comprising the RF drive, photoinjector, accelerator, and electron-generating and electron-scattering laser systems. This system uses a 120 Hz, 250 pC, 2 ps, 0.35 mm mrad electron beam with 250 MeV maximum energy in an X-band accelerator scattering off a 150 mJ, 10 ps, 532 nm laser to generate 5 Multiplication-Sign 10{sup 10} photons/eV/s/Sr at 0.5 MeV with an overall bandwidth of less than 1%. The source will be able to produce photons up to energies of 2.5 MeV. We also discuss Compton scattering gamma-ray source predictions given by numerical codes.
Calculation of nuclear data for incident energies to 200 MeV with the FKK-GNASH code system

International Nuclear Information System (INIS)

Chadwick, M.B.; Young, P.G.

1993-02-01

We describe how the FKK-GNASH code system has been extended to calculate nucleon-induced reactions up to 200 MeV, and used to predict (p,xn) and (p,xp) cross sections on 208 Pb at incident energies of 25, 45, 80 and 160 MeV, for an intermediate energy code intercomparison. Details of the reaction mechanisms calculated by FKK-GNASH are given, and the calculational procedure is described
Beam dynamics studies of the photo-injector in low-charge operation mode for the ERL test facility at IHEP

International Nuclear Information System (INIS)

Jiao Yi; Xiao Ouzheng

2014-01-01

The energy recovery linac test facility (ERL-TF), which is a compact ERL-FEL (free electron laser) two-purpose machine, was proposed at the Institute of High Energy Physics, Beijing. As one important component of the ERL-TF, the photo-injector that started with a photocathode direct-current gun has been designed. In this paper, optimization of the injector beam dynamics in low-charge operation mode is performed with iterative scans using Impact-T. In addition, the dependencies between the optimized beam quality and the initial offset at cathode and element parameters are investigated. The tolerance of alignment and rotation errors is also analyzed. (authors)
Forecasting E > 50-MeV Proton Events with the Proton Prediction System (PPS)

Science.gov (United States)

Kahler, S. W.; White, S. M.; Ling, A. G.

2017-12-01

Forecasting solar energetic (E > 10 MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (> 50 MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E > 50-MeV proton events > 1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986 to 2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all > M5 solar X-ray flares; (2) all > 200 sfu 8800-MHz bursts with associated > M5 flares; (3) all > 500 sfu 8800-MHz bursts; and (4) all > 5000 sfu 8800-MHz bursts. For X-ray flare inputs the forecasted event peak intensities and fluences are compared with observed values. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude.
Multiphoton photoemission from a copper cathode illuminated by ultrashort laser pulses in an RF photoinjector.

Science.gov (United States)

Musumeci, P; Cultrera, L; Ferrario, M; Filippetto, D; Gatti, G; Gutierrez, M S; Moody, J T; Moore, N; Rosenzweig, J B; Scoby, C M; Travish, G; Vicario, C

2010-02-26

In this Letter we report on the use of ultrashort infrared laser pulses to generate a copious amount of electrons by a copper cathode in an rf photoinjector. The charge yield verifies the generalized Fowler-Dubridge theory for multiphoton photoemission. The emission is verified to be prompt using a two pulse autocorrelation technique. The thermal emittance associated with the excess kinetic energy from the emission process is comparable with the one measured using frequency tripled uv laser pulses. In the high field of the rf gun, up to 50 pC of charge can be extracted from the cathode using a 80 fs long, 2 microJ, 800 nm pulse focused to a 140 mum rms spot size. Taking into account the efficiency of harmonic conversion, illuminating a cathode directly with ir laser pulses can be the most efficient way to employ the available laser power.
Multiphoton Photoemission from a Copper Cathode Illuminated by Ultrashort Laser Pulses in an rf Photoinjector

International Nuclear Information System (INIS)

Musumeci, P.; Gutierrez, M. S.; Moody, J. T.; Moore, N.; Rosenzweig, J. B.; Scoby, C. M.; Travish, G.; Cultrera, L.; Ferrario, M.; Filippetto, D.; Gatti, G.; Vicario, C.

2010-01-01

In this Letter we report on the use of ultrashort infrared laser pulses to generate a copious amount of electrons by a copper cathode in an rf photoinjector. The charge yield verifies the generalized Fowler-Dubridge theory for multiphoton photoemission. The emission is verified to be prompt using a two pulse autocorrelation technique. The thermal emittance associated with the excess kinetic energy from the emission process is comparable with the one measured using frequency tripled uv laser pulses. In the high field of the rf gun, up to 50 pC of charge can be extracted from the cathode using a 80 fs long, 2 μJ, 800 nm pulse focused to a 140 μm rms spot size. Taking into account the efficiency of harmonic conversion, illuminating a cathode directly with ir laser pulses can be the most efficient way to employ the available laser power.
Study of the /sup 12/N 2. 43 MeV level. [Differential cross sections; 44 MeV /sup 3/He; 52 MeV p

Energy Technology Data Exchange (ETDEWEB)

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

1976-10-11

The differential cross sections have been measured for the reactions /sup 12/C(/sup 3/He, /sup 3/He')/sup 12/C(17.77 MeV 0/sup +/ T = 1) and /sup 12/C(/sup 3/He, t)/sup 12/N(2.43 MeV) at Esub(/sup 3/He) = 44 MeV. The similar shapes of the angular distributions and the relative magnitudes of the cross sections suggest that the /sup 12/N 2.43 MeV level is the 0/sup +/ T = 1 analog to the /sup 12/C 17.77 MeV level. The reaction /sup 14/N(p, t)/sup 12/N(2.43 MeV) at Esub(p) = 52 MeV is also studied. The strength with which this level is excited in this reaction is consistent with reasonable two-step calculations assuming the 2.43 MeV level to have Jsup(..pi..) = 0/sup +/.
Microwave system of the 7-10 MeV electron linear accelerator ALIN for medical applications

International Nuclear Information System (INIS)

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

1978-01-01

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

Science.gov (United States)

Chen, Y.; Krasilnikov, M.; Stephan, F.; Gjonaj, E.; Weiland, T.; Dohlus, M.

2018-05-01

We propose a three-dimensional fully electromagnetic numerical approach for the simulation of RF photoinjectors for coherent light sources. The basic idea consists in incorporating a self-consistent photoemission model within a particle tracking code. The generation of electron beams in the injector is determined by the quantum efficiency (QE) of the cathode, the intensity profile of the driving laser as well as by the accelerating field and magnetic focusing conditions in the gun. The total charge emitted during an emission cycle can be limited by the space charge field at the cathode. Furthermore, the time and space dependent electromagnetic field at the cathode may induce a transient modulation of the QE due to surface barrier reduction of the emitting layer. In our modeling approach, all these effects are taken into account. The beam particles are generated dynamically according to the local QE of the cathode and the time dependent laser intensity profile. For the beam dynamics, a tracking code based on the Lienard-Wiechert retarded field formalism is employed. This code provides the single particle trajectories as well as the transient space charge field distribution at the cathode. As an application, the PITZ injector is considered. Extensive electron bunch emission simulations are carried out for different operation conditions of the injector, in the source limited as well as in the space charge limited emission regime. In both cases, fairly good agreement between measurements and simulations is obtained.
Extension of the calibration of an NE-213 liquid scintillator based pulse height response spectrometer up to 18 MeV neutron energy and leakage spectrum measurements on bismuth at 8 MeV and 18 MeV neutron energies

International Nuclear Information System (INIS)

Fenyvesi, A.; Valastyan, I.; Olah, L.; Csikai, J.; Plompen, A.; Jaime, R.; Loevestam, G.; Semkova, V.

2011-01-01

Monoenergetic neutrons were produced at the Van de Graaff accelerator of the EC-JRC-Institute for Reference Materials and Measurements (IRMM, Geel, Belgium). An air-jet cooled D_2-gas target (1.2 bar, ΔE_d = 448 keV) was bombarded with E_d =4976 keV deuterons to produce neutrons up to E_n = 8 MeV energy via the D(d,n)"3He reaction. Higher energy neutrons up to E_n = 18 MeV were produced via the T(d,n)"4He reaction by bombarding a TiT target with E_d =1968 keV deuterons. Pulse height spectra were measured at different neutron energies from E_n = 8 MeV up to E_n = 18 MeV with the NE-213 liquid scintillator based Pulse Height Response Spectrometer (PHRS) of UD-IEP. The energy calibration of the PHRS system has been extended up to E_n = 18 MeV. Pulse height spectra induced by gamma photons have been simulated by the GRESP7 code. Neutron induced pulse height spectra have been simulated by the NRESP7 and MCNP-POLIMI codes. Comparison of the results of measurements and simulations enables the improvement of the parameter set of the function used by us to describe the light output dependence of the resolution of the PHRS system at light outputs of L > 2 light units. Also, it has been shown that the derivation method for unfolding neutron spectra from measured pulse height spectra performs well when relative measurements are done up to E_n = 18 MeV neutron energy. For matrix unfolding purposes, the NRESP7 code has to be preferred to calculate the pulse height response matrix of the PHRS system. Leakage spectra of neutrons behind bismuth slabs of different thicknesses have been measured with the PHRS system by using monoenergetic neutrons. The maximum slab thickness was d = 14 cm. Simulations of the measurements have been carried out with the MCNP-4c code. The necessary nuclear cross-sections were taken from the from the ENDF/B-VII and JEFF.3.1 data libraries. For both libraries, the agreement of measured and simulated neutron spectra is good for the 5 MeV ≤ En ≤ 18 MeV
3.5 MeV pulsed power system for LIA injector

International Nuclear Information System (INIS)

Li Jin; Dai Guangsen; Liu Xiaoping; Zhang Kaizhi; Li Xin; Li Yuan; Xia Liansheng; Xie Min; Zhang Linwen; Deng Jianjun; Ding Bonan

2005-01-01

A 3.5 MeV injector for linear induction accelerator has been built up at Institute of Fluid Physics, China Academy of Engineering Physics. The injector is based on the principle of inductive adder. It consists of 12 induction cells. Seven induction cells are on the cathode stem side, which are connected in series, and provide about 2 MV on the cathode of the diode. The other five are connected in series on the anode stem side and provide about 1.5 MV on the anode of the diode. A 3.5 MV pulsed power system to provide energy for the injector has been designed, which consists of two Marx generators, 12 water insulated Blumleins, and trigger system. Charge voltage of each water insulated Blumlein is 200 kV. A 300 kV/90 ns high voltage pulse is fed into one induction cell since load impedance is higher. The pulsed power system can generate an intense electron beam with 2-3 kA. (authors)

Beam Dynamics a Integrated Plane Wave Transformer Photoinjector at S- and X- band

Science.gov (United States)

Rosenzweig, J. B.; Ding, X.; Pellegrini, X.; Serafini, L.; Yu, D.

1997-05-01

The beam dynamics of an integrated S-band rf photoinjector based on the plane wave transformer concept, proposed as part of an SBIR collaboration between UCLA and DULY Research, are studied. The intial design, which calls for an 11.5 cell structure run at a peak on-axis accelerating field of 60 MV/m, and has a compact solenoid around the intial 2.5 cells, is based on the recently developed theory of emittance compensation(L.Serafini, and J.B. Rosenzweig, submitted to Physical Review E.). It calls for matching the beam onto an envelope which is a generalized Brillouin flow, producing a beam which diminishes in transverse size as the square root of the accelerating beam energy. This condition produces a minimized emittance, which for the S-band case is 1 mm-rad at at charge of 1 nC. This design is also scaled to produce nearly identical performance at X-band, giving an injector appropriate to running an FEL at the SLAC NLCTA. It is noted that these designs are insensitive to rf emittance increase, allowign a choice of injection phase, and the option to compress the emitted pulse.
Forecasting E > 50-MeV proton events with the proton prediction system (PPS)

Science.gov (United States)

Kahler, Stephen W.; White, Stephen M.; Ling, Alan G.

2017-11-01

Forecasting solar energetic (E > 10-MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (≥50-MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E ≥ 50-MeV proton events >1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986-2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all ≥M5 solar X-ray flares; (2) all ≥200 sfu 8800-MHz bursts with associated ≥M5 flares; (3) all ≥500 sfu 8800-MHz bursts; and (4) all ≥5000 sfu 8800-MHz bursts. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude, and argue that the longitude-dependence employed by PPS does not match modern observations. Use of the radio fluxes as the PPS driver tends to result in too many false alarms at the 500 sfu threshold, and misses more events than the soft X-ray predictor at the 5000 sfu threshold.
Performance of the high brightness linac for the Advanced Free Electron Laser Initiative at Los Alamos

International Nuclear Information System (INIS)

Sheffield, R.L.; Austin, R.H.; Chan, K.D.C.; Gierman, S.M.; Kinross-Wright, J.M.; Kong, S.H.; Nguyen, D.C.; Russell, S.J.; Timmer, C.A.

1993-01-01

The AFEL accelerator has produced beams of greater than 2 x 10 12 A/m 2 at 1 nC (brightness = 2*I/var-epsilon 2 , with I greater than 100 A and var-epsilon of than 2 π mm-mrad normalized ms emittance). The 1300 MHz standing-wave accelerator uses on-axis coupling cells. The electron source is a photoinjector with a CsK 2 Sb photocathode. The photoinjector is an integral part of a single 11-cell accelerator structure. The accelerator operates between 12 and 18 MeV. The beam emittance growth in the accelerator is minimized by using a photoinjector, a focusing solenoid to correct the emittance growth due to space charge, and a special design of the coupling slots between accelerator cavities to minimize quadrupole effects. This paper describes the experimental results and compares those results with PARMELA simulation. The simulation code PARMELA was modified for this effort. This modified version uses SUPERFISH files for the accelerator cavity fields, MAFIA files for the fields due to the coupling slots in the accelerator cells, and POISSON files for the solenoid field in the gun region
Triple differential cross section for angle, atomic number and energy (or angular momentum transfer) calculated for the 280MeV 40Ar+58Ni (or 365 MeV 63Cu+197Au) system in a simple model

International Nuclear Information System (INIS)

Berlanger, M.; Grange, P.; Richert, J.; Hofmann, H.; Ngo, C.

1978-01-01

A dynamical model including both dissipation and statistical fluctuations is applied to the computation of triple differential cross sections for deep inelastic reactions. It is seen that for different Z values the overall pattern of the cross section (calculated, for the 280 MeV 40 Ar+ 58 Ni system) as a function of E and theta is fairly well reproduced - the mean angular momentum transfer for the 365MeV 63 Cu+ 197 Au system is calculated and compared with γ-multiplicity measurements. In both applications, possible implications of the remaining discrepancies are discussed
Modified 3½-Cell SC Cavity Made of Large Grain Niobium for the FZD SRF Photoinjector

CERN Document Server

Murcek, P; Michel, P; Moeller, K; Arnold, A; Teichert, J; Xiang, R; Freitag, M; Kneisel, P

2010-01-01

An SRF photoinjector has been successfully tested in FZD under the collaboration of BESSY, DESY, FZD, and MBI. In order to improve the gun cavity quality and thus reach a higher gradient, a new 3+1/2 superconducting cavity is being fabricated in cooperation with JLab. The modified cavity is made of large grain niobium, composed of one filter choke, one special designed half-cell (gun-cell) and three TESLA cavities. In this paper, the main updates of the new cavity design will be explained in detail. The deformation of the filter choke and the gun-cell, which is caused by pressure fluctuation in the He-line and also by the effect of the Lorentz force, will be minimized by stiffening between the filter choke and the gun-cell. Meanwhile, the cathode hole in the choke and gun-cell is enlarged for better rinsing. To simplify assembly, the NbTi pick-up will be welded directly on the wall of filter choke.
Relativistic acceleration and retardation effects on photoemission of intense electron short pulses, in RF-FEL photoinjectors

International Nuclear Information System (INIS)

Dolique, J.M.; Coacolo, M.

1991-01-01

In high-power free electron lasers, self-field effects in the electron beam are often the most important phenomenon on which the beam quality depends. These effects are generally conceived as space-charge effects, and described by a Poisson equation in a beam frame. In RF-FEL photoinjectors, the electrons of the intense short pulse produced by laser irradiation are submitted, just after their photoemission, to such a strong acceleration that relativistic acceleration and retardation effects are discussed, from the rigorous calculation of the Lienard-Wiechert velocity- and acceleration electric and magnetic fields, as a function of RF-electric field and beam parameters. The beam pulse is assumed to be axisymmetric, with a constant photoemitted current density. Consequences for the maximum current density that can be extracted are considered (the 'self-field limit,' a name more appropriate than 'space-charge limit' for the present conditions where electro-dynamic phenomena play an important role)
Evidence for two narrow pp resonances at 2020 MeV and 2200 MeV

CERN Document Server

Benkheiri, P; Bouquet, B; Briandet, P; D'Almagne, B; Dang-Vu, C; De Rosny, G; Eisenstein, B I; Ferrer, A; Fleury, P; Grossetête, B; Irwin, G; Jacholkowski, A; Lahellec, A; Nguyen, H; Petroff, P; Richard, F; Rivet, P; Roudeau, P; Rougé, A; Rumpf, M; Six, J; Thénard, J M; Treille, D; Volte, A; Yaffe, D; Yiou, T P; Yoshida, H

1977-01-01

From the study of the reaction pi /sup -/p to p/sub F/pp pi /sup -/ using a fast proton (p/sub F/) trigger device in the CERN Omega spectrometer, the authors find evidence for two narrow pp states produced mainly in association with a Delta degrees (1232) and a N degrees (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M/sub 1/=2020+or-3 MeV, Gamma /sub 1 /=24+or-12 MeV and M/sub 2/=2204+or-5 MeV, Gamma /sub 2/=16/sub -16 //sup +20/ MeV. The data are consistent with a small production of the narrow approximately 1935 MeV resonance already reported. Production cross sections for these new pp resonances are given. (8 refs).
Development of the integrated control system for the microwave ion source of the PEFP 100-MeV proton accelerator

Science.gov (United States)

Song, Young-Gi; Seol, Kyung-Tae; Jang, Ji-Ho; Kwon, Hyeok-Jung; Cho, Yong-Sub

2012-07-01

The Proton Engineering Frontier Project (PEFP) 20-MeV proton linear accelerator is currently operating at the Korea Atomic Energy Research Institute (KAERI). The ion source of the 100-MeV proton linac needs at least a 100-hour operation time. To meet the goal, we have developed a microwave ion source that uses no filament. For the ion source, a remote control system has been developed by using experimental physics and the industrial control system (EPICS) software framework. The control system consists of a versa module europa (VME) and EPICS-based embedded applications running on a VxWorks real-time operating system. The main purpose of the control system is to control and monitor the operational variables of the components remotely and to protect operators from radiation exposure and the components from critical problems during beam extraction. We successfully performed the operation test of the control system to confirm the degree of safety during the hardware performance.
A design study of a 100 MeV race-track microtron/pulse-stretcher accelerator system

International Nuclear Information System (INIS)

Alvinsson, R.; Eriksson, M.

1976-04-01

A proposed design of an accelerator system with large duty-factor is described. The system is composed of a race-track microtron and a pulse-stretcher. The maximum particle energy is 100 MeV and the beam current is estimated to be up to 10 μA within +- 100 keV. The intended use is mainly for nuclear physics experiments with high precision, where the combination of large mean current and limited pulse intensity is essential. (Auth.)
Fabrication, Treatment and Testing of a 1.6 Cell Photo-injector Cavity for HZB

International Nuclear Information System (INIS)

Kneisel, P.; Kamps, T.; Knobloch, J.; Kugeler, O.; Neumann, A.; Nietubyc, R.; Sekutowicz, J.K.

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Forschungszentrum Dresden (FZD) and JLab we have fabricated and tested after appropriate surface treatment a 1.5 cell, 1300 MHz RRR niobium photo-injector cavity to be used in a demonstration test at BESSY*. Following a baseline test at JLab, the cavity received a lead spot coating of ∼ 8 mm diameter deposited with a cathode arc at the Soltan Institute on the endplate made from large grain niobium. It had been demonstrated in earlier tests with a DESY built 1.5 cell cavity - the original design - that a lead spot of this size can be a good electron source, when irradiated with a laser light of 213 nm. In the initial test with the lead spot we could measure a peak surface electric field of ∼ 29 MV/m; after a second surface treatment, carried out to improve the cavity performance, but which was not done with sufficient precaution, the lead spot was destroyed and the cavity had to be coated a second time. This contribution reports about the experiences and results obtained with this cavity.
Preliminary physical design of 7 MeV proton RFQ for the accelerator driven-energy system

International Nuclear Information System (INIS)

Luo Zihua

2000-01-01

The preliminary physical design of 7 MeV proton RFQ for the ADS (Accelerator Driven-energy System) is briefly described. The design features and the basic parameters and the design version of the RFQ are discussed. The matches between IS and RFQ and between RFQ and CCDTL/DTL are also discussed. The ideas of research for the RFQ are presented
Fusion with projectiles from carbon to argon at energies between 20A MeV and 60A MeV

International Nuclear Information System (INIS)

Galin, J.

1986-01-01

Fusion reactions are known to be the dominant reaction channel at low bombarding energies and can now be investigated with a large variety of projectiles at several tens of MeV per nucleon. The gross characteristics of the fusion process can be studied by measuring global quantities, such as the linear momentum transferred from projectile to target and the dissipated energy of the reaction. The strong correlation between these two quantities is demonstrated at moderate bombarding energies, with a Ne projectile on a U target. It is expected that light particle (charged or neutron) multiplicity measurements can be extended to this higher energy domain and be used to selectively filter these collisions, according to their degree of violence. A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MeV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behavior. Finally, the decay of highly excited (E* similarly ordered 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space
NSLS 3: Conceptual design report: 750 MeV e+ or e- injector

International Nuclear Information System (INIS)

1986-05-01

The 750 MeV positron or electron injector is comprised of an electron linear accelerator which accelerates an intense beam of electrons to an energy of about 250 MeV, a positron converter, a second linear accelerator that boosts the final positron energy to 750 MeV, and a damping ring in which radiation damping is used to reduce the emittance of the positron beam for injection into the storage rings. The reasons for the need of a new injector are enumerated. The conceptual design of the system and its component systems are described, as well as project cost, schedule, and manpower requirements
The 600 MeV Saclay electron linac: 40000 hour operation

International Nuclear Information System (INIS)

Netter, F.

1977-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Lopez, David Juarez [Univ. of Guanajuato (Mexico)

2015-08-01

Fermilab Accelerator Science and Technology Facility has produced its first beam with an energy of 20 MeV. This energy is obtained by the acceleration at the Electron Gun and the Capture Cavity 2 (CC2). When fully completed, the accelerator will consist of a photoinjector, one International Liner Collider (ILC)-type cryomodule, multiple accelerator R&D beamlines, and a downstream beamline to inject 300 MeV electrons into the Integrable Optics Test Accelerator (IOTA). We calculated the total energy of the beam and the corresponding energy to the Electron Gun and CC2. Subsequently, a Beam Position Monitors (BPM) error analysis was done, to calculate the device actual resolution.
Nuclear disassembly of the (Pb+Au) system at Elab=29 MeV per nucleon

International Nuclear Information System (INIS)

Piasecki, E.; Kordyasz, A.; Bresson, S.; Crema, E.; Galin, J.; Guerreau, D.; Morjean, M.; Paulot, C.; Pouthas, J.; Jastrzebski, J.; Pienkowski, L.; Skulski, W.; Lott, B.; Quednau, B.; Schroder, W.U.; Toeke, J.

1990-01-01

Nuclei, with Z up to 82, emitted in the 208 Pb+ 197 Au reaction at E lab =29 MeV per nucleon, have been measured as a function of the associated neutron multiplicity. The data reveal the presence of strong correlations between character of a collision and neutron multiplicity. The trends suggest a disassembly of the nuclear system into a large number of nucleons and small fragments in the events with the highest neutron multiplicity. In such events, approximately one third of the neutrons are released from the system and fragments yields decrease in an exponential fashion with increasing mass
High brightness beams and applications

International Nuclear Information System (INIS)

Sheffield, R.L.

1995-01-01

This paper describes the present research on attaining intense bright electron beams. Thermionic systems are briefly covered. Recent and past results from the photoinjector programs are given. The performance advantages and difficulties presently faced by researchers using photoinjectors is discussed. The progress that has been made in photocathode materials, both in lifetime and quantum efficiency, is covered. Finally, a discussion of emittance measurements of photoinjector systems and how the measurement is complicated by the non-thermal nature of the electron beam is presented
Magnifying lens for 800 MeV proton radiography

International Nuclear Information System (INIS)

Merrill, F. E.; Campos, E.; Espinoza, C.; Hogan, G.; Hollander, B.; Lopez, J.; Mariam, F. G.; Morley, D.; Morris, C. L.; Murray, M.; Saunders, A.; Schwartz, C.; Thompson, T. N.

2011-01-01

This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.
The Digital Feedback RF Control System of the RFQ and DTL1 for 100 MeV Proton Linac of PEFP

CERN Document Server

Yu In Ha; Cho, Yong-Sub; Han, Yeung-Jin; Kang Heung Sik; Kim, Sung-Chul; Kwon, Hyeok-Jung; Park, In-Soo; Tae Kim, Do; Tae Seol, Kyung

2005-01-01

The 100 MeV Proton linear accelerator (Linac) for the PEFP (Proton Engineering Frontier Project) will include 1 RFQ and 1 DTL1 at 350 MHz as well as 7 DTL2 cavities at 700 MHz. The low level RF system with the digital feedback RF control provides the field control to accelerate a 20mA proton beam from 50 keV to 20 MeV with a RFQ and a DTL1 at 350M Hz. The FPGA-based digital feedback RF control system has been built and is used to control cavity field amplitude within ± 1% and relative phase within ± 1°. The fast digital processing is networked to the EPICS-based control system with an embedded processor (Blackfin). In this paper, the detailed description of the digital feedback RF control system will be described with the performance test results.
The KAERI 10 MeV Electron Linac - Description and Operational Manual

Energy Technology Data Exchange (ETDEWEB)

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

2005-06-15

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

The KAERI 10 MeV Electron Linac - Description and Operational Manual

International Nuclear Information System (INIS)

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

2005-06-01

The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting
Physics design of a 70 MeV high intensity cyclotron, CYCIAE-70

International Nuclear Information System (INIS)

Zhang Tianjue; An Shizhong; Wang Chuan; Yin Zhiguo; Wei Sumin; Li Ming; Yang Jianjun; Ji Bin; Jia Xianlu; Zhong Junqing; Yang Fang

2011-01-01

This paper introduces the physics design of a 70 MeV high intensity cyclotron at China Institute of Atomic Energy (CIAE), which is aimed for multiple uses including radioactive ion-beam (RIB) production. The machine adopts a compact structure of four straight sectors, capable of accelerating two kinds of beams, i.e. H − and D − . The proton and deuteron beam will be extracted in dual opposite directions by charge exchange stripping devices. The energy of the extracted proton beam is in the range 35–70 MeV with an intensity up to 700 μA. The corresponding values for the deuteron beam are 18–33 MeV and 40 μA. This paper will present the main characteristics and parameters in the design of the 70 MeV cyclotron, the results of the basic beam dynamics study, as well as the physics in the design of the different systems, including the main magnet, RF, injection and extraction systems, etc.
Design study of prototype accelerator and MeV test facility for demonstration of 1 MeV, 1 A negative ion beam production

International Nuclear Information System (INIS)

Inoue, Takashi; Hanada, Masaya; Miyamoto, Kenji; Ohara, Yoshihiro; Okumura, Yoshikazu; Watanabe, Kazuhiro; Maeno, Shuichi.

1994-08-01

In fusion reactors such as ITER, a neutral beam injector of MeV class beam energy and several tens MW class power is required as one of candidates of heating and current drive systems. However, the beam energy of existing high power accelerators are one order of magnitude lower than the required value. In order to realize a neutral beam injector for the fusion reactor, 'Proof-of-Principle' of such high energy acceleration is a critical issue at a reactor relevant beam current and pulse length. An accelerator and an accelerator facility which are necessary to demonstrate the Proof-of-Principle acceleration of negative ion beams up to 1 MeV, have been designed in the present study. The accelerator is composed of a cesium-volume type ion source and a multi-stage electrostatic acceleration system [Prototype Accelerator]. A negative hydrogen ion beam with the current of about one ampere (1 A) can be accelerated up to 1 MeV at a low operating pressure. Two types of acceleration system, a multi-multi type and a multi-single type, have been studied. The test facility has sufficient capability for the test of the Prototype Accelerator [MeV Test Facility]. The dc high voltage generator for negative ion acceleration is a Cockcroft-Walton type and capable of delivering 1 A at 1 MV (=1 MW) for 60 s. High voltage components including Prototype Accelerator are installed in a SF 6 vessel pressurized at 6 kg/cm 2 to overcome high voltage gradients. The vessel and the beamline are installed in a X-ray shield. (author)
Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

International Nuclear Information System (INIS)

Deluca, P.M.; Barschall, H.H.; McDonald, J.C.

1985-01-01

For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183+-0.015 10 -8 cGy cm 2 and 0.210+-0.016 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297+-0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184+-0.019 10 -8 cGy cm 2 in agreement with the present result
Measurement of Ay(θ) for n+208Pb from 6 to 10 MeV and the neutron-nucleus interaction over the energy range from bound states at -17 MeV up to scattering at 40 MeV

International Nuclear Information System (INIS)

Roberts, M.L.; Felsher, P.D.; Weisel, G.J.; Chen, Z.; Howell, C.R.; Tornow, W.; Walter, R.L.; Horen, D.J.

1991-01-01

High-accuracy measurements of A y (θ) data for elastic scattering and inelastic scattering to the first excited state for n+ 208 Pb have been performed at 6, 7, 8, 9, and 10 MeV. In addition, σ(θ) was measured at 8 MeV. These data provide an important subset for the growing database for the n+ 208 Pb system from bound-state energies to energies above 40 MeV, the limit of the range of interest here. This database has been interpreted via several approaches. First, a conventional Woods-Saxon spherical optical was used to obtain three potential representations for the energy range from 4 to 40 MeV: ''best fits'' at each energy, constant-geometry global fit with linear energy dependences for the potential strengths for the range 4.0--40 MeV, and an extension of the latter model to allow a linear energy dependence on the radii and diffuseness. A preference for a complex spin-orbit interaction was observed in all cases. Second, the dispersion relation was introduced into the spherical optical model to obtain a more ''realistic'' representation. In our approach, the strength and shape of the real potential was modified by calculating the dispersion-relation contributions that originate from the presence of the surface and volume imaginary terms. Two potentials were developed, one based only on the scattering data (from 4.0 to 40 MeV) and another based additionally on single-particle and single-hole information down to a binding energy of 17 MeV. In addition, the σ(θ) and A y (θ) measurements were compared to earlier conventional and dispersion-relation models. One of the latter of these included an l dependence in the absorptive surface term, and we applied this model in the 6- to 10-MeV region to describe all the σ(θ) and the new A y (θ)
Comparison of biological and genomic characteristics between a newly isolated mink enteritis parvovirus MEV-LHV and an attenuated strain MEV-L.

Science.gov (United States)

Mao, Yaping; Wang, Jigui; Hou, Qiang; Xi, Ji; Zhang, Xiaomei; Bian, Dawei; Yu, Yongle; Wang, Xi; Liu, Weiquan

2016-06-01

A virus isolated from mink showing clinical signs of enteritis was identified as a high virulent mink enteritis parvovirus (MEV) based on its biological characteristics in vivo and in vitro. Mink, challenged with this strain named MEV-LHV, exhibited severe pathological lesions as compared to those challenged with attenuated strain MEV-L. MEV-LHV also showed higher infection and replication efficiencies in vitro than MEV-L. Sequence of the complete genome of MEV-LHV was determined and analyzed in comparison with those in GenBank, which revealed that MEV-LHV shared high homology with virulent strain MEV SD12/01, whereas MEV-L was closely related to Abashiri and vaccine strain MEVB, and belonged to a different branch of the phylogenetic tree. The genomes of the two strains differed by insertions and deletions in their palindromic termini and specific unique mutations (especially VP2 300) in coding sequences which may be involved in viral replication and pathogenicity. The results of this study provide a better understanding of the biological and genomic characteristics of MEV and identify certain regions and sites that may be involved in viral replication and pathogenicity.
An 8 MeV H- cyclotron to charge the electron cooling system for HESR

International Nuclear Information System (INIS)

Pakhomchuk, V.; Papash, A.

2006-01-01

A compact cyclotron to accelerate negative hydrogen ions up to 8 MeV is considered as optimal solution to the problem of charging the high-voltage terminal of the electron cooling system for High Energy Storage Ring at GSI (HESR Project, Darmstadt). Physical as well as technical parameters of the accelerator are estimated. Different types of commercially available cyclotrons are compared as a possible source of a 1 mA H - beam for the HESR. An original design based on the application of well-established technical solutions for commercial accelerators is proposed
Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

International Nuclear Information System (INIS)

Deluca, P.M. Jr.; Barschall, H.H.; Haight, R.C.; McDonald, J.C.

1984-01-01

For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183 +- 0.015 10 -8 cGy cm 2 and 0.210 +- 0.16 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297 +- 0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184 +- 0.019 10 8 cGy cm 2 in agreement with the present result. 9 refs., 4 figs., 2 tabs
0,01-5 MeV heavy ion accelerators

International Nuclear Information System (INIS)

Golubev, V.P.; Ivanov, A.S.; Nikiforov, S.A.; Svin'in, M.P.; Tarvid, G.V.; Troshikhin, A.G.; Fedotov, M.T.

1983-01-01

The results of development of an accelerating complex on the base of the UP-2-1 heavy ion charge exchange accelerator and IMPLANT-500 high-voltage heavy ion accelerator are given. The accelerating complex provides overlapping of the 0.01 MeV to 5 MeV energy range at accelerated beam currents of 10 -3 -10 -6 A order. The structural features of accelerators and their basic units and systems are considered. The UP-2-1 accelerator is designed for researches in the field of experimental physics and applied problem solutions. The IMPLANT-500 accelerator is designed for commercial ion-beam facilities with closed loop of silicon plate treatment
Transverse and longitudinal emittance measurements in the ELSA linac

International Nuclear Information System (INIS)

Loulergue, A.; Dowell, D.H.; Joly, S.; De Brion, J.P.; Haouat, G.; Schumann, F.

1997-01-01

The ELSA RF linac photoinjector has been designed to deliver high-brightness electron beams. The present paper deals with the transverse and longitudinal emittance measurements, at different locations along the ELSA beam line, and the analysis of their variations as a function of the photoinjector parameters : magnetic field generated by the anode focusing lens, bunch charge and pulse duration. While transverse emittance has been already studied in other similar installations, there has been little study of the electron beam longitudinal dynamics. Experimental results are presented and compared to simulation-code expectations. For 2.0 nC, 85 A electron bunches, a normalized rms emittance of 2 π mm mrad and a brightness of 4.5 x 10 13 A/(π m rad) 2 at the linac exit have been measured as well as less than 10 keV rms energy spread (or less than 0.1% at 16.5 MeV). (orig.)
Polarization measurements for P-12C elastic scattering between 40-75 MeV

International Nuclear Information System (INIS)

Kato, S.; Okada, K.; Kondo, M.; Shimizu, A.; Hosono, K.; Saito, T.; Matsuoka, N.; Nagamachi, S.; Nisimura, K.; Tamura, N.

1980-01-01

Absolute values of the polarization in p- 12 C elastic scattering have been measured at 60.0 and 64.5 MeV at 47.5 0 in the laboratory system using a double scattering method and a method to measure an asymmetry with a polarized beam. The results are P(60.0 MeV, 47.5 0 ) = 0.965 +- 0.011 and P(64.5 MeV, 47.5 0 ) = 0.975 +- 0.011. Based on these values, the polarization measurements have been extended to the energy range from 40-75 MeV at several angles around 47.5 0 using the polarized proton beam and the energy degrader. Differential cross sections and polarizations from 15-115 0 are also presented at 65 MeV. These data will be valuable for the monitoring of beam polarization in this energy region. (orig.)
Study of transfer induced fission and fusion-fission reactions for 28 Si + 232 Th system at 340 MeV

International Nuclear Information System (INIS)

Prete, G.; Rizzi, V.; Fioretto, E.; Cinausero, M.; Shetty, D.V.; Pesente, S.; Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E.; Boiano, A.; Ordine, A.; Gelli, N.; Lucarelli, F.; Bortignon, P.F.; Saxena, A.; Nayak, B.K.; Biswas, D.C.; Choudhury, R.K.; Kapoor, R.S.

2001-01-01

Full text: Fission induced by nucleons transfer has been investigated in the reaction 28 Si + 232 Th at 340 MeV. Looking at the projectile-like-fragments (PLF), the fission yield increases as the transfer increases, but a decreases is observed for transfers with DZ . Light charged particles in coincidence with PLF and Fission have been detected with large solid angle and show an increasing multiplicity as the Z of PLF is reduced and a constant value when fission is requested. The present results indicate inhibition of transfer induced fission reaction for higher Z transfer and increasing probability for decay through charged particle evaporation. Fission is the dominant decay process in heavy reactions involving fissile systems but the dynamical evolution of the composite system is largely governed by the formation and decay mechanisms. Important insight into the formation and the survival probability of the heavy composite nuclei formed in heavy ion collisions can be gained by simultaneously investigate the fission process and light particle emission over a continuous range of excitation energy, angular momentum and fissility. This can be achieved by studying fission induced by transfer of nucleons between the interacting projectile and the target nucleus. In the present work, we have carried out measurements on multinucleon transfer induced fission reactions in 28 Si + 232 Th system at Elab = 340 MeV. The experiment has been performed at the Laboratori Nazionale di Legnaro (LNL) using the 8pLP detector in its final configuration with 257 DE-E telescopes. The backward detectors were used to measure both light charged particles and fission fragments. The projectile-like fragments were detected using separate DE-E telescopes around the grazing angle. Two neutron detectors were placed at a distance of 115.5 cm from the target to measure neutrons emitted in coincidence with fission fragments. Here we present the results of the data analysis of transfer induced fission
A 1MeV, 1A negative ion accelerator test facility

International Nuclear Information System (INIS)

Hanada, M.; Dairaku, M.; Inoue, T.; Miyamoto, K.; Ohara, Y.; Okumura, Y.; Watanabe, K.; Yokoyama, K.

1995-01-01

For the Proof-of-Principle test of negative ion acceleration up to 1 MeV, the beam energy required for ITER, a negative ion test facility named MeV Test Facility (MTF) and an ion source/accelerator have been designed and constructed. They are designed to produce a 1 MeV H- beam at a low source pressure of 0.13Pa. The MTF has a power supply system, which constituts of a 1MV, 1A, 60 s Cockcroft-Walton type dc high energy generator and power supplies for negative ion generation and extraction (ion source power supplies). The negative ion source/accelerator is composed of a cesiated volume source and a 5-stage, multi-aperture, electrostatic accelerator. The MTF and the ion source/accelerator have been completed, and the accelertion test up to 1 MeV of the H- ions has started. (orig.)
Study of evaporation in Ca + Ca deep inelastic scattering at 400 MeV and setting-up of a conversational computing system

International Nuclear Information System (INIS)

Ameaume, A.

1979-01-01

The study of inelastic interactions between symmetrical systems allows to calculate the number of nucleons lost by evaporation; the identity of initial particles, within a two body hypothesis in the exit channel, implies a symmetry in the charge and mass distributions of the final nuclei. But these nuclei, in the first stage of reaction, are emitted with some excitation energy, so the observer detects only the cold products resulting from their de-excitation by evaporation. The study of the 40 Ca + 40 Ca system at 400 MeV, with an E-ΔE telescope in the laboratory angular range from 10 to 80 degrees, allowed to calculate number of lost charges ΔZ = 20 - Z versus the total excitation energy Esub(x) of the intermediate system, where Z represents the mean value of charge distributions at fixed Esub(x) and center-of-mass angle theta. The setting-up of an iterative calculation of ΔZ = f(Esub(x)) was necessary to access the Esub(x) energies before evaporation. The results are consistent with an energy thermalization hypothesis and show a linear increase of ΔZ versus Esub(x), independently of theta. The charge loss rate for one excited calcium varies from 1.6 for Esub(x) = 50 MeV to 4.8 for Esub(x) = 150 MeV [fr
High-resolution Auger spectroscopy on 79 MeV Ar5+, 89 MeV Ar6+, and 136 MeV Ar7+ ions after excitation by helium

International Nuclear Information System (INIS)

Schneider, T.

1988-01-01

In this thesis the atomic structure of highly excited Ar 6+ and Ar 7+ ions was studied. For this 79 MeV Ar 5+ , 89 MeV Ar 6+ , and 136 MeV Ar 7+ ions of a heavy ion accelerator were excited by a He gas target to autoionizing states and the Auger electrons emitted in the decay were measured in highly-resolving state. The spectra were taken under an observational angle of zero degree relative to the beam axis in order to minimize the kinematical broadening of the Auger lines. (orig./HSI) [de
Cross sections and analyzing powers of 15N(p,n)15O at 200 MeV and 494 MeV

International Nuclear Information System (INIS)

Ciskowski, D.E.

1989-11-01

Differential cross sections and analyzing powers have been measured for the 15 N(p,n) 15 O(g.s.) reaction at bombarding energies of 200 MeV and 494 MeV. The 494 MeV data were obtained at the LAMPF Neutron Time-Of-Flight Facility on an 82 m flight path with a resolution of about 2.7 MeV. The 200 MeV data were obtained at IUCF on a 76m flight path with a resolution of about 1.1 MeV. At both energies, the measured analyzing power is small, the magnitude is less than .2 for momentum transfers of less than 1 fm -1 . In contrast, both Relativistic and standard DWIA calculations predict a maximum of A=-.7 near q=0.7 fm -1 . 53 refs., 44 figs
Study of silicon tip photocathodes in DC and RF photo-injectors

International Nuclear Information System (INIS)

Jaber, Zakaria

1999-01-01

Nowadays the electron beams with a high intensity are particularly interesting in research and the applied physics. Producing such beams for which high intensity and low emittance are synonyms with efficiency, means developing new high luminosity electron sources, i.e. the photocathodes. This thesis, essentially experimental, is oriented in this way. After an introduction of Clermont-Ferrand and the LAL of Orsay experimental apparatus where the experiments took place, the chapter one presents the field emission and the photo-field emission. Then, we prove that the quantum efficiency of the photocathodes with silicon tips is higher for wavelengths near 800 nm. This fact is essential because it allows the use of lasers in the fundamental wavelength - Titan-Saphir for instance. In the chapter 2, we remind how the silicon tips are realized and how to improve surface conditions. Procedures and the surface analysis with the SEM and XPS are described. With a Nd-Yag laser, pumped with laser diode setting up with the participation of IRCOM Opticians of Limoges, the photocathode supplied 1 Ampere per pulse at a quantum efficiency of 0.25%. The description of this experiment and the results are the object of the chapter 3. The space charge outside the photocathode space prevents the electrons to go through. The Child-Langmuir formula limits the current with the DC gun at about 30 Ampere. To improve this result we have to use a photo-injector. In chapter 4 we prove that the silicon tip photocathode are compatible with RF gun requirements by PRIAM modeling and low level measure in a cold model of CANDELA RF gun. Technical department of CERN helped us to prepare this very sensitive experiment. (author)
Measurement of the total reaction cross section for interactions between heavy ions (application to the system 12C+12C at 112MeV)

International Nuclear Information System (INIS)

Cherkaoui-Tadili, R.

1982-01-01

The total reaction cross-section σsub(R) for interactions between heavy ions is predicted to decrease rapidly with the energy of the incident projectile over the energy range 10 MeV/A - 100 MeV/A. We present here an experimental met σsub(R) to test the model based predictions. The method consists in counting the number of all incoming projectiles and the number of out going projectiles that did not interact with the target. The difference between these two numbers corresponds to the number of particles that reacted with the target nuclei and is therefore proportional to σsub(R). Values of σsub(R) have been measured for the system 12 C + 12 C at two incident energies of 112 MeV and 996 MeV. The results of 1444 +- 70 (112 MeV) and 994 +- 50 (996 MeV) show a total reaction cross-section decreasing with energy as predicted from the Glauber model and optical model fits to elastic scattering [fr
Exclusive measurements of light fragment production at forward angles in Ne-Pb and Ne-NaF collisions at E/A=400 MeV and 800 MeV

International Nuclear Information System (INIS)

Bastid, N.; Alard, J.P.; Arnold, J.; Augerat, J.; Biagi, F.; Crouau, M.; Charmensat, P.; Dupieux, P.; Fraysse, L.; Marroncle, J.; Montarou, G.; Parizet, M.J.; Qassoud, D.; Rahmani, A.; Schimmerling, W.

1990-01-01

Emission of light fragments at small angles is studied in relativistic heavy ion collisions using the Diogene plastic wall for both symmetrical and non-symmetrical target-projectile systems with 400 MeV per nucleon and 800 MeV per nucleon incident neon nuclei. Efficiency of multiplicity measurements in the small angle range for the selection of central or peripheral collisions is confirmed for asymmetric systems. Differential production cross sections of Z=1 fragments show evidence for the existence of two emitting sources. The apparent temperature of each source is obtained from comparison with a thermodynamical model. (orig.)
Étude de la production de rayonnement X par diffusion Compton sur l’installation ELSA

OpenAIRE

Chauchat , Anne-Sophie

2011-01-01

Compton scattering by collisions between relativistic electron beam and laser beam is a way to produce X-rays. Laser beam is seen as an undulator which gives electrons a periodic waved motion. This radiation emitted by electrons motion has some characteristics close to those of synchrotron radiation but can be produced by smaller machines. ELSA facility at CEA DAM DIF is a linear electron accelerator (17 MeV) running with a photoinjector and a laser (532 nm). Characteristics of electrons and ...

14 MeV neutrons physics and applications

CERN Document Server

Valkovic, Vladivoj

2015-01-01

Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac
High power 1 MeV neutral beam system and its application plan for the international tokamak experimental reactor

Energy Technology Data Exchange (ETDEWEB)

Hemsworth, R S [ITER Joint Central Team, Naka, Ibaraki (Japan)

1997-03-01

This paper describes the Neutral Beam Injection system which is presently being designed for the International Tokamak Experimental Reactor, ITER, in Europe Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D{sup 0} to the ITER plasma for a pulse length of >1000 s. Each injectors uses a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D{sup -}. This will be neutralized by collisions with D{sub 2} in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. ITER is scheduled to produce its first plasma at the beginning of 2008, and the planning of the R and D, construction and installation foresees the neutral injection system being available from the start of ITER operations. (author)
Design of the MYRRHA 17-600 MeV Superconducting Linac

CERN Document Server

Biarrotte, J-L; Bouly, F; Carneiro, J-P; Vandeplassche, D

2013-01-01

The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.
Fabrication, Tuning, Treatment and Testing of Two 3.5 Cell Photo-Injector Cavities for the ELBE Linac

International Nuclear Information System (INIS)

Arnold, A.; Murcek, P.; Teichert, J.; Xiang, R.; Eremeev, G. V.; Kneisel, P.; Stirbet, M.; Turlington, L.

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Thomas Jefferson Lab National Accelerator Facility (TJNAF) we have fabricated and tested two 1.3 GHz 3.5 cell photo-injector cavities from polycrystalline RRR niobium and large grain RRR niobium, respectively. The cavity with the better performance will replace the presently used injector cavity in the ELBE linac. The cavities have been fabricated and pre-tuned at TJNAF, while the more sophisticated final field tuning, the adjustment of the external couplings and the field profile measurement of transverse electric modes for RF focusing was done at HZDR. The following standard surface treatment and the vertical test was carried out at TJNAF's production facilities. A major challenge turned out to be the rinsing of the cathode cell, which has small opening (O-slash10mm) to receive the cathode stalk. Another unexpected problem encountered after etching, since large visible defects appeared in the least accessible cathode cell. This contribution reports about our experiences, initial results and the on-going diagnostic work to understand and fix the problems
BNL superconducting RF guns - technology challenges as ERL sources

International Nuclear Information System (INIS)

Burrill, A.; Ben-Zvi, I.; Calaga, R.; Chang, X.; Hahn, H.; Kayran, D.; Kewisch, J.; Litvinenko, V.; McIntyre, G.; Nicoletti, A.; Pate, D.; Rank, J.; Scaduto, J.; Rao, T.; Wu, K.; Zaltsman, A.; Zhao, Y.; Bluem, H.; Cole, M.; Falletta, M.; Holmes, D.; Peterson, E.; Rathke, J.; Schultheiss, T.; Todd, A.; Wong, R.; Lewellen, J.; Funk, W.; Kneisel, P.; Phillips, L.; Preble, J.; Janssen, D.; Nguyen-Tuong, V.

2005-01-01

The design, fabrication and commissioning of a 703.75 MHz SRF photoinjector with a retractable multi-alkali photocathode designed to deliver 0.5A average current at 100% duty factor is the present undertaking of the electron cooling group in the Collider Accelerator Division of Brookhaven National Labs. This photoinjector represents the state of the art in photoinjector technology, orders of magnitude beyond the presently available technology, and should be commissioned by 2007. The RandD effort presently underway, and the focus of this paper, will address the numerous technological challenges that must be met for this project to succeed. These include the novel physics design of the cavity, the challenges of inserting and operating a multi-alkali photocathode in the photoinjector at these high average currents, and the design and installation of a laser system capable of delivering the required 10s of watts of laser power needed to make this photoinjector operational
Mean field for the p + 90Zr system in the energy range -60 MeV 90Zr from a dispersive optical-model analysis

International Nuclear Information System (INIS)

Romanovsky, E.A.; Bespalova, O.V.; Goncharov, S.A.; Pleshkov, D.V.; Spasskaya, T.I.

2000-01-01

Data on the scattering of protons with energies 5 MeV 90 Zr nuclei and data on the energies of proton particle and hole levels in the A + 1 and A - 1 systems with A = 90 are analyzed within the dispersive optical model. The parameters of the mean proton field for 90 Zr are determined in the energy range -60 MeV 3 He), ( 3 He, d), (n, d), and (d, n) reactions for levels near the Fermi surface and in (e, e'p) and (p, 2p) reactions for deep levels
Product conveying system for 10 MeV electron beam accelerator for electron beam centre, Kharghar, Navi Mumbai

International Nuclear Information System (INIS)

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

2003-01-01

In industrial radiation processing applications using accelerators, product conveying system plays a vital role in exposing the product to high energy electron beam for imparting specified dose to the product and delivering required through puts. The speed of the conveyor corresponds to a definite time of exposure of the product in the radiation zone. Design of suitable conveyor system for a variety of products with differing dose requirements call for a conveyor with wide speed range. This paper discusses the design features of a suitable under beam conveyor system for 10 MeV, 10 kW accelerator for processing a range of products including medical and food products
Small angle particle-particle correlation measurements in the reactions 280 MeV 40Ar+27Al and 670 MeV 55Mn+12C

International Nuclear Information System (INIS)

Milosevich, Zoran; Vardaci, Emanuele; DeYoung, Paul A.; Brown, Craig M.; Kaplan, Morton; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Barton, Matthew; Karol, Paul J.; McMahan, Margaret A.

2001-01-01

Small-angle particle-particle correlations were measured in the two matching reactions 280 MeV 40 Ar+ 27 Al and 670 MeV 55 Mn+ 12 C. These two reactions were used to produce the composite nucleus, 67 Ga*, at the same initial excitation energy of 127 MeV, but with different entrance channel angular momentum distributions. A simple trajectory model was used to compute the average emission times between various particle pairs, and comparisons with the data show that there is a significant difference in the deexcitation of the composite nucleus formed from the two reactions. Statistical model calculations were compared to the experimental observations with the added constraint that the model input parameters were consistent with those derived from observed charged-particle energy spectra and angular distributions. It was found that the calculated correlation functions were insensitive to the input spin distributions, but agreed fairly well with the data from the lower-spin system. The higher-spin reaction data were poorly reproduced by the calculations
Mechanical design of beam extractor system for cyclotron proton 13 MeV

International Nuclear Information System (INIS)

Ihwanul Aziz; Widdi Usada

2012-01-01

Mechanical design of beam extractor system for 13 MeV proton cyclotron has been carried out. In cyclotron there are two extractor systems, the first is electrostatic deflector system, and the second is stripper system. This stripper serves to change negative charged of hydrogen ions to become positive charged hydrogen ions (protons). In proton cyclotron, the carbon foil is used as a stripper. Mechanical extractor system consists of a carbon foil holder and a driver system to control the position of foil holder and to change the foil. The driver system consists of a stepper motor extractor, a feed-through, a gear, a shaft, and a buffer. After some calculation the obtained component data as the foil follow holder is made of aluminum has total length of 12.25 mm, total width of 10 mm and the total thickness of 2.5 mm, while the length of each extractor arm is made of aluminum 90 mm, width is 30 mm, its height is 10 mm , the total volume is 7,392 x 10-5 and a mass of 0.1995 kg. Extractor drive system includes a stepper motor having a maximum of 4 lb-ft of torque, feed through, gear, shaft, and a buffer. Required torque is 0.16 Nm or 0.12 lb-ft diameter shaft to support the extractor arm is 29 mm. Bolt fastener for the buffer is a type of metric M6 bolt, so that the used seals viton O-ring with seal diameter of 6 mm and DN 40 CF flange. (author)
2 MeV/20 kW industrial electron beam accelerator vis-s-vis its vacuum system

International Nuclear Information System (INIS)

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

2003-01-01

Full text: Electron beam accelerators in the energy range 200 keV to 10 MeV have been extensively used for many radiation processing applications that include polymerization, polymer modifications, radiation sterilization, food irradiation and gem coloration. The accelerator technology is a multidisciplinary one wherein production of stable vacuum in various accelerator systems is of utmost importance to achieve required output beam parameters like beam energy and current for processing industrial products at large through puts on continuous basis. A 2 MeV, 20 kW industrial electron beam accelerator has been in operation since 2001 at BARC-BRIT complex, Navi Mumbai for commercial and R and D applications like crosslinking of wire and cables, heat shrinkable tubes, PE O rings, PTEE degradation and color enhancement in diamonds. The machine is a ILU-6 type pulse RF accelerator consisting of a single resonator copper cavity of 1.2 m diameter and 1.2 m height (volume:∼ 1.5 m3) placed inside a stainless steel container (called cavity container) and a s.s. beam extraction window wherein vacuum needs to be maintained at a minimum 10-6 torr. Four sputter ion pumps are directly fixed on the cavity container to obtain maximum pumping efficiency. The fore vacuum is generated using a combination rotary and a roots pump. The beam extraction widow has a 50 and 956 m thick titanium foil acting as the exit window for electrons from the vacuum into air. Both the cavity and the beam extraction window are coupled through a gate valve which acts as a vacuum separator isolating the systems from each other during foil puncture, scanning system failure or any other related problems. This paper reports details of the vacuum system, measurements, vacuum leaks and detection and the operational experience related to maintenance and troubleshooting exercises that have been carried in the accelerator
Study of the gamma spectra emitted in a nuclear reaction - Measurement of the half-lives of the levels 6.13 MeV, 6.92 MeV and 7.12 MeV of 16O

International Nuclear Information System (INIS)

Leccia, F.

1967-01-01

When the energy shifts of the gamma spectrum released during a nuclear reaction are important compared with the detector resolution, the comparison of the experimental spectrum with theoretical spectra allows us to determine the half-life of the initial state of the transition. The calculation of the experimental spectrum implies to know the slowing-down of the recoil nucleus in the matter in order to take into account the Doppler effect. For recoil energies in the range of the MeV and for solid media, the Lindhard theory agrees well with experimental data. The phenomenon of deflection which appears at very low energies must be taken into account by restraining the measurement domain. By choosing an adequate media we can measure half-lives in the domain 1 and 100 fs without needing to take into account deflection effects. We have measured the half-life of the first 3 energy levels of 16 O (6.135 MeV, 6.923 MeV and 7.121 MeV), these levels are reached through the reaction 19 F(p,αγ) 16 O with proton incident energies ranging from 0.872 MeV to 2.42 MeV. We have used a coaxial germanium semi-conductor with lithium additions that was connected to an amplification line of Ortec type. 2 kinds of target have been used: calcium fluoride and copper fluoride evaporated on tantalum support. We have obtained the following values for the half-life: (16±4) fs for the 6.923 MeV level, (18±4) fs for the 7.121 MeV level, and for the 6.135 MeV we can only give a lower limit since the gamma decay occurs when the nucleus is at rest τ > 200 fs
Positron acceleration to 200 MeV

International Nuclear Information System (INIS)

Leboutet, H.

1983-01-01

220 MeV is the energy that has to be obtained in routine operation. A standard 12m girder with SLED II can give 220 MeV minus a few percent due to not riding at the crest of the wave. In order to have the 200 MeV with only one girder, a klystron at full power all the time would be required - kept brand new. Then, for safety it is necessary to use two klystrons as designated in the SLC design. Having two klystrons gives freedom for the choice of the best arrangement. Since there will be excess rf power, it can be traded against higher gradient, shorter waveguides, larger apertures (lower shunt impedence)
Neutron multiplicity in deep inelastic collisions: 400 MeV Cu + Au system

International Nuclear Information System (INIS)

Tamain, B.; Chechik, R.; Ruchs, H.; Hanappe, F.; Morjean, M.; Ngo, C.; Peter, J.; Dakowski, M.; Lucas, B.; Mazur, C.; Ribrag, M.; Signarbieux, C.

1979-01-01

The authors have detected in nine different positions of space the neutrons associated with the collision of 63 Cu on 197 Au at 400 MeV bombarding energy. The deep inelastic products were detected at two different angles: close to the gazing angle and 30 0 forwards of it. Their measses were measured using a time-of-flight technique. The neutrons were detected in coincidence with the fragments - the efficiency of the neutron detectors was measured relatively to a 252 Cf source during beam time. The neutron threshold was set at 300 keV. Within an accuracy of 10% all the emitted neutrons are evaporated by the fully accelerated deep inelastic fragments. It is shown that the excitation energy is shared between the fragments in proportion to their masses and that the relaxation time for internal equilibration of the composite system is very short (approximately 10 -22 s). (Auth.)
New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-11

For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm{sup 3} TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm){sup 3} medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm){sup 3} ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from ~10% to ~100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.
A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

International Nuclear Information System (INIS)

Kumar, M. Vinay; Krishnaveni, S.; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani

2015-01-01

The impact of 30MeV boron 4+ and 60MeV oxygen 8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor
Progress report on the 14-MeV fission cross section measurements

International Nuclear Information System (INIS)

1979-01-01

The development of a recoil proton monitor was completed. It will be used to measure the neutron flux in the 14-MeV fisson cross section measurements. Extensive calculations of the efficiency of this monitor were made and compared with the calculations of other authors. It is clear that a major source of uncertainty in the efficiency is the lack of precise knowledge of the angular distribution of the n-p elastic scattering cross section. This leads to a change in efficiency of 3% depending on the form of the angular distribution that is used. A 4πβ-γ coincidence system was assembled to investigate the K-correction in determining the absolute activity of foil sources. Iron foils will be used as secondary flux standards in comparing the 14-MeV neutron flux with the fluxes in other laboratories, so this is an important correction to measure. The target and target holders that will be used in the 14-MeV measurements were designed and constructed. Preparations were completed to measure the angular distribution of the fission fragments produced in neutron-induced fission at 14 MeV. 2 figures
Recoil proton polarization of neutral pion photoproduction from proton in the energy range between 400 MeV and 1142 MeV

International Nuclear Information System (INIS)

Kato, S.; Miyachi, T.; Sugano, K.; Toshioka, K.; Ukai, K.

1979-08-01

The recoil proton polarization of the reaction γp → π 0 p were measured at a C.M. angle of 100 0 for incident photon energies between 451 and 1106 MeV, and at an angle of 130 0 for energies from 400 MeV to 1142 MeV. One photon decayed from a π 0 -meson and a recoil proton were detected in coincidence. Two kinds of polarization scatterers were employed. In the range of proton kinetic energy less than 420 MeV and higher than 346 MeV, carbon plates and liquid hydrogen were used for determining the polarization. Results are compared with recent phenomenological analyses. From the Comparison between the present data and the asymmetry data given by the polarized target, the contribution of the invariant amplitudes A 3 can be estimated to be small at 100 0 . (author)
Experimental determination of the cross sections of the n-3He-system in the energy range of 1 to 40 MeV

International Nuclear Information System (INIS)

Haesner, B.

1982-08-01

Cross sections have been measured in the n+ 3 He-system over a broad energy range. The experiments were conducted using the pulsed white neutron beam at the Karlsruhe Neutron Time of Flight Facility. The total cross sections were measured from 1-40 MeV using the 190 m flight path with 1.5 ns time resolution. This represents a substantial improvement over previous measurements. Angular distributions (THETAsub(c.m.) = 33 0 -179 0 ) for the elastic n- 3 He scattering were measured simultaneously in the energy range from 5 to 30 MeV. A liquid 3 He scintillation detector was used as the scatterer. The statistical errors are less than 2% for most (> 90%) of the data. Through the use of the L 3 He detector absolute cross sections for the neutron induced reactions 3 He(n,p)T and 3 He(n,d)D could be measured from 1 to 30 MeV. These measurements are in good agreement with the results of the corresponding (p,n) and (d,n) reactions using detailed balance. (orig.) [de
200 MeV RF linac for synchrotron injection

International Nuclear Information System (INIS)

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

1992-01-01

Construction has been completed on an electron linear accelerator for the Brookhaven National Laboratory. This accelerator will be used for the injection of a 200 MeV electron beam into a synchrotron for lithography experiments. This paper describes the conceptual design of the linac, its e-gun pulser, and its control and timing systems. 3 figs., ref
Conversion efficiency of lead for 30-200 MeV photons

International Nuclear Information System (INIS)

Darriulat, P.; Gygi, E.; Holder, M.; McDonald, K.T.; Pugh, H.G.; Schneider, F.; Tittel, K.

1975-01-01

The conversion efficiency of lead has been measured as a function of thickness for 44 MeV, 94 MeV and 177 MeV photons, and as a function of energy between 29 MeV and 177 Mev for thickness of one and two radiation lengths. Some additional information on multiplicity of secondary tracks and on their angular distribution was obtained using a small streamer chamber. The results obtained confirm the shower calculations of Messel and Crawford. (Auth.)

Investigation of transversal nuclear excitation in 208Pb at excitation energies between 6 MeV and 8 MeV using inelastic electron scattering

International Nuclear Information System (INIS)

Frey, R.W.

1978-01-01

Using high resolution inelastic electron scattering magnitic dipole and quadrupole excitations in 208 Pb were investigated in the energy range between 6 MeV and 8 MeV. The electron energy was 50 MeV and 63.5 MeV. With a mean absolute energy resolution of 33 kev. 44 excited states were found in the above energy range. The measured angular distributions were compared with DWBA-calculations using random phase approximated wave functions. (FKS)
CHARACTERIZATION OF 27 MEV PROTON BEAM GENERATED BY TOP-IMPLART LINEAR ACCELERATOR.

Science.gov (United States)

De Angelis, C; Ampollini, A; Basile, E; Cisbani, E; Della Monaca, S; Ghio, F; Montereali, R M; Picardi, L; Piccinini, M; Placido, C; Ronsivalle, C; Soriani, A; Strigari, L; Trinca, E; Vadrucci, M

2018-01-29

The first proton linear accelerator for tumor therapy based on an actively scanned beam up to the energy of 150 MeV, is under development and construction by ENEA-Frascati, ISS and IFO, under the Italian TOP-IMPLART project. Protons up to the energy of 7 MeV are generated by a customized commercial injector operating at 425 MHz; currently three accelerating modules allow proton delivery with energy up to 27 MeV. Beam homogeneity and reproducibility were studied using a 2D ionizing chamber, EBT3 films, a silicon diode, MOSFETs, LiF crystals and alanine dosimetry systems. Measurements were taken in air with the detectors at ~1 m from the beam line exit window. The maximum energy impinging on the detectors surface was 24.1 MeV, an energy suitable for radiobiological studies. Results showed beam reproducibility within 5% and homogeneity within 4%, on a circular surface of 16 mm in diameter. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Record high-average current from a high-brightness photoinjector

Energy Technology Data Exchange (ETDEWEB)

Dunham, Bruce; Barley, John; Bartnik, Adam; Bazarov, Ivan; Cultrera, Luca; Dobbins, John; Hoffstaetter, Georg; Johnson, Brent; Kaplan, Roger; Karkare, Siddharth; Kostroun, Vaclav; Li Yulin; Liepe, Matthias; Liu Xianghong; Loehl, Florian; Maxson, Jared; Quigley, Peter; Reilly, John; Rice, David; Sabol, Daniel [Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States); and others

2013-01-21

High-power, high-brightness electron beams are of interest for many applications, especially as drivers for free electron lasers and energy recovery linac light sources. For these particular applications, photoemission injectors are used in most cases, and the initial beam brightness from the injector sets a limit on the quality of the light generated at the end of the accelerator. At Cornell University, we have built such a high-power injector using a DC photoemission gun followed by a superconducting accelerating module. Recent results will be presented demonstrating record setting performance up to 65 mA average current with beam energies of 4-5 MeV.
6 MeV RF Linac for cargo scanning and industrial radiography

International Nuclear Information System (INIS)

2017-01-01

RF Linac-based X-ray sources are very widely used for cargo-scanning and industrial X-ray radiography applications. A 6 MeV on-axis coupled-cavity S-band RF linac has been designed, developed and tested successfully at Electron Beam Centre, Navi Mumbai. This facility falls under the purview of BARC Safety Council, which has conducted safety reviews and awarded regulatory clearances for the operation of the linac system. This paper outlines the salient features of the 6 MeV linac, its safety aspects and test results. A brief history of regulatory aspects is also presented
Fusion with projectiles form carbon to argon at energies between 20A and 60A MeV

International Nuclear Information System (INIS)

Galin, J.

1986-03-01

A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MEV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behaviour. Finally, the decay of highly excited (E* approximately 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space
Suppression of X-radiation from 2 MeV ion electrostatic accelerator

International Nuclear Information System (INIS)

Ignat'ev, I.G.; Miroshnichenko, V.I.; Sirenko, A.M.; Storizhko, V.E.

2008-01-01

The paper presents results concerning studies of X-radiation from 2 MeV ion electrostatic accelerator 'Sokol' used for nuclear microprobe analysis. The radiation protection system of the accelerator was developed and tested. Tests of the system of the accelerator show that it reduces doses rate by two orders of magnitude
Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code

Science.gov (United States)

Peri, Eyal; Orion, Itzhak

2017-09-01

High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.
The reaction p12C→ηX from Tp=800 MeV to Tp=1500 MeV

International Nuclear Information System (INIS)

Chiavassa, E.; Dellacasa, G.; De Marco, N.; De Oliveira Martins, O.; Gallio, M.; Guaita, P.; Musso, A.; Piccotti, A.; Scomparin, E.; Vercellin, E.

1998-01-01

The reaction p 12 C→nX has been studied, at several proton kinetic energies ranging from 800 MeV to 1500 MeV, at the proton synchrotron Saturne at Saclay. The measured doubly differential cross-sections are presented and discussed in the framework of a simple theoretical model. The model fails in describing the deepest subthreshold data while the above-threshold data are fairly well reproduced. (orig.)
Review of neutron data: 10 to 40 MeV

Energy Technology Data Exchange (ETDEWEB)

Haight, R.C.

1977-04-01

Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed.
Review of neutron data: 10 to 40 MeV

International Nuclear Information System (INIS)

Haight, R.C.

1977-04-01

Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed
Measurement of neutron captured cross-sections in 1-2 MeV

Energy Technology Data Exchange (ETDEWEB)

Kim, Gi Dong; Kim, Young Sek; Kim, Jun Kon; Yang, Tae Keun [Korea Institutes of Geoscience and Mineral Resources, Taejeon (Korea)

2001-04-01

The measurement of neutron captured reaction cross sections was performed to build the infra system for the production of nuclear data. MeV neutrons were produced with TiT target and {sup 3}T(p,n){sup 3}He reaction. The characteristics of TiT thin film was analyzed with ERD-TOF and RBS. The results was published at Journal of the Korea Physical Society (SCI registration). The energy, the energy spread and the flux of the produced neutron were measured. The neutron excitation functions of {sup 12}C and {sup 16}O were obtained to confirm the neutron energy and neutron energy spread. The neutron energy spread found to be 1.3 % at the neutron energy of 2.077 MeV. The {sup 197}Au(n,{gamma}) reaction was performed to obtain the nerutron flux. The maximum neutron flux found to be 1 x 10{sup 8} neutrons/sec at the neutron energy of 2 MeV. The absolute efficiency of liquid scintillation detector was obtained in the neutron energy of 1 - 2 MeV. The fast neutron total reaction cross sections of Cu, Fe, and Au were measured with sample in-out method. Also the neutron captured reaction cross sections of {sup 63}Cu were measured with fast neutron activation method. The measurement of neutron total reaction cross sections and the neutron captured reaction cross sections with fast neutrons were first tried in Korea. The beam pulsing system was investigated and the code of calculating the deposition spectrums for primary gamma rays was made to have little errors at nuclear data. 25 refs., 28 figs., 14 tabs. (Author)
Ultra high vacuum system of the 3 MeV electron beam accelerator

International Nuclear Information System (INIS)

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

2003-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Kato, Takao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1997-11-01

A 200-MeV proton linear accelerator for the Japanese Hadron Project (JHP) has been designed. It consists of a 3-MeV radio-frequency quadrupole linac (RFQ), a 50-MeV drift tube linac (DTL) and a 200-MeV separated-type drift tube linac (SDTL). A frequency of 324 MHz has been chosen for all of the rf structures. A peak current of 30 mA (H{sup -} ions) of 400 {mu}sec pulse duration will be accelerated at a repetition rate of 25 Hz. A future upgrade plan up to 400 MeV is also presented, in which annular-coupled structures (ACS) of 972 MHz are used in an energy range of above 150 or 200 MeV. One of the design features is its high performance for a beam-loss problem during acceleration. It can be achieved by separating the transition point in the transverse motion from that of the longitudinal motion. The transverse transition at a rather low-energy range decreases the effects of space-charge, while the longitudinal transition at a rather high-energy range decreases the effects of nonlinear problems related to acceleration in the ACS. Coupled envelope equations and equipartitioning theory are used for the focusing design. The adoption of the SDTL structure improves both the effective shunt impedance and difficulties in fabricating drift tubes with focusing magnets. An accurate beam-simulation code on a parallel supercomputer was used for confirming any beam-loss problem during acceleration. (author)
Fission cross section measurements at the LLL 100-MeV linac

International Nuclear Information System (INIS)

Browne, J.C.

1975-01-01

The fission cross section for 235 U was measured from thermal energy to 20 MeV in several steps. First, the cross section was measured from 8 MeV to 20 MeV relative to the n,p scattering cross section and then from thermal to one MeV relative to 6 Li(n,α). In addition, a measurement of the ratio of the fission cross sections of 235 U and 238 U relative to 235 U has been completed in the range 1 keV to 30 MeV for 233 U and 100 keV to 30 MeV for 238 U. Statistical uncertainties are less than 4 percent. (U.S.)
Parity violation in proton-proton scattering at 230 MEV

International Nuclear Information System (INIS)

Birchall, J.; Bowman, J.D.; Davis, C.A.

1988-01-01

Below /similar to/300 MeV six meson-nucleon coupling strengths are required to describe the weak interaction of nucleons. Many experiments have found parity-violating effects in nuclear systems, but only four significant, independent constraints exist. A new measurement is proposed where measurable effects are predicted with minimal dependence on nuclear interaction models, yielding information complementary to previous results. This is a measurement of the parity-violating analyzing power. A/sub z/ in p-p scattering at 230 MeV, which is shown to be sensitive to the weak rho-nucleon coupling. This measurement, at a precision of +- 2 x 10/sup -8/, together with a proposed measurement by the University of Washington group at I.L.L. of the parity-violating neutron spin rotation, will provide the fifth and sixth independent constraints needed to determine the weak meson-nucleon coupling constants
Photospallation reactions of 133Cs and 139La by 100 MeV- and 200 MeV bremsstrahlungs

International Nuclear Information System (INIS)

Sakamoto, K.; Toramoto, H.; Hamajima, Y.; Okada, K.; Dohniwa, M.

1984-01-01

Spallation yields relative to the 196 Au yield from 197 Au(γ,n) of 26 to 46 nuclides of Sb, Te, I, Xe, Cs and/or Ba and La from 133 Cs and 139 La targets irradiated with bremsstrahlungs of end energies of 100 MeV and 200 MeV were radiochemically determined. The isomeric yield ratios for 132 La and 131 Ba from the ( 139 La + 100 MeV-γ), 132 La, 131 Ba, 121 Te and 119 Te from the ( 139 La + 200 MeV-γ, and 120 I, 121 Te and 119 Te from the ( 133 Cs +- 200 MeV-γ) were also determined. The isotopic yields from the (γ,yn) reactions decrease exponentially with increase of y up to 5, and show no dependence on energy and targets studied, indicating that the reactions of a few neutron emissions occur at energies lower than 100 MeV. When the product yields from the (γ,xpyn) reactions were plotted against (x + y) for each x (isotopic distribution), a regular variation of the Gaussian distributions, typical of nuclear spallation, was observed. Isobaric mass distributions and charge dispersions were deduced to extract characteristic features of these reactions. The isobaric distributions due only to photons of 100 MeV to 200 MeV, which were obtained by subtracting the 100 MeV-yields from the 200 MeV-yields, are very close to a symmetric one peaking at about 8 amu from the target masses. Nuclear charges are also dispersed symmetrically, with most probable N/Zsub(p) of about 1.3 replaced by about 1 amu to the neutron-deficient side from the beta stability valley in all the cases studied. Parameters included in Rudstam's semi-empirical formula were examined by comparing with the observed yield curves. The P values of 0.45 and 0.65, chosen for a better fit to the 200 MeV data on 133 Cs and 139 La, respectively, were larger than the predictions reported in the literature. The magic number effects of 139 La may explain the target-differences in mass distributions. (orig.)
High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor

Energy Technology Data Exchange (ETDEWEB)

Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu

1996-10-01

A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)
Cluster decay channel in 238U + 40Ar (243 MeV)

International Nuclear Information System (INIS)

Pyatkov, Yu.V.; Penionzhkevich, Yu.Eh.; Osetrov, O.I.

1999-01-01

The reaction 238 U + 40 Ar (E lab = 243 MeV) was studied. For the first time a pronounced fine structure (FS) in the form of distinct peaks has been observed in the mass yields of the fragments of the 278 110 nuclear system decay at the initial excitation of about 60 MeV. The FS peaks are located in the vicinity of the mass numbers A ∼ 70, 100, 130, which are specific for magic nuclei (clusters) of Ni, Ge, Zr, Sn, Sr. The FS peaks contain only low-energy events linked with the very elongated prescission configurations of the system. Some events are observed which can be treated as an indication of ternary fission via such configurations with the appearance of two equal clusters. Hence presumably the collinear cluster tripartition channel is realized observed earlier in the spontaneous fission of 248 Cm and 252 Cf nuclei
First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

CERN Multimedia

Linac4 Project Team

2013-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Blomberg, Ben [NICADD, DeKalb; Mihalcea, Daniel [NICADD, DeKalb; Panuganti, Harsha [NICADD, DeKalb; Piot, Philippe [Fermilab; Brau, Charles [Vanderbilt U.; Choi, Bo [Vanderbilt U.; Gabella, William [Vanderbilt U.; Ivanov, Borislav [Vanderbilt U.; Mendenhall, Marcus [Vanderbilt U.; Lynn, Christopher [Swarthmore Coll.; Sen, Tanaji [Fermilab; Wagner, Wolfgang [Forschungszentrum Dresden Rossendorf

2014-07-01

In this contribution we describe the technical details and experimental setup of our study aimed at producing high-brightness channeling radiation (CR) at Fermilab’s new user facility the Advanced Superconducting Test Accelerator (ASTA). In the ASTA photoinjector area electrons are accelerated up to 40-MeV and focused to a sub-micron spot on a ~40 micron thick carbon diamond, the electrons channel through the crystal and emit CR up to 80-KeV. Our study utilizes ASTA’s long pulse train capabilities and ability to preserve ultra-low emittance, to produce the desired high average brightness.

The LLNL/UCLA high gradient inverse free electron laser

Energy Technology Data Exchange (ETDEWEB)

Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)

2012-12-21

We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.
Status and initial commissioning of a high gain 800 nm SASE FEL

CERN Document Server

Tremaine, Aaron M; Murokh, A; Musumeci, P; Pellegrini, C; Rosenzweig, J; Babzien, M; Ben-Zvi, I; Johnson, E; Malone, R; Rakowsky, G; Skaritka, J; Wang, X J; Yu, L H; Van Bibber, K A; Hill, J M; Le Sage, G P; Carr, R; Cornacchia, M; Nuhn, H D; Ruland, R; Nguyen, D C

2000-01-01

We describe the status and initial commissioning of the Visible to Infrared SASE Amplifier (VISA) experiment. VISA uses a strong focusing 4 m undulator, the Brookhaven National Laboratory ATF linac with an energy of 72 MeV, and a photoinjector electron source. The VISA fundamental radiation wavelength is near 800 nm and the power expected at saturation is near 60 MW. Power, angular and spectral measurements are planned for the VISA radiation and these results will be analyzed and compared with SASE FEL theory and computer simulation. In addition, the induced electron beam micro-bunching will be measured using coherent transition radiation.
Status and initial commissioning of a high gain 800 nm SASE FEL

International Nuclear Information System (INIS)

Tremaine, A.; Frigola, P.; Murokh, A.; Musumeci, P.; Pellegrini, C.; Rosenzweig, J.; Babzien, M.; Ben-Zvi, I.; Johnson, E.; Malone, R.; Rakowsky, G.; Skaritka, J.; Wang, X.J.; Yu, L.H.; Van Bibber, K.A.; Hill, J.M.; Le Sage, G.P.; Carr, R.; Cornacchia, M.; Nuhn, H.-D.; Ruland, R.; Nguyen, D.C.

2000-01-01

We describe the status and initial commissioning of the Visible to Infrared SASE Amplifier (VISA) experiment. VISA uses a strong focusing 4 m undulator, the Brookhaven National Laboratory ATF linac with an energy of 72 MeV, and a photoinjector electron source. The VISA fundamental radiation wavelength is near 800 nm and the power expected at saturation is near 60 MW. Power, angular and spectral measurements are planned for the VISA radiation and these results will be analyzed and compared with SASE FEL theory and computer simulation. In addition, the induced electron beam micro-bunching will be measured using coherent transition radiation
An Injector for the CLIC Test Facility (CTF3)

CERN Document Server

Braun, H; Rinolfi, Louis; Zhou, F; Mouton, B; Miller, R; Yeremian, A D

2000-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed.
An Injector for the CLIC Test Facility (CTF3)

International Nuclear Information System (INIS)

Miller, Roger H.

2001-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed
An injector for the CLIC test Facility (CTF3)

CERN Document Server

Braun, Hans-Heinrich; Rinolfi, L.; Zhou, F.; Mouton, B.; Miller, R.; Yeremian, D.

2008-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed.
The Fermilab 400-MeV Linac Upgrade

International Nuclear Information System (INIS)

Schmidt, C.W.

1993-05-01

The Fermilab Linac Upgrade will increase the linac energy from 201 MeV to 401.5 MeV. Seven accelerating modules, composed of 805-MHz side-coupled cells, will accelerate H - beams from 116.5 to 401.5 MeV. The side-coupled structure (SCS) has been built, tuned, tested to full power, and placed in the linac enclosure along side the operating Linac. All seven accelerating modules, each containing four sections of sixteen cells, have been connected to 12-MW power klystrons and tested to full power for a significant period. The transition section to match the beam from the 201.25-MHz drift-tube linac to the SCS, consisting of a sixteen-cell cavity and a vernier four-cell cavity, has also been tested at full power. A new import line from the Linac to the Booster synchrotron with a new Booster injection girder is to be installed. Removal of the last four Alvarez linac tanks (116.5 to 201 MeV) and beam-line installation of the Upgrade components is to begin in early June 1993 and should take about 12 weeks. Beam commissioning of the project will follow and normal operation is expected in a short period. In preparation for beam commissioning, studies are being done with done operating linac to characterize the beam at transition and prepare for phase, amplitude and energy measurements to commission the new linac. The past, present and future activities of the 400-MeV Upgrade will be reviewed
Measures of gamma rays between 0,3 MeV and 3,0 MeV and of the 0,511 MeV annihilation line coming from Galactic Center Region

International Nuclear Information System (INIS)

Jardim, M.V.A.

1982-04-01

The detection of the flux of the electron-positron annihilation line coming from the Galactic Center direction allows one to estimate the rate of positrons production and the corresponding luminosity. The results of measurements of the annihilation line flux intensity at 0.511 MeV, obtained with a balloon borne experiment to measure gamma rays in the energy interval 0.3 to 3 MeV are presented. The detector looked at the galactic disk in the longitude interval -31 0 0 and observed a flux intensity of (6.70 +- 0.85) x 10 -3 photons cm -2 s -1 , which is in good agreement with the flux value estimated assuming that the Galactic Center is a line source emitting uniformly. Some likely sources of positrons and annhilation regions are also discussed. The results for the continuum spectrum emitted from the Galactic Center in the energy interval 0.3 to 0.67 MeV are presented and compared with measurements had already made. (Author) [pt
Emission of light charged particles from fragments produced on fission of uranium nuclei by 153 MeV protons and 1700 MeV negative pions

International Nuclear Information System (INIS)

Belovitzky, G.E.; Shteingrad, O.M.

2000-01-01

The mechanism underlying the emission of light charged particles (LCP) with Z = 1, 2 from fragments produced in fission of uranium nuclei by 153 MeV protons and 1700 MeV negative pions was studied. It was found that LCP accompanying the fission by pions are emitted from non-accelerated fragments immediately after the fission, whereas in the case of 153 MeV protons, the LCP are emitted from the accelerated heavy fragments. The number of LCP emitted in the course of pion-induced fission is 0.7 per fission event, which exceeds by a factor of 30 the corresponding number for 153 MeV protons [ru
Gamma ray multiplicity study associated at fast fission in Ne + Re at 220 MeV and Ar + Ho at 315 MeV collisions

International Nuclear Information System (INIS)

Martin, V.

1987-11-01

Angular momentum transfer to fission fragments has been studied with the measurement of gamma-ray deexcitation in the 220 MeV Ne + Re and 315 MeV Ar + Ho systems. These reactions lead to the same fusion nucleus with the same excitation energy. The critical angular momentum for fission in the Ne + Re system is close to the angular momentum where the fission barrier of the fusion nucleus vanishes. In the Ar + Ho system, the critical angular momentum is much more larger than the angular momentum and the fast fission process is then expected to occur in that system. The measurement of the widths of the fission fragment mass distribution strengthens this hypothesis: the width is equal to 42 ± 2 u.m.a in the Ne + Re system and 56 ± 4 u.m.a in the Ar + Ho system. The results obtained by measuring the gamma-ray multiplicity associated with the fission modes show that the spin transferred to the fragments is large and confirm the excitation of some collective rotational modes in the exit channel such as bending and wriggling modes. The evolution of the gamma-ray multiplicity as a function of the total kinetic energy shows a marked behaviour in the two systems: in the Ne + Re system, the multiplicity decreases when the kinetic energy increases in the Ar + Ho system the multiplicity increases when the kinetic energy increases. The information extracted from these results show that the mass distribution associated with the fast fission process has a symetric shape, but this information is not sufficient to isolate unambiguously the partial wave domain associated with the conventional fission and the fast fission phenomena, respectively [fr
Neutron Energy Spectra from Neutron Induced Fission of 235U at 0.95 MeV and of 238U at 1.35 and 2.02 MeV

Energy Technology Data Exchange (ETDEWEB)

Almen, E; Holmqvist, B; Wiedling, T

1971-09-15

The shapes of fission neutron spectra are of interest for power reactor calculations. Recently it has been suggested that the neutron induced fission spectrum of 235U may be harder than was earlier assumed. For this reason measurements of the neutron spectra of some fissile isotopes are in progress at our laboratory. This report will present results from studies of the energy spectra of the neutrons emitted in the neutron induced fission of 235U and 238U. The measurements were performed at an incident neutron energy of 0.95 MeV for 235U and at energies of 1.35 and 2.02 MeV for 238U using time-of-flight techniques. The time-of-flight spectra were only analysed at energies higher than those of the incident neutrons and up to about 10 MeV. Corrections for neutron attenuation in the uranium samples were calculated using a Monte Carlo program. The corrected fission neutron spectra were fitted to Maxwellian temperature distributions. For 235U a temperature of 1.27 +- 0.01 MeV gives the best fit to the experimental data and for 238U the corresponding values are 1.29 +- 0.03 MeV at 1.35 MeV and 1.29 +- 0.02 MeV at 2.02 MeV
Activation analysis course experiments with a 14-MeV neutron generator

International Nuclear Information System (INIS)

Miller, D.A.; Miller, G.E.

1976-01-01

The use of a 14 MeV neutron generator system in the radiochemistry teaching program of the Chemistry Department of the University of California at Irvine is described. Several different types of experiment are outlined to indicate the broad applicability of such a system to an instructional program in Chemistry. The program has encompassed instruction of undergraduates, graduate students and a Summer Institute Workshop for College Professors
Escaping 1 MeV tritons in TFTR

International Nuclear Information System (INIS)

Zweben, S.J.; Strachan, J.D.; Boivin, R.; Cavallo, A.; Fredrickson, E.D.; McGuire, K.; Mynick, H.E.; White, R.B.

1989-01-01

1 MeV tritons created by D-D reactions can simulate the 'single-particle' behavior expected with 3.5 MeV D-T alphas, since the gyroradii and slowing-down of these two particles are similar. This paper describes measurements of the flux of escaping 1 MeV tritons from the TFTR plasma during high power D 0 →D neutral beam injection, and shows that in most cases the observed triton loss is consistent with the classical (single-particle) first-orbit loss model. In this model tritons are lost if their first orbit intersects the wall due to their large banana width, while almost all tritons confined on their first orbit should stay confined until thermalized. The triton detectors are ZnS(Ag) scintillator screens housed in light-tight boxes located just outside the plasma boundary at the bottom of the TFTR vessel. They are particle 'pinhole' cameras which can resolve the triton flux vs. pitch angle (to ±5 o ), energy (to ±50 %), and time (to <20 μsec). The 2-D images of triton flux onto these scintillators are optically coupled to either an intensified TV camera or to photomultiplyer tubes for fast time resolution. The soft x-ray background in an earlier prototype has been eliminated. Although there are presently 8 such detectors in TFTR, this paper discusses results from only the detector located just below the vessel center (R=259 cm, r=102 cm). Note that the '1 MeV triton' signal discussed below also has about a 30 % contribution from 3 MeV protons; however, since these two particles have identical gyroradii they should behave alike. 5 refs., 5 figs
MeV Mott polarimetry at Jefferson Lab

International Nuclear Information System (INIS)

Steigerwald, M.

2001-01-01

In the recent past, Mott polarimetry has been employed only at low electron beam energies (≅100 keV). Shortly after J. Sromicki demonstrated the first Mott scattering experiment on lead foils at 14 MeV (MAMI, 1994), a high energy Mott scattering polarimeter was developed at Thomas Jefferson National Accelerator Facility (5 MeV, 1995). An instrumental precision of 0.5% was achieved due to dramatic improvement in eliminating the background signal by means of collimation, shielding, time of flight and coincidence methods. Measurements for gold targets between 0.05 μm and 5 μm for electron energies between 2 and 8 MeV are presented. A model was developed to explain the depolarization effects in the target foils due to double scattering. The instrumental helicity correlated asymmetries were measured to smaller than 0.1%
Creation of Nuclear Data Base up to 150 MeV and corresponding scaling approach for ADS

International Nuclear Information System (INIS)

Shubin, Y. N.; Gai, E. V.; Ignatyuk, A. V.; Lunev, V. P.

1997-01-01

The status of nuclear data in the energy region up to 150 MeV is outlined. The specific physical reasons for the detailed investigations of nuclear structure effects is noted out. The necessity of the development of Nuclear Data System for ADS is stressed. The program for the creation of nuclear data base up to 150 MeV and corresponding scaling approach for ADS is proposed. (Author) 14 refs
An I = 1 enhancement at a mass of 1550 MeV in the (Λπ) and (Σπ)-systems

International Nuclear Information System (INIS)

Dionisi, C.; Armenteros, R.; Diaz, J.; Gavillet, Ph.; Gay, J.B.; Gurtu, A.; Hemingway, R.J.; Mazzucato, M.; Trepagnier, P.; Blokzijl, R.; Massaro, G.G.G.; Jongejans, B.; Engelen, J.; Timmermans, J.J.; Walle, R.T. van de; Foster, B.; Lamb, P.R.; McDowell, W.L.

1978-01-01

Evidence is presented for an I = 1 enhancement observed in the reactions K - p → Λ(Σ)K 0 1 K +- π -+ at 4.2 GeV/c incident momentum. The mass and width of the proposed new Y* are, respectively, (1553 +- 7) MeV) and (80 +- 30) MeV. A decay branching ratio Σπ/(Σπ + Λπ) = (35 +- 12)% is also obtained. (Auth.)
Klystron High Power Operation for KOMAC 100-MeV Proton Linac

Energy Technology Data Exchange (ETDEWEB)

Seol, Kyung-Tae; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [KAERI, Daejeon (Korea, Republic of)

2015-05-15

The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. Nine sets of 1MW klystrons have been operated for the 100-MeV proton linac. The klystron filament heating time was approximately 5700 hours in 2014, and RF operation time was 2863.4 hours. During the high power operation of the klystron, unstable RF waveforms appeared at the klystron output, and we have checked and performed cavity frequency adjustments, magnet and heater current, reflection from a circulator, klystron test without a circulator, and the frequency spectrum measurement. Nine sets of the klystrons have been operated for the KOMAC 100-MeV proton linac. The klystron filament heating time was 5700 hours and RF operation time was 2863.4 hours during the operation in 2014. Some klystrons have unstable RF waveforms at specific power level. We have checked and tested the cavity frequency adjustment, reflection from a circulator, high power test without a circulator, and frequency spectrum at the unstable RF.
Nucleon-nucleon partial-wave analysis to 1100 MeV

International Nuclear Information System (INIS)

Arndt, R.A.; Hyslop, J.S. III; Roper, L.D.

1987-01-01

Comprehensive analyses of nucleon-nucleon elastic-scattering data below 1100 MeV laboratory kinetic energy are presented. The data base from which an energy-dependent solution and 22 single-energy solutions are obtained consists of 7223 pp and 5474 np data. A resonancelike structure is found to occur in the 1 D 2 , 3 F 3 , 3 P 2 - 3 F 2 , and 3 F 4 - 3 H 4 partial waves; this behavior is associated with poles in the complex energy plane. The pole positions and residues are obtained by analytic continuation of the ''production'' piece of the T matrix obtained in the energy-dependent solution. The new phases differ somewhat from previously published VPIandSU solutions, especially in I = 0 waves above 500 MeV, where np data are very sparse. The partial waves are, however, based upon a significantly larger data base and reflect correspondingly smaller errors. The full data base and solution files can be obtained through a computer scattering analysis interactive dial-in (SAID) system at VPIandSU, which also exists at many institutions around the world and which can be transferred to any site with a suitable computer system. The SAID system can be used to modify solutions, plan experiments, and obtain any of the multitude of predictions which derive from partial-wave analyses of the world data base
Gamma ray multiplicities in deep inelastic collisions for the Cu+Au 400 MeV system. Interpretation based on collective modes

International Nuclear Information System (INIS)

Berlanger, M.; Borderie, B.; Chapoulard, D.

1981-01-01

For the Cu + Au 400 MeV system γ ray multiplicities have been measured. The mean value of the transferred angular momentum, the variances, the repartition of angular momentum between the fragments have been deduced. It is shown that, early in the reaction the building of angular momentum is a very fast process. For longer times, additional angular momentum is induced in the fragments due to the excitation of collective modes. The properties of such modes have been analysed
Linac4 crosses the 100 MeV threshold

CERN Multimedia

Corinne Pralavorio

2016-01-01

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

160 MeV $H^-$ Injection into the CERN PSB

CERN Document Server

Weterings, W; Borburgh, J; Fowler, T; Gerigk, F; Goddard, B; Hanke, K; Martini, M; Sermeus, L

2007-01-01

The H- beam from the proposed LINAC4 will be injected into the four existing rings of the PS Booster at 160 MeV. A substantial upgrade of the injection region is required, including the modification of the beam distribution system and the construction of a new H- injection system. This paper discusses beam dynamics and hardware requirements and presents the results of optimisation studies of the injection process for different beam characteristics and scenarios. The resulting conceptual design of the injection region is presented, together with the main hardware modifications and performance specifications.
120 MeV Ag ion induced effects in Au/HfO2/Si MOSCAPs

Science.gov (United States)

Manikanthababu, N.; Prajna, K.; Pathak, A. P.; Rao, S. V. S. Nageswara

2018-05-01

HfO2/Si thinfilms were deposited by RF sputtering technique. 120 MeV Ag ion irradiation has been used to study the electrical properties of Au/HfO2/Si MOSCAPs. SHI (120 MeV Ag) induced annealing, defects creation and intermixing effects on the electrical properties of these systems have been studied. Here, we have observed that the high electronic excitation can cause a significant reduction of leakage currents in these MOSCAP devices. Various quantum mechanical tunneling phenomenon has been observed from the I-V characteristics.
Cross-section calculations for neutron-induced reactions up to 50 MeV

International Nuclear Information System (INIS)

Yamamuro, Nobuhiro.

1996-01-01

In the field of accelerator development, medium-energy reaction cross-section data for structural materials of accelerator and shielding components are required, especially for radiation protection purposes. For a d + Li stripping reaction neutron source used in materials research, neutron reaction cross sections up to 50 MeV are necessary for the design study of neutron irradiation facilities. The current version of SINCROS-II is able to calculate neutron and proton-induced reaction cross sections up to ∼ 50 MeV with some modifications and extensions of the cross-section calculation code. The production of isotopes when structural materials and other materials are bombarded with neutrons or protons is calculated using a revised code in the SINCROS-II system. The parameters used in the cross-section calculations are mainly examined with proton-induced reactions because the experimental data for neutrons above 20 MeV are rare. The status of medium mass nuclide evaluations for aluminum, silicon, chromium, manganese, and copper is presented. These data are useful to estimate the radiation and transmutation of nuclei in the materials
Correlations of light particles in the reaction 40Ar on 197Au at E/A=200 MeV

International Nuclear Information System (INIS)

Kunde, G.J.

1990-08-01

For the study of small-angle correlations of light particles an experiment at the SATURNE synchrotron with 40 Ar on 197 Au at an incident energy of E/A=200 MeV was performed. A hodoscope consisting of an 8x8 matrix of silicon-cesium iodide detectors was applied under a mean angle of 40 degrees. The evaluation of the coincident particle information was performed via correlation functions, which were determined for systems with Z ≤ = 3. For three different fragments emission temperatures were measured via the determination of population ratios for particle-unstable states. Furthermore by means of p-p correlations the reaction volume was studied. The results are: For 5 Li a mean emission temperature of 6.4 -1.0 1.1 MeV resulted, for 4 He a mean emission temperature of 5.4 -1.2 +1.8 MeV was found. The temperature of 2.3 -0.2 0.6 MeV determined for 8 Be is strongly influenced by feeding. For the states at 21.1 and 22.1 MeV in 4 He a dependence of the temperature on the kinetic sum energy of the coincident particles was found, a temperature growth with increasing sum energy of about 3 MeV over the measured range of the sum energies resulted. Via p-p correlations a source radius of 5.8 ± 0.3 fm was determined. The correction for protons from sequential decays leads to radii, which are about 1 fm smaller. The radii and radius ratios for different ranges of the sum energy of the protons were analyzed. The measured emission temperatures are about 1 MeV higher than the values for the same system at E/A = 60 MeV. The temperatures correspond in the model of the statistical multifragmentation to an excitation energy of about 2 GeV, while they follow in the model of the sequential fragment emission for an excitation energy of about 1 GeV. (orig.) [de
Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV

Energy Technology Data Exchange (ETDEWEB)

Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)

2017-01-15

The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.
Scattering of 130 MeV helions on 58Ni

International Nuclear Information System (INIS)

Djaloeis, A.; Alderliesten, C.; Bojowald, J.; Oelert, W.; Turek, P.

1982-01-01

Angular distributions for the tau + 58 Ni scattering to the (g.s., 0 + ) (1.45 MeV, 2 + ) and giant resonance (Esub(x) approximately 63Asup(-1/3) MeV) states in 58 Ni have been measured at Esub(tau) = 130 MeV in an angular range thetasub(c.m.) = 6 0 -83 0 . Optical model and DWBA analyses have been performed. The use of helion optical potentials with either a volume (Woods-Saxon) or a surface (Woods-Saxon derivative) absorption results in good fits to the g.s. and 1.45 MeV data. However, the volume absorption gives consistently a better fit quality. The discrete ambiguity of the helion optical potential has been resolved in favour of the shallow potential family. The giant resonance is found to have a dominant quadrupole (L=2) character with about 6% (EWSR) L=4 admixture. (Auth.)
Study of the thermal oxidation of titanium and zirconium under argon ion irradiation in the low MeV range (E = 15 MeV)

International Nuclear Information System (INIS)

Do, N.-L.

2012-01-01

We have shown that argon ion irradiation between 1 and 15 MeV produces damage on both titanium and zirconium surfaces, taking the form of accelerated oxidation and/or craterization effects, varying as a function of the projectile energy and the annealing atmosphere (temperature and pressure) simulating the environmental conditions of the fuel/cladding interface of PWR fuel rods. Using AFM, we have shown that the titanium and zirconium surface is attacked under light argon ion bombardment at high temperature (up to 500 C) in weakly oxidizing medium (under rarefied dry air pressure ranging from 5,7 10 -5 Pa to 5 10 -3 Pa) for a fixed fluence of about 5 10 14 ions.cm -2 . We observed the formation of nano-metric craters over the whole titanium surface irradiated between 2 and 9 MeV and the whole zirconium surface irradiated at 4 MeV, the characteristics of which vary depending on the temperature and the pressure. In the case of the Ar/Ti couple, the superficial damage efficiency increases when the projectile energy decreases from 9 to 2 MeV. Moreover, whereas the titanium surface seems to be transparent under the 15-MeV ion beam, the zirconium surface exhibits numerous micrometric craters surrounded by a wide halo. The crater characteristics (size and superficial density) differ significantly from that observed both in the low energy range (keV) where the energy losses are controlled by ballistic collisions (Sn) and in the high energy range (MeV - GeV) where the energy losses are controlled by electronic excitations (Se), which was not completely unexpected in this intermediate energy range for which combined Sn - Se stopping power effects are possibly foreseen. Using XPS associated to ionic sputtering, we have shown that there is an irradiation effect on thermal oxidation of titanium, enhanced under the argon ion beam between 2 and 9 MeV, and that there is also an energy effect on the oxide thickness and stoichiometry. The study conducted using Spectroscopic
A miniature small size 3 MeV deuteron linear accelerator

International Nuclear Information System (INIS)

Baranov, L.N.; Bryzgalov, G.A.; Verbovskij, V.V.; Kovpak, N.E.; Onoprienko, V.T.; Papkovich, V.G.; Khizhnyak, N.A.; Shulika, N.G.; Yashin, V.P.

1975-01-01

Basic characteristics are presented of the small-size linear deuteron accelerator for 3 MeV, the accelerating system of which operates at H-wave. It is shown that the usage of such accelerating systems makes it possible to reduce the resonator volume by more than 30 times, whereas the capacity of the evacuating devices as well as the total HF supply power are decreased. Owing to a relatively large wave length, particle injection energy may be reduced to 100-150 keV
The H(n,n) cross section in the 20 MeV to 350 MeV range

International Nuclear Information System (INIS)

1997-01-01

The differential H(n,n) cross section has been used as a standard relative to which other neutron emission cross sections, e.g., elastic or inelastic scattering, have been measured in several Mev region and these measured values are compared with the VL40 solution of R. Arndt, and R.L. Workman, Nuclear Data Standards for Nuclear Measurements, H. Conde (ed.). NEANDC-311, INDC (SEC)-101, 1992, p. 17. For hydrogen, the differential elastic scattering cross section can be directly related to the total cross section, since no other channels of importance are open below the pion production threshold at about 280 MeV (the capture and Bremsstrahlung cross section are very small). 16 refs, 3 figs
14 MeV proton activation analysis

International Nuclear Information System (INIS)

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

1985-01-01

A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14 N (p,n) 14 O, (Tsub(1/2)=71 s). The 14 O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)
Physics design of a 10 MeV injector test stand for an accelerator-driven subcritical system

Science.gov (United States)

Yan, Fang; Pei, Shilun; Geng, Huiping; Meng, Cai; Zhao, Yaliang; Sun, Biao; Cheng, Peng; Yang, Zheng; Ouyang, Huafu; Li, Zhihui; Tang, Jingyu; Wang, Jianli; Sui, Yefeng; Dai, Jianping; Sha, Peng; Ge, Rui

2015-05-01

The 10 MeV accelerator-driven subcritical system (ADS) Injector I test stand at Institute of High Energy Physics (IHEP) is a testing facility dedicated to demonstrate one of the two injector design schemes [Injector Scheme-I, which works at 325 MHz], for the ADS project in China. The injector is composed of two parts, the linac part and the beam dump line. The former is designed on the basis of 325 MHz four-vane type copper structure radio frequency quadrupole and superconducting (SC) spoke cavities with β =0.12 . The latter is designed to transport the beam coming out of the SC section of the linac to the beam dump, where the beam transverse profile is fairly enlarged and unformed to simplify the beam target design. The SC section consists of two cryomodules with 14 β =0.12 Spoke cavities, 14 solenoid and 14 BPMs in total. The first challenge in the physics design comes from the necessary space required for the cryomodule separation where the periodical lattice is destroyed at a relatively lower energy of ˜5 MeV . Another challenge is the beam dump line design, as it will be the first beam dump line being built by using a step field magnet for the transverse beam expansion and uniformity in the world. This paper gives an overview of the physics design study together with the design principles and machine construction considerations. The results of an optimized design, fabrication status and end to end simulations including machine errors are presented.
Characterisation of a compton suppressed clover detector for high energy gamma rays (5 MeV ≤ E ≤ 11 MeV)

International Nuclear Information System (INIS)

Saha Sarkar, M.; Kshetri, Ritesh; Raut, Rajarshi; Mukherjee, A.; Goswami, A.; Ray, S.; Basu, P.; Majumder, H.; Bhattacharya, S.; Dasmahapatra, B.; Sinha, Mandira; Ray, Maitreyee

2004-01-01

The Clover detectors in their add back mode have been seen to be excellent tools for detecting high energy gamma rays (≥ 2 MeV). Recently studies were carried out on the characteristics of a Compton suppressed Clover germanium detector up to 5 MeV using a radioactive 66 Ga (T 1/2 =9.41 h) source for the first time
A simple and powerful XY-Type current monitor for 30 MeV IPEN/CNEN-SP cyclotron

Energy Technology Data Exchange (ETDEWEB)

Barcellos, Henrique; Matsuda, Hylton; Sumyia, Luiz Carlos do A.; Junqueira, Fernando de C.; Costa, Osvaldo L. da, E-mail: hbolivei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

A water-cooled XY-type current monitor was designed and built in the Cyclotrons Laboratory of the Nuclear and Energy Research Institute (IPEN). It is a very simple design and easily adaptable to the cyclotron beam lines. Tests were done demonstrating to be an instrument of great assistance in proton beam position along beam transport line and target port. Nowadays the XY-type current monitor has been widely used in {sup 18}F-FDG routine productions, employing irradiation system which were originally designed for productions on 18 MeV cyclotron accelerator only, however, applying the XY-type current monitor the target port may be exchanged between the 30 MeV and 18 MeV cyclotrons and the observed results are in perfect agreement with expected. (author)
p-p analyzing power excitation function between 510 and 725 MeV

International Nuclear Information System (INIS)

Beurtey, R.; Arvieux, J.; Boivin, M.; Boyard, J.L.; Durand, J.M.; Combes-Comets, M.P.; Courtat, P.; Gacougnolle, R.; Le Bornec, Y.; Garcon, M.

1993-01-01

In an earlier experiment some evidence was observed for narrow dibaryons in the analyzing power excitation function of p-p elastic scattering at √s=2160 MeV and 2192 MeV, with width Γ≅13-14 MeV. A different procedure has been carried out at the SATURNE synchrotron, in order to obtain a very high accuracy of the analyzing power for a large number of energies between 510 and 725 MeV. The results show no evidence for any structure with width ∼5 to 20 MeV. The reasons at the difference between the two experiments are discussed. (K.A.) 2 refs., 3 figs
Systematic study of multi-nucleon transfer reactions for 12C + 58Ni and 12C + 56Fe systems at ELab(12C) = 45 and 60 MeV

International Nuclear Information System (INIS)

Roy, B.J.; Jha, V.; Biswas, D.C.; Parmar, A.; Mohanty, Biraja; Oswal, M.; Jhingan, Akhil; Nandi, T.

2013-01-01

With a motivation to understand the reaction mechanism aspects, systematic study of multi-nucleon transfer in different projectile + target combinations has been made. Data taken at the BARC-TIFR Pelletron - LINAC facility, Mumbai for the systems 18 O+ 206 Pb and 18 O+ 12 C both studied at an incident energy of E( 18 O) = 140.4 MeV are reported in different communications to this proceedings. The present communication reports the measurements for 58 Ni( 12 C, x) and 56 Fe( 12 C, x) at incident 12 C energies of E( 12 C) = 45 and 60 MeV carried out at the pelletron accelerator facility, IUAC, Delhi
7-MeV electron LINAC based pulse radiolysis facility at RPCD, BARC

International Nuclear Information System (INIS)

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

2017-01-01

7-MeV electron LINAC based pulse radiolysis facility is operational in Chemistry Group of BARC since 1986. The Accelerator is housed in B-132 room in basement of Modular Labs. BARC Accelerator was procured from Radiation Dynamics Inc. UK and its detection system was indigenously developed
XRD study of yttria stabilized zirconia irradiated with 7.3 MeV Fe, 10 MeV I, 16 MeV Au, 200 MeV Xe and 2.2 GeV Au ions

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-01

To simulate energetic neutron irradiation effects, yttria-stabilized zirconia (YSZ) which is one of the major materials for electrical corrosion potential sensors (ECP sensors) was irradiated with heavy ions at energies ranging from 7.3 MeV to 2.2 GeV. Ion irradiation effects on the lattice structure were analyzed using the X-ray diffraction (XRD). The increase in lattice constant was induced by the ion irradiation. It was dominated by the elastic collision process and not by the electronic excitation process. The lattice disordering which was observed as a broadening of XRD peaks was also induced by the irradiation especially for 200 MeV Xe ion irradiation. The present result suggests that the expansion and/or the disordering of YSZ lattice induced by energetic neutrons may affect the durability of a joint interface between a metal housing and YSZ membrane for the usage of ECP sensors in nuclear power reactors.
The tagged photon beam facility at the Bonn 500 MeV synchrotron

International Nuclear Information System (INIS)

Arends, J.; Eyink, J.; Hartmann, H.; Hegerath, A.; Mecking, B.; Ros, H.

1982-01-01

A facility for the investigation of medium energy photonuclear reactions is described. A bremsstrahlung tagging system produces a precisely known flux of monochromatic photons in the energy range between 100 and 450 MeV. Resolution and intensity of the system are given. Photoemitted particles can be detected in various large solid angle detectors. The performance of the facility and future developments are discussed. (orig.)
Inter-comparison of High Energy Files (neutron-induced, from 20 to 150 MeV)

Energy Technology Data Exchange (ETDEWEB)

Lee, Young-Ouk; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-11-01

Recent new applications using accelerator-driven system require well-tested nuclear data when modeling the interaction of neutrons above 20 MeV. This work is aimed to review evaluation methods applied in currently available neutron high energy files above 20 to 150 MeV, to inter-compare their evaluated cross sections on some important isotopes, and to analyze resulting discrepancies. Through out these, integrities and consistencies of the high energy files are checked, applicability of physics models and evaluation methodologies are assessed, and some directions are derived to improve and expand current JENDL High Energy File. (author)
Elastic scattering of 7Li + 27Al at several angles in the 7-11 MeV energy range

International Nuclear Information System (INIS)

Abriola, D.; Carnelli, P.; Arazi, A.; Figueira, J.M.; Capurro, O.A.; Cardona, M.A.; Fernandez Niello, J.O.; Hojman, D.; Fimiani, L.; Grinberg, P.; Martinez Heimann, D.; Marti, G.V.; Negri, A.E.; Pacheco, A.J.

2010-01-01

Elastic cross sections for the 7 Li + 27 Al system were measured at laboratory energies between 7 and 11 MeV in steps of 0.25 MeV, and angles between 135 o and 170 o in steps of 5 o . Excitation functions for the elastic scattering were measured using an array of eight Si surface-barrier detectors whereas a solid-state telescope was used to estimate and subtract background from other reactions. Contamination from α particles arising from the 7 Li breakup process at E lab ≥ 10 MeV makes the use of these energies inadvisable for RBS applications. The present results are compared with previous data obtained at 165 o (E lab ≤ 6 MeV), 140 o and 170 o (E lab ≤ 8 MeV). The experimental data were analyzed in terms of the Optical Model. Two different energy-independent potentials were found. These optical potentials allow an interpolation with physical meaning to other energies and scattering angles. The experimental cross sections will be uploaded to the IBANDL database.

Investigation of the neutron-proton-interaction in the energy range from 20 to 50 MEV

International Nuclear Information System (INIS)

Wilczynski, J.

1984-07-01

In the framework of the investigation of the isospin singlet part of the nucleon-nucleon-interaction in the energy range below 100 MeV two experiments were conducted, which were selected by sensitivity calculations. At the Karlsruhe polarized neutron facility POLKA the analyzing powers Asub(y) and Asub(yy) of the elastic n vector-p- and n vector-p vector-scattering were measured in the energy range from 20 to 50 MeV. The results of this epxeriment are compared to older data. In the energy range from 20 to 50 MeV the new data were analyzed together with other selected data of the nucleon-nucleon-system in phase shift analyses. The knowledge of the isospin singlet phase shifts 1 P 1 and 3 D 3 was improved by the new data. (orig./HSI) [de
Sustained >100 MeV Gamma-Ray Emission: A Monitor for >300 MeV SEP Protons at the Sun

Science.gov (United States)

Share, G. H.; Murphy, R. J.

2017-12-01

Solar γ radiation is the product of proton and ion interactions in the solar atmosphere. The spectrum and temporal characteristics of the emission provides fundamental information on the ions at the Sun. Until the launch of the Fermi satellite, with its Large Area Telescope (LAT) sensitive to radiation above 100 MeV, most of the γ-ray observations were made in the nuclear energy range with radiation arising from interaction of one to tens of MeV ions produced in solar flares. Since 2008 the LAT has detected 30 high-energy γ-ray events with temporal and spectral characteristics that are distinct from the associated solar flare. We call this radiation Sustained Gamma-Ray Emission (SGRE) and briefly summarize its characteristics reported in a recent paper. The γ-ray spectra are consistent with pion decay radiation produced by protons above 300 MeV. The onset of the radiation most often occurs after the impulsive flare and the emission can last several hours. We find that the number of protons responsible for the SGRE is typically more than 10 times the number of flare-accelerated protons. These characteristics require that there be an additional source of energy to accelerate the protons to hundreds of MeV to produce the SGRE. As 28 of the 30 SGRE events are accompanied by fast CMEs, it is likely that these protons are accelerated by the same shock that produces gradual SEPs. We find that the number of protons >500 MeV in the accompanying SEPs is typically about 50-100 times the number of protons that return to the Sun to produce the SGRE. There also appear to be correlations between the numbers of SEP and SGRE protons and durations of >100 MeV SEP proton and SGRE events. We find that for all SGRE events where there were flare observations, the accompanying impulsive X-radiation reached energies >100 keV. In a limited study of 18 solar events with CME speeds >800 km/s we also find that the median SEP proton flux is 25 times higher when flare hard X-rays exceed 100
Zone plate imaging of 14-MeV neutrons

International Nuclear Information System (INIS)

Lerche, R.A.; Lane, S.M.; Hawryluk, A.M.; Ceglio, N.M.

1986-01-01

At Livermore we are interested in imaging the thermonuclear burn region of fusion targets irradiated at our Nova laser facility. We expect compressed core diameters to be 10's of microns, and would like images with better than 10-μm resolution. Alpha particle images provided the first direct information about the thermonuclear burn geometry in thin walled exploding pusher targets. In future high density target experiments, only highly penetrating radiations like the 14-MeV neutrons will escape the target core to provide information about the burn region. To make the measurement with a neutron ''pinhole'' camera requires a 10μm pinhole through about 10 cm of material and 10 14 to 10 15 source neutrons. Penumbral imaging offers some improvement over a pinhole. Zone plate coded imaging (ZPCI) techniques are particularly well suited for imaging small objects like the compressed core of a laser fusion target. We have been using ZPCI techniques to image nonpenetrating radiations like x rays and alpha particles for about 10 years. The techniques are well developed. Imaging penetrating radiations like 14-MeV neutrons using ZPCI techniques has several possible advantages. The large solid angle subtended by the Zone plate might substantially reduce the required target neutron yield needed to produce a useful image, and a neutron zone plate system with 10-μm resolution might be easier to fabricate and characterize than a pinhole system. This paper explores the use of ZPCI techniques with penetrating radiation
Development of a “Fission-proxy” Method for the Measurement of 14-MeV Neutron Fission Yields at CAMS

Energy Technology Data Exchange (ETDEWEB)

Gharibyan, Narek [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-10-25

Relative fission yield measurements were made for 50 fission products from 25.6±0.5 MeV alpha-induced fission of Th-232. Quantitative comparison of these experimentally measured fission yields with the evaluated fission yields from 14-MeV neutron-induced fission of U-235 demonstrates the feasibility of the proposed fission-proxy method. This new technique, based on the Bohr-independence hypothesis, permits the measurement of fission yields from an alternate reaction pathway (Th-232 + 25.6 MeV α → U-236* vs. U-235 + 14-MeV n → U-236*) given that the fission process associated with the same compound nucleus is independent of its formation. Other suitable systems that can potentially be investigated in this manner include (but are not limited to) Pu-239 and U-237.
RBE comparison between rapid electrons of 20 MeV and 45 MeV with survival rate, DNA synthesis, DNA reparation and nucleoid sedimentation

International Nuclear Information System (INIS)

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

1982-01-01

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

International Nuclear Information System (INIS)

Venezia, V.C.; Univ. of North Texas, Denton, TX; Haynes, T.E.; Agarwal, A.; Lucent Technologies, Murray Hill, NJ; Gossmann, H.J.; Eaglesham, D.J.

1997-04-01

The diffusion of Sb and B markers has been studied in vacancy supersaturations produced by MeV Si implantation in float zone (FZ) silicon and bonded etch-back silicon-on-insulator (BESOI) substrates. MeV Si implantation produces a vacancy supersaturated near-surface region and an interstitial-rich region at the projected ion range. Transient enhanced diffusion (TED) of Sb in the near surface layer was observed as a result of a 2 MeV Si + , 1 x 10 16 /cm 2 , implant. A 4x larger TED of Sb was observed in BESOI than in FZ silicon, demonstrating that the vacancy supersaturation persists longer in BESOI than in FZ. B markers in samples with MeV Si implant showed a factor of 10x smaller diffusion relative to markers without the MeV Si + implant. This data demonstrates that a 2 MeV Si + implant injects vacancies into the near surface region
η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV

Science.gov (United States)

Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.

2010-11-01

The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.
Evolution of the reaction 40Ar + Ag from E/A = 7 to 34 MeV

International Nuclear Information System (INIS)

Alexander, J.M.

1991-01-01

The 4π charged-particle multidetector AMPHORA has been used to study the reaction 40 Ar + nat Ag from 270 - 1,356 MeV. Charged-particle multiplicity distributions show a low-multiplicity group associated with peripheral collisions and a high multiplicity group associated with central collisions. Average multiplicities for central collisions increase with increasing projectile energy, indicating ever-increasing collision violence. Angular distributions of emitted protons are essentially isotorpic for θ ≥ 80 degree in a reference frame characterized by the empirical systematics of linear momentum transfer (i.e. ∼ 100% to ∼ 70% from 7-34 MeV/nucleon). Spectra of these protons at side angles are evaporation-like in shape and indicate relative effective temperatures of 3, 6, 8, and 12 MeV for beam energies of 7, 17, 27 and 34 MeV respectively. Azimuthal angular correlations between various pairs are consistent with spin-driven emission from emitter sources of reasonable spin values. In short, these results support a classical picture of extensively thermalized emitter nuclei even for initial excitation energies of ∼ 5 MeV per system nucleon and spins of ≥ 100ℎ
Measurements of 14 MeV neutron multiplication in spherical beryllium shells

International Nuclear Information System (INIS)

Moellendorff, U. von; Alevra, A.V.; Giese, H.; Kappler, F.; Klein, H.; Klein, H.; Tayama, R.

1995-01-01

New results of spherical-shell transmission measurements with 14MeV neutrons on pure beryllium shells up to 17cm thick are reported. The total leakage neutron multiplications were measured using a Bonner sphere system. Independently, the leakage neutron spectra were measured over the entire energy range, 15MeV to thermal energies, by proton-recoil and time-of-flight methods. The total leakage multiplications are in excellent agreement with three-dimensional Monte Carlo calculations using beryllium nuclear data based on the Young and Stewart evaluation. The leakage in the evaporation energy window confirms the Be(n,2n) cross-section of the Young and Stewart evaluation rather than that used in the ENDF/B-VI library. At energies below 1keV, a surplus of leakage neutrons over the calculation is found for smaller beryllium thicknesses. (orig.)
Cross section ratio and angular distributions of the reaction p + d → 3He + η at 48.8 MeV and 59.8 MeV excess energy

International Nuclear Information System (INIS)

Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J.; Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P.; Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J.; Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J.; Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A.; Berlowski, M.; Stepaniak, J.; Bhatt, H.; Lalwani, K.; Varma, R.; Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M.; Coderre, D.; Ritman, J.; Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P.; Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A.; Fedorets, P.; Foehl, K.; Goswami, A.; Grigoryev, K.; Kirillov, D.A.; Piskunov, N.M.; Klos, B.; Stephan, E.; Weglorz, W.; Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A.; Kupsc, A.; Pszczel, D.; Mikirtychiants, M.; Pyszniak, A.; Roy, A.; Sawant, S.; Serdyuk, V.; Sopov, V.; Yamamoto, A.; Yurev, L.; Zabierowski, J.

2014-01-01

We present new data for angular distributions and on the cross section ratio of the p+d → 3 He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)
Test of virtual photon theory. [Cross sections, square-well potential, 0 to 300 MeV

Energy Technology Data Exchange (ETDEWEB)

Dressler, E T; Tomusiak, E L [Saskatchewan Univ., Saskatoon (Canada). Saskatchewan Accelerator Lab.

1976-11-30

In order to extract a photodisintegration cross section in the c.m. system from an electrodisintegration cross section measured in the lab system, one has to assume that the electrons are mostly scattered forward and that the monopole contributions are negligible. To test the validity of these approximations, a square well potential was assumed for the initial and final states and the photodisintegration cross section was calculated exactly within this model. These results were then compared with the results one would obtain using the virtual photon theory approximations for electron energies of 0-300 MeV and excitation energies up to 40 MeV. In comparing the two results, it is shown how and why the virtual photon theory approximations fail in certain kinematical regions.
Design of 6 MeV X-band electron linac for dual-head gantry radiotherapy system

Science.gov (United States)

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

2017-12-01

A compact 6 MeV electron linac is being developed at Sungkyunkwan University, in collaboration with the Korea atomic energy research institute (KAERI). The linac will be used as an X-ray source for a dual-head gantry radiotherapy system. X-band technology has been employed to satisfy the size requirement of the dual-head gantry radiotherapy machine. Among the several options available, we selected a pi/2-mode, standing-wave, side-coupled cavity. This choice of radiofrequency (RF) cavity design is intended to enhance the shunt impedance of each cavity in the linac. An optimum structure of the RF cavity with a high-performance design was determined by applying a genetic algorithm during the optimization procedure. This paper describes the detailed design process for a single normal RF cavity and the entire structure, including the RF power coupler and coupling cavity, as well as the beam dynamics results.
Production of radionuclides by 14 MeV neutron generator

International Nuclear Information System (INIS)

Alfassi, Z.B.

1983-01-01

Due to the short half-lives of these nuclides they have to be produced in situ or at least not far from the place of use. The cost of 14 MeV neutron generators have been compared with the typical middle-sized cyclotrons and it was found that the capital costs are much lower in the case of neutron generators. This is the main reason for the availability of 14 MeV neutron generators in many scientific institutes compared to the scarcity of cyclotrons. Lately, the use of 14 MeV neutrons for cancer therapy was studied in several medical centers. A number of hospitals and cancer research centers have high intensity 14 MeV neutron generators for this purpose. The advantages of using short-lived in-house produced radionuclides suggest the use of the available 14 MeV neutron generators for biological studies and in medical diagnosis. 14 MeV neutron generators can be used to produce some of the medically useful radionuclides, such as /sup 18/F, /sup 80/Br, /sup 199m/Hg, and others. However, the amount required for medicine can only be prepared by the new high intensity neutron generators, used for neutron therapy and not by the smaller ones, commonly used in university laboratories (--10/sup 11/ n/sec). On the other hand, these relatively small neutron generators can be used for the preparation of radionuclides for biological studies. They facilitate the study of metabolism of elements for which radionuclides cannot be usually purchased due to short half-lives or the high price of the long-lived ones, such as /sup 34m/Cl, /sup 18/F, /sup 28,29/Al, /sup 27/Mg, and others. An example is the work done on the fate of Al and Mg in rats using /sup 28/Al and /sup 27/Mg./sup 13/
Subnanosecond pulsing of an 1 MeV ELIT electron accelerator by beam deflection

International Nuclear Information System (INIS)

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

1984-01-01

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

Energy Technology Data Exchange (ETDEWEB)

Dowell, D.H.; Adamski, J.L.; Hayward, T.D. [Boeing Defense & Space Group, Seattle, WA (United States)] [and others

1995-12-31

A 1-kW average power, visible wavelength FEL is described, based on a 120-MeV, 0.1. A macropulse average current linac operating at a duty factor of 0. 6% and having average beam power of 70 kW. The accelerator will employ a demonstrated photoinjector, 18-MeV, 433-MHz linac as an injector, followed by a 1300-MHz longitudinal phase space {open_quotes} linearizer,{close_quotes} a magnetic buncher chicane, and seven 1300-MHz, pulsed traveling wave linac sections. The magnets used to transport the beam from the linac to the FEL centerline, the 5-m THUNDER wiggler, and the optical resonator will be reclaimed from previous FEL demonstration experiments. We expect to attain pulse lengths of 7 ps for 3.5 nC, with minimal distortion of the pulse profile and normalized rms emittance of 7.5 {+-} 2.5 {pi} mm-mr. FELEX projects a laser conversion efficiency of 4.3 %, yielding average output of 3 kW.
COMMISSIONING AND FIRST RESULTS FROM CHANNELING RADIATION AT FAST

Energy Technology Data Exchange (ETDEWEB)

Halavanau, A. [NIU, DeKalb; Mihalcea, D. [NIU, DeKalb; Broemmelsiek, D. [Fermilab; Edstrom, D. [Fermilab; Sen, T. [Fermilab; Romanov, A. [Fermilab; Ruan, J. [Fermilab; Shiltsev, V. [Fermilab; Kobak, P. [BYU-I; Rush, W. [Kansas U.; Hyun, J. [Tsukuba, Graduate U. Adv. Studies

2016-10-18

X-rays have widespread applications in science and industry, but developing a simple, compact, and high-quality X-ray source remains a challenge. Our collaboration has explored the possible use of channeling radiation driven by a 50 MeV low-emittance electron beam to produce narrowband hard X-rays with photon energy of 40 to 140 keV [8,9,11]. Here we present the simulated X-ray spectra including the background bremsstrahlung contribution, and a description of the required optimization of the relevant electron-beam parameters necessary to maximize brilliance of the resulting X-ray beam. Results are presented from our test of this, carried out at the Fermilab Accelerator Science & Technology (FAST) facility’s 50-MeV low-energy electron injector. As a result of the beam parameters, made possible by the photo-injector based SRF linac, the average brilliance at FAST was expected to be about one order of magnitude higher than that in previous experiments.
Data management design: nucleon-nucleon data bank (0 to 1200 MeV)

International Nuclear Information System (INIS)

Signell, P.; Freiheit, F.

1981-01-01

This is a guide to the design of the on-line data records in this bank, covering all energies and particle combinations up to about 1200 MeV. The design of the bank's management system satisfies almost all of the conditions set forth in the proposed Design Principles for Physics Data Banks
A P + DEUTERON PROTON POLARIMETER AT 200 MEV.

Energy Technology Data Exchange (ETDEWEB)

HUANG,H.; ROSER,T.; ZELENSKI,A.; KURITA,K.; STEPHENSON,E.; TOOLE,R.

2002-06-02

There has been concern about the analyzing power of the p-Carbon polarimeter at the end of 200 MeV LINAC of BNL. A new polarimeter based on proton-deuteron scattering was installed and we have repeated the calibration of proton-Carbon scattering at 12 degrees and 200 MeV against proton-deuteron scattering. The result is consistent with the value of A=0.62 now used to measure the beam polarization at the end of the LINAC.
The 200 MeV cyclotron facility

International Nuclear Information System (INIS)

1987-01-01

Beams of protons with several different energies have now been successfully transported between the injector cyclotron SPC1 and the SSC. Some small modifications to the placement of steering magnets and diagnostic equipment have been made in the light of our operational experience, which should improve the ease of tuning this beamline. Proton beams up to 200 MeV in energy have been transported to the experimental areas, where experiments in nuclear physics have been successful conducted. Three of the experimental beamlines are now in operation. Beams of 66 MeV protons have also been transported to targets in the isotope production vault, without difficulty. Field mapping of the remaining quadrupoles on site has been completed. Installation of and alignment of magnets up to the beam swinger is also complete, although the beam tube itself, plus vacuum and diagnostic equipment must still be tackled. The beam swinger has been designed and detailed in the drawing office, and is now being manufactured locally. The beamline elements for the sepctrometer beamline remain to be purchased. A personal computer has been purchased for controlling the field-mapping equipment for the spectrometer magnets, which are being manufactured in this country. A number of computer programs have been written for conversion of calibrated quadrupole and dipole magnet field data to absolute current values for the control system. Other programs permit diagnostic measurements of beam profiles to be used to calculated the beam emittance, or to set steering magnets so that the beam is correctly aligned
Cross section ratio and angular distributions of the reaction p + d → {sup 3}He + η at 48.8 MeV and 59.8 MeV excess energy

Energy Technology Data Exchange (ETDEWEB)

Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Department of Nuclear Physics, Warsaw (Poland); Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Physikalisches Institut der Universitaet Tuebingen, Kepler Center fuer Astro- und Teilchenphysik, Tuebingen (Germany); Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Berlowski, M.; Stepaniak, J. [National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Bhatt, H.; Lalwani, K.; Varma, R. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (India); Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Coderre, D.; Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (Germany); Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Fedorets, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Foehl, K. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Goswami, A. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (India); Grigoryev, K. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); RWTH Aachen, III. Physikalisches Institut B, Physikzentrum, Aachen (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (Russian Federation); Kirillov, D.A.; Piskunov, N.M. [Joint Institute for Nuclear Physics, Veksler and Baldin Laboratory of High Energiy Physics, Moscow region (Russian Federation); Klos, B.; Stephan, E.; Weglorz, W. [University of Silesia, August Chelkowski Institute of Physics, Katowice (Poland); Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A. [Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Kupsc, A.; Pszczel, D. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Mikirtychiants, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (DE); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (RU); Pyszniak, A. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (SE); Jagiellonian University, Institute of Physics, Krakow (PL); Roy, A. [Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (IN); Sawant, S. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (IN); Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Serdyuk, V. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Sopov, V. [State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (RU); Yamamoto, A. [High Energy Accelerator Research Organization KEK, Tsukuba, Ibaraki (JP); Yurev, L. [Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Zabierowski, J. [National Centre for Nuclear Research, Department of Cosmic Ray Physics, Lodz (PL); Collaboration: WASA-at-COSY Collaboration

2014-06-15

We present new data for angular distributions and on the cross section ratio of the p+d → {sup 3}He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)

Application of calorimeters for 5 MeV EB and bremsstrahlung dosimetry

DEFF Research Database (Denmark)

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

1993-01-01

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

International Nuclear Information System (INIS)

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

1993-01-01

Graphite and water calorimeters, which were developed for use with 10 MeV electron beams (EB) at Riso National Laboratory, were used for process validation and routine dosimeter calibration at a 5 MeV EB. Water calorimeters were used for reference measurements for 5 MeV EB, the response was found to be directly proportional to the beam current and the variation among three water calorimeters was less than ± 2% in the range of 10 to 40 kGy. CTA PMMA RCD dosimeters were calibrated by irradiating the dosimeters and water calorimeters simultaneously. The water calorimeter was proved to be an useful tool at 5 MeV EB. Graphite calorimeters gave reproducible readings within 3.3 % relative errors (95% confidence level) for X-ray measurement. (Author)
Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations

Energy Technology Data Exchange (ETDEWEB)

Goosman, D.R.

1984-08-14

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

International Nuclear Information System (INIS)

Goosman, D.R.

1984-01-01

The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table
ANC of 6.92 MeV (2"+) and 7.12 MeV (1"-) states from sub-Coulomb "1"2C("6Li,d) data

International Nuclear Information System (INIS)

Mondal, Ashok; Basu, C.; Adhikari, S.

2016-01-01

The determination of the astrophysical S-factor of the "1"2C(α,γ) reaction at 300 keV requires a R-matrix extrapolation. This is because a direct measurement of this reaction at 300 keV is almost impossible due to the very small cross-section. The R-matrix extrapolation requires as input the asymptotic normalization constant (ANC) of mainly two "1"6O states states viz. 6.92 MeV and 7.12 MeV on which the fit is most sensitive. The ANC of these two states have been determined from indirect measurements, mainly from "1"2C("6Li,d) and "1"2C("7Li,t) alpha transfer reactions. Most of these measurements are done at above barrier energies as cross-sections are larger. In this work, we determine the ANC of the 6.92 MeV and 7.12 MeV states of "1"6O using the "1"2C("6Li,d) data of Heikkinen et al measured at 4.5 to 5.0 MeV incident energies. The data spans over a larger angular span in comparison to Avila though the former data do not cover the very backward angles as in the Avila data. As the Heikkinen data has never been analyzed to extract the ANC we report the results of our analysis of the data
Neutron-induced fission of uranium isotopes up to 100 MeV

International Nuclear Information System (INIS)

Lestone, J.P.; Gavron, A.

1994-01-01

The statistical-model description of the neutron-induced fission of U isotopes has been developed using densities of intrinsic states and spin cutoff parameters obtained directly from appropriate Nilsson model single-particle levels. The first-chance fission cross sections are reproduced well when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second-chance fission, we must: (1) assume that the triaxial level-density enhancement is washed out at an excitation energy of approximately 7 MeV above the triaxial barriers with a width of approximately 1 MeV, implying a γ deformation for the first barriers where 10<γ<20 degree, and (2) include preequilibrium particle emission in the calculations. Above an incoming-neutron kinetic energy of approximately 17 MeV, our statistical model U(n,f) of cross sections increasingly overestimates the experimental data. This is not surprising since, at these high energies, little data exist on the scattering of neutrons to help guide the choice of optical-model parameters. A satisfactory reproduction of all of the available U(n,f) cross sections above 17 MeV is obtained by scaling our calculated compound-nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV
Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

Energy Technology Data Exchange (ETDEWEB)

Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

2006-10-15

Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)
Momentum transfer with light ions at energies from 70 MeV to 1000 MeV

International Nuclear Information System (INIS)

Saint Laurent, F.; Conjeaud, M.; Dayras, R.; Harar, S.; Oeschler, H.; Volant, C.

1982-01-01

Angular correlations of fission fragments induced by bombarding a 232 Th target with protons, deuterons and alpha particles of energies from 70 MeV to 1000 MeV have been measured. They give information about the forward momentum imparted to the fissioning nuclei. We present the average values of the transferred linear momentum ([p vertical stroke vertical stroke ]) as a function of the incident energy and propose a classification into three regimes of dominating processes leading to fission: (I) low-energy behaviour, for E/A less than 10 MeV/u [p vertical stroke vertical stroke ]/psub(i) approx. equal to 1. (II) Between 10 MeV/u and about 70 MeV/u, [p vertical stroke vertical stroke ]/psub(i) decreases progressively down to 0.5 but remains proportional to the projectile mass. (III) The region between 70 MeV/u and about 1000 MeV/u corresponds to a transition region where the projectiles, whatever their masses, tend to transfer the same momentum. (orig.)
Microbeam line of MeV heavy ions for materials modification and in-situ analysis

International Nuclear Information System (INIS)

Horino, Yuji; Chayahara, Akiyoshi; Kiuchi, Masato; Fujii, Kanenaga; Satoh, Mamoru; Takai, Mikio.

1990-01-01

A microbeam line for MeV heavy ions of almost any element has been developed for microion-beam processing such as maskless MeV ion implantation and its in-situ analysis. Beam spot sizes of 4.0 μm x 4.0 μm for 3 MeV C 2+ and 9.6 μm x 4.8 μm for 1.8 MeV Au 2+ beams were obtained. Maskless MeV gold ion implantation to a silicon substrate and in-situ microanalysis before and after ion implantation were demonstrated. (author)
A 600 MeV cyclotron for radioactive beam production

International Nuclear Information System (INIS)

Clark, D.J.

1993-01-01

The magnetic field design for a 600 MeV proton cyclotron is described. The cyclotron has a single stage, a normal conducting magnet coil and a 9.8 m outside yoke diameter. It has 8 sectors, with a transition to 4 sectors in the center region. The magnetic field design was done using 1958 Harwell rectangular ridge system measurements and was compared with recent 3-dimensional field calculations with the program TOSCA at NSCL. The center region 4--8 sector transition focussing was also checked with TOSCA
Status of the 160 MeV H- Injection into the CERN PSB

CERN Document Server

Weterings, W; Benedetto, E; Borburgh, J; Bracco, C; Carli, C; Goddard, B; Hanke, K; Mikulec, B; Newborough, A; Noulibos, R; Tan, J

2012-01-01

The 160 MeV H- beam from the LINAC4 will be injected into the 4 superimposed rings of the PS Booster (PSB) with a new H- charge-exchange injection system. This entails a massive upgrade of the injection region. The hardware requirements and constraints, the performance specifications and the design of the H- injection region are described.
Neutron-induced fission cross sections of uraniums up to 40 MeV

Energy Technology Data Exchange (ETDEWEB)

Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus); Hasegawa, A.

1998-11-01

Statistical theory of nuclear reactions, well-proved below 20 MeV, is applied for {sup 235}U and {sup 238}U fission data analysis up to {approx}40 MeV. It is shown that measured data could be reproduced. Chance structure of measured fission cross section is provided, it`s validity is supported by description of data for competing (n,xn)-reactions. Role of fissility of target nucleus is addressed. It seems that gap in incident neutron energy interval of 20 MeV - 50 MeV, below which evaluation approaches are well-developed, and above which simplified statistical approaches are valid, could be covered. (author)
Inelastic proton scattering at 800 MeV to the 12C 15.11-MeV state: A search for nuclear critical opalescence

International Nuclear Information System (INIS)

Haji-Saeid, M.; Glashausser, C.; Igo, G.; Cornelius, W.; Gazzaly, M.; Irom, F.; McClelland, J.; Moss, J.M.; Pauletta, G.; Thiessen, H.A.; Whitten, C.A. Jr.

1980-01-01

The differential cross section for the reaction 12 C(p,p') 12 C* (15.11 MeV, 1 + , T=1) has been measured at 800 MeV; the range of the angular distribution corresponds to momentum transfers of 0.7--2.4 fm -1 [(1-3.3)m/sub π/]. The cross section decreases almost exponentially at large angles; no maximum is observed in the region where nuclear critical opalescence might be expected
Technical preparations for the in-vessel 14 MeV neutron calibration at JET

International Nuclear Information System (INIS)

Batistoni, P.; Popovichev, S.; Crowe, R.; Cufar, A.; Ghani, Z.; Keogh, K.; Peacock, A.; Price, R.; Baranov, A.; Korotkov, S.; Lykin, P.; Samoshin, A.

2017-01-01

Highlights: • The JET 14 MeV neutron calibration requires a neutron generator to be deployed inside the vacuum vessel by means of the remote handling system. • A neutron generator of suitable intensity and compliant with physics, remote handling and safety requirements has been identified and procured.The scientific programme of the preparatory phase devoted to fully characterizing the selected 14 MeV neutron generator is discussed. • The aim is to measure the absolute neutron emission rate within (± 5%) and the energy spectrum of emitted neutron as a function of angles. • The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are discussed. - Abstract: The power output of fusion devices is measured from their neutron yields which relate directly to the fusion yield. In this paper we describe the devices and methods that have been prepared to perform a new in situ 14 MeV neutron calibration at JET in view of the new DT campaign planned at JET in the next years. The target accuracy of this calibration is ±10% as required for ITER, where a precise neutron yield measurement is important, e.g., for tritium accountancy. In this paper, the constraints and early decisions which defined the main calibration approach are discussed, e.g., the choice of 14 MeV neutron source and the deployment method. The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are also discussed. The existing JET remote-handling system will be used to deploy the neutron source inside the JET vessel. For this purpose, compatible tooling and systems necessary to ensure safe and efficient deployment have been developed. The scientific programme of the preparatory phase is devoted to fully characterizing the selected 14 MeV neutron generator to be used as the calibrating source, obtain a better understanding of the limitations of the
Technical preparations for the in-vessel 14 MeV neutron calibration at JET

Energy Technology Data Exchange (ETDEWEB)

Batistoni, P., E-mail: paola.batistoni@enea.it [ENEA, Department of Fusion and Nuclear Safety Technology, I-00044, Frascati, Rome (Italy); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Popovichev, S. [CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Crowe, R. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Cufar, A. [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000, Ljubljana (Slovenia); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Ghani, Z. [CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Keogh, K. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Peacock, A. [JET Exploitation Unit, Abingdon, Oxon, OX14 3DB (United Kingdom); Price, R. [Remote Applications in Challenging Environments (RACE), Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Baranov, A.; Korotkov, S.; Lykin, P.; Samoshin, A. [All-Russia Research Institute of Automatics (VNIIA), 22, Sushchevskaya str., 127055, Moscow (Russian Federation)

2017-04-15

Highlights: • The JET 14 MeV neutron calibration requires a neutron generator to be deployed inside the vacuum vessel by means of the remote handling system. • A neutron generator of suitable intensity and compliant with physics, remote handling and safety requirements has been identified and procured.The scientific programme of the preparatory phase devoted to fully characterizing the selected 14 MeV neutron generator is discussed. • The aim is to measure the absolute neutron emission rate within (± 5%) and the energy spectrum of emitted neutron as a function of angles. • The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are discussed. - Abstract: The power output of fusion devices is measured from their neutron yields which relate directly to the fusion yield. In this paper we describe the devices and methods that have been prepared to perform a new in situ 14 MeV neutron calibration at JET in view of the new DT campaign planned at JET in the next years. The target accuracy of this calibration is ±10% as required for ITER, where a precise neutron yield measurement is important, e.g., for tritium accountancy. In this paper, the constraints and early decisions which defined the main calibration approach are discussed, e.g., the choice of 14 MeV neutron source and the deployment method. The physics preparations, source issues, safety and engineering aspects required to calibrate directly the JET neutron detectors are also discussed. The existing JET remote-handling system will be used to deploy the neutron source inside the JET vessel. For this purpose, compatible tooling and systems necessary to ensure safe and efficient deployment have been developed. The scientific programme of the preparatory phase is devoted to fully characterizing the selected 14 MeV neutron generator to be used as the calibrating source, obtain a better understanding of the limitations of the
Design and research of RF system for 10 MeV compact cyclotron

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

A 10 MeV compact cyclotron (CYCHU-10) has been developing in Huazhong University of Science and Technology (HUST). The RF system includes a 10 kW RF power generator and a resonance cavity. There is no automatic frequency tuning equipment in the cavity due to space limitations, so the generator must search and track the cavity resonant frequency. AD9850 synthesizer is used to generate RF signal in the experimental prototype, and a fine sinusoidal waveform around 99 MHz is obtained with the method of picking up a special aliased signal from the synthesizer’s output, and the output power level can be set by regulating the resistor connected to the Pin ’Rset’. The final stage amplifier based on tetrode operates in the grounded cathode configuration, and the schematic of the tetrode circuit is illustrated. The method of searching the resonant frequency is discussed in detail. For the sake of a compact and robust structure, the resonance cavity will adopt non-uniform characteristic impedance coaxial structure, and the magnet surface electroplated with copper will be used as dummy Dees. The precise shapes and dimensions of the cavity are designed and simulation results are carried out in this paper. The distributions of electromagnetic field are illustrated by means of numerical calculation analysis, and the wooden model test is preformed as well.
MeV ion beam interaction with polymer films containing cross-linking agents

International Nuclear Information System (INIS)

Evelyn, A. L.

1999-01-01

Polymer films containing cross linking enhancers were irradiated with MeV alpha particles to determine the effects of MeV ion beam interaction on these materials. The contributed effects from the electronic and nuclear stopping powers were separated by irradiating stacked thin films of polyvinyl chloride (PVC), polystyrene (PS) and polyethersulfone (PES). This layered system allowed most of the effects of the electronic energy deposited to be experienced by the first layers and the last layers to receive most of the effects of the nuclear stopping power. RGA, Raman microprobe analysis, RBS and FTIR measured changes in the chemical structures of the irradiated films. The characterization resolved the effects of the stopping powers on the PVC, PS and PES and the results were compared with those from previously studied polymers that did not contain any cross linking agents
The Energy Dependence of Flow in Ni Induced Collisions from 400A to 1970A MeV

International Nuclear Information System (INIS)

Chance, J.; Brady, F.; Cebra, D.; Kintner, J.; Partlan, M.; Romero, J.; Albergo, S.; Caccia, Z.; Costa, S.; Insolia, A.; Potenza, R.; Romanski, J.; Russo, G.; Tuve, C.; Bieser, F.; Cebra, D.; Lisa, M.; Matis, H.; McMahan, M.; McParland, C.; Olson, D.; Rai, G.; Rasmussen, J.; Ritter, H.; Symons, T.; Wieman, H.; Wienold, T.; Choi, Y.; Elliott, J.; Gilkes, M.; Hauger, J.; Hirsch, A.; Hjort, E.; Porile, N.; Scharenberg, R.; Srivastava, B.; Tincknell, M.; Warren, P.; Chacon, A.; Wolf, K.

1997-01-01

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400 endash 1970)A MeV Ni+Au and (1000 endash 1970)A MeV Ni+Cu reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems. copyright 1997 The American Physical Society
DoPET: an in-treatment monitoring system for proton therapy at 62 MeV

Science.gov (United States)

Rosso, V.; Belcari, N.; Bisogni, M. G.; Camarlinghi, N.; Cirrone, G. A. P.; Collini, F.; Cuttone, G.; Del Guerra, A.; Milluzzo, G.; Morrocchi, M.; Raffaele, L.; Romano, F.; Sportelli, G.; Zaccaro, E.

2016-12-01

Proton beam radiotherapy is highly effective in treating cancer thanks to its conformal dose deposition. This superior capability in dose deposition has led to a massive growth of the treated patients around the world, raising the need of treatment monitoring systems. An in-treatment PET system, DoPET, was constructed and tested at CATANA beam-line, LNS-INFN in Catania, where 62 MeV protons are used to treat ocular melanoma. The PET technique profits from the beta+ emitters generated by the proton beam in the irradiated body, mainly 15-O and 11-C. The current DoPET prototype consists of two planar 15 cm × 15 cm LYSO-based detector heads. With respect to the previous versions, the system was enlarged and the DAQ up-graded during the years so now also anthropomorphic phantoms, can be fitted within the field of view of the system. To demonstrate the capability of DoPET to detect changes in the delivered treatment plan with respect to the planned one, various treatment plans were used delivering a standard 15 Gy fraction to an anthropomorphic phantom. Data were acquired during and after the treatment delivery up to 10 minutes. When the in-treatment phase was long enough (more than 1 minute), the corresponding activated volume was visible just after the treatment delivery, even if in presence of a noisy background. The after-treatment data, acquired for about 9 minutes, were segmented finding that few minutes are enough to be able to detect changes. These experiments will be presented together with the studies performed with PMMA phantoms where the DoPET response was characterized in terms of different dose rates and in presence of range shifters: the system response is linear up to 16.9 Gy/min and has the ability to see a 1 millimeter range shifter.
DoPET: an in-treatment monitoring system for proton therapy at 62 MeV

International Nuclear Information System (INIS)

Rosso, V.; Belcari, N.; Bisogni, M.G.; Camarlinghi, N.; Guerra, A. Del; Morrocchi, M.; Sportelli, G.; Zaccaro, E.; Cirrone, G.A.P.; Cuttone, G.; Milluzzo, G.; Raffaele, L.; Romano, F.; Collini, F.

2016-01-01

Proton beam radiotherapy is highly effective in treating cancer thanks to its conformal dose deposition. This superior capability in dose deposition has led to a massive growth of the treated patients around the world, raising the need of treatment monitoring systems. An in-treatment PET system, DoPET, was constructed and tested at CATANA beam-line, LNS-INFN in Catania, where 62 MeV protons are used to treat ocular melanoma. The PET technique profits from the beta+ emitters generated by the proton beam in the irradiated body, mainly 15-O and 11-C. The current DoPET prototype consists of two planar 15 cm × 15 cm LYSO-based detector heads. With respect to the previous versions, the system was enlarged and the DAQ up-graded during the years so now also anthropomorphic phantoms, can be fitted within the field of view of the system. To demonstrate the capability of DoPET to detect changes in the delivered treatment plan with respect to the planned one, various treatment plans were used delivering a standard 15 Gy fraction to an anthropomorphic phantom. Data were acquired during and after the treatment delivery up to 10 minutes. When the in-treatment phase was long enough (more than 1 minute), the corresponding activated volume was visible just after the treatment delivery, even if in presence of a noisy background. The after-treatment data, acquired for about 9 minutes, were segmented finding that few minutes are enough to be able to detect changes. These experiments will be presented together with the studies performed with PMMA phantoms where the DoPET response was characterized in terms of different dose rates and in presence of range shifters: the system response is linear up to 16.9 Gy/min and has the ability to see a 1 millimeter range shifter.

1 1/2 years of experience with a 10 MeV self-shielded on-line e-beam sterilization system

International Nuclear Information System (INIS)

Lambert, Byron; Tang, Fuh-Wei; Riggs, Brian; Allen, Thomas; Williams, C.B.

2000-01-01

The Vascular Intervening Group of the Guidant Corporation (Guidant IV) has been operating a self-shielded, 10 MeV 4 kW, electron beam sterilization system since July of 1988. The system was designed, built and installed in a 70 square meter area in an existing Guidant manufacturing facility by Titan Scan Corporation and performance of the system was validated in conformance with 1S0-11137 standards. The goal of this on-site e-beam system was 'just in time' JIT, sterilization, i.e. the ability to manufacture, sterilize and ship, high intrinsic value medical devices in less than 24 hours. The benefits of moving from a long gas sterilization cycle of greater than one week to a JIT process were envisioned to be a) speed to market with innovated new products b) rapid response to customer requirements c) reduced inventory carrying costs and finally manufacturing and quality system efficiency. The ability of Guidant to realize these benefits depended upon the ability of the Guidant VI business units to adapt to the new sterilization modality and functionality and on the overall system reliability. This paper reviews the operating experience to date and the overall system reliability. (author)
Upper limit on the inner radiation belt MeV electron intensity

Science.gov (United States)

Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

2015-01-01

No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Key Points Quantified upper limit of MeV electrons in the inner belt Actual MeV electron intensity likely much lower than the upper limit More detailed understanding of relativistic electrons in the magnetosphere PMID:26167446
A gas ionisation Direct-STIM detector for MeV ion microscopy

International Nuclear Information System (INIS)

Norarat, Rattanaporn; Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef; Roux, Adrien; Stoppini, Luc; Whitlow, Harry J.

2015-01-01

Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas
Neutron induced fission of U isotopes up to 100 MeV

International Nuclear Information System (INIS)

Lestone, J.P.; Gavron, A.

1993-01-01

We have developed a statistical model description of the neutron induced fission of U isotopes using densities of intrinsic states and spin cut off parameters obtained directly from appropriate Nilsson model single particle levels. The first chance fission cross sections are well reproduced when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second chance fission, we need to: (1) assume that the triaxial level density enhancement is washed out at an excitation energy of ∼7 MeV above the triaxial barriers with a width of ∼1 MeV, implying a γ deformation for the first barriers of 10 degree < γ < 20 degree; and (2) include pre-equilibrium particle emission in the calculations. Above an incoming neutron kinetic energy of ∼17 MeV our statistical model U(n,f) cross sections increasingly overestimate the experimental data when so called ''good'' optical model potentials are used to calculate the compound nucleus formation cross sections. This is not surprising since at these high energies little data exists on the scattering of neutrons to help guide the choice of optical model parameters. A satisfactory reproduction of all the available U(n,f) cross sections above 17 MeV is obtained by a simple scaling of our calculated compound nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV
γ rays of 0.3-30 MeV from PSR0833 - 45

International Nuclear Information System (INIS)

Tuemer, O.T.; Long, J.; O'Neill, T.; Zych, A.; White, R.S.

1984-01-01

Pulsed γ rays from the Vela pulsar PSR0833-45 are reported for the first time at the medium energies, E, of 0.3-30 MeV. They were observed with the double scatter γ-ray telescope 31 days after a large glitch in the pulsar period. The first and second pulses were detected from single scatters in the top scintillators, S1, at energies > 0.3 MeV, and by double scatters from all detector cell pairs at energies of 1-30 MeV. The phase separation of the two pulses is 0.43 +- 0.02 at the same absolute phases previously found by SAS 2 and COS B for E > 35 MeV. The energy distribution with six points from 0.3 to 30 MeV appears to bend away from the COS B power law at the lower energies and is well below the HEAO 1 upper limits. (author)
Search for an elusive 4.4-MeV α emitter in uranium minerals

International Nuclear Information System (INIS)

Dougan, R.J.; Illige, J.D.; Hulet, E.K.

1979-12-01

A search for an unidentified 4.4-MeV α-emitter in Belgian Congo pitchblende and uranium raffinates is described, and a history of observations of 4.4-MeV activity over the last 55 years in radiogenic haloes, zinc ores, monazite, thorite, huttonite, ultrabasic and other abyssal rocks, osmiridium, uranium ores, and raffinates of uranium is given. No evidence of excess 4.4-MeV activity was shown in any of the chemically separated fractions investigated. Upper limits for 4.4-MeV α activity in each of four studied samples are given
On-site bridge inspection with partial CT by 3.95Mev X-band linac source

International Nuclear Information System (INIS)

Wu, Wenjing; Zhu, Haito; Jin, Ming

2012-01-01

Since more and more bridges built several decades ago in Japan have become aged and dangerous, the non-destructive evaluation of those bridges is really an urgent problem. CT system with portable 3.95MeV linacs for bridge inspection is considered to work on-site, considering the law of Japanese radiation protection allows using linacs up to 4MeV outside radiation controlled area. The system would confirm the internal steel situation of bridges and analyze structural strain and stress with 3D model built from sectional imaging to evaluate load-bearing performance. The reconstruction process of bridge imaging is based on partial scanned data because bridge shape confines possible scanning angle to smaller than 180deg and a few translations. A small concrete sample with internal steel bars and attachment accessories is scanned in laboratory as preliminary work. (author)
Beam dynamics design of the 211 MeV APT normal conducting linac

International Nuclear Information System (INIS)

Young, L.M.; Billen, J.H.; Takeda, H.; Wood, R.L.

1998-01-01

This paper describes the normal conducting linac design that is part of the Accelerator for Production of Tritium (APT) project. The new version of PARMILA designed this linac. This linac accepts the beam from the 6.7 MeV radio frequency quadrupole without a separate matching section. At about 10 MeV, it has a smooth transition in the length of period from 8βλ to 9βλ in quadrupole focusing lattice. This adjustment of the period was needed to provide sufficient space for the quadrupole focusing magnets and beam diagnostic equipment. The linac consists of the coupled cavity drift tube linac up to 97 MeV and coupled cavity linac above 97 MeV
Thermoluminescence response of Ge-, Al- and Nd- doped optical fibers by 6 MeV - electron and 6 MeV - photon irradiations

International Nuclear Information System (INIS)

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

2015-01-01

In this paper, we report the prediction of thermoluminescence responses of Neodymium-doped SiO 2 optical fibre with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MeV - electron irradiations without requirement for experimental measurements. A technique has been developed to calculate prediction of 6 MeV - electron response of Neodymium-doped SiO 2 optical fibre by observing the measured TL response of 6 MV - photon and the ratio of known measured photon/electron yield ratio distribution for Ge-doped, Al-doped optical fibre and standard TLD 100 dosimeter. The samples were kept in gelatin capsule an irradiated with 6 MV - photon at the dose range from 0.5 Gy to 4.0 Gy. Siemens model Primus 3368 linear accelerator located at Hospital Sultan Ismail, Johor Bahru has been used to deliver the photon beam to the samples. We found the average response ratio of 6 MV - photon and 6 MeV - electron in Ge-doped, Al-doped optical fibre and standard TLD-100 dosimeter are 0.83(3). Observing the measured value of 6 MV - photon irradiation this average ratio is useful to find the prediction of thermoluminescence responses by 6 MeV - electron irradiation of Neodymium-doped SiO 2 optical fibre by the requirement for experimental measurements with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MV - photon irradiations.
Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the {sup 15}N(p,n) reaction as neutron source; Messung von Wirkungsquerschnitten fuer die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der {sup 15}N(p,n)-Reaktion als Neutronenquelle

Energy Technology Data Exchange (ETDEWEB)

Poenitz, Erik

2010-04-26

In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The {sup 15}N(p,n){sup 15}O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the {sup 15}N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure {sup 209}Bi and {sup 181}Ta samples at 4 MeV incident neutron energy
Measurement of the angular distribution of 14 MeV neutrons scattered inelastically from the 0+ level at 7.65 MeV to {sup 12}C (1964); Mesure de la distribution angulaire a 14 MeV de neutrons de diffusion inelastique sur le niveau 0+ de 7,65 MeV du {sup 12}C (1964)

Energy Technology Data Exchange (ETDEWEB)

Szabo, I [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1963-11-15

Inelastic scattering of 14 MeV neutrons from {sup 12}C and angular distribution for the 0{sup +} (7,65 MeV) level, with a time-of-flight spectrometer (over-all resolution 1.4 ns), gives strong forward maximum {sigma}({theta} 15 deg.) {approx_equal} 8 mb/sr suggesting a direct-interaction process. (author) [French] Realisation d'un spectrometre de neutrons rapides a temps-de-vol de resolution totale 1,4 ns. Application: {sup 12}C (n,n') {sup 12}C (7,65 MeV) donnant {sigma}{sub t} {approx_equal} 20 mb, une forte emission vers l'avant {sigma}({theta} 15 deg.) {approx_equal} 8 mb/sr indiquont un processus d'interaction directe. (auteur)
Construction of a bi parametric analysis system. Application to the study of the decay of the 16.11 MeV level of {sup 12}C; Realisation d'un ensemble d'analyse biparametrique. Application a l'etude de la desintegration du niveau de 16,11 MeV du {sup 12}C

Energy Technology Data Exchange (ETDEWEB)

Engelhardt, H D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1966-11-15

A baroreceptor analysis system has been assembled to measure {alpha}-{alpha} spectra in coincidence (resolution 2 {tau} = 10 ns). The correlations in energy and angle of the {alpha}-particles emitted from the reaction {sup 11}B(p,{alpha}) have been studied using 163 keV protons produced by a Van-de-Graaff accelerator. Evidence has been obtained for the sequential decay of {sup 12}C{sup *} (16.11 MeV) via the 0{sup +} and 2{sup +} states of {sup 8}Be. Contributions from the {sup 8}Be{sup *}(4{sup +}) level or from the simultaneous break-up of {sup 12}C{sup *} (16.11 MeV) into three {alpha}-particles cannot be excluded. (author) [French] On a mis au point un dispositif d'analyse biparametrique de spectres {alpha}-{alpha} en coincidences (resolution 2 {tau} = 10 ns). On a etudie, a l'aide de ce dispositif et d'un accelerateur Van de Graaff la correlation d'energie et angulaire entre les particules a de la reaction {sup 11}B(p,{alpha}) a une energie de protons E{sub p} = 163 keV. On a mis en evidence la desintegration sequentielle du {sup 12}C{sup *} (16.11 MeV) par les etats (0{sup +} et 2{sup +}) du {sup 8}Be. La contribution d'un niveau (4{sup +}) du {sup 8}Be{sup *} ou d'une desintegration simultanee du {sup 12}C{sup *} (16,11 MeV) en 3 {alpha} ne peut pas etre exclue. (auteur)
<600> MeV synchro-cyclotron

CERN Multimedia

CERN PhotoLab

1971-01-01

One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.
MeV fullerene impacts on mica

Energy Technology Data Exchange (ETDEWEB)

Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

1997-09-01

Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.
Photon mass energy absorption coefficients from 0.4 MeV to 10 MeV for silicon, carbon, copper and sodium iodide

International Nuclear Information System (INIS)

Oz, H.; Gurler, O.; Gultekin, A.; Yalcin, S.; Gundogdu, O.

2006-01-01

The absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy absorption coefficients for gamma rays with an incident energy range between 0.4 MeV and 10 MeV in silicon, carbon, copper and sodium iodide. The mass energy absorption coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.
Photon mass energy absorption coefficients from 0.4 MeV to 10 MeV for silicon, carbon, copper and sodium iodide

Energy Technology Data Exchange (ETDEWEB)

Oz, H.; Gurler, O.; Gultekin, A. [Uludag University, Bursa (Turkmenistan); Yalcin, S. [Kastamonu University, Kastamonu (Turkmenistan); Gundogdu, O. [University of Surrey, Guildford (United Kingdom)

2006-07-15

The absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy absorption coefficients for gamma rays with an incident energy range between 0.4 MeV and 10 MeV in silicon, carbon, copper and sodium iodide. The mass energy absorption coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.
17O(n,α)14C cross section from 25 meV to approximately 1 MeV

International Nuclear Information System (INIS)

Koehler, P.E.; Graff, S.M.

1991-01-01

We have measured the 17 O(n,α) 14 C cross section from thermal energy to approximately 1 MeV. A bump in the data near 3 keV could be fitted by a state whose properties are consistent with a known subthreshold J π =1 - level at E x =8.039 MeV. The cause of the 1/v cross section near thermal energy could not be determined although the known 2 + state at 8.213 MeV was found to be too narrow to contribute much to the thermal cross section. Our data are compared to measurements made via the inverse reaction. There are many differences between the two sets of data. The astrophysical reaction rate was calculated from the measured cross section. This reaction plays a role in the nucleosynthesis of heavy elements in nonstandard big-bang models. At big-bang temperatures, the experimental rate was found to be in fair agreement with the rate estimated from the previously known properties of states of 18 O in this region. Furthermore, using the available information from experiments, it was estimated that the 17 O(n,α) 14 C rate is approximately a factor of 10 3 --10 4 times larger than the 17 O(n,γ) 18 O rate at big-bang temperatures. As a result, there may be significant cycling between 14 C and 17 O resulting in a reduction of heavy-element nucleosynthesis
Elastic and inelastic scattering of {sup 15}N ions by {sup 9}Be at 84 MeV

Energy Technology Data Exchange (ETDEWEB)

Rudchik, A.T., E-mail: rudchik@kinr.kiev.ua [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Chercas, K.A. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Kemper, K.W. [Physics Department, Florida State University, Tallahassee, FL 32306-4350 (United States); Rusek, K. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Rudchik, A.A.; Herashchenko, O.V. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Koshchy, E.I. [Kharkiv National University, pl. Svobody 4, 61077 Kharkiv (Ukraine); Pirnak, Val.M. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Piasecki, E.; Trzcińska, A. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Sakuta, S.B. [Russian Research Center “Kurchatov Institute”, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Siudak, R. [H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Strojek, I. [National Center for Nuclear Researches, ul. Hoża 69, PL-00-681 Warsaw (Poland); Stolarz, A. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Ilyin, A.P.; Ponkratenko, O.A.; Stepanenko, Yu.M.; Shyrma, Yu.O. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Szczurek, A. [H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Uleshchenko, V.V. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine)

2016-03-15

Angular distributions of the {sup 9}Be + {sup 15}N elastic and inelastic scattering were measured at E{sub lab}({sup 15}N) = 84 MeV (E{sub c.m.} = 31.5 MeV) for the 0–6.76 MeV states of {sup 9}Be and 0–6.32 MeV states of {sup 15}N. The data were analyzed within the optical model and coupled-reaction-channels method. The elastic and inelastic scattering, spin reorientations of {sup 9}Be in ground and excited states and {sup 15}N in excited states as well as the most important one- and two-step transfer reactions were included in the channels-coupling scheme. The parameters of the {sup 9}Be + {sup 15}N optical potential of Woods–Saxon form as well as deformation parameters of these nuclei were deduced. The analysis showed that the {sup 9}Be + {sup 15}N pure potential elastic scattering dominates at the forward angles whereas the ground state spin reorientation of {sup 9}Be gives a major contribution to the elastic scattering cross sections at the large angles. Contributions from particle transfers are found to be negligible for the present scattering system.
Plasma production for the 50 MeV plasma lens experiment at LBL

International Nuclear Information System (INIS)

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

1994-06-01

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

Science.gov (United States)

Bellaveglia, M.; Gallo, A.; Piersanti, L.; Pompili, R.; Gatti, G.; Anania, M. P.; Petrarca, M.; Villa, F.; Chiadroni, E.; Biagioni, A.; Mostacci, A.

2015-05-01

The SPARC LAB complex hosts a 150 MeV electron photo-injector equipped with an undulator for FEL production (SPARC) together with a high power TW laser (FLAME). Recently the synchronization system reached the performance of < 100 fsRMS relative jitter between lasers, electron beam and RF accelerating fields. This matches the requirements for next future experiments: (i) the production of X-rays by means of Thomson scattering (first collisions achieved in 2014) and (ii) the particle driven PWFA experiment by means of multiple electron bunches. We report about the measurements taken during the machine operation using BAMs (Bunch Arrival Monitors) and EOS (Electro-Optical Sampling) system. A new R and D activity concerning the LWFA using the external injection of electron bunches in a plasma generated by the FLAME laser pulse is under design. The upgrade of the synchronization system is under way to guarantee the < 30 fs RMS jitter required specification. It foresees the transition from electrical to optical architecture that mainly affects the reference signal distribution and the time of arrival detection performances. The new system architecture is presented together with the related experimental data.

(p,t) reaction on /sup 12/C, /sup 54/Fe and /sup 208/Pb at 80 MeV. [80 MeV, angular distributions, zerio-range DWBA

Energy Technology Data Exchange (ETDEWEB)

Shepard, J R; Anderson, R E; Kraushaar, J J; Ristinen, R A [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; Comfort, J R [Pittsburgh Univ., PA (USA). Dept. of Physics; King, N S.P. [Los Alamos Scientific Lab., NM (USA); Bacher, A; Jacobs, W W [Indiana Univ., Bloomington (USA). Dept. of Physics

1979-06-11

Angular distributions have been measured for the low-lying levels of the residual nuclei for the /sup 12/C, /sup 54/Fe and /sup 208/Pb(p,t) reactions at E/sub p/ = 80 MeV. The shapes of these angular distributions are generally well reproduced by the zero-range distorted-wave Born approximation (DWBA). Enhancement factors extracted from the data show that the DWBA predicts relative strengths consistent with those observed at lower bombarding energies. However, the overall empirical DWBA normalization at E/sub p/ = 80 MeV is observed to be 1/12(1/4) of that required at 40 MeV for /sup 208/Pb(/sup 54/Fe).
Analyzing power for the 16O(p,n)16F (4-, 6.37 MeV) reaction at 134 MeV

International Nuclear Information System (INIS)

Madey, R.; Fazely, A.; Anderson, B.D.; Baldwin, A.R.; Kalenda, A.M.; McCarthy, R.J.; Tandy, P.C.; Watson, J.W.; Bertozzi, W.; Buti, T.; Finn, M.; Kovash, M.; Pugh, B.; Foster, C.C.

1982-01-01

We measured the analyzing power for the 16 O(p,n) 16 F (4 - , 6.37 MeV) reaction at 134.0 MeV and the differential cross section for the same reaction at 135.2 MeV. The shape of the cross section for the transition to this unnatural parity stretched state is described well by a distorted-wave impulse-approximation calculation using a (πd/sub 5/2/, νp/sub 3/2//sup ts-1/) 4 /sub -/ configuration and the effective interaction derived by Love and Franey from nucleon-nucleon phase shifts. The analyzing power from this calculation reproduces all of the qualitative features of the data and supports the use of the impulse approximation as an excellent starting point for describing the reaction mechanism. Quantitative agreement between the experimental and theoretical analyzing power can be improved by eliminating the imaginary tensor term of this interaction and taking the real part to be that derived by Love from the Sussex matrix elements. The sensitivity of the calculations to the choice of optical potentials and the importance of spin-orbit distortion is explored
Actinide neutron-induced fission up to 20 MeV

International Nuclear Information System (INIS)

Maslov, V.M.

2001-01-01

Fission and total level densities modelling along with double-humped fission barrier parameters allow to describe available actinide neutron-induced fission cross section data in the incident neutron energy range of ∼ 10 keV - 20 MeV. Saddle asymmetries relevant to shell correction model calculations influence fission barriers, extracted by cross section data analysis. The inner barrier was assumed axially symmetric in case of U, Np and Pu neutron-deficient nuclei. It is shown that observed irregularities in neutron-induced fission cross section data in the energy range of 0.5-3 MeV could be attributed to the interplay of few-quasiparticle excitations in the level density of fissioning and residual nuclei. Estimates of first-chance fission cross section and secondary neutron spectrum model were validated by 238 U fission, (n,2n) and (n,3n) data description up to 20 MeV. (author)
Actinide neutron-induced fission up to 20 MeV

Energy Technology Data Exchange (ETDEWEB)

Maslov, V M [Radiation Physics and Chemistry Problems Institute, Minsk-Sosny (Belarus)

2001-12-15

Fission and total level densities modelling along with double-humped fission barrier parameters allow to describe available actinide neutron-induced fission cross section data in the incident neutron energy range of {approx} 10 keV - 20 MeV. Saddle asymmetries relevant to shell correction model calculations influence fission barriers, extracted by cross section data analysis. The inner barrier was assumed axially symmetric in case of U, Np and Pu neutron-deficient nuclei. It is shown that observed irregularities in neutron-induced fission cross section data in the energy range of 0.5-3 MeV could be attributed to the interplay of few-quasiparticle excitations in the level density of fissioning and residual nuclei. Estimates of first-chance fission cross section and secondary neutron spectrum model were validated by {sup 238}U fission, (n,2n) and (n,3n) data description up to 20 MeV. (author)
Synchronous phase and energy measurement system for a 6.7-MeV H- beam

International Nuclear Information System (INIS)

Gilpatrick, J.D.; Meyer, R.E.; Wells, F.D.; Power, J.F.; Shafer, R.E.

1988-01-01

A noninterceptive measurement system has been built to measure the energy and synchronous phase of a 6.7-MeV proton beam drifting from the ramped-gradient, drift-tube linac (RGDTL) in the accelerator test stand (ATS) facility. Axially-symmetric, capacitive probes used in these measurements produce signals that are proportional to the beam image current on their inner rings. Signals from two of these probes separated by 92.6 cm are down-converted from 425 to 20 MHz. The phase difference between these 20-MHz signals is then detected with an electronic, phase-comparator circuit. The phase-comparator signal output is a voltage that is related to momentum of the beam. A phase comparison is also provided between the 425-MHz fundamental rf field inside the RGDTL and the capacitive probe located nearest the RGDTL output. The total estimated error for the absolute and relative energy measurement is less than +- 12.2 and +- 3.1 keV, respectively. The total estimated error for the relative synchronous phase measurement is less than +-1/degree/. Beam energy versus synchronous phase experimental data agree with computer simulations. 3 refs., 3 figs., 1 tab
Elastic Scattering of 7Li+27Al at Backward Angles in the 7-11 MeV Energy Range for Application in RBS

International Nuclear Information System (INIS)

Carnelli, P. F. F.; Arazi, A.; Cardona, M. A.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Abriola, D.; Capurro, O. A.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Fernandez Niello, J. O.

2010-01-01

We have measured elastic excitation functions for the 7 Li+ 27 Al system, in an energy range close to its Coulomb barrier (E lab = 8.4 MeV) in steps of 0.25 MeV. For this purpose, an array of eight surface-barrier detectors was used. To get an insight on the background composition (mainly α particles), a telescope-detector was used for atomic-number identification. Identical measurements for the 6 Li+ 27 Al system are planned for the near future.
The shielding performance of multilayer composite shielding structures to 14.8 MeV fast neutrons

International Nuclear Information System (INIS)

Shen Zhiqiang; Kang Qing; Xu Jun; Wang Zhenggang; Lu Nan

2014-01-01

Cement-based round thin-layer samples mixed with 30% quality content of barite, and 20% quality content of carbide boron has Prepared, the same-diameter sliced samples of pure graphite and pure polyethylene has cut, then, samples combination and cross stack order has designed, formed four species Multilayer Composite shield structure, at last, neutron attenuation measurements has been done by experimental system of using 14.8 MeV neutrons from the 5SDH-2 accelerator and long counter composition, penetrating rate of samples and the shield structure to 14.8 MeV fast neutron has tested, and attenuation section has calculated. Results show that 14.8 MeV fast neutrons to higher penetration rates of thin layer samples, attenuation cross section of samples distinguish small between each other, must be increasing the thickness of the samples to reduce the experimental uncertainty; through composed of attenuation cross section and thickness parameters of composite structure, can more accurately predict the shielding ability of composite structures, error between calculation results and experimental results in 4%. (authors)
Measurement of neutron-induced fission cross-sections of Th232, U238, U233 and Np237 relative to U235 from 1 MeV to 200 MeV

Energy Technology Data Exchange (ETDEWEB)

Shcherbakov, O.A.; Laptev, A.B.; Petrov, G.A. [Petersburg Nuclear Physics Inst., Gatchina, Leningrad district (Russian Federation); Fomichev, A.V.; Donets, A.Y.; Osetrov, O.I.

1998-11-01

The measurements of neutron-induced cross-section ratios for Th232, U238, U233 and Np237 relative to U235 have been carried out in the energy range from 1 MeV up to 200 MeV using the neutron time-of-flight spectrometer GNEIS based on 1 GeV proton synchrocyclotron. Below 20 MeV, the results of present measurements are roughly in agreement with evaluated data though there are some discrepances to be resolved. (author)
Analyzing power measurements for 209Bi(n,n) at 6 and 9 MeV and consistent dispersive optical-model analyses for n+209Bi and n+208Pb from -20 to +80 MeV

International Nuclear Information System (INIS)

Weisel, G.J.; Tornow, W.; Howell, C.R.; Felsher, P.D.; AlOhali, M.; Roberts, M.L.; Das, R.K.; Walter, R.L.; Mertens, G.

1996-01-01

High-accuracy measurements of A y (θ) data for elastic scattering for n+ 209 Bi have been performed at 6 and 9 MeV. The data are incorporated into a large database of σ(θ), A y (θ), and σ T for n+ 209 Bi covering the energy range 1.0 endash 80 MeV. A complementary database is constructed for n+ 208 Pb and a dispersive optical-model analysis is performed for both scattering systems while constraining many of the parameters to be identical for both systems. A good representation of both databases is obtained with conventional geometry and spin-orbit parameters. The 208 Pb model predicts quite well the measured energies of valence single-particle and single-hole bound states. Occupation probabilities and spectroscopic factors for the same bound states are also calculated. Finally, a fully constrained model is presented in which the only differences between the n+ 208 Pb and the n+ 209 Bi systems are the Fermi energy and the isospin dependence in the real volume potential. copyright 1996 The American Physical Society
(n, Xn) cross sections measurements at 96 MeV

International Nuclear Information System (INIS)

Sagrado Garcia, Inmaculada C.

2006-01-01

Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n, Xn) reactions in this energy range. Neutron double differential cross sections measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL laboratory, in Uppsala (Sweden). The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 deg.-98 deg.). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100 MeV). The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparisons between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its original treatment of nucleon-nucleus reactions. (author) [fr
A sub-50meV spectrometer and energy filter for use in combination with 200kV monochromated (S)TEMs.

Science.gov (United States)

Brink, H A; Barfels, M M G; Burgner, R P; Edwards, B N

2003-09-01

A high-energy resolution post-column spectrometer for the purpose of electron energy loss spectroscopy (EELS) and energy-filtered TEM in combination with a monochromated (S)TEM is presented. The prism aberrations were corrected up to fourth order using multipole elements improving the electron optical energy resolution and increasing the acceptance of the spectrometer for a combination of object area and collection angles. Electronics supplying the prism, drift tube, high-tension reference and critical lenses have been newly designed such that, in combination with the new electron optics, a sub-50 meV energy resolution has been realized, a 10-fold improvement over past post-column spectrometer designs. The first system has been installed on a 200 kV monochromated TEM at the Delft University of Technology. Total system energy resolution of sub-100 meV has been demonstrated. For a 1s exposure the resolution degraded to 110 meV as a result of noise. No further degradation in energy resolution was measured for exposures up to 1 min at 120 kV. Spectral resolution measurements, performed on the pi* peak of the BN K-edge, demonstrated a 350 meV (FWHM) peak width at 200 kV. This measure is predominantly determined by the natural line width of the BN K-edge.
Coherent pion production induced by 300 MeV and 600 MeV deuterons

International Nuclear Information System (INIS)

Aslanides, E.; Bergdolt, A.M.; Bing, O.; Fassnacht, P.; Hibou, F.

1982-01-01

Experimental data on (d,π - ) reactions at 300 and 600 MeV incident energy are presented. Inclusive spectra on 6 Li, 9 Be and 10 B targets near the kinematical limit do not show the usual scaling behaviour. For the two-body reaction 6 Li (d,π - ) 8 B the lowest-energy discrete states of the final nucleus were clearly resolved and the cross sections for pion production leading to those states have been determined. (orig.)
Theoretical approach of the photoinjector exit aperture influence on the wake field driven by an electron beam accelerated in an RF gun of free-electron laser 'ELSA'

CERN Document Server

Salah, W

2000-01-01

The wake field generated in the cylindrical cavity of an RF photoinjector, by a strongly accelerated electron beam, has been analytically calculated (Salah, Dolique, Nucl. Instr. and Meth. A 437 (1999) 27) under the assumption that the perturbation of the field map by the exit hole is negligible as long as the ratio: exit hole radius/cavity radius is lower than approximately 1/3. Shown experimentally in the different context of a long accelerating structure formed by a sequence of bored pill-box cavity (Figuera et al., Phys. Rev. Lett. 60 (1988) 2144; Kim et al., J. Appl. Phys. 68 (1990) 4942), this often-quoted result must be checked for the wake field map excited in a photo injector cavity. Further, in the latter case, the empirical rule in question can be broken more easily because, due to causality, the cavity radius to be considered is not the physical radius but that of the part of the anode wall around the exit hole reached by the beam electromagnetic influence. We present an analytical treatment of th...
A 30 MeV H- cyclotron for isotope production

International Nuclear Information System (INIS)

Baartman, R.; Kleevan, W.J.; Laxdal, R.E.; Milton, B.F.; Otter, A.J.; Pearson, J.B.; Poirier, R.L.; Schmor, P.W.; Schneider, H.R.; Erdman, K.L.; Walker, Q.

1989-01-01

Because of an expanding market for radioisotopes there is a need for a new generation of cyclotrons designed specifically for this purpose. We describe such a cyclotron currently under construction. It is a 30 MeV H - design that exploits a newly developed high brightness multicusp ion source which is capable of H - currents of up to 5 mA. This together with careful beam matching then makes feasible accelerated H - beam intensities of 500 μA. The cyclotron being built is a four sector radial ridge design with two 45 degree dees in opposite valleys. Beam extraction is by stripping to H + in a thin graphite foil. Two extraction probes will allow simultaneous extraction of two beams, each with an intensity of up to 200 μA. Energy variation from 15 MeV to 30 MeV is achieved by varying the radial position of the extraction foil. 7 refs., 4 figs., 1 tab
Gamma rays from the de-excitation of 12C*(15.11MeV) and 12C*(4.44MeV) as probes of energetic particle spectra

International Nuclear Information System (INIS)

Crannell, C.J.; Ramaty, R.; Crannell, H.

1977-01-01

The flux of 15.11 MeV γ rays relative to the flux 4.44 MeV γ rays has been calculated from measured cross sections for excitation of the corresponding states of 12 C and from experimental determinations of the branching ratios for direct de-excitation of these states to the ground state. Because of the difference in threshold energies for excitation of these two levels, the relative intensities in the two lines are particularly sensitive to the spectral distribution of energetic particles which excite the corresponding nuclear levels. For both solar and cosmic emission, the observability of the 15.11 MeV line is expected to be enhanced by low source-background continuum in this ener
Longitudinal phase-space matching between microtrons at 185 MeV

International Nuclear Information System (INIS)

Takeda, H.

1983-01-01

Electrons are accelerated to 185 MeV by a microtron. Then, they are injected into another microtron to boost the net energy up to a few GeV. Between the two microtrons both longitudinal and transverse phase-space matching are required. In this paper, we consider a longitudinal phase-ellipse matching which utilizes triple left-right-left sector dipoles to induce a negative phase-angle shear. This is accomplished because a high-energy particle travels a shorter distance through the dipole system than a low-energy particle
Cross-sections for formation of {sup 89}Zr{sup m} through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction over neutron energy range 13.73 MeV to 14.77 MeV

Energy Technology Data Exchange (ETDEWEB)

Attar, F.M.D. [Department of Physics, University of Pune, Pune-411007 (India); Mandal, R. [Department of Physics, University of Pune, Pune-411007 (India); Indian Institute of Technology, Kharagpur (India); Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Saxena, A. [Nuclear Physics Division, BARC, Mumbai (India); Ashokkumar,; Ganesan, S. [Reactor Physics Design Division, BARC, Mumbai (India); Kailas, S. [Nuclear Physics Division, BARC, Mumbai (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

2008-04-01

The cross-sections for formation of metastable state of {sup 89}Zr ({sup 89}Zr{sup m}, 0.588 MeV, 4.16 m) through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction induced by 13.73 MeV to 14.77 MeV neutrons were measured for the first time and also theoretically estimated using Empire-II and Talys programs. At 13.73 MeV neutron energy, the {sup 89}Zr nuclei can be excited to metastable state, {sup 89}Zr{sup m}, when the first and the second emitted neutrons have energies lower than the most probable energy {approx}0.64 MeV. The probability of exciting {sup 89}Zr nuclei to energy levels higher than 0.588 MeV and therefore of populating the metastable state through decay process increases with increasing neutron energy. The measured cross-sections vary from 41{+-}3mb to 221{+-}15mb over neutron energies 13.73 MeV to 14.77 MeV, and are in agreement with the cross-sections estimated using Empire-II code. The formation of {sup 89}Zr{sup m} is favoured when the first and the second reaction neutrons are emitted with the most probable energies rather than lower energy, except for 13.73 MeV neutrons.
Production of 14 MeV neutrons from D-D neutron generators

International Nuclear Information System (INIS)

Cecil, F.E.; Nieschmidt, E.B.

1986-01-01

The production of 14 MeV neutrons from a D-D neutron generator resulting from tritium buildup from the d(d,p)t reaction in the target is discussed. The effect of the 14 MeV neutrons on fast neutron activation analysis with D-D neutron generators is evaluated. (orig.)
The ANL 50 MeV H- Injector: 35 year anniversary

International Nuclear Information System (INIS)

Stipp, V.; Brumwell, F.; McMichael, G.

1996-01-01

The H - Injector at ANL consists of a 750 keV Cockcroft-Walton preaccelerator and an Alvarez type 50 MeV Linac. The accelerator was originally constructed as the source of protons for the Zero Gradient Synchrotron (ZGS). The first proton beam was extracted from the preaccelerator in 1961. The accelerator is presently used as the injector for the Intense Pulsed Neutron Source (IPNS), a 500 MeV rapid cycling synchrotron with a spallation-neutron target. During most of the time since turn-on over 15 years ago, the IPNS facility availability has rarely dropped below 90% and has averaged 95% over the last ten years. During the same period, the 50 MeV injector availability has averaged 99%. Performance and improvements over the 35 year period is discussed
Excitation energy partition in deeply inelastic collisions between 40Ar and Ag at 27 MeV per nucleon

International Nuclear Information System (INIS)

Borderie, B.; Rivet, M.F.; Cabot, C.; Fuchs, H.; Gardes, D.; Hanappe, F.; Jouan, D.; Montoya, M.

1991-01-01

The dynamics of the two partners produced in dissipative collisions has been experimentally studied for the system 40 Ar+Ag at 27 MeV per nucleon. Primary masses of the fragments can then be calculated; the excitation energy partition between the two fragments is derived from the number of particles evaporated by each fragment. We found that this division evolves from equipartition to a repartition close to thermal equilibrium in the excitation energy range 300-350 MeV or interaction times 5-10x10 -22 s. (orig.)

Ion beam induced luminescence from diamond using an MeV ion microprobe

Energy Technology Data Exchange (ETDEWEB)

Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1993-12-31

Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.
Ion beam induced luminescence from diamond using an MeV ion microprobe

Energy Technology Data Exchange (ETDEWEB)

Bettiol, A A; Jamieson, D N; Prawer, S; Allen, M G [Melbourne Univ., Parkville, VIC (Australia). School of Physics

1994-12-31

Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.
Neutron-neutron quasifree scattering in nd breakup at 10 MeV

Science.gov (United States)

Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.

2016-03-01

The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.
Development of the accelerating system

Energy Technology Data Exchange (ETDEWEB)

Jang, Jiho; Kwon, H. J.; Kim, D. I.; Kim, H. S.; Ryu, J. Y.; Park, B. S.; Seol, K. T.; Yun, S. P.; Song, Y. G.; Cho, Y. S.

2013-02-15

One of the main purposes of the 'Development of the Accelerating System' is developing a 100-MeV proton linac which accelerate proton beams from 20 MeV to 100 MeV by using 7 DTL (drift tube linac) tanks. Two of them were finished in the 2-nd stage of the project. The remaining part was also successfully fabricated and installed at Gyeongju site of KAERI. The MEBT is an essential component to extract and supply 20-MeV proton beams to users, and to match proton beams to the next accelerating structure for 100-MeV acceleration. The development of the MEBT has successfully finished. The project also developed the digital LLRF (low level RF) system which control the accelerating field within 1% in magnitude and 1 degree in phase. This system has been successfully tested in the 20-MeV linac operation at Daejeon site of KAERI. The modified version of the digital LLRF system will be used in the 100-MeV linac operation. The project also developed the beam diagnostic system. They are the strip-line type beam position monitor (BPM), the beam current monitor (CT), the beam loss monitor (BLM), and the emittance measurement system. They are used to measure the characteristics of the 20-MeV proton beams. The project also developed the EPIC-based control system. It is used to monitor the status of the accelerator and components, and to remotely control accelerator components. It has been used and modified in the 20-MeV linac operation. The modified version of the LLRF, diagnostics and control systems will be used in 100-MeV linac operation.
Two body photodisintegration of the deuteron from 100 to 800 MeV

International Nuclear Information System (INIS)

Crawford, R.; Annand, J.R.M.; Anthony, I.; Altieri, S.; Pavia Univ.; Audit, G.; D'Hose, N.

1996-01-01

The total and the differential cross sections for the D(γ,p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author)
A 30 MeV H- cyclotron for isotope production

International Nuclear Information System (INIS)

Milton, B.F.; Dawson, R.; Erdman, K.L.

1989-05-01

Because of an expanding market for radioisotopes there is a need for a new generation of cyclotrons designed specifically for this purpose. TRIUMF is cooperating with a local industrial company in designing and constructing such a cyclotron. It will be a four sector H - cyclotron, exploiting the newly developed high brightness multicusp ion source. This source with H - current capability in excess of 5 mA makes feasible accelerated H - beam intensities of up to 500 μA. Beam extraction is by stripping to H + in a thin graphite foil. Extraction of two high-intensity beams, with energy variable from 15 to 30 MeV is planned. The use of an external ion source, provision of a good vacuum in the acceleration region, and the careful choice of materials for components in the median plane leads to a cyclotron that will have low activation and can be easily serviced in spite of the very high operating beam intensities. A design extension to 70 MeV using many of the design features of the 30 MeV cyclotron can be easily made. Such a machine with a good quality variable energy beam is a highly desirable source of protons for isotope production, injection into higher energy high intensity acceleration, injection into higher energy high intensity accelerators, and as an irradiation facility for ocular melanomas. Design of the 30 MeV cyclotron is well advanced and construction is in progress
The total angular moment selectivity in 7Li(α, α) 7Li(4.63 MeV, 7/2-) reaction at Eα = 27.2 MeV

International Nuclear Information System (INIS)

Dmitrenko, V.N.; Kozyr', Yu.E.

1995-01-01

The DWBA calculation of tensor polarisation of residual nuclei for direct inelastic scattering 7 Li(α, α) 7 Li(4.63 MeV, 7/2 - ) gives the lest approximation to experimental data at selected total angular moment and parity values J π 13/2 + . The microscopic coupled channel calculation also predicts a significant role of total angular moment states with J ≥ 13/2. at E α 27.2 MeV
Irradiation effects of 11 MeV protons on ferritic steels

International Nuclear Information System (INIS)

Hamaguchi, Yoshikazu; Kuwano, Hisashi; Misawa, Toshihei

1985-01-01

It is considered that ferritic/martensitic steels are the candidate of the first wall materials for future fusion reactors. The most serious problem in the candidate materials is the loss of ductility due to the elevation of ductile-brittle transition temperature by the high dpa irradiation of neutrons. 14 MeV neutrons produced by D-T reaction cause high dpa damage and also produce large quantity of helium and hydrogen atoms in first wall materials. Those gas atoms also play an important role in the embrittlement of steels. The main purpose of this work was to simulate the behavior of hydrogen produced by the transmutation in the mechanical properties of ferritic steels when they were irradiated with 11 MeV protons. The experimental procedure and the results of hardness, the broadening of x-ray diffraction lines, Moessbauer spectroscopy and small punch test are reported. High energy protons of 10 - 20 MeV are suitable to the simulation experiment of 14 MeV neutron radiation damage. But the production of the active nuclei emitting high energy gamma ray and having long life, Co-56, is the most serious problem. Another difficulty is the control of irradiation temperature. A small irradiation chamber must be developed. (Kako, I.)
Pleiades: A Sub-picosecond Tunable X-ray Source at the LLNL Electron Linac

International Nuclear Information System (INIS)

Slaughter, Dennis; Springer, Paul; Le Sage, Greg; Crane, John; Ditmire, Todd; Cowan, Tom; Anderson, Scott G.; Rosenzweig, James B.

2002-01-01

The use of ultra fast laser pulses to generate very high brightness, ultra short (fs to ps) pulses of x-rays is a topic of great interest to the x-ray user community. In principle, femto-second-scale pump-probe experiments can be used to temporally resolve structural dynamics of materials on the time scale of atomic motion. The development of sub-ps x-ray pulses will make possible a wide range of materials and plasma physics studies with unprecedented time resolution. A current project at LLNL will provide such a novel x-ray source based on Thomson scattering of high power, short laser pulses with a high peak brightness, relativistic electron bunch. The system is based on a 5 mm-mrad normalized emittance photo-injector, a 100 MeV electron RF linac, and a 300 mJ, 35 fs solid-state laser system. The Thomson x-ray source produces ultra fast pulses with x-ray energies capable of probing into high-Z metals, and a high flux per pulse enabling single shot experiments. The system will also operate at a high repetition rate (∼ 10 Hz). (authors)
Physics design of the CIADS 25 MeV demo facility

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu-Hui, E-mail: liush@impcas.ac.cn [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Zhi-Jun; Jia, Huan [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); He, Yuan, E-mail: hey@impcas.ac.cn [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Dou, Wei-Ping; Qin, Yuan-Shuai; Chen, Wei-Long [Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 (China); Yan, Fang [Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing 100049 (China)

2017-01-21

A superconducting linac has been proposed and under constructed to demonstrate the key technology and the feasibility for CIADS(China Initiative Accelerator Driven System)linac. This linac will accelerate the 10 mA proton beam to 25 MeV. There are some challenges in the physics design for the high power superconducting accelerator. In this paper, we focus on the matching between different cryomodules (CMs) and the frequency jump. This paper presents the physics design study together with the design principles and the simulation results with machine errors.
MeV ion-beam analysis of optical data storage films

Science.gov (United States)

Leavitt, J. A.; Mcintyre, L. C., Jr.; Lin, Z.

1993-01-01

Our objectives are threefold: (1) to accurately characterize optical data storage films by MeV ion-beam analysis (IBA) for ODSC collaborators; (2) to develop new and/or improved analysis techniques; and (3) to expand the capabilities of the IBA facility itself. Using H-1(+), He-4(+), and N-15(++) ion beams in the 1.5 MeV to 10 MeV energy range from a 5.5 MV Van de Graaff accelerator, film thickness (in atoms/sq cm), stoichiometry, impurity concentration profiles, and crystalline structure were determined by Rutherford backscattering (RBS), high-energy backscattering, channeling, nuclear reaction analysis (NRA) and proton induced X-ray emission (PIXE). Most of these techniques are discussed in detail in the ODSC Annual Report (February 17, 1987), p. 74. The PIXE technique is briefly discussed in the ODSC Annual Report (March 15, 1991), p. 23.
Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

Science.gov (United States)

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

2013-05-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass.
Study of the neutron-proton interaction in the 300 to 700 MeV energy region. Annual progress report, 1982-1983

International Nuclear Information System (INIS)

Northcliffe, L.C.

1983-01-01

Progress by the LAMPF user group from Texas A and M University is described. The principal activities since last year's report have included four months of data taking to complete LAMPF Experiment No. 518 (Polarized Beam and Target Experiments in the p-p System. Phase II. Measurements of A/sub zz/ and A/sub xz/ for the d/sub π/ + Channel and for the Elastic Channel from 500 to 800 MeV) which began running in mid-June 1982. There were also about six weeks of data taking on LAMPF Experiment No. 664 (The Measurement of the Polarization Transfer Coefficients A/sub t/' and D/sub t/ at 500, 650 and 800 MeV for the Reaction d(polarized p, polarized n)2p), and one week of data taking at 800 MeV on LAMPF Experiment No. 590 (Measurement of D(theta) in p-n and n-p Scattering at 800, 650 MeV and Other Energies with Associated p-p Measurements). In addition there were preparations for LAMPF Experiment No. 665 (The Measurement of np Elastic Scattering Spin Correlation Parameters with L- and S-Type Polarized Beam and Target between 500 and 800 MeV) which began running last month and will continue until the end of the year
Energy monitoring device for 1.5-2.4 MeV electron beams

Energy Technology Data Exchange (ETDEWEB)

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

2010-03-11

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

Science.gov (United States)

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

2010-03-01

An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.
Nuclear and activation characteristics of materials in 14.1-MeV and 2.5-MeV neutron field

International Nuclear Information System (INIS)

Seki, Yasushi; Takeyasu, Yuuichi.

1988-11-01

The nuclear and activation characteristics of various materials and elements of interest in terms of fusion reactor design are calculated and the results are graphically shown. The elements and materials are placed in a simple geometry modelling a blanket and shield of a fusion reactor. The neutrons with 14.1-MeV and 2.5-MeV energy are generated from the region represented as D-T and D-D plasma, respectively. The following activation characteristics after neutron irradiation are shown for each material and element; 1. Time evolution of induced activity, 2. Time evolution of decay heat, 3. Delayed gamma-ray dose distribution, 4. Decay heat distribution. In addition to the above activation characteristics, nuclear characteristics during the neutron irradiation, e.g. neutron energy spectra, neutron and gamma-ray flux distribution, nuclear heating distributions, and neutron and gamma-ray dose rate are also shown. (author)
The evaluation of H total cross section from 20 MeV to 2 GeV

Energy Technology Data Exchange (ETDEWEB)

Tingjin, Liu [Chinese Nuclear Data Center, Beijing, BJ (China)

1996-06-01

The H total cross section was evaluated in the neutron energy region from 20 to 2000 MeV. The recommended experimental data were fitted by using Spline fit program with knot optimization, the fit values are taken as recommended ones. The data are compared with those from ENDF/B-6 (<100 MeV), the differences are 0.5%{approx}2.0% from 20 to 40 MeV, and almost the same in the energy region 40{approx}100 MeV.
Measurement of the energy spectrum with proportional counters with spherical cathodes between 20 keV and 2.5 MeV with the propagation of 14 MeV neutrons in liquid nitrogen and liquid air

International Nuclear Information System (INIS)

Schneider-Kuehnle, P.

1974-01-01

This work deals with the measurement of the energy spectrum of a 14 MeV neutron source in liquid nitrogen and liquid air in the energy region of 20 keV to 2.5 MeV as a function of the distance from the source. The measured results together with those of a scintispectrometer which measures the energies between 2.5 MeV and 14 MeV, are to serve as experimentally-supported input data for shielding calculations and are to enable the checking of transport theoretical calculations. (orig./LH) [de
Two body photodisintegration of the deuteron from 100 to 800 MeV

Energy Technology Data Exchange (ETDEWEB)

Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

1996-01-01

The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.
29Si(d,3He)28Al reaction at 29 MeV

International Nuclear Information System (INIS)

Vernotte, J.; Berrier-Ronsin, G.; Fortier, S.; Hourani, E.; Kalifa, J.; Khendriche, A.; Maison, J.M.; Rosier, L.H.; Rotbard, G.

1994-01-01

The 29 Si(d, 3 He) 28 Al reaction has been investigated at 29 MeV incident energy. Observations using a split-pole magnetic spectrograph have been made of 55 levels of 28 Al in the range of excitation energy between 0 and 6.7 MeV. Most of them have been identified with 28 Al levels which have been previously observed by other techniques. The spectroscopic factors have been obtained for 23 of these levels through distorted-wave Born approximation analyses of measured angular distributions. The levels at E x =3.105 and 3.762 MeV have been definitely assigned J π =1 + and 0 + , respectively. Four levels which are populated through the pickup of a l p =1 proton have been observed at E x =4.998, 5.406, 6.021, and 6.652 MeV. The excitation energies and spectroscopic factors for positive-parity states were compared with the results of a recent, complete sd-shell space, shell-model calculation. This comparison led to the identification of 21 shell-model levels with experimental levels. This comparison seems accurate enough to make very likely the J π =3 + assignment for the levels at E x =2.988 and 4.597 MeV which were previously assigned J π =(1,3) +

Los Alamos High-Brightness Accelerator FEL (HIBAF) facility

Energy Technology Data Exchange (ETDEWEB)

Cornelius, W.D.; Bender, S.; Meier, K.; Thode, L.E.; Watson, J.M.

1989-01-01

The 10-/mu/m Los Alamos free-electron laser (FEL) facility is being upgraded. The conventional electron gun and bunchers have been replaced with a much more compact 6-MeV photoinjector accelerator. By adding existing parts from previous experiments, the primary beam energy will be doubled to 40 MeV. With the existing 1-m wiggler (/lambda//sub w/ = 2.7 cm) and resonator, the facility can produce photons with wavelengths from 3 to 100 /mu/m when lasing on the fundamental mode and produce photons in the visible spectrum with short-period wigglers or harmonic operation. After installation of a 150/degree/ bend, a second wiggler will be added as an amplifier. The installation of laser transport tubes between the accelerator vault and an upstairs laboratory will provide experimenters with a radiation-free environment for experiments. Although the initial experimental program of the upgraded facility will be to test the single accelerator-master oscillator/power amplifier configuration, some portion of the operational time of the facility can be dedicated to user experiments. 13 refs., 5 figs., 6 tabs.
Anisotropic deformation of metallo-dielectric core-shell colloids under MeV ion irradiation

International Nuclear Information System (INIS)

Penninkhof, J.J.; Dillen, T. van; Roorda, S.; Graf, C.; Blaaderen, A. van; Vredenberg, A.M.; Polman, A.

2006-01-01

We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO 2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks
Anisotropic deformation of metallo-dielectric core shell colloids under MeV ion irradiation

Science.gov (United States)

Penninkhof, J. J.; van Dillen, T.; Roorda, S.; Graf, C.; van Blaaderen, A.; Vredenberg, A. M.; Polman, A.

2006-01-01

We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks.
Cross-sections for some millisecond beta activities. [14. 7 MeV

Energy Technology Data Exchange (ETDEWEB)

Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Dept. of Physics

1979-06-01

An on-line irradiation system involving pulsed beam technique has been developed to handle the millisecond isomers produced in nuclear reactions with 14.7 MeV neutrons. The system originally used to measure the half-lives of a number of millisecond gamma-active isomers has been extended to handle the millisecond pure beta-activities produced in nuclear reactions. An end-window type GM counter has been employed to measure the produced beta activities of /sup 6/He and /sup 9/Li in /sup 7/ /sup 6/Li((n,d))/sup 6/He, /sup 9/Be(n,..cap alpha..)/sup 6/He and /sup 9/Be(n,p)/sup 9/Li reactions.
Identification of a pseudoscalar state at 1440 MeV in J/psi radiative decays

International Nuclear Information System (INIS)

Edwards, C.; Partridge, R.; Peck, C.; Porter, F.C.; Antreasyan, D.; Gu, Y.F.; Irion, J.; Kollmann, W.; Richardson, M.; Strauch, K.; Wacker, K.; Weinstein, A.; Aschman, D.; Burnett, T.; Cavalli-Sforza, M.; Coyne, D.; Newman, C.; Sadrozinski, H.F.W.; Gelphman, D.; Hofstadter, R.; Horisberger, R.; Kirkbride, I.; Kolanoski, H.; Koenigsmann, K.; Lee, R.; Liberman, A.; O'Reilly, J.; Osterheld, A.; Pollock, B.; Tompkins, J.; Bloom, E.D.; Bulos, F.; Chestnut, R.; Gaiser, J.; Godfrey, G.; Kiesling, C.; Lockman, W.; Oreglia, M.; Scharre, D.L.

1982-01-01

From a partial-wave analysis of the KK-barπ system in the decay J/psi→γK + K - π 0 , it is determined that the quantum numbers of the KK-barπ resonance at 1440 MeV, previously identified as the E(1420), are J/sup P/C = 0 -+ . This new particle has been named the iota
Study of two photon production process in proton-proton collisions at 216 MeV

International Nuclear Information System (INIS)

Khrykin, A.S.

2002-01-01

The energy spectrum for high energy γ-rays (Eγ ≥ 10 MeV) from the process pp → γγX emitted at 90 deg. in the laboratory frame has been measured at 216 MeV. The resulting photon energy spectrum extracted from γ - γ coincidence events consists of a narrow peak (5.3σ) at a photon energy of about 24 MeV and a relatively broad peak (3.5σ) in the energy range of (50 - 70) MeV. This behavior of the photon energy spectrum is interpreted as a signature of the exotic dibaryon resonance d 1 * with a mass of about 1956 MeV which is assumed to be formed in the radiative process pp → γd 1 * followed by its electromagnetic decay via the d 1 * → ppγ mode. The experimental spectrum is compared with those obtained by means of Monte Carlo simulations
Multiplicity of particles per primary reaction at 1500 MeV for the nuclei used on the accelerator-driven systems

Energy Technology Data Exchange (ETDEWEB)

Demirkol, Iskender, E-mail: idemirkol@bingol.edu.tr [Faculty of Art and Science, Bingoel University, Bingoel (Turkey); Tel, Eyyup [Faculty of Art and Science, Osmaniye Korkut Ata University, Osmaniye (Turkey)

2011-05-15

Research highlights: > We estimated multiplicities of particles in collision of 1500 MeV proton. > We used the CEM model, INC model and Evaporation model. > The particle multiplicities are nearly constant as the mass number-A increases. > Particle-particle interactions are dominant in the high-energy particles. > Conversion to the stabil state by gamma emitting is more probable. - Abstract: Multiplicities of neutron and other particles per incident proton in collision of 1500 MeV energetic proton beam with Bi, Au, Pb, W, Th, Hg, U, Fe and Cu thin targets have been estimated with the Cascade-Exciton Model (CEM), intranuclear cascade (INC) and Evaporation model. The calculations have been made using simulation codes based on specific models which describe elementary production of particles in nuclear reactions. The obtained results have been compared with the available data.
Photocathode guns for single pass X-ray FELs

International Nuclear Information System (INIS)

Palmer, D.T.

1997-10-01

The present state of the art in photoinjector designs will be presented in this review. The authors discuss both proposed and operational photoinjectors with operating frequencies from L-band (1.424 GHz) to X-band (11.424 GHz). Also a novel pulsed DC gun will be presented. All the RF photoinjector discussed here use an emittance compensation scheme to align the different slices of the electron beam to decrease the beams normalized rms emittance
Study of the reaction pp → π+d at 576 MeV

International Nuclear Information System (INIS)

Aebischer, D.; Favier, B.; Greeniaus, G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.C.; Rapin, D.; Werren, D.W.

1975-01-01

A 576 MeV polarized proton beam has been used to study the pp → π + d reaction for small centre of mass π-production angles. The final state π and d were observed using a system of multiwire proportional chambers. The presence of a term in cos 4 thetasub(cm) for the differential cross-section has been tested. The left-right π production asymmetry for a transversely polarized beam has also been measured. (Auth.)
Confinement of 2,4 MeV deuterons by plasmoids and focalization of electron beams in plasma focus discharges

International Nuclear Information System (INIS)

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

1982-01-01

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

International Nuclear Information System (INIS)

Zweben, S.J.; Boivin, R.; Chang, C.S.; Hammett, G.; Mynick, H.E.

1991-07-01

Confinement studies of MeV ions will play an important role in the research leading to burning plasmas in tokamaks, since any significant radial transport of MeV alpha particles will affect the heating rate or heating profiles of these plasmas. Because the energy, gyroradius, and collisionality of these MeV ions is very different from that of the background plasma, their transport rates cannot be assumed equal to those of the bulk plasma ions. Note that the desired confinement time for 3.5 MeV alphas is set by their thermalization time, which can be up to τ th,α ∼1 sec for the steady-state phase of ITER, requiring D 2 /sec. This is equivalent to over ∼100,000 alpha particle transits of the torus. 28 refs., 24 figs., 2 tabs
High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

Science.gov (United States)

Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

2016-06-01

From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.
High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xu, E-mail: emmazhang103@gmail.com [China Institute of Atomic Energy (China); Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming [China Institute of Atomic Energy (China); Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir [BEST Cyclotron Inc (Canada)

2016-06-01

From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN–LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.
Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the 15N(p,n) reaction as neutron source

International Nuclear Information System (INIS)

Poenitz, Erik

2010-01-01

In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The 15 N(p,n) 15 O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the 15 N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure 209 Bi and 181 Ta samples at 4 MeV incident neutron energy. Results are compared with other
Micro-Bunched Beam Production at FAST for Narrow Band THz Generation Using a Slit-Mask

Energy Technology Data Exchange (ETDEWEB)

Hyun, J. [Sokendai, Tsukuba; Crawford, D. [Fermilab; Edstrom Jr, D. [Fermilab; Ruan, J. [Fermilab; Santucci, J. [Fermilab; Thurman-Keup, R. [Fermilab; Sen, T. [Fermilab; Thangaraj, J. C. [Fermilab

2018-04-01

We discuss simulations and experiments on creating micro-bunch beams for generating narrow band THz radiation at the Fermilab Accelerator Science and Technology (FAST) facility. The low-energy electron beamline at FAST consists of a photoinjector-based RF gun, two Lband superconducting accelerating cavities, a chicane, and a beam dump. The electron bunches are lengthened with cavity phases set off-crest for better longitudinal separation and then micro-bunched with a slit-mask installed in the chicane. We carried out the experiments with 30 MeV electron beams and detected signals of the micro-bunching using a skew quadrupole magnet in the chicane. In this paper, the details of micro-bunch beam production, the detection of micro-bunching and comparison with simulations are described.
Operation of the high-brightness linac for the advanced free-electron laser initiative at Los Alamos

International Nuclear Information System (INIS)

Sheffield, R.L.; Austin, R.H.; Chan, K.C.D.; Gierman, S.M.; Kinross-Wright, J.M.; Kong, S.H.; Nguyen, D.C.; Russell, S.J.; Timmer, C.A.

1993-01-01

Free-electron lasers and high-energy physics accelerators have increased the demand for very high-brightness beam sources. This paper describes the design of an accelerator which has produced beams of 2.1 π mm-mrad at 1 nC and emittances of 3.7 and 6.5 π mm-mrad for 2 and 3 nC, respectively. The accelerator has been operated between 10 and 18 MeV. The beam emittance growth in the accelerator is minimized by using a photoinjector electron source integrated into the design of the linac, a focusing solenoid to correct the emittance growth caused by space charge, and a special design of the coupling slots between accelerator cavities to minimize quadrupole effects. The FEL has recently operated at 5 microns
Peculiarities of the coherent spontaneous synchrotron radiation of dense electron bunches

International Nuclear Information System (INIS)

Balal, N.; Bratman, V. L.; Savilov, A. V.

2014-01-01

In a short section of homogeneous magnetic field, quasi-plane electron bunches from linear accelerators with laser-driven photo-injectors at moderate particle energies can generate strongly directed, very short and powerful terahertz electromagnetic pulses with a broad frequency spectrum. The formulas for radiation fields, their spectra and efficiency of radiation are presented in a very simple analytical form using expressions for the fields of an arbitrary moving charged plane. The self-action and mutual interaction of thin electron layers are estimated. It is shown that the radiation with frequencies of up to (1–3) THz can be effectively generated by electrons with energies (4–6) MeV in a short and relatively weak magnetic field of (4–10) kOe
Peculiarities of the coherent spontaneous synchrotron radiation of dense electron bunches

Energy Technology Data Exchange (ETDEWEB)

Balal, N. [Ariel University, Ariel (Israel); Bratman, V. L. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Savilov, A. V., E-mail: savilov@appl.sci-nnov.ru [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)

2014-02-15

In a short section of homogeneous magnetic field, quasi-plane electron bunches from linear accelerators with laser-driven photo-injectors at moderate particle energies can generate strongly directed, very short and powerful terahertz electromagnetic pulses with a broad frequency spectrum. The formulas for radiation fields, their spectra and efficiency of radiation are presented in a very simple analytical form using expressions for the fields of an arbitrary moving charged plane. The self-action and mutual interaction of thin electron layers are estimated. It is shown that the radiation with frequencies of up to (1–3) THz can be effectively generated by electrons with energies (4–6) MeV in a short and relatively weak magnetic field of (4–10) kOe.
DEPFET detectors for direct detection of MeV dark matter particles

Energy Technology Data Exchange (ETDEWEB)

Baehr, A.; Ninkovic, J.; Treis, J. [Max-Planck-Gesellschaft Halbleiterlabor, Munich (Germany); Kluck, H.; Schieck, J. [Institut fuer Hochenergiephysik, Oesterreichische Akademie der Wissenschaften, Vienna (Austria); Atominstitut, Technische Universitaet Wien, Vienna (Austria)

2017-12-15

The existence of dark matter is undisputed, while the nature of it is still unknown. Explaining dark matter with the existence of a new unobserved particle is among the most promising possible solutions. Recently dark matter candidates in the MeV mass region received more and more interest. In comparison to the mass region between a few GeV to several TeV, this region is experimentally largely unexplored. We discuss the application of a RNDR DEPFET semiconductor detector for direct searches for dark matter in the MeV mass region. We present the working principle of the RNDR DEPFET devices and review the performance obtained by previously performed prototype measurements. The future potential of the technology as dark matter detector is discussed and the sensitivity for MeV dark matter detection with RNDR DEPFET sensors is presented. Under the assumption of six background events in the region of interest and an exposure of 1 kg year a sensitivity of about anti σ{sub e} = 10{sup -41} cm{sup 2} for dark matter particles with a mass of 10 MeV can be reached. (orig.)
Development of Power System for Medium Energy Accelerator

International Nuclear Information System (INIS)

Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Seol, Kyung Tae; Jang, Ji Ho; Cho, Yong Sub; Hong, In Seok; Kim, Kyung Ryul

2008-05-01

The main goal of the studies are to develop a power supply system used for 100MeV proton accelerator and to operate 20MeV accelerator which has been installed in KAERI site. The 100MeV proton accelerator uses RF cavity to accelerate beams and need RF amplifier, klystron. To operate the klystron, a high power pulse power supply is required and the power supply system should have high quality because the reliability of the power supply has critical impact on the overall reliability of accelerator system. Therefore, high power pulse power system and related technology development are inevitable for 100MeV accelerator system development. 20MeV accelerator system has been developed and installed in KAERI site, which will be used as an injector for 100MeV accelerator and supply 20MeV beam to users. A study on the 20MeV accelerator characteristics should be performed to operate the machine efficiently. In addition, this machine can be used as a test bench for developing the 100MeV accelerator components. Therefore, not only the hardware so called 'high voltage power supply', but the related technology of the high quality high voltage power system and man power can be obtained from the results of this studies. The test results of the 20MeV accelerator can be utilized as a basis for efficient operation of 100MeV accelerator and these are the ultimate objective and necessities of the study

Evidence for detection of 1--10 MeV emission from the Taurus region in 1971 August

International Nuclear Information System (INIS)

Gruber, D.E.; Ling, J.C.

1977-01-01

The Taurus region was scanned in mid-1971 during three balloon flights with an actively shielded NaI detector sensitive between 0.2 and 10 MeV. Below 1 MeV, these observations yielded measurements and upper limits consistent with extensions of the X-ray power laws of 0.0035 (E/1 MeV) -2 /sup ./ 2 photons (cm 2 s MeV) -1 and 0.0008(E/1 MeV) -2 /sup ./ 1 photons (cm 2 s MeV) -1 for the Crab Nebula and NP 0532, respectively. Above 1 MeV an apparent unpulsed flux, enhanced well above the extrapolated Crab Nebula power law, was observed during the 1971 August 8 flight; it was the most sensitive of the three. For the NP 0532 above 1 MeV on the same date, the measured upper limit of a factor of 8 above the extrapolated power law excludes only the possibility of a large flare-up. The possibility that the observation reported here for 1971 August 8 was a purely instrumental effect, or was produced by environmental radiations, is thoroughly examined, with negative results. If of cosmic origin, the emission must have been short-term (approx.days, months), because other observations in 1973 and 1974 have shown null results. The possibility of variable MeV range emission is discussed in the context of other reported variable emissions in recent years from the Crab and the Taurus region
Depth distribution of damage in copper irradiated with MeV, Ni and He ions

International Nuclear Information System (INIS)

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

1975-01-01

Transmission electron microscopy was used to study radiation damage as a function of depth caused by 58 and 4-MeV 58 Ni and 1-MeV He ions in copper single crystals at ambient temperature. The experimental damage density vs penetration depth distributions were compared with calculations based on the atomic collision theory of Lindhard et al. (LSS). For 58-MeV Ni ions, the calculated damage profile using the theoretical LSS value of the electronic stopping parameter (k = 0.167) agrees well with experiment. However, for 4-MeV Ni ions it is necessary to use k = 0.12 to get agreement with the experimental data. In the case of 1-MeV He, the depth location of the calculated damage peak is in good agreement with experiment when the electronic stopping determined by Chu and Powers is used whereas it is about 15 percent too close to the surface using the tables of Northcliffe and Schilling. (auth)
Scattering of antiprotons from carbon at 46.8 MeV

International Nuclear Information System (INIS)

Garetta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Janouin, S.; Legrand, D.; Mallet-Lemaire, M.C.; Mayer, B.; Pain, J.; Drake, D.M.; Peng, J.C.

1984-01-01

Antiproton-carbon elastic and inelastic scattering cross sections have been measured at 46.8 MeV over an angular range 6 0 0 with a magnetic spectrometer. Fits to the elastic and inelastic 4.44 MeV excited state cross sections put realistic limits on the strengths of the real and imaginary parts of the antiproton-carbon optical potential. The continuum cross section due to carbon break-up appears to be smaller than it is for corresponding proton data. (orig.)
Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV

Science.gov (United States)

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

2018-02-01

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

Science.gov (United States)

Krauss, A; Kapsch, R-P

2018-02-06

For the ionometric determination of the absorbed dose to water, D w , in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q , are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm × 10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.
Number transmission of 0.6 and 0.8MeV electrons in elemental materials

International Nuclear Information System (INIS)

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

1975-01-01

The number transmissions of electrons in Be, Al, Cu and Ag were obtained experimentally for well collimated electron beams of 0.6 and 0.8 MeV. Experimental results of the present work join smoothly to the previous ones of 1.0 MeV to 2.0 MeV electrons. The ratios of extrapolated range Rsub(ex) to true range R 0 give generally minimum values near 1 MeV (approximately 2mc 2 ) as well as the stopping power. An investigation was done for empirical equation of the form eta=exp(-xP/CEsup(m)), where E is the incident electron energy, x, penetration depth, and p, C and m are the parameters determined from experimental data. (author)
Elastic scattering of polarized protons by 20Ne between 4.5 Mev and 5.5 Mev

International Nuclear Information System (INIS)

Avila A, O.L.

1979-01-01

Starting with the study of 20 Ne(p,p) 20 nuclear reaction, we obtained information about the nuclear structure of 21 Na. The experiment was made at Notre Dame University; a target of 20 Ne was bombarded with polarized protons, changing the incident energy of them between 4.5 Mev and 5.5 Mev at intervals of 10 keV. Fourteen detectors were set covering angles from 35 degrees until 165 degrees, with intervals of 10 degrees each. In this form measurements for computing polarization and differential sections were obtained, with them an analysis of runnings of phase was made, and the parameters associated with two of the excited levels of the composed formed nucleous 21 Na, that are viewed as resonances in the section were settled; those resonances correspond to a level Psub(3/2) of energy excitation 6.877, a total width of 36 keV, and a level Fsub(7/2) of energy excitation 6.992 and total width of 48 keV. I hope that these results will be part of a set of values that will be utilized in order to confront them with the existent nuclear models. (author)
Calculation of nucleon production cross sections for 200 MeV deuterons

International Nuclear Information System (INIS)

Ridikas, D.; Mittig, W.

1997-01-01

The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick 9 Be, 56 Fe and 238 U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.)
Helium production cross section Measurement of Pb and Sn for 14.9 MeV neutrons

Energy Technology Data Exchange (ETDEWEB)

Takao, Yoshiyuki; Fujimoto, Toshihiro; Ozaki, Shuji; Muramasu, Masatomo; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori; Ikeda, Yujiro

1998-03-01

Helium production cross sections of lead and tin for 14.9 MeV neutrons were measured by helium accumulation method. Lead and tin samples were irradiated with FNS, an intense d-T neutron source of JAERI. The amount of helium produced in the samples by the neutron irradiation was measured with the Helium Atoms Measurement System (HAMS) at Kyushu University. As the samples contained a small amount of helium because of their small helium production cross sections at 14.9 MeV, the samples were evaporated by radiation from a tungsten filament to decrease background gases at helium measurement. Uncertainties of the present results were less than {+-}4.4%. The results were compared with other experimental data in the literature and also compared with the evaluated values in JENDL-3.2. (author)
Search for substructure in anti pp total cross section in the 2200 MeV mass region

International Nuclear Information System (INIS)

Peaslee, D.C.; DeMarzo, C.; Guerriero, L.

1975-01-01

The anti pp total cross section is measured in an apparatus with a small target and high resolution beam in order to supplement previous work by looking for narrow structure that might be hidden in broad-mass bins. One could set limits on the partial widths of bosons coupling to the anti pp system. The product of an unknown production cross section and a partial width was determined. From the data the existence of resolution-sized structure above the smooth fit with the product of cross section and width greater than 7 MeV mb. It can be shown that a Breit--Wigner resonance of spin J coupled to the anti pp system in this region must have partial width GAMMA/sub anti pp/ less than 1.8/(2J + 1) MeV. Also it is found that the broad enhancement observed in the anti pp total cross section persists without modification in an observation with mass resolution six times that of previous work
Neutron-induced 2.2 MeV background in gamma ray telescopes

International Nuclear Information System (INIS)

Zanrosso, E.M.; Long, J.L.; Zych, A.D.; White, R.S.; Hughes Aircraft Co., Los Angeles, CA)

1985-01-01

Neutron-induced gamma ray production is an important source of background in Compton scatter gamma ray telescopes where organic scintillator material is used. Most important is deuteron formation when atmospheric albedo and locally produced neutrons are thermalized and subsequently absorbed in the hydrogenous material. The resulting 2.2 MeV gamma line essentially represents a continuous isotropic source within the scintillator itself. Interestingly, using a scintillator material with a high hydrogen-to-carbon ratio to minimize the neutron-induced 4.4 MeV carbon line favors the np reaction. The full problem of neutron-induced background in Compton scatter telescopes has been previously discussed. Results are presented of observations with the University of California balloon-borne Compton scatter telescope where the 2.2 MeV induced line emission is prominently seen
Calibration in photon radiation fields with energies above 3 MeV

International Nuclear Information System (INIS)

Bueermann, L.

1997-01-01

For determination of the response of dosemeters and dose ratemeters for photon energies above 3 MeV, the PTB uses reference radiation fields generated via the nuclear reactions 12 (p, p' γ) 12 C (4.4 MeV) and 19 F(p,αγ) 16 O (6-7 MeV). As a maximum, kerma rates of 1 mGy/h released in air can be achieved at 1 m distance from the target. The air kerma in the reference fields is determined with two different methods, i.e. by spectrometry using a Ge detector, and by ionometry using a graphite cavity ionisation chamber. The total uncertainty of the value determined for the air kerma (collision radiation) in the reference fields is 50% at a confidence level of 68.3%. (orig./CB) [de
Exposure times and ratio of readings produced by irradiation of thermoluminescence dosemeters in PTB neutron standard fields between 0.1 MeV and 19 MeV

International Nuclear Information System (INIS)

Jahr, R.; Guldbakke, S.; Cosack, M.

1979-06-01

6 LiF and 7 LiF thermoluminescence dosimeters (TLD) irradiated in a standard field of monoenergetic neutrons (Esub(n) = 0.1 MeV to 19 MeV), respond as well to the photon as to the neutron component of this radiation field. The ratio of the two TLD readings as well as the duration of irradiation required to obtain a preset TLD reading are calculated as a function of the neutron energy. (orig.) [de
Spectrum of atmospheric gamma rays to 10 MeV at lambda = 40 deg. [as function of altitude

Science.gov (United States)

Peterson, L. E.; Schwartz, D. A.; Ling, J. C.

1973-01-01

Results of measurements of the differential counting rate spectra due to atmospheric gamma rays as a function of altitude to 3.6 g/sq cm over Texas. Two gain settings and a 128-channel pulse height analyzer were used to cover the range from 0.2 to 10 MeV. The detector was a 7.6 x 7.6 cm NaI crystal, which was surrounded on five sides by a 2-cm-thick plastic anticoincidence shield for charged particle rejection. The system had a nearly isotropic response to photons above 0.2 MeV. The spectrum at ceiling appeared as a steep continuum with a power-law index of about 1.4. The only obvious feature was the 0.51-MeV positron annihilation line. The spectral shape was independent for depths less than 20 g/sq cm, the absolute intensity varying in proportion to the intensity of the cosmic ray secondary charged particles. Also, at depths less than 30 g/sq cm the observed flux variation with altitude can be described in terms of an empirical depth-dependent source function.
Elastic scattering of 16O+16O at energies E/A between 5 and 8 MeV

International Nuclear Information System (INIS)

Nicoli, M. P.; Haas, F.; Freeman, R. M.; Aissaoui, N.; Beck, C.; Elanique, A.; Nouicer, R.; Morsad, A.; Szilner, S.; Basrak, Z.

1999-01-01

The elastic scattering of 16 O+ 16 O has been measured at nine energies between E lab =75 and 124 MeV. The data cover up to 100 degree sign in the c.m. and can be described in terms of phenomenological and folding model potentials which reproduce the main features observed. In agreement with studies at higher energies in this and similar systems, refractive effects are present in the angular distributions at all energies. In particular, the passage of Airy minima through 90 degree sign at E c.m. =40, 47.5, and 62 MeV explains the deep minima observed in the excitation function. The real part of the optical potential is found to vary very little with energy over the studied interval, but the imaginary part shows a rapid change in its shape at incident energy about 90 MeV. Nonetheless, the energy dependence of the volume integral of the real and imaginary parts is in agreement with dispersion relation predictions. (c) 1999 The American Physical Society
Construction of a 1 MeV Electron Accelerator for High Precision Beta Decay Studies

Science.gov (United States)

Longfellow, Brenden

2014-09-01

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

International Nuclear Information System (INIS)

Zhu Peiran; Liu Jiarui; Zhang Jinping; Yin Shiduan

1989-01-01

An MeV He + microbeam has been used to analyse a microscale semiconductor structure. The 2 MeV He + ion beam is limited to 25 μm diameter by a set of diaphragms and is further focused by a quadrupole quadruplet to 3μm diameter. The incident beam current on the sample is about 0.3 nA. The Rutherford backscattering (RBS) technique is applied to the measurement of the composition and depth profile in the near-surface region of a semiconductor integrated circuit. (author)
MeV He microbeam analysis of a semiconductor integrated circuit

Energy Technology Data Exchange (ETDEWEB)

Zhu Peiran; Liu Jiarui; Zhang Jinping; Yin Shiduan

1989-01-01

An MeV He/sup +/ microbeam has been used to analyse a microscale semiconductor structure. The 2 MeV He/sup +/ ion beam is limited to 25 /mu/m diameter by a set of diaphragms and is further focused by a quadrupole quadruplet to 3/mu/m diameter. The incident beam current on the sample is about 0.3 nA. The Rutherford backscattering (RBS) technique is applied to the measurement of the composition and depth profile in the near-surface region of a semiconductor integrated circuit.
Loss of alpha-like MeV fusion products from TFTR

International Nuclear Information System (INIS)

Zweben, S.J.; Boivin, R.L.; Diesso, M.; Hayes, S.E.; Hendel, H.W.; Park, H.; Strachan, J.D.

1990-03-01

A detailed comparison between the observed and expected loss of alpha-like MeV fusion products in TFTR is presented. The D-D fusion products (mainly the 1 MeV triton) were measured with an 2-D imaging scintillation detector. The expected first-orbit loss was calculated with a simple Lorentz orbit code. In almost all cases the measured loss was consistent with the expected first-orbit loss model. Exceptions are noted for small major radius plasmas and during strong MHD activity. 37 refs., 28 figs
Coulomb dissociation of {sup 8}B at 254 A MeV

Energy Technology Data Exchange (ETDEWEB)

Suemmerer, K; Boue, F; Baumann, T; Geissel, H; Hellstroem, M; Koczon, P; Schwab, E; Schwab, W; Senger, P; Surowiecz, A [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Iwasa, N; Ozawa, A [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); [RIKEN Institute of Physical and Chemical Research, Saitama (Japan); Surowka, G [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); [Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Blank, B; Czajkowski, S; Marchand, C; Pravikoff, M S [Centre d` Etudes Nucleaires de Bordeaux-Gradignan, 33 (France); Foerster, A; Lauer, F; Oeschler, H; Speer, J; Sturm, C; Uhlig, F; Wagner, A [Technische Univ. Darmstadt (Germany); Gai, M [Connecticut Univ., Storrs, CT (United States). Dept. of Physics; Grosse, E [Inst. fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany); Kohlmeyer, B [Philipps Univ., Marburg (Germany). Fachbereich Physik; Kulessa, R; Walus, W [Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Motobayashi, T [Rikkyo Univ., Tokyo (Japan). Dept. of Physics; Teranishi, T [RIKEN Institute of Physical and Chemical Research, Saitama (Japan)

1998-06-01

As an alternative method for determining the astrophysical S-factor for the {sup 7}Be(p,{gamma}){sup 8}B reaction we have measured the Coulomb dissociation of {sup 8}B at 254 A MeV. From our preliminary results, we obtain good agreement with both the accepted direct-reaction measurements and the low-energy Coulomb dissociation study of Iwasa et al. performed at about 50 A MeV. (orig.)

Pb(n,2n) cross section at 14.1 MeV

International Nuclear Information System (INIS)

Zhou Delin

1991-01-01

Pb is a potential candidate for the neutron multiplier of the fusion reactor, so its (n, 2n) cross section at 14 MeV is of importance. This work is carried out to get a new evaluation of Pb (n,2n) cross section at 14.1 MeV for checking the angle-integrated neutron emission cross section. The equal weight averaged value 2252 +- 40 Mb is adopted in the evaluation
Calculation of neutron cross sections on iron up to 40 MeV

International Nuclear Information System (INIS)

Arthur, E.D.; Young, P.G.

1980-01-01

The development of high energy d + Li neutron sources for fusion materials radiation damage studies will require neutron cross sections up to 40 MeV. Experimental data above 15 MeV are generally sparse or nonexistent, and reliance must be placed upon nuclear-model calculations to produce the needed cross sections. To satisfy such requirements for the Fusion Materials Irradiation Test Facility (FMIT), neutron cross sections have been calculated for 54 56 Fe between 3 and 40 MeV. These results were joined to the existing ENDF/B-V evaluation below 3 MeV. In this energy range, most neutron reactions can be described using the Hauser-Feshbach statistical model with corrections for preequilibrium and direct-reaction effects. To properly use these models to obtain realistic cross sections, emphasis must be placed upon the determination of suitable input parameters (optical model sets, gamma-ray strength functions, level densities) valid over the energy range of the calculation. To do this, several types of independent data were used to arrive at consistent parameter sets as described
Crosslinking of commercial polyethylenes by 10 MeV electrons

International Nuclear Information System (INIS)

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

1995-08-01

Commercial polyethylenes were irradiated with 10 MeV electrons to induce crosslinking. The gel fraction data measured as a function of total dose suggests that crosslinking proceeds on irradiation, as expected. A number of the properties of the irradiated polyethylenes, such as the degree of oxidation, crystallinity and thermal degradation, were studied by Fourier transform infrared/photo acoustic spectroscopy, X-ray diffraction, and a pyrolysis technique coupled with gas chromatography and mass spectrometry. The results of this study suggest that commercial polyethylenes can be crosslinked to a gel fraction of ∼70%, required for wire and cable applications, by 10 MeV electrons. (author). 35 refs., 6 figs
Two-body photodisintegration of the deuteron from 100 to 800 MeV

Energy Technology Data Exchange (ETDEWEB)

Crawford, R.; Ahrens, J.; Altieri, S.; Annand, J.R.M.; Anthony, I.; Audit, G.; Beck, R.; Braghieri, A.; D`Hose, N.; Hall, S.; Isbert, V.; Kellie, J.D.; Kerhoas, S.; MacCormick, M.; MacGeorge, J.C.; Medaglia, R.; Miller, G.J.; Murphy, L.Y.; Owens, R.O.; Pedroni, P.; Pinelli, T.; Tamas, G.; Wallace, P.A. [Glasgow Univ. (United Kingdom). Dept. of Phys. and Astron.]|[Mainz Univ. (Germany). Inst. fuer Kernphys.]|[INFN, Sezione di Pavia (Italy)]|[Pavia Univ. (Italy). Dipartimento di Fisica Nucleare e Teorica]|[CEA-DAPNIA/SPhN, 91 - Gif-sur-Yvette (France)

1996-06-24

The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. Using the large acceptance detector DAPHNE in conjunction with the Glasgow tagging spectrometer, high precision results with small systematic errors were obtained. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 {sup circle} -160 {sup circle} in 10 {sup circle} intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and comparison with some recent theoretical calculations. (orig.).
Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

CERN Document Server

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

2005-01-01

An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.
Vessel wall damage by X-rays and 15 MeV neutrons

International Nuclear Information System (INIS)

Aarnoudse, M.W.

1979-01-01

In two simple mucopolysaccharide systems, synovial fluid and subcutaneous connective tissue membranes, the degrading effects of 200 kVp X-rays and 15 MeV neutrons is compared. Due to the depolymerization of the mucopolysaccharides the viscosity of synovial fluid decreases and the permeability of the connective tissue membranes for saline increases after irradiation. In both systems a RBE of 0.6 has been found for fast neutrons. The atheromatous changes in the wall of elastic arteries (lipid penetration into the vessel wall and the formation of plaques consisting of large, lipid-filled foam cells) are studied in the carotid arteries of hypercholesterolemic rabbits, two months after irradiating the arteries with different doses of X-rays or neutrons. (Auth.)
High-quality beam generation using an RF gun and a 150 MeV microtron

Science.gov (United States)

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

2000-11-01

Low-emittance sub-picosecond electron pulses are expected to be used in a wide field, such as free electron laser, laser acceleration, femtosecond X-ray generation by Inverse Compton scattering, pulse radiolysis, etc. In order to produce the low-emittance sub-picosecond electron pulse, we are developing a compact Racetrack Microtron (RTM) with a new 5 MeV injection system adopting a laser photo cathode RF gun (Washio et al., Seventh China-Japan Bilateral Symposium on Radiation Chemistry, October 28, Cengdu, China, 1996). The operation of RTM has been kept under a steady state of beam loading for long pulse mode so far (Washio et al., J. Surf. Sci. Soc. Jpn. 19 (2) (1998) 23). In earlier work (Washio et al., PAC99, March 31, New York, USA, 1999), we have succeeded in the numerical simulation for the case of single short pulse acceleration. Finally, the modified RTM was demonstrated as a useful accelerator for a picosecond electron pulse generation under a transient state of beam loading. In the simulation, a picosecond electron pulse was accelerated to 149.6 MeV in RTM for the injection of 5 MeV electron bunch with a pulse length of 10 ps (FWHM), a charge of 1 nC per pulse, and an emittance of 3 πmm mrad.
Measurement of 197Au(tau,xnyp) excitation functions for 15 MeV <= Esub(tau) <= 135 MeV and analysis in the framework of the hybrid model

International Nuclear Information System (INIS)

Bousshid, O.

1981-01-01

The (tau,xnyp)-reactions on 197 Au were measured. The 3 He incident energy was between 15 MeV and 135 MeV. The experiments were carried out using the stacked-foils technique. Cross sections were determind from the activity of the residual nuclei. The (tau,xn)-excitation functions were measured for 2 = 70 MeV as well as x >= 7 were measured for the first time. Further the (tau,pxn)- and (tau,2pxn)-excitation functions, which were not known so far, have now been measured. The analysis within the framework of the hybrid model for precompound-nuclear-reactions followed by an evaporation cascade, resulted in the best agreement between experimental data and theoretical model calculation using an initial exciton number nsub(o) = 5 (1n+3p+1h). The region of validity of the hybrid model for complex projectiles is discussed. (orig.) [de
Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC

Energy Technology Data Exchange (ETDEWEB)

Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others

2017-02-11

Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.
Calculation of nucleon production cross sections for 200 MeV deuterons

Energy Technology Data Exchange (ETDEWEB)

Ridikas, D.; Mittig, W.

1997-12-31

The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick {sup 9}Be, {sup 56}Fe and {sup 238}U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.). 31 refs.
CESAR, 2 MeV electron storage ring; construction period; general view.

CERN Multimedia

Service Photo; CERN PhotoLab

1962-01-01

A general view of the 2-MeV electron storage-ring model during the last stages of assembly. The injection line for the electrons enters at the bottom of the picture (under the ladder) and meets the ring at the back, to the right. Near there, Joseph Karouanton (S.G.T.E, Paris) (inside the ring), and Marcel Bernasconi (AR Division) are seen testing for leaks in the vacuum system. In white coats are Mervin Barnes (left) and Boony Bruggerman (AR Division), considering the reading shown by one of the vacuum gauges.
Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-31

Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.
Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

Energy Technology Data Exchange (ETDEWEB)

Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)

2013-09-21

The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.
Kerma factors and reaction cross sections for n + 12C between 15 and 18 MeV

International Nuclear Information System (INIS)

Tornow, W.; Chen, Z.M.; Baird, K.; Walter, R.L.

1988-01-01

Differential elastic and inelastic (4.44 MeV) neutron scattering cross sections from 12 C are presented at 15.6, 16.8 and 17.3 MeV. The existing 18.2 MeV differential cross-section data were combined with newly measured analysing power data to parametrise neutron scattering at this energy. The 12 C recoil kerma factors were calculated and reaction cross sections were obtained from a phase-shift analysis and coupled channel analyses in the 15.6-18.2 MeV energy range. (author)
Neutron scattering differential cross sections of carbon and bismuth at 37 MeV

International Nuclear Information System (INIS)

Zhou Zuying; Tang Hongqing; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Walter, R.L.; Tornow, W.; Howell, C.; Braun, R.; Roper, C.; Chen Zemin; Chen Zhengpeng; Chen Yingtang

1997-01-01

Elastic differential cross sections of 37 MeV neutrons scattered from carbon and bismuth were measured in the angular range 11 to 160 degrees by means of the multi-detector TOF facility. The 37 MeV neutrons were produced via the T(d,n) 4 He reaction in a tritium gas target. The pulsed 20 MeV deuteron beam was provided by the HI-13 tandem accelerator. The angular distribution of scattered neutrons from carbon and bismuth were measured in the angular range 11 degree to 145 degree and 11 degree to 160 degree respectively in steps of about 3 degree
Ion shaking in the 200 MeV XLS-ring

International Nuclear Information System (INIS)

Bozoki, E.; Kramer, S.L.

1992-01-01

It has been shown that ions, trapped inside the beam's potential, can be removed by the clearing electrodes when the amplitude of the ion oscillation is increased by vertically shaking the ions. We will report on a similar experiment in the 200 Mev XLS ring. The design of the ion clearing system for the ring and the first results obtained, were already reported. In the present series of experiments, RF voltage was applied on a pair of vertical strip-lines. The frequency was scanned in the range of the ion (from H 2 to CO 2 ) bounce frequencies in the ring (1--10 MHz). The response of the beam size, vertical betatron tune and lifetime was studied
Stripping Foil Issues for H- Injection into the CERN PSB at 160 MeV

CERN Document Server

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

2010-01-01

Beam physics considerations for the stripping foil of the 160 MeV PSB H- injection systems are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The different beam loss mechanisms are quantified in the context of the aperture limits, operational considerations and collimation requirements.
Structural, thermal and optical behavior of 84 MeV oxygen and 120 MeV silicon ions irradiated PES

International Nuclear Information System (INIS)

Samra, Kawaljeet Singh; Thakur, Sonika; Singh, Lakhwant

2011-01-01

In order to study structural, thermal and optical behavior, thin flat samples of polyethersulfone were irradiated with oxygen and silicon ions. The changes in properties were analyzed using different techniques viz: X-ray diffraction, thermo-gravimetric analysis, Fourier transform infrared, UV-visible and photoluminescence spectroscopy. A noticeable increase in the intensity of X-ray diffraction peaks was observed after irradiation with 84 MeV oxygen ions at low and medium fluences, which may be attributed to radiation-induced cross-linking in polymer. Fourier transform infrared and thermo-gravimetric analysis corroborated the results of X-ray diffraction analysis. No noticeable change in the Fourier transform infrared spectra of oxygen ion irradiated polyethersulfone were observed even at the highest fluence of 1 x 10 13 ions cm -2 , but after irradiation with silicon ions, a reduction in intensity of almost all characteristic bands was revealed. An increase in the activation energy of decomposition of polyethersulfone was observed after irradiation with 84 MeV oxygen ions up to medium fluences but degradation was revealed at higher fluences. Similar trends were observed by photoluminescence analysis.
European Collaboration for High-Resolution Measurements of Neutron Cross Sections between 1 MeV and 250 MeV

CERN Multimedia

Leal, L C; Kitis, G; Guber, K H; Yuasa nakagawa, K; Koehler, P E; Quaranta, A

2002-01-01

The experimental determination of neutron cross section data has always been of primary importance in Nuclear Physics. Many of the salient features of nuclear levels and densities can be determined from the resonant structure of such cross sections and of their decay scheme. An associated importance of precise neutron induced reaction cross sections has resulted from the worldwide interest in Accelerator Driven Systems (ADS) that has emerged at CERN and elsewhere. Many applications, such as accelerator-based transmutation of nuclear waste, energy amplification medical research, astrophysical applications and also fusion research require nuclear data that quantitatively and qualitatively go beyond the presently available traditional evaluation.\\\\ \\\\We consider a spallation driven TOF facility at the CERN-PS with an unprecedented neutron flux (1000 times the existing ones) in the broad energy range between 1 eV and 250 MeV and with very high energy resolution. The present concept for an intense neutron source m...
HIGH ENERGY, HIGH BRIGHTNESS X-RAYS PRODUCED BY COMPTON BACKSCATTERING AT THE LIVERMORE PLEIADES FACILITY

International Nuclear Information System (INIS)

Tremaine, A M; Anderson, S G; Betts, S; Crane, J; Gibson, D J; Hartemann, F V; Jacob, J S; Frigola, P; Lim, J; Rosenzweig, J; Travish, G

2005-01-01

PLEIADES (Picosecond Laser Electron Interaction for the Dynamic Evaluation of Structures) produces tunable 30-140 keV x-rays with 0.3-5 ps pulse lengths and up to 10 7 photons/pulse by colliding a high brightness electron beam with a high power laser. The electron beam is created by an rf photo-injector system, accelerated by a 120 MeV linac, and focused to 20 (micro)m with novel permanent magnet quadrupoles. To produce Compton back scattered x-rays, the electron bunch is overlapped with a Ti:Sapphire laser that delivers 500 mJ, 100 fs, pulses to the interaction point. K-edge radiography at 115 keV on Uranium has verified the angle correlated energy spectrum inherent in Compton scattering and high-energy tunability of the Livermore source. Current upgrades to the facility will allow laser pumping of targets synchronized to the x-ray source enabling dynamic diffraction and time-resolved studies of high Z materials. Near future plans include extending the radiation energies to >400 keV, allowing for nuclear fluorescence studies of materials

A Coherent Compton Backscattering High Gain FEL using an X-Band Microwave Undulator

CERN Document Server

Pellegrini, C; Travish, G

2005-01-01

We describe a proposed high-gain FEL using an X-band microwave undulator and operating at a wavelength of about 0.5 μm. The FEL electron beam energy is 65 MeV. The beam is produced by the NLCTA X-band linac at SLAC, using an S-band high-brightness photoinjector. The undulator consists of a circular waveguide with an rf wave counter-propagating with respect to the electron beam. The undulator is powered with two high-power X-band klystrons and a dual-moded pulse compressor recently developed at SLAC. This system is capable of delivering flat-top rf pulses of up to 400 ns and a few hundred megawatts. The equivalent undulator period is 1.4 cm, the radius of the circular pipe is 1 cm, and the undulator parameter is about 0.4 for a helical undulator configuration, obtained using two cross-polarized TE modes, or larger for a planar configuration, using one rf polarization. The undulator is about four meters long. The FEL will reach saturation within this distance when operated in a SASE mode. We describe t...
Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

International Nuclear Information System (INIS)

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

2015-01-01

The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D 10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation. - Highlights: • 10 MeV eBeam energy was attenuated to 2.9±0.22 MeV using HDPE sheets. • Attenuation of eBeam energy does not affect the inactivation kinetics of Salmonella. • Microbial inactivation is independent of eBeam energy in the range of 3–10 MeV
Elastic Neutron Scattering at 96 MeV from {sup 12}C and {sup 208}Pb

Energy Technology Data Exchange (ETDEWEB)

Klug, J.; Blomgren, J.; Atac, A. [and others

2003-04-01

A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from {sup 12}C and {sup 208}Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory.
Neutron total and scattering cross sections of 6Li in the few MeV region

International Nuclear Information System (INIS)

Smith, A.; Guenther, P.; Whalen, J.

1980-02-01

Neutron total cross sections of 6 Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx. 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;α)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file
In vitro activation of bone with 14 MeV neutrons

International Nuclear Information System (INIS)

Holmberg, P.; Hyvoenen, M.; Tarvainen, M.

1978-01-01

Samples of compact bone, bone marrow and spongiosa of cow femur have been irradiated in vitro with 14 MeV neutrons. The Ca/P ratio for compact bone was found to be 2.16+-0.24. The suitability of using 14 MeV neutrons and the 31 P(n, α) 28 Al reaction for studying the bone mineral composition in vitro is discussed. It was demonstrated that 14 MeV neutrons can be used for the determination of calcium and phosphorus in bone with the aid of the 44 Ca(n, p) 44 K and 31 P(n, α) 28 Al reactions, respectively. As the Ca/P ratio for compact bone is known, the calcium content can be deduced indirectly from a determination of the phosphorus. This method has the advantage of not requiring moderator materials, as in the case when the 48 Ca(n, γ) 49 Ca reaction is employed. The half-life of the 28 Al activity is short (T=2.243 m) so that only short irradiation times are necessary. (T.G.)
Study of tapered glass capillary focusing MeV ion beam

International Nuclear Information System (INIS)

Gong Zhiyu; Yan Sha; Ma Hongji; Nie Rui; Xue Jianming; Wang Yugang

2012-01-01

In recent years, tapered glass capillary ion beam focusing is developing rapidly. It is attractive for simple, compact, low cost and easy use. However, the focusing mechanism for MeV ion beams is still indistinct. We present several experimental results of focusing 2 MeV He + beam. Ion beams were focused by tapered glass capillaries with various outlet inner diameters from several micron to hundred micron. The current densities, angle divergences and energy spectra of the transmitted ion beams are measured. The results proved that 2 MeV He + ions can focused and guided by our capillaries. The energy spectra show that a great part of transmitted ions experienced obvious energy loss, which is different from results of others research groups. We discussed the reason and charged it to the larger incident angle. Considered the incident ions with larger incident angle, the charge will distribute in a layer of micro meter depth in the capillary’s inner wall, but not the surface. The energy loss and many other spectra characters can be explained in this way.
Valence and inner proton hole states in 207Tl via the (d,3He) reaction at 108 MeV

International Nuclear Information System (INIS)

Langevin-Joliot, H.; Gerlic, E.; Guillot, J.; Van de Wiele, J.

1983-01-01

The excitation energy spectra of the residual nucleus 207 Tl have been investigated up to 14 MeV using the (d, 3 He) reaction at 108 MeV. New groups and high lying structures are first observed up to 8.3 MeV, in addition to the five known low lying levels. Beyond a minimum at 7.13 MeV, weaker structures are observed riding over an asymetric bump located around 9 MeV. DWBA analysis of angular distributions have allowed l attributions and the determination of valence and inner hole spectroscopic factors. It is found that the valence levels at 1.33 MeV, 1.67 MeV and 3.47 MeV exhaust respectively about 65%, 60% and 45% of the 1hsub(11/2), 2dsub(5/2) and 1gsub(7/2) sum rules. The missing strengths are found below 8.3 MeV. The 2dsub(5/2) and 1gsub(7/2) holes contribute mainly to some well concentrated groups, whereas the 1hsub(11/2) strength is distributed more smoothly. Small contributions of 1gsub(9/2) and 2p strengths are tentatively identified below 7.13 MeV. The highest lying energy region up to 14 MeV may approximately account for the 1gsub(9/2) and (1fsub(5/2)) total sum-rule and about 70% of the 2p strength. The 1gsub(9/2) strength gives the largest contribution to the asymetric bump around 9 MeV. The deduced experimental strength functions are compared with theoretical calculations
Tritium production in thorium by 135 MeV protons

International Nuclear Information System (INIS)

Lefort, M.; Simonoff, G.; Tarrago, X.; Bibron, R.

1960-01-01

We have measured the cross-section of tritium production by bombardment of thorium by 135 MeV protons in the Orsay synchro-cyclotron. The tritium was separated from the targets by heating in a graphite crucible with a high-frequency generator, under hydrogen gas pressure. Tritiated water was synthesised and the tritium was measured with liquid scintillator. A value of 19.5 ± 0.05 mbarns was obtained for the tritium-cross section and ten percent of tritons have energies higher than 35 MeV. This large cross-section is attributed to a double pick-up process. Reprint of a paper published in Le Journal de Physique et le Radium, t. 20, p. 959, dec 1959 [fr
A direct electron detector for time-resolved MeV electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

2017-03-01

The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.
First experience with carbon stripping foils for the 160 MeV H- injection into the CERN PSB

Science.gov (United States)

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

2018-05-01

160 MeV H- beam will be delivered from the new CERN linear accelerator (Linac4) to the Proton Synchrotron Booster (PSB), using a H- charge-exchange injection system. A 200 µg/cm2 carbon stripping foil will convert H- into protons by stripping off the electrons. The H- charge-exchange injection principle will be used for the first time in the CERN accelerator complex and involves many challenges. In order to gain experience with the foil changing mechanism and the very fragile foils, in 2016, prior to the installation in the PSB, a stripping foil test stand has been installed in the Linac4 transfer line. In addition, parts of the future PSB injection equipment are also temporarily installed in the Linac4 transfer line for tests with a 160 MeV H- commissioning proton beam. This paper describes the foil changing mechanism and control system, summarizes the practical experience of gluing and handling these foils and reports on the first results with beam.
Environmental Values (2-MEV and Appreciation of Nature

Directory of Open Access Journals (Sweden)

Franz X. Bogner

2018-01-01

Full Text Available When monitoring the long history of empirical instruments for environmental attitude measurement, the Two Major Environmental Value model (2-MEV with its two higher order factors: Preservation (PRE and Utilization (UTL has repeatedly and independently been confirmed. PRE assesses preferences towards conservation of nature and the environment, whilst UTL measures preferences towards utilization/exploitation of nature. The latter, however, does not yet include the positive aspects of benefitting from the (enjoyable use of nature. Consequently, besides the established 2-MEV-battery, additional items from an “Appreciation of Nature” (APR scale were applied to an Irish sample of 289 secondary school students (age: M = 14.3 years. Responses to the altogether 30-item battery were applied on an oblique rotation by using the Promax procedure: UTL and PRE appeared as orthogonally related factors, APR correlated to PRE with 0.283. Based on loading scores, the item number for each subscale was further reduced to make the analysis more manageable in educational outreach sites; on those sites, where completing questionnaires may well be quite unpopular, they are very much needed for planning and fine-tuning educational programs. Therefore, extending the 2-MEV scale with an added scale for Appreciation may help: (i to judge participants’ feedback for adjusting/balancing program contents better; and (ii to promote appreciation as a successful strategy for shifting individuals away from their individual exploitative preferences.
Design and performance of the 40 MeV linac and beam transport system for the 1 GeV synchrotron radiation source at SORTEC

International Nuclear Information System (INIS)

Shiota, M.; Hiraki, A.; Mizota, M.; Iida, T.; Haraguchi, M.; Kuno, K.; Nakamura, S.; Ohno, M.; Tomimasu, T.

1990-01-01

A 1 Gev synchrotron radiation source (SOR) system has been installed and is now being adjusted at SORTEC corporation. This paper reports the configuration and the beam test results of the 40 MeV electron linac (pre-injector) and the beam transport line to the electron synchrotron used in this system. The output beam from the linac must be low emittance, small energy spread, and stable in energy. The beam transport line must also efficiently lead the beam from the linac to the electron synchrotron. This linac produced the beam current of 130 mA, with an energy spread of 1.3 % (FWHM), and an emittance of 0.7 πmm·mrad. The beam characteristics were verified by various beam monitors on the beam transport line. (author)
Diffusion of alpha-like MeV ions in TFTR

International Nuclear Information System (INIS)

Boivin, R.L.; Zweben, S.J.; Chang, C.S.; Hammett, G.; Mynick, H.E.; White, R.B.

1991-01-01

Single particle confinement of alpha particles is of crucial importance in reactor-grade tokamaks like BPX and ITER. Besides the well-known process of first-orbit losses, mechanisms that could lead to significant loss of alpha particles are turbulence-induced diffusion and toroidal field ripple stochastic diffusion. These two mechanisms have been separately studied in TFTR using two different detectors (one at the bottom of the machine and the other near the outer midplane) which can detect escaping charged fusion products, namely the 1 MeV triton and the 3 MeV proton in D-D plasmas (and also the 3.5 MeV alpha in D-T). The main difficulty in this type of experiment lies in the necessity of distinguishing the diffusion process from the always-present first-orbit loss-process. In this paper, we show how these two processes can be distinguished using the pitch-angle discrimination of the detectors. The pitch-angle is defined here as the angle of the particle trajectory with respect to the toroidal direction and so is a measure of the ion magnetic moment, μ. Results obtained at the midplane would be the first reported evidence of TF ripple diffusion in a tokamak. (author) 3 refs., 2 figs
Design and performance of a 3.3-MeV linear induction accelerator (LIA)

International Nuclear Information System (INIS)

Cheng Nianan; Zhang Shouyun; Tao Zucong

1992-01-01

A 3.3-MeV linear induction accelerator (LIA) has been designed and constructed at the China Academy of Engineering Physics. The parameters of 3.4 MeV, 2 kA, 80 ns and 1 x 10 4 A/(rad.cm) 2 have been achieved. It has been used for SG-1 FEL experiments. The accelerator is mounted on a movable frame so that , after moving 3 m transversely, it can be assembled with more modules into a 10-MeV LIA. The authors summarize the physics and engineering aspects of the LIA facility and describe the measuring means of characters for the beam
A possible approach to 14MeV neutron moderation: A preliminary study case.

Science.gov (United States)

Flammini, D; Pilotti, R; Pietropaolo, A

2017-07-01

Deuterium-Tritium (D-T) interactions produce almost monochromatic neutrons with about 14MeV energy. These neutrons are used in benchmark experiments as well as for neutron cross sections assessment in fusion reactors technology. The possibility to moderate 14MeV neutrons for purposes beyond fusion is worth to be studied in relation to projects of intense D-T sources. In this preliminary study, carried out using the MCNP Monte Carlo code, the moderation of 14MeV neutrons is approached foreseeing the use of combination of metallic materials as pre-moderator and reflectors coupled to standard water moderators. Copyright © 2017 Elsevier Ltd. All rights reserved.
Novel digital K-edge imaging system with transition radiation from an 855-MeV electron beam

CERN Document Server

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

2001-01-01

A novel K-edge imaging method has been developed at the Mainz Microtron MAMI aiming at a very efficient use of the transition radiation (TR) flux generated by the external 855-MeV electron beam in a foil stack. A fan-like quasi-monochromatic hard X-ray beam is produced from the +or-1-mrad-wide TR cone with a highly oriented pyrolytic graphite (HOPG) crystal. The absorption of the object in front of a 30 mm*10 mm pn charge-coupled device (pn-CCD) photon detector is measured at every pixel by a broad-band energy scan around the K-absorption edge. This is accomplished by a synchronous variation of the lateral crystal position and the electron beam direction which defines also the direction of the TR cone. The system has been checked with a phantom consisting of a 2.5- mu m thick molybdenum sample embedded in a 136- or 272- mu m-thick copper bulk foil. A numerical analysis of the energy spectrum for every pixel demonstrates that data as far as +or-0.75 keV away from the K edge of molybdenum at 20 keV still improv...
Processing of interlaced images in 4–10 MeV dual energy customs system for material recognition

Directory of Open Access Journals (Sweden)

S. Ogorodnikov

2002-10-01

Full Text Available The aim of this article is to demonstrate the practical value of radioscopic differentiation of materials in the 1–10 MeV energy range to the work of customs services. The proposed method for achieving singling out and identifying four basic groups of materials according to an atomic number is complex. Atomic numbers are identified using high- and low-energy profiles obtained through the irradiation of materials on an alternate pulse-by-pulse basis. This is done using a bremsstrahlung beam with 8 MeV/4 MeV dual boundary energies and by using scintillating crystals coupled with silicon photodiodes as detecting elements. An image segmentation technique is then used to discern the distribution of an atomic number on any given image. The color visualization of integral absorption and a material’s atomic composition is carried out according to the intensity hue saturation (IHS colorization scheme. The experiments were carried out on a full-scale prototype of an 8 MeV customs inspection system developed by the Efremov Research Institute.
Measurement of (n,Xn) reaction cross sections at 96 MeV

International Nuclear Information System (INIS)

Sagrado Garcia, Melle Inmaculada C.

2006-10-01

Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)
High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

Science.gov (United States)

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

2018-03-01

The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.
Elastic scattering of 90 - 120 MeV 3He particles and unique optical potential

International Nuclear Information System (INIS)

Hyakutake, M.; Matoba, M.; Kumabe, I.; Fukada, M.; Komatuzaki, T.

1978-01-01

The elastic scattering of 109.2 MeV 3 He particles by 40 Ca, 58 Ni, 90 Zr and 116 Sn has been investigated over a wide angular range. The elastic scattering cross sections have been analyzed in terms of the optical model. The data for each nucleus studied were sufficient to eliminate the discrete ambiguity in the strength of the optical potential; the unique potential which fits the data has real well depth of about 100 MeV and a corresponding volume integral per nucleon pair of about 310 MeV fm 3 . The elastic scattering of 3 He particles by 58 Ni has been further measured at bombarding energies of 89.3 and 118.5 MeV, and the incident-energy dependence of the optical potential of 3 He particles for 58 Ni was obtained. (author)

Three-dimensional simulation studies of 10 MeV, 352.2 MHz drift ...

Indian Academy of Sciences (India)

It is proposed to build a drift tube Linac (DTL) at Raja Ramanna Centre for Advanced Technology, Indore, India, that will form a part of the future Spallation Neutron Source. This DTL will accelerate 30 mA H-ion beam from 3 MeV to 10 MeV. The DTL is designed to operate at 352.2 MHz with a maximum duty cycle of 3%.
Evidence for nonequilibrium particle emission before symmetric disintegration of a composite system formed in the 16O+40Ca reaction at 230 MeV

International Nuclear Information System (INIS)

Brzychczyk, J.; Grotowski, K.; Majka, Z.; Micek, S.; Planeta, R.; Fabris, D.; Hagel, K.; Natowitz, J.B.; Nebbia, G.; Belery, P.; Cohilis, P.; El Masri, Y.; Gregoire, G.

1987-01-01

Measurement of fragment-fragment correlations in the reaction of 230 MeV 16 O with 40 Ca and of 280 MeV 32 S with 24 Mg have been used to isolate processes in which symmetric decay follows nonequilibrium emission of one or two alpha particles. At the higher energy per nucleon, in contrast to previous observations for lower velocity projectiles, nonequilibrium emission followed by symmetric decay has approximately the same probability as the symmetric fission following complete fusion. (orig.)
High-resolution observation of phase contrast at 1MeV. Amorphous or crystalline objects

International Nuclear Information System (INIS)

Bourret, A.; Desseaux, J.

1975-01-01

Many authors have stressed the possibilities of high voltage to improve resolution, but owing to numerous experimental difficulties the resolution limit at 1MeV, which lies around 1A for conventional lenses, has so far been unattainable. Thus the phase contrast at 1MeV has not been studied on evaporated objects. On the other hand the fringes of crystal planes have been observed at 1MeV. the CEN-G microscope having been considerably modified it has been possible to observe the phase contrast of amorphous or crystalline objects [fr
Nuclear size comparison of even titanium isotopes using 140-MeV α-particle scattering

International Nuclear Information System (INIS)

Roberson, P.L.; Goldberg, D.A.; Wall, N.S.; Woo, L.W.; Chen, H.L.

1979-01-01

Systematic variations in nuclear-matter distributions have been determined by analyzing the measured elastic scattering of 140-MeV alpha particles from /sup 46,48,50/Ti. The ''unique'' optical potentials obtained (J/sub R//4A approx. = 300 MeV fm 3 , J/sub I//4A approx. = 100 MeV fm 3 ) indicate that isotopic differences occur primarily in the strength of the imaginary potential. The rms matter radii increase with A, in contrast to those of the charge distributions. The matter-radius results are in agreement with Hartree-Fock calculations
Beam diagnostics using transition radiation produced by a 100 Mev electron beam

International Nuclear Information System (INIS)

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

1991-01-01

We report on several experiments using the optical transition radiation (OTR) produced by a 100 MeV electron beam. In using a sensitive video camera coupled with a digital image processing system an accurate and simple beam profile monitor has been devised. In measuring with a photo-multiplier the radiation emitted in a small solid angle around the direction of the OTR emission, a signal very sensitive to beam energy variations has been obtained. These experiments have been carried out on the Saclay ALS linac
Using 3.05 MeV resonance for determination of oxygen impurities

International Nuclear Information System (INIS)

Burkova, I.E.; Polyanskij, V.N.; Yatis, A.A.

1983-01-01

The method of determining oxygen impurities behind thin films using the isolated resonance in the 16 O(α, α) 16 O reaction at E=3.048 MeV with the width GITA approximately 20 keV, is considered. Cross section in resonance is σsUb(R) = 0.95 b apd it increases cross section of Rutherford scattering by the factor of 25. The conclusion is made on the possibility of using 3.048 MeV resonance when investigating Me-Si film structures
MEV Energy Electrostatic Accelerator Ion Beam Emittance Measurement

OpenAIRE

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

2014-01-01

The testing equipment was designed, manufactured and tried out permitting measurements of total current, current profile and emittance of an ion beam extracted from the ion beam. MeV energy electrostatic accelerator ion H + beam emittance measurement results are presented.
High energy (MeV) ion-irradiated π-conjugated polyaniline: Transition from insulating state to carbonized conducting state

International Nuclear Information System (INIS)

Park, S.K.; Lee, S.Y.; Lee, C.S.; Kim, H.M.; Joo, J.; Beag, Y.W.; Koh, S.K.

2004-01-01

High energy (MeV) C 2+ , F 2+ , and Cl 2+ ions were irradiated onto π-conjugated polyaniline emeraldine base (PAN-EB) samples. The energy of an ion beam was controlled to a range of 3-4.5 MeV, with the ion dosage varying from 1x10 12 to 1x10 16 ions/cm 2 . The highest dc conductivity (σ dc ) at room temperature was measured to be ∼60 S/cm for 4.5 MeV Cl 2+ ion-irradiated PAN-EB samples with a dose of 1x10 16 ions/cm 2 . We observed the transition of high energy ion-irradiated PAN-EB samples from insulating state to conducting state as a function of ion dosage based on σ dc and its temperature dependence. The characteristic peaks of the Raman spectrum of the PAN-EB samples were reduced, while the D-peak (disordered peak) and the G peak (graphitic peak) appeared as the ion dose increased. From the analysis of the D and G peaks of the Raman spectra of the systems compared to multiwalled carbon nanotubes, ion-irradiated graphites, and annealed carbon films, the number of the clusters of hexagon rings with conducting sp 2 -bonded carbons increased with ion dosage. We also observed the increase in the size of the nanocrystalline graphitic domain of the systems with increasing ion dosage. The intensity of normalized electron paramagnelic resonance signal also increased in correlation with ion dose. The results of this study demonstrate that π-conjugated pristine PAN-EB systems changed from insulating state to carbonized conducting state through high energy ion irradiation with high ion dosage
Structural analysis and evaluation of actual PC bridge using 950 keV/3.95 MeV X-band linacs

Science.gov (United States)

Takeuchi, H.; Yano, R.; Ozawa, I.; Mitsuya, Y.; Dobashi, K.; Uesaka, M.; Kusano, J.; Oshima, Y.; Ishida, M.

2017-07-01

In Japan, bridges constructed during the strong economic growth era are facing an aging problem and advanced maintenance methods have become strongly required recently. To meet this demand, we develop the on-site inspection system using 950 keV/3.95 MeV X-band (9.3 GHz) linac X-ray sources. These systems can visualize in seconds the inner states of bridges, including cracks of concrete, location and state of tendons (wires) and other imperfections. At the on-site inspections, 950 keV linac exhibited sufficient performance. But, for thicker concrete, it is difficult to visualize the internal state by 950 keV linac. Therefore, we proceeded the installation of 3.95 MeV linac for on-site bridge inspection. In addition, for accurate evaluation, verification on the parallel motion CT technique and FEM analysis are in progress.
Polarization measurements in p-p elastic scattering between 398 and 572 MeV

International Nuclear Information System (INIS)

Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.C.; Rapin, D.; Werren, D.W.

1977-01-01

Measurements of the analyzing power for p-p elastic scattering at 398, 455, 497, 530, and 572 MeV are reported. A system of multiwire proportional chambers placed directly in a polarized beam was used to observe the angular region 1.5 0 0 . An increase in P(theta) is observed as a function of both scattering angle and incident kinetic energy. Electromagnetic-nuclear interference is used to obtain direct information in the nuclear interaction. (Auth.)
Th{sup 232} (n,2n) Th{sup 231} cross section from threshold to 20.4 Mev

Energy Technology Data Exchange (ETDEWEB)

Butler, J P; Santry, D C

1961-07-01

The excitation curve for the reaction Th{sup 232} (n,2n) Th{sup 231} has been measured by the activation method from the threshold energy, 6.34 Mev, to 20.4 Mev, relative to the known cross section for the S{sup 32} (n, p) P{sup 32} reaction. Monoenergetic neutrons were obtained from the D (d,n) He{sup 3} and T (d,n) He{sup 4} reactions employing a Tandem Van de Graaff accelerator. From threshold to 9.0 Mev, the (n,2n) cross section rises rapidly, reaching its maximum value of 1.88 {+-} 0.09 barns in the region of 9.5 to 11.0 Mev. Above 11.5 Mev the (n,2n) cross section decreases due to competition of the (n,3n) and (n,2nf) reactions and at 20.4 Mev it has a value of 0.22{sub 5} {+-} 0.01{sub 5} barns. (author)
Neutron and proton transmutation-activation cross section libraries to 150 MeV for application in accelerator-driven systems and radioactive ion beam target-design studies

International Nuclear Information System (INIS)

Koning, A.J.; Chadwick, M.B.; MacFarlane, R.E.; Mashnik, S.; Wilson, W.B.

1998-05-01

New transmutation-activation nuclear data libraries for neutrons and protons up to 150 MeV have been created. These data are important for simulation calculations of radioactivity, and transmutation, in accelerator-driven systems such as the production of tritium (APT) and the transmutation of waste (ATW). They can also be used to obtain cross section predictions for the production of proton-rich isotopes in (p,xn) reactions, for radioactive ion beam (RIB) target-design studies. The nuclear data in these libraries stem from two sources: for neutrons below 20 MeV, we use data from the European activation and transmutation file, EAF97; For neutrons above 20 MeV and for protons at all energies we have isotope production cross sections with the nuclear model code HMS-ALICE. This code applies the Monte Carlo Hybrid Simulation theory, and the Weisskopf-Ewing theory, to calculate cross sections. In a few cases, the HMS-ALICE results were replaced by those calculated using the GNASH code for the Los Alamos LA150 transport library. The resulting two libraries, AF150.N and AF150.P, consist of 766 nuclides each and are represented in the ENDF6-format. An outline is given of the new representation of the data. The libraries have been checked with ENDF6 preprocessing tools and have been processed with NJOY into libraries for the Los Alamos transmutation/radioactivity code CINDER. Numerous benchmark figures are presented for proton-induced excitation functions of various isotopes compared with measurements. Such comparisons are useful for validation purposes, and for assessing the accuracy of the evaluated data. These evaluated libraries are available on the WWW at: http://t2.lanl.gov/. 21 refs
Simulations of Beam Quality in a 13 MeV PET Cyclotron

Directory of Open Access Journals (Sweden)

A. Pramudita

2015-12-01

Full Text Available Simulation of the trajectories of negative hydrogen ion (H− beam in a 13 MeV PET cyclotron (DECY-13 were carried out by using the Runge-Kutta (RK4 approximation method and Scilab 5.4.1. The magnetic and electric fields were calculated using Opera-3d/TOSCA softwares at 1 mm resolution. The cyclotron is of a fourth-harmonics type, meaning that the acceleration occurs four times per cycle, with a radiofrequency (RF field of 77.66 MHz frequency and 40 kV amplitude. The calculations and simulations show that the maximum distance between the ion source and the puller is about 6 mm, while the maximum width of the beam at 13 MeV is about 10 mm, and the initial phase between the RF field and the beam ranges from -10° to 10°, with a yield of about 10% of the beam from the ion source getting accelerated to 13 MeV.
Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

Energy Technology Data Exchange (ETDEWEB)

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

1993-10-01

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

Directory of Open Access Journals (Sweden)

CHEOL HO PYEON

2013-02-01

Full Text Available Neutron spectrum analyses of spallation neutrons are conducted in the accelerator-driven system (ADS facility at the Kyoto University Critical Assembly (KUCA. High-energy protons (100 MeV obtained from the fixed field alternating gradient accelerator are injected onto a tungsten target, whereby the spallation neutrons are generated. For neutronic characteristics of spallation neutrons, the reaction rates and the continuous energy distribution of spallation neutrons are measured by the foil activation method and by an organic liquid scintillator, respectively. Numerical calculations are executed by MCNPX with JENDL/HE-2007 and ENDF/B-VI libraries to evaluate the reaction rates of activation foils (bismuth and indium set at the target and the continuous energy distribution of spallation neutrons set in front of the target. For the reaction rates by the foil activation method, the C/E values between the experiments and the calculations are found around a relative difference of 10%, except for some reactions. For continuous energy distribution by the organic liquid scintillator, the spallation neutrons are observed up to 45 MeV. From these results, the neutron spectrum information on the spallation neutrons generated at the target are attained successfully in injecting 100 MeV protons onto the tungsten target.
Kerma factors and reaction cross sections for n + /sup 12/C between 15 and 18 MeV

Energy Technology Data Exchange (ETDEWEB)

Tornow, W.; Chen, Z.M.; Baird, K.; Walter, R.L.

1988-07-01

Differential elastic and inelastic (4.44 MeV) neutron scattering cross sections from /sup 12/C are presented at 15.6, 16.8 and 17.3 MeV. The existing 18.2 MeV differential cross-section data were combined with newly measured analysing power data to parametrise neutron scattering at this energy. The /sup 12/C recoil kerma factors were calculated and reaction cross sections were obtained from a phase-shift analysis and coupled channel analyses in the 15.6-18.2 MeV energy range.
200-MeV bremsstrahlung tagged photon beams at Sendai

International Nuclear Information System (INIS)

Hirose, K.; Chiba, M.; Inoue, M.; Kanda, H.; Kimura, R.; Kino, K.; Kobayashi, Y.; Konno, O.; Maeda, K.; Miyase, H.; Miyamoto, A.; Ohtsuki, T.; Saito, A.; Suda, T.; Takahashi, K.; Tamae, T.; Terasaki, Y.; Terasawa, T.; Tsubota, H.; Tsuruta, T.; Utoyama, M.; Yuuki, H.; Yamaguchi, Y.; Yamazaki, H.

2006-01-01

A new beam line for photonuclear reaction experiments using tagged photons has been constructed to take advantage of the completion of the 1.2-GeV STretcher Booster (STB) ring at the Laboratory of Nuclear Science (LNS), Tohoku University. A photon tagging system was installed at the end of the new beam line. It provides bremsstrahlung tagged photon beams in an energy range from 0.2E 0 to 0.8E 0 MeV at the incident electron energy E 0 with an energy resolution of ΔE/E∼10 -2 . The tagged photon intensity I= 6 photons/s is available for typical photonuclear reaction experiments. We introduce the basic parameters of the tagged photons by showing the commissioning data
Start To End Simulation for the SPARX Project

CERN Document Server

Vaccarezza, Cristina; Boscolo, Manuela; Ferrario, Massimo; Fusco, Valeria; Giannessi, Luca; Migliorati, Mauro; Palumbo, Luigi; Quattromini, Marcello; Ronsivalle, Concetta; Serafini, Luca; Spataro, Bruno; Vescovi, Mario

2005-01-01

The first phase of the SPARX project now funded by Government Agencies, is an R&D activity focused on developing techniques and critical components for future X-ray facilities. The aim is the generation of electron beams with the ultra-high peak brightness required to drive FEL experiments. The FEL source realization will develop along two lines: (a) the use of the SPARC high brightness photoinjector to test RF compression techniques and the emittance degradation in magnetic compressors due to CSR, (b) the production of radiation in the range of 3-5 nm, both in SASE and SEEDED FEL configurations, in the so called SPARXINO test facility, upgrading the existing Frascati 800 MeV LINAC. In this paper we present and discuss the preliminary start to end simulations results.
Femtosecond single electron bunch generation by rotating longitudinal bunch phase space in magnetic field

International Nuclear Information System (INIS)

Yang, J.; Kondoh, T.; Kan, K.; Kozawa, T.; Yoshida, Y.; Tagawa, S.

2006-01-01

A femtosecond (fs) electron bunching was observed in a photoinjector with a magnetic compressor by rotating the bunch in longitudinal phase space. The bunch length was obtained by measuring Cherenkov radiation of the electron beam with a femtosecond streak camera technique. A single electron bunch with rms bunch length of 98 fs was observed for a 32 MeV electron beam at a charge of 0.17 nC. The relative energy spread and the normalized transverse emittance of the electron beam were 0.2% and 3.8 mm-mrad, respectively. The effect of space charge on the bunch compression was investigated experimentally for charges from 0.17 to 1.25 nC. The dependences of the relative energy spread and the normalized beam transverse emittance on the bunch charge were measured
Three-fold increase of M1 strength in 40Ar at 10 MeV excitation energy

Science.gov (United States)

Tornow, Werner; Finch, Sean; Krishichayan, Fnu; Tonchev, Anton

2017-09-01

We reexamined the excitation energy region of 40Ar around 9.8 MeV with the goal of determining the known M1 strength located at 9.76 MeV more accurately. The physics motivation was based on the fact that i) the neutrino-nucleus interaction cross section is proportional to the M1 strength of a nucleus, ii) DUNE, the Deep Underground Neutrino Experiment at SURF will be using liquid argon as detector medium, iii) the energy spectrum of supernova neutrinos is peaked at approximately 10 MeV. Mono-energetic and linearly polarized photons of 9.88 MeV were produced via Compton backscattering of 548 nm FEL photons from 543 MeV electrons at the High-Intensity γ-ray Source (HI γS) facility at TUNL. The 1.25 cm diameter photon beam with energy spread of 300 keV (FWHM) interacted with argon gas contained in a high-pressure cell. The cell was viewed with HPGe detectors placed at 90o relative to the incident photon beam in the horizontal and vertical planes to distinguish between E1 and M1 de-excitation γ-rays. Our re-measurement provided an increase in M1 strength by a factor of approximately 3, mostly due to the discovery that the known level in 40Ar at 9.84 MeV is of M1 character and not of E1 character, as previously thought. In addition to the already known M1 state at 9.76 MeV, we observed weaker M1 states at 9.70, 9.81, 9.87, and 9.89 MeV.

Elastic scattering for 16O + 12C at 140 MeV and 218 MeV

International Nuclear Information System (INIS)

Galindo U, A.

1981-01-01

In this work, angular distribution of cross sections have been measured for 12 C( 16 O, 16 O) 12 C at two energies. The measurements were carried out in 0.5 0 intervals between 5 0 -19.5 0 C (lab.) at 140 MeV, 4.5 0 -14.5 0 at 218 MeV. An optical model analysis of these strong structure angular distributions was done. Good fits of the data were obtained using the optical model search code GENOA with a full Woods-Saxon potential form. This yielded parameters subject to considerable ambiguities as it is known to occur for strongly absorbed particles. These ambiguities were explored in detail and it was found that both the real and the imaginary parts present some characteristics that have been found before for the real potential (as Igo relation for continous ambiguities and the fact that potentials with different diffusivities tend to have the same value at the strong absorption radii). It was found, among other results, that the real volume integral, the mean square radius, as well as the total reaction cross section (σsub(r)) cannot be determined unambiguously. A strong correlation was found between σsub(r) and the imaginary diffusivity. A systematic study of how the variation of the potential parameters affects the angular distribution is presented and some features of the diffraction structure of the angular distribution are discussed. (author)
Elastic scattering of antiprotons from carbon, calcium, and lead at 180 MeV

International Nuclear Information System (INIS)

Garreta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Drake, D.M.; Janouin, S.; Legrand, D.; Lemaire, M.C.; Mayer, B.; Pain, J.; Peng, J.C.

1984-01-01

Angular distributions for elastic scattering of 180 MeV antiprotons from 12 C, 40 Ca, and 208 Pb have been measured over a wide angular range with a magnetic spectrometer. In general, microscopic calculations agree fairly well with the data. Optical-model fits with Woods-Saxon parametrization determine the magnitude and the relative strength of the real and imaginary potentials at the nuclear surface. When the shape of the potentials is derived from that of the charge distribution, the depth of the real potential is found to be shallow (30 MeV 0 12 C scattering at 46.8 MeV and with a recent analysis of anti p-atom data. (orig.)
Gold standard capture cross section from 100 keV to 15 MeV

International Nuclear Information System (INIS)

Ryves, T.B.

1982-01-01

The capture cross section of gold is now generally accepted as the principal reference standard, and therefore in this review only gold is considered. Recent measurements of the gold capture cross section in the unresolved region are discussed and compared with the ENDF/B-V evaluation. It is concluded that in the energy interval 100 to 2000 keV the present uncertainty in the evaluation is +-8%, in the interval 2 to 3.5 MeV the uncertainty is +-4%, in ther interval 3.5 to 14 MeV more measurements are needed before a realistic error can be assigned, and from 14 to 15 MeV the uncertainty is +-10%. Several recommendations for future work have been made
Alpha-deuteron elastic scattering around 40 MeV

International Nuclear Information System (INIS)

De, A.; Karmakar, S.; Roychaudhury, T.; Dasgupta, S.S.; Chintalapudi, S.N.; Ismail, M.; Banerjee, S.R.; Divatia, A.S.

1989-01-01

Differential cross section for alpha-deuteron elastic scattering has been measured at several energies around 40 MeV incident alpha. General behaviour of angular distributions remaining close to that predicted by Faddeev type calculations, a sharp energy dependence is observed. (author). 8 refs
Pion production from deuterium by the bombardment with polarized protons of 277 and 500 MeV

International Nuclear Information System (INIS)

Lolos, G.J.; Auld, E.G.; Giles, G.; Jones, G.; McParland, B.; Ottewell, D.; Walden, P.L.; Zeigler, W.

1982-11-01

Analyzing power measurements of the (anti) pd → tπ + reaction are reported at incident proton energies of 277 and 500 MeV. The 277 MeV results span the angular range from 70 0 to 130 0 in the centre of mass while the two 500 MeV measurements at large angles were taken as a check of published results. With the angular distribution of the analyzing power at 277 MeV being now available, an examination of the energy dependence of the analyzing power shows that it exhibits characteristics closely resembling the shape and magnitude of the distribution observed for nuclei in the 9-12 mass range
Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes; Diffusion elastique et inelastique des protons de 2 a 10 MeV par les isotopes du lithium

Energy Technology Data Exchange (ETDEWEB)

Laurat, M [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten {mu}g/cm{sup 2}) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of {sup 8}Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [French] Nous decrivons le dispositif experimental mis au point pour effectuer les mesures de spectrometrie et de section efficace absolue pour les reactions induites par des protons acceleres par un Van de Graaff Tandem 12 MeV. Les particules sont detectees par des jonctions au silicium, le poids des cibles (de l'ordre d'une dizaine de {mu}g/cm{sup 2}), mesure par la methode du quartz. L'ensemble de l'appareillage a ete controle par l'etude de la diffusion des protons par le lithium 6, et nous a permis de preciser les diffusions elastiques et inelastiques (excitation du 1er niveau) des protons de 2 a 9 MeV par le lithium 7. La structure observee a permis de determiner les spin et parite les plus probables de six niveaux du {sup 8}Be entre 19 et 25 MeV d'energie d'excitation. (auteur)
Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes; Diffusion elastique et inelastique des protons de 2 a 10 MeV par les isotopes du lithium

Energy Technology Data Exchange (ETDEWEB)

Laurat, M. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten {mu}g/cm{sup 2}) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of {sup 8}Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [French] Nous decrivons le dispositif experimental mis au point pour effectuer les mesures de spectrometrie et de section efficace absolue pour les reactions induites par des protons acceleres par un Van de Graaff Tandem 12 MeV. Les particules sont detectees par des jonctions au silicium, le poids des cibles (de l'ordre d'une dizaine de {mu}g/cm{sup 2}), mesure par la methode du quartz. L'ensemble de l'appareillage a ete controle par l'etude de la diffusion des protons par le lithium 6, et nous a permis de preciser les diffusions elastiques et inelastiques (excitation du 1er niveau) des protons de 2 a 9 MeV par le lithium 7. La structure observee a permis de determiner les spin et parite les plus probables de six niveaux du {sup 8}Be entre 19 et 25 MeV d'energie d'excitation. (auteur)
Effects of repulsive three-body force in 12C + 12C scattering at 100A MeV

Directory of Open Access Journals (Sweden)

W.W. Qu

2015-12-01

Full Text Available The angular distribution of 12C + 12C scattering at an incident energy of 100A MeV has been measured. The elastic and inelastic scatterings in 12C to the excitation energies of up to ∼45 MeV were measured simultaneously for the first time with the high-resolution Grand Raiden spectrometer at the Research Center for Nuclear Physics (RCNP. The angular distributions of the elastic scattering to the ground state (01+ and inelastic scattering to the 4.44 MeV (21+ excited state were precisely obtained in the angular range of 1.0°–7.5° with a step of 0.1°. Additionally, the angular distribution was obtained for the sum of the cross sections for excitation energies above the 4.44 MeV state up to 11 MeV, which includes the 7.65 MeV (02+, 9.64 MeV (31−, and 10.30 MeV (22+ states, in addition to probably the simultaneous excitation of the 4.44 MeV state in the projectile and the target nuclei. Those combined data provide a means to study the effects of channel coupling on the elastic cross section. The observed angular distributions are compared with theoretical calculations based on three double-folding models with complex G-matrix interactions, the CEG07b, MPa, and ESC models. The importance of three-body repulsive forces included in the CEG07b and MPa models will be discussed.
Modification of Modulating Anode Voltage Supply of Klystron for PEFP 20 MeV Linac

International Nuclear Information System (INIS)

Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Cho, Yong Sub

2011-01-01

The klystron (TH2089F, THALES) for PEFP 20MeV proton linear accelerator has a triode type electron gun and the modulating anode voltage should be supplied. The klystron has gone through some modification in the modulating anode voltage supply circuit. Formerly, the mod-anode voltage was supplied by using the tetrode-controlled voltage divider. This system requires addition power supply for the tetrode and the grid control circuit. Recently we modified the mod-anode supply from the tetrode-controlled voltage divider to a resistive voltage divider. The resistors for the previous voltage divider were installed at a supporter with high voltage bushing structure next to the klystron. In the previous system, the resistors were exposed to the air and their size was very bulky, length of which was about 1m long. To reduce the space occupied by the voltage divider and to improve the electrical insulation performance, the voltage dividing resistors were moved into the oil tank of the klystron. During the operation of the 20 MeV linac, the klystron parameters were measured. In this paper, the modification of the voltage divider and the operational characteristics of the klystron with modified voltage divider circuit are presented
3 MeV DC accelerator, EBC Kharghar

International Nuclear Information System (INIS)

Bakhtsingh, R.I.; Acharya, S.

2017-01-01

The Accelerator and Pulse Power Division (APPD) has designed and developed a 3 MeV, 10 mA DC electron beam accelerator at Electron Beam Centre, Kharghar, Navi Mumbai. This machine has been utilized for reduction of SO_x and NO_x in simulated flue gases and treatment of waste water to reduce COD and BOD
Experimental apparatus to determine lead attenuation coefficients for photons of 0.511 MeV

International Nuclear Information System (INIS)

Vargas, Luis C.B.; Cardoso, Domingos O.; Gavazza, Sérgio; Morales, Rudnei K.; Oliveira, Luciano S. R.

2017-01-01

Radioactive gamma-emitting sources with higher energies than 1.022 MeV, may interact with matter by pair production process, generating two photons of 0.511 MeV in the positron annihilation, that may contribute to increase doses in both IOE´s or public. National regulatory agencies require a radiation protection plan and a shielding project to consider the influence of these photons in the licensing procedure. This work will present all steps for the development of the experimental apparatus for determination of the attenuation coefficients for photons with energy of 0.511 MeV in lead. (author)
Investigations on the electron bunch distribution in the longitudinal phase space at a laser driven RF electron source for the European X-FEL

Energy Technology Data Exchange (ETDEWEB)

Roensch, Juliane

2010-01-15

The Photoinjector Test facility at DESY, Zeuthen site, (PITZ) is aiming for the optimization of electron guns for SAS-FELs. For this it is necessary to investigate the characteristics of the six dimensional phase space of the bunch produced by a photoinjector. This thesis is focused on the analysis of the longitudinal properties of the electron bunch distribution, this means the temporal current distribution and the momentum distribution as well as the correlation of both properties. The complete distribution of the electron bunch in longitudinal phase space of a photoinjector was measured directly for the first time at a beam momentum of about 5 MeV/c, using an existing apparatus. This system had been designed for an accelerating gradient of 40 MV/m. Its subcomponents were analysed to understand sources of uncertainties of the measurement system. The usage of higher accelerating gradients in the gun (60 MV/m, resulting in a beam momentum of about 6.8 MeV/c) demands major modifications of the existing measurement system for the longitudinal phase space distribution. An upgrade of the facility by an additional accelerating cavity required the design of further longitudinal diagnostics systems for the analysis at higher momenta (up to 40 MeV/c). Measurements of the longitudinal beam properties to determine the influence of different operation parameters, like RF launch phase, charge, accelerating field gradient and laser distribution were performed and compared to simulations. (orig.)
Investigations on the electron bunch distribution in the longitudinal phase space at a laser driven RF electron source for the European X-FEL

International Nuclear Information System (INIS)

Roensch, Juliane

2010-01-01

The Photoinjector Test facility at DESY, Zeuthen site, (PITZ) is aiming for the optimization of electron guns for SAS-FELs. For this it is necessary to investigate the characteristics of the six dimensional phase space of the bunch produced by a photoinjector. This thesis is focused on the analysis of the longitudinal properties of the electron bunch distribution, this means the temporal current distribution and the momentum distribution as well as the correlation of both properties. The complete distribution of the electron bunch in longitudinal phase space of a photoinjector was measured directly for the first time at a beam momentum of about 5 MeV/c, using an existing apparatus. This system had been designed for an accelerating gradient of 40 MV/m. Its subcomponents were analysed to understand sources of uncertainties of the measurement system. The usage of higher accelerating gradients in the gun (60 MV/m, resulting in a beam momentum of about 6.8 MeV/c) demands major modifications of the existing measurement system for the longitudinal phase space distribution. An upgrade of the facility by an additional accelerating cavity required the design of further longitudinal diagnostics systems for the analysis at higher momenta (up to 40 MeV/c). Measurements of the longitudinal beam properties to determine the influence of different operation parameters, like RF launch phase, charge, accelerating field gradient and laser distribution were performed and compared to simulations. (orig.)
Optimisation of 12 MeV electron beam simulation using variance reduction technique

International Nuclear Information System (INIS)

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

2017-01-01

Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 10 7 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 10 7 to 20 × 10 7 . In this study, 5 MeV electron cut-off with 10 × 10 7 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy. (paper)
Energy dissipation process for 100-MeV protons and the nucleon-nucleon interactions in nuclei

International Nuclear Information System (INIS)

Cowley, A.A.; Chang, C.C.; Holmgren, H.D.; Silk, J.D.; Hendrie, D.L.; Koontz, R.W.; Roos, P.G.; Samanta, C.; Wu, J.R.

1980-01-01

Coincidence studies of two protons emitted from p+ 58 Ni at 100 MeV have been carried out. The proton spectra in coincidence with scattered protons suffering an average energy loss of 60 MeV are similar to those resulting from 60-MeV incident protons. This suggests that the initial interaction of the incident proton is with a bound nucleon and that one or both of these nucleons are emitted or initiates a cascade leading to more complex states
Study of the D(p,π+)T and 9Be(p,π+)10Be from 400 to 800MeV

International Nuclear Information System (INIS)

Aslanides, E.; Bauer, T.; Bertini, R.; Beurtey, R.; Bimbot, L.; Bing, O.; Boudard, A.; Brochard, F.; Bruge, G.; Catz, H.; Chaumeaux, A.; Couvert, P.; Duchazeaubeneix, J.C.; Duhm, H.; Garreta, D.; Gorodetzky, P.; Habault, J.; Hibou, F.; Igo, G.; Le Bornec, Y.; Lugol, J.C.; Matoba, M.; Tatischeff, B.; Terrien, Y.

Pion production on CD 2 and 9 Be targets has been observed using the high resolution, energy loss, spectrometer SPES I. Differential cross sections for the D(p,π + ) reaction have been determined at 410, 605 and 809MeV and for the 9 Be(p,π + ) reaction at 410 and 605MeV. The 3.37MeV (2 + ) state in 10 Be is populated preferentially, but a significant part of the transition strength seems to populate the ground state and the higher lying multiplets at about 6.1MeV, 7.4MeV and 9.4MeV [fr
History of the ZGS 500 MeV booster.

Energy Technology Data Exchange (ETDEWEB)

Simpson, J.; Martin; R.; Kustom, R.

2006-05-09

The history of the design and construction of the Argonne 500 MeV booster proton synchrotron from 1969 to 1982 is described. This accelerator has since been in steady use for the past 25 years to power the Argonne Intense Pulsed Neutron Source (IPNS).
A technique for determining electron losses for a 20 MeV microtron

International Nuclear Information System (INIS)

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

1999-01-01

A 22 orbit, 20 MeV electron microtron is used as a preaccelerator for the 700 MeV booster synchrotron at INDUS-1, CAT, Indore. Estimation of electron losses at the RF cavity from each orbit is important in obtaining the radiation doses from the body of the microtron. Radiation mapping of the microtron can be used to estimate these loss terms as an alternate to actual measurement by using a measuring probe. (author)
The gas bubbles distribution in 600 MeV protons irradiated aluminium

International Nuclear Information System (INIS)

Gavillet, D.; Martin, J.L.; Victoria, M.; Green, W.

1984-01-01

In order to simulate the damage produced by 14 MeV fusion neutrons, thin foils of high purity Al have been irradiated by a proton beam of 580 MeV (120μA). After irradiation at temperatures higher than 0.5 Tm transmission electron microscope observations of gas bubbles distribution were performed. At 200 0 C a uniform distribution of bubbles has been observed inside the grain. The average distance between bubbles and their density have been determined. The gas pressure inside the bubbles has been estimated [fr
Surface structural determination of UO2(111) using MeV ions

International Nuclear Information System (INIS)

Thompson, K.A.; Ellis, W.P.; Taylor, T.N.; Valone, S.M.; Maggiore, C.J.

1983-01-01

The UO 2 (111) surface was studied using MeV ions incident along the and directions. In addition, this surface was well characterized by LEED and Auger analysis. A resonance at 3.05 MeV for 4 He elastic scattering from 16 O made it possible to study the surface peaks for uranium and oxygen simultaneously. By combining previous surface studies with detailed analysis of the surface peaks and rocking curves for this compound material, an outward relaxation of 0.19 A +- 0.01 A was determined for uranium

Determination of partial decay widths for the 2-, 8.87 MeV level in 16O

International Nuclear Information System (INIS)

Vermeer, W.J.; Poletti, A.R.

1982-01-01

The E2/M1 mixing ratios for the decays of the 2 - , 8.87 MeV level in 16 O to the 1 - , 7.12 MeV and 3 - , 6.13 MeV levels were measured. The results were delta(2 - → 1 - )= + 2.1 +- 0.5 and delta(2 - → 3 - )= + 2.90 +- 0.20. These are compared with previous experiments and with shell-model predictions. (author)
Cross-sections for the formation of isomeric pair {sup 75}Ge{sup m,g} through (n, 2n), (n, p) and (n, {alpha}) reactions measured over 13.73 MeV to 14.77 MeV and calculated from near threshold to 20 MeV neutron energies

Energy Technology Data Exchange (ETDEWEB)

Attar, F.M.D.; Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Kailas, S. [Nuclear Physics Division, BARC, Mumbai-400085 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

2009-09-15

The cross-sections for formation of isomeric pair, {sup 75}Ge{sup m}({sigma}{sub m}) and {sup 75}Ge{sup g}({sigma}{sub g}), through {sup 76}Ge(n, 2n), {sup 75}As(n, p) and {sup 78}Se(n, {alpha}) reactions were measured at 13.73 MeV, 14.42 MeV and 14.77 MeV neutrons and also estimated using EMPIRE-II and TALYS codes over neutron energies from near threshold to 20 MeV. For each (n, 2n), (n, p) and (n, {alpha}) reaction, the cross-section initially increases with neutron energy, but starts decreasing as the neutron energy exceeds the respective threshold of (n, 3n), (n, pn) and (n, {alpha}n) reactions. The higher values of {sigma}{sub m} relative to {sigma}{sub g} reveal that the transitions of the excited {sup 75}Ge from higher energy levels to metastable state (7{sup +}/2) are favored as compared to unstable ground state (1{sup -}/2). The present values of cross sections for formation of {sup 75}Ge{sup m,g} through (n, 2n) and (n, {alpha}) reactions are lower, and that of (n, p) reaction are higher compared to most of the corresponding literature cross-sections.
Light charged particle emission in the matched reactions 280 MeV 40Ar+27Al and 670 MeV 55Mn+12C: Inclusive studies

International Nuclear Information System (INIS)

Brown, Craig M.; Milosevich, Zoran; Kaplan, Morton; Vardaci, Emanuele; DeYoung, Paul; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Karol, Paul J.; McMahan, Margaret A.

1999-01-01

In order to test the statistical model's ability to predict the behavior of relatively light mass systems (A≅67) with large angular momenta, two matched heavy ion nuclear reactions were used to produce 67 Ga * composite nuclei at an excitation energy of 127 MeV. Light charged particles (protons, deuterons, tritons, and α particles) were used as probes to characterize the composite systems and track the deexcitation processes. From these measurements, energy spectra, cross sections, angular distributions, anisotropy ratios, and particle multiplicities were deduced. Measuring many degrees of freedom provides a stringent test for the statistical models. What is found is that models which did well in predicting the behavior of heavy composite systems (A≅150), are unable to simultaneously reproduce energy spectra, angular distributions, and particle multiplicities for the lighter systems (A≅67), where angular momentum plays a dominant role. This implies that more rigorous models and/or additional physics are needed to understand the behavior of the hot, high-spin nuclear matter in this mass region. (c) 1999 The American Physical Society
Digital neutron/gamma discrimination with an organic scintillator at energies between 1 MeV and 100 MeV

Energy Technology Data Exchange (ETDEWEB)

Comrie, A.C. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Buffler, A., E-mail: andy.buffler@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Smit, F.D. [iThemba LABS, Somerset West 7129 (South Africa); Wörtche, H.J. [INCAS" 3, Dr. Nassaulaan 9. 9400 AT Assen (Netherlands)

2015-02-01

Three different digital implementations of pulse shape discrimination for pulses from an EJ301 liquid scintillator detector are presented, and illustrated with neutrons and gamma-rays produced by an Am–Be radioisotopic source, a D–T generator and beams produced by cyclotron-accelerated protons of energies 42, 62 and 100 MeV on a Li target. A critical comparison between the three methods is provided.
Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

International Nuclear Information System (INIS)

Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

1985-01-01

These measurements were undertaken as a consequence of our failure early this year to accelerate Au +46 ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV 197 Au +17 from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV 197 Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs
Charge-state distributions of 100, 175, 275, and 352 MeV gold ions emerging from thin carbon foils

Energy Technology Data Exchange (ETDEWEB)

Martin, J.A.; Auble, R.L.; Erb, K.A.; Jones, C.M.; Olsen, D.K.

1985-01-01

These measurements were undertaken as a consequence of our failure early this year to accelerate Au/sup +46/ ions in the Oak Ridge Isochronous Cyclotron using an injected beam of 352 MeV /sup 197/Au/sup +17/ from the 25 MV tandem accelerator. Following that unsuccessful test, we made a preliminary measurement of the charge-state distribution of 352 MeV /sup 197/Au ions emerging from a carbon foil using the bending magnet that is a part of the cyclotron beam injection system. The measured mean charge was approx.38.5, about 4.5 charge-states lower than predicted by the Sayer semi-empirical formula. The measurements reported here were done more precisely and systematically confirm that preliminary result. 12 refs., 5 figs., 4 tabs.
Differential cross section measurements for the 6Li(n,t)alpha reaction in the few MeV region

Energy Technology Data Exchange (ETDEWEB)

Devlin, Matthew J [Los Alamos National Laboratory; Taddeucci, Terence N [Los Alamos National Laboratory; Hale, Gerald M [Los Alamos National Laboratory; Haight, Robert C [Los Alamos National Laboratory; O' Donnell, Johhn M [Los Alamos National Laboratory

2008-01-01

New measured differential cross sections of tritons and alpha particles following the {sup 6}Li(n,t){alpha} reaction are reported for incident neutron energies between 0.2 and approximately 20 MeV. The neutrons were produced by spallation at the WNR facility at the Los Alamos Neutron Science CEnter (LANSCE), with the incident neutron energy determined by the time-of-flight method. Four E-{Delta}E telescopes were used at eight laboratory angles. These data have been incorporated into a prior R-matrix fit for the compound {sup 7}Li system, and result in an (n,t) reaction cross section that is 4% to 10% higher than previous evaluations in the 1-3 MeV incident neutron energy region.
Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

International Nuclear Information System (INIS)

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

2013-01-01

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

International Nuclear Information System (INIS)

Bell, Z.W.; Chaklov, V.L.; Golovkov, V.M.

1998-01-01

Accelerator-based photoneutron sources have enjoyed wide use and offer the advantages of long term stability, ease of control and absence of radioactive materials. The authors report here measurements of the yield of photoneutrons from a neutron generator using a compact betatron (466 kg total weight, 900 by 560 by 350 mm betatron dimensions) at the Institute of Introscopy of the Tomsk Polytechnic University. Electrons were accelerated to energies up to 10 MeV and produced a bremsstrahlung beam with a dose rate of 0.16 Gy/min (at 10 MeV, 1 meter from the bremsstrahlung target) to irradiate LiD, Be, depleted U, and Pb neutron-producing targets. The angular distributions of photoneutrons produced by bremsstrahlung beams were measured with a long counter and integrated to determine neutron yield. In addition, neutron time of flight spectra were recorded from all targets using a 15 meter flight path perpendicular to the photon beam. The maximum observed yields were 5.2 x 10 4 n/rad/gram target obtained with LiD, 1.7 x 10 4 n/rad/gram from Be, 3.3 x 10 3 n/rad/gram from U, and 7.5 x 10 2 n/rad/gram from Pb. Optimization of target dimensions, shape, and positioning is expected to increase the yield from the LiD target by a factor of 35. With the increased yield, this compact betatron-based system could find application in the interrogation of waste containers for fissile material
Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

International Nuclear Information System (INIS)

Holmqvist, B.; Johansson, S.G.; Lodin, G.; Wiedling, T.; Kiss, A.

1966-12-01

Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer
Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

Energy Technology Data Exchange (ETDEWEB)

Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T [AB Atomenergi, Nyko eping (Sweden); Kiss, A [Inst. for Experimental Physics, Univ. of Debrecen, De brecen (Hungary)

1966-12-15

Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer.
Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Madejski, Grzegorz M. [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Rikkyo Univ., Tokyo (Japan). Dept. of Physics

2013-09-24

While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10^-12 erg/cm²/s^-1 at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.
Probing the cosmic x-ray and MeV gamma ray background radiation through the anisotropy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki [Stanford Univ., CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States); Madejski, Grzegorz M. [Stanford Univ., CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States); Rikkyo Univ., Tokyo (Japan)

2013-09-24

While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once future hard X-ray all sky satellites achieve a sensitivity better than 10–12 erg cm–2 s–1 at 10-30 keV or 30-50 keV—although this is beyond the sensitivities of current hard X-ray all sky monitors—angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.
Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

CERN Document Server

Zhuikov, B L; Konyakhin, N A; Vincent, J

1999-01-01

A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 mu A and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial sup 8 sup 2 Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry ...
FIRST LIGHT: MeV ASTROPHYSICS FROM THE MOON

Energy Technology Data Exchange (ETDEWEB)

Miller, Richard S. [University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Lawrence, David J., E-mail: richard.s.miller@uah.edu [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

2016-06-01

We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5–9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4 σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.
Coherent optical transition radiation and self-amplified spontaneous emission generated by chicane-compressed electron beams

Directory of Open Access Journals (Sweden)

A. H. Lumpkin

2009-04-01

Full Text Available Observations of strongly enhanced optical transition radiation (OTR following significant bunch compression of photoinjector beams by a chicane have been reported during the commissioning of the Linac Coherent Light Source accelerator and recently at the Advanced Photon Source (APS linac. These localized transverse spatial features involve signal enhancements of nearly a factor of 10 and 100 in the APS case at the 150-MeV and 375-MeV OTR stations, respectively. They are consistent with a coherent process seeded by noise and may be evidence of a longitudinal space charge microbunching instability which leads to coherent OTR emissions. Additionally, we suggest that localized transverse structure in the previous self-amplified spontaneous emission (SASE free-electron laser (FEL data at APS in the visible regime as reported at FEL02 may be attributed to such beam structure entering the FEL undulators and inducing the SASE startup at those “prebunched” structures. Separate beam structures 120 microns apart in x and 2.9 nm apart in wavelength were reported. The details of these observations and operational parameters will be presented.
Performances of the Alpha-X RF gun on the PHIL accelerator at LAL

Science.gov (United States)

Vinatier, T.; Bruni, C.; Roux, R.; Brossard, J.; Chancé, S.; Cayla, J. N.; Chaumat, V.; Xu, G.; Monard, H.

2015-10-01

The Alpha-X RF-gun was designed to produce an ultra-short (laser-driven plasma accelerator with a short wavelength accelerating medium. It has been demonstrated on PHIL (Photo-Injector at LAL) that the coaxial RF coupling, chosen to preserve the gun field cylindrical symmetry, is perfectly understood and allows reaching the required peak accelerating field of 100 MV/m giving beam energy of 6.3 MeV. Moreover, a quite low beam rms relative energy spread of 0.15% at 3.8 MeV has been measured, completely agreeing with simulations. Dark current, quantum efficiencies and dephasing curves measurements have also been performed. They all show high values of the field enhancement factor β, which can be explained by the preparation of the photocathodes. Finally, measurements on the transverse phase-space have been carried out, with some limitations given by the difficult modelization of one of the PHIL solenoid magnets and by the enlargement of the beam transverse dimensions due to the use of YAG screens. These measurements give a normalized rms transverse emittance around 5π mm mrad, which does not fulfill the requirement for the Alpha-X project.
Acquisition of the ANL 4-MeV electrostatic accelerator. Progress report, September 1, 1975--August, 1976

International Nuclear Information System (INIS)

Dixon, D.R.

1976-01-01

The operation of the ANL 4-MeV accelerator for the reporting period September 1, 1975 through August 31, 1976 is described. Some improvements and modifications to the accelerator and associated equipment, as well as maintenance problems are reported. Activities on the three research projects and a subsequent modification are summarized. Progress on the shift of research activities from the BYU 2-MeV accelerator to the 4-MeV accelerator is described
Observations of galactic center for annihilation line at 0.511 MeV

International Nuclear Information System (INIS)

Jayanthi, U.B.; Martin, I.M.; Braga, J.; Neri, J.A.C.F.; Jardim, M.V.A.; Rao, K.R.

1983-10-01

The presence of the 0.511 MeV gamma line emission from galactic center is well-established from various balloon experiments. Recent results in 1980-82 from balloon and satellite experiments show significant decrease in this line intensity. To confirm these results a fly on balloon is performed with a large area sodium iodide detector to measure 0.511 MeV line from galactic center. The preliminary results indicate flux -3 photons cm -2 s -1 . (Author) [pt
Radiological safety research of food irradiation with 7.5 MeV X-rays

International Nuclear Information System (INIS)

Yang Bin; Tang Weidong; Zhang Yue; Xu Tao; Jin Jianqiao; Ye Mingyang

2012-01-01

China and America both have 7.5 MeV high energy X-ray accelerator. The radiological safety of food irradiated with 7.5 MeV X-rays (bremsstrahlung) has been investigated. Samples of meat and meat ash were located in a large volume of fresh meat at the position of the highest photoneutron fluence and irradiated to an X-ray dose of 15 kGy, twice the maximum dose allowed by the US FDA for meat irradiation. An evaluation of the corresponding radiation exposure from ingestion of the irradiated product has been compared to natural background radiation. The paper concludes that the risk to individuals from intake of food irradiated with X-rays from 7.5 MeV electrons, even with a broad energy spectrum, would be trivial. The common target materials are Au, Ta and W. The U.S, requires only Au and Ta can be used as food irradiation target materials and China has not yet relevant provisions. The first 7.5 MeV accelerator for food irradiation in China is under built, and will do the explore research for the choice of target material. (authors)

Some links on this page may take you to non-federal websites. Their policies may differ from this site.