We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for ...

The search for mono-energetic protons are always of great interests, both for science and for many applications, among the medical therapy of cancer and fast ignition of laser fusion. Radiation Pressure Acceleration (RPA) of quasi-monoenergetic protons by illuminating an ultra thin foil ...

Results are presented from three-dimensional numerical simulations carried out to study different regimes of proton acceleration from plane targets (such as double- and single-layer foils, homogeneous foils of light and heavy ions, and mass-limited targets) irradiated by laser pulses of moderate intensity. It is shown that, in the interaction of a laser ...

We consider the effect of laser beam shaping on proton acceleration in the interaction of a tightly focused pulse with ultrathin double-layer solid targets in the regime of directed Coulomb explosion. In this regime, the heavy ions of the front layer are forced by the laser to expand predominantly in the direction of the pulse propagation, forming a moving ...

We consider the effect of laser beam shaping on proton acceleration in the interaction of a tightly focused pulse with ultrathin double-layer solid targets in the regime of directed Coulomb explosion. In this regime, the heavy ions of the front layer are forced by the laser to expand predominantly in the direction of the pulse propagation, forming a moving ...

We present scaling studies of proton acceleration by short pulse, intense lasers in the region of radiation pressure acceleration of ultra thin foil. By defining the monoenergetic proton as having energy spread less than 10 percent in 2D PIC simulation, we studied the ...

We report on the acceleration of impurity-free quasimononenergetic proton beams from an initially gaseous hydrogen target driven by an intense infrared (?=10 ?m) laser. The front surface of the target was observed by optical probing to be driven forward by the radiation pressure of the laser. A proton beam of ?MeV energy was ...

The theoretical research works on proton and ion acceleration done by our group are reviewed. A complex target consisting of a front horizontal slice adjoining a conventional heavy ion and proton double-layer slab are used to produce more-fast moving hot electrons to enhance the target-normal sheath acceleration ...

The laser acceleration of proton beams with quasi-monoenergetic features in the energy spectra from microdot targets is investigated by numerical simulation. The formation of these spectral peaks is strongly dependent on the interplay between different ion species in the target. The scaling of the spectral peak's energy, and number of ...

By using multidimensional particle-in-cell simulations, we present a new regime of stable proton beam acceleration which takes place when a two-ion-species shaped foil is illuminated by a circularly polarized laser pulse. In the simulations, the lighter protons are nearly instantaneously separated from the heavier carbon ions due to ...

By using multidimensional particle-in-cell simulations, we present a new regime of stable proton beam acceleration which takes place when a two-ion-species shaped foil is illuminated by a circularly polarized laser pulse. In the simulations, the lighter protons are nearly instantaneously separated from the heavier carbon ions due to ...

The uses of high-current positive-ion accelerators for low-cross-section reactions are discussed. The use of low intrinsic efficiency detectors and the low counting rate for some experiments using the accelerator are discussed. The production of monoenergetic, variable-energy gamma rays in the nonresonance capture of ...

Energy- and angular distributions of neutrons behind concrete side shielding of proton accelerators were calculated. Simple arguments are given to understand the characteristic shape of the neutron spectrum. Calculations were repeated to receive data for simple shielding estimations. The dose equivalent attenuation coefficient of concrete for ...

Laser driven ion acceleration arises from charge separation effects caused by an ultrahigh intensity laser pulse. Limited mass targets confine the accelerated electrons within the target size and prevent the large area spreading seen in extended foil targets. Furthermore, if the target size is smaller than the laser wavelength and focal spot diameter, ...

Laser driven ion acceleration arises from charge separation effects caused by an ultrahigh intensity laser pulse. Limited mass targets confine the accelerated electrons within the target size and prevent the large area spreading seen in extended foil targets. Furthermore, if the target size is smaller than the laser wavelength and focal spot diameter, ...

We present analytic theory of monoenergetic protons acceleration by short pulse laser irradiation on a thin foil with specific thickness suggested by Yan et al. in simulations. The laser ponderomotive force pushes the electrons forward, leaving ions behind until the space charge field balances the ponderomotive force at distance ...

We present a scheme for proton acceleration from a moving double layer formed by an ultraintense circularly polarized laser pulse with intensity 1021-1023 W cm-2 irradiated on a combination target. The target is composed of a thin overdense proton-rich foil located at the front followed by an underdense gas region behind with an ...

Multistaged acceleration of solid-density thin foils by ultraintense circularly polarized laser pulse is investigated. A stable radiation pressure acceleration (RPA) stage is first established. Higher dimensional effects such as transverse instabilities and enhanced electron heating then gradually make the initially opaque foil transparent to the laser ...

Particle acceleration based on high intensity laser systems (a process known as laser-plasma acceleration) has achieved high quality particle beams that compare favourably with conventional acceleration techniques in terms of emittance, brightness and pulse duration. A long-term difficulty associated with laser-plasma ...

The effect of laser pulse shaping on the proton acceleration by a tightly focused pulse from ultra-thin double layer solid targets in the regime of Directed Coulomb Explosion (DCE) is discussed. The theoretical model and the results of PIC simulations of this regime are presented. In DCE regime the foil is first accelerated by the ...

We consider the effect of laser beam shaping on proton acceleration in the interaction of a tightly focused pulse with ultrathin double-layer solid targets in the regime of directed Coulomb explosion. In this regime, the heavy ions of the front layer are forced by the laser to expand predominantly in the direction of the pulse propagation, forming a moving ...

We present theoretical and numerical studies of the acceleration of monoenergetic protons in a double layer formed by the laser irradiation of an ultra-thin film. The stability of the foil is investigated by direct Vlasov-Maxwell simulations for different sets of laser-plasma parameters. It is found that the foil is stable, due to the ...

The Rayleigh-Taylor (RT) hydrodynamic instability can compromise the shell integrity during the acceleration phase of Inertial Confinement Fusion (ICF) implosions. RT-induced magnetic fields on the order of a mega-Gauss have been theoretically predicted and simulated, but never measured. If present, these self-generated fields will reduce the heat flux and affect the implosion ...

Human cancer cells are irradiated by laser-driven quasi-monoenergetic protons. Laser pulse intensities at the 5�1019-W/cm2 level provide the source and acceleration field for protons that are subsequently transported by four energy-selective dipole magnets. The transport line delivers 2.25 MeV ...

We report the first, to our knowledge, experimental investigation of proton acceleration by a laser in an overdense gas jet, in particular first direct experimental observations of quasi-monoenergetic spectra of ions accelerated by radiation pressure of relativistically intense circularly polarized laser radiation. ...

Proton irradiation set up at 14UD BARC-TIFR Pelletron Accelerator Facility at TIFR is being utilized to conduct experiments for variety of applications including, production of radionuclides such as 52Mn, 96Tc and 236Pu and for monoenergetic high energy neutrons production via Li (p, n) Be reaction. The installation and commissioning ...

Recent experiments at the LLNL Petawatt Laser have demonstrated the generation of intense, high energy beams of electrons and ions from the interaction of ultra-intense laser light with solid targets. Focused laser intensities as high as 6 x 10{sup 20} W/cm{sup 2} are achieved, at which point the quiver energies of the target electrons extend to {approx}10 MeV. In this new, fully relativistic ...

Recent breakthroughs in short pulse laser technology resulted in (i) generation of ultra-high intensity (2�1022 W/cm2) and (ii) ultra-high contrast (10-11) short pulses at the Hercules facility of the University of Michigan, which has created the possibility of exploring a new regime of ion acceleration - the regime of Directed Coulomb Explosion (DCE). In this regime of ...

A scheme for producing quasimonoenergetic proton beams is presented. In the scheme, a thin solid target with a tiny hole on its backside is employed. The optimal hole diameter is of the order of the laser spot size so that a localized uniform sheath field can be generated in the hole. Particle-in-cell simulations demonstrate that the highly localized uniform fields can produce ...

The Solar Electron and Proton Telescope (SEPT) on board the twin spacecraft STEREO A and B measures electrons and ions in the energy range from 60 to above 400 keV with an energy resolution of 10%. On 19 October 2009, when STEREO-B was already 1.03 AU away from the Earth, a strong and prolonged almost monoenergetic ion event has been observed with the SEPT ...

Linearly polarized laser radiation accelerates electrons to very high velocities and these electron form a sheath layer on the rear side of thin targets where preferentially protons are accelerated. When mass-limited targets are used, the lateral transport of the absorbed laser energy is reduced and the ...

was built into this unit to generate and to accelerate protons up to 30 keV, and a high purity scandium tritide target with a scandium�to�triton atomic ratio of 1:2.0\\Sigma0.2 was included. The techniques . . . . . . . . . . . . . . . . . . 84 4.1.1 Substrate Preparation . . . . . . . . . . . . . . . . . . . . . . . . 85 4.1.2 Scandium

Studies of interaction of a cloud of submicrometer water droplets with ultrashort (40 fs) and intense ({approx}2x10{sup 19} W/cm{sup 2}) laser pulses demonstrate an efficient acceleration of protons and oxygen ions. Due to a high ratio of the volume to the enveloping surface of a single droplet and a large number of droplets in a focal volume, efficient ...

Studies of interaction of a cloud of submicrometer water droplets with ultrashort (40 fs) and intense (~2�1019 W/cm2) laser pulses demonstrate an efficient acceleration of protons and oxygen ions. Due to a high ratio of the volume to the enveloping surface of a single droplet and a large number of droplets in a focal volume, efficient laser pulse ...

- mum HWHM radius of 22.5 m. Proton spectrometers determined that 107 �109 D 3 He and DD protons wereMonoenergetic proton backlighter for measuring E and B fields and for radiographing implosions 2006 A novel monoenergetic proton backlighter source and matched imaging ...

Time-gated, monoenergetic radiography with 15-MeV protons provides unique measurements of implosion dynamics in direct-drive inertial-confinement fusion. Images obtained during acceleration, coasting, deceleration, and stagnation display a comprehensive picture of spherical implosions. Critical information inferred from such images, ...

By using multidimensional particle-in-cell simulations, we present a new regime of stable proton beam acceleration which takes place when a two-ion-species shaped foil is illuminated by a circularly polarized laser pulse. In the simulations, the lighter protons are nearly instantaneously separated from the heavier carbon ions due to ...

... Title : Detection of Protons in CR-39 Plastic Track Detector. ... Abstract : CR-39 plastic is used as a detector to observe monoenergetic protons. ...

A tomographic diagnosis method was developed to systematically resolve the injection and acceleration processes of a monoenergetic electron beam in a laser-wakefield accelerator. It was found that all the monoenergetic electrons are injected at the same location in the plasma column and ...

Laser plasma acceleration of electrons: Towards the production of monoenergetic beamsa... K with underdense plasma is investigated experimentally using a range of laser parameters and energetic electron beyond that which can be produced from single stage plasma wave acceleration and direct laser

Simulations based on the coupled relativistic equations of motion show that protons stemming from laser-plasma processes can be efficiently post-accelerated employing single and crossed pulsed laser beams focused to spot radii on the order of the laser wavelength. We demonstrate that the crossed beams produce quasi-monoenergetic ...

An ultra-intense short-pulsed laser interacting with a uniform underdense plasma with near-critical density is investigated by 2.5-dimensional particle-in-cell simulations. It is found that a collimated proton beam with maximum energy up to the GeV was generated. The corresponding proton acceleration mechanism is analyzed. The laser ...

Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment ...

Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment ...

Currently, energy spectra of laser accelerated proton beams are far from being monoenergetic. For their application in radiation therapy, energy selection systems using magnetic fields have been proposed to single out particles with the desired energy. These systems allow the choice of protons between a lowest and ...

A method is devised to approximate the spatially averaged momentum distribution function for the accelerated particles at the end of the active lifetime of a supernova remnant. The authors confine themselves to the test particle approximation and oversimplify adiabatic losses, but include unsteady shock motion, evolving shock strength, and non-uniform gas flow effects on the ...

Neutrons can be produced with low-energy ion accelerators for many applications, such as the characterisation of neutron detectors, the irradiation of biological samples and the study of the radiation damage in electronic devices. Moreover, accelerator-based neutron sources are under development for boron neutron capture therapy (BNCT). Thin targets are ...

The authors consider a system in which a planar shock propagates into a plasma where the magnetic field consists of a uniform background component that is nearly parallel to the shock surface (i.e., the shock is nearly perpendicular) plus a random component that is transverse to the background field. The random component is a superposition of Alfven waves with a wide range of wavelengths and with ...

A new vacuum-insulated tandem accelerator capable of producing a 5-mA proton beam with energy up to 2 MeV was used to produce a mono-energetic beam of 9.17-MeV gamma rays from the resonant production reaction, 13C(p,?)14N, at 1.76 MeV. A graphite target enriched with 13C capable of withstanding the proton beam ...

The 8 and 27 keV monoenergetic neutron calibration fields have been developed by using (45)Sc(p, n)(45)Ti reaction. Protons from a 4-MV Pelletron accelerator are used to bombard a thin scandium target evaporated onto a platinum disc. The proton energies are finely adjusted to the resonance to generate the 8 and 27 ...

... Descriptors : *LINEAR ACCELERATORS, *PROTON ACCELERATORS, *COLLIDER ACCELERATORS, SYMPOSIA, VACUUM CHAMBERS ...

... Descriptors : *Linear accelerators, *Ion accelerators, *Particle accelerator components, *Electron accelerators, *Proton accelerators, Electron beams ...

We report our recent progress using a high-power, picosecond CO2 laser for Thomson scattering and ion acceleration experiments. These experiments capitalize on certain advantages of long-wavelength CO2 lasers, such as their high number of photons per energy unit and beneficial wavelength- scaling of the electrons' ponderomotive energy and critical plasma frequency. High X-ray ...

The position-to-energy calibration of a Thomson parabola ion spectrometer (TPIS) was measured using proton beams from the 1.7 MV tandem pelletron accelerator at SUNY Geneseo. The TPIS was designed for use on the multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE). The TPIS implements parallel electric and magnetic fields to ...

Persistent disparities between the energy scales used for broad-spectrum neutron source studies and monoenergetic neutron source studies has prompted an investigation of various factors which affect the determination of an energy scale for monoenergetic accelerators. Yield curves and neutron energy spectra were calculated for some ...

Protons have a well defined range in matter. A detector, therefore, placed near the end of range of a monoenergetic proton beam becomes a very sensitive measure of changes in the mass of material which the beam has traversed. This property of protons can ...

Laser-induced particle accelerators have been recognized as a potential proton source for radiotherapeutic applications in recent years. However, there are still major difficulties--especially regarding the resulting proton spectra--to overcome for a successful application in the clinic. Here we elaborate on the physics of double-layer ...

Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the ...

Proton radiography using energetic protons from accelerator producing high contrast and poor spatial

A tomographic method based on laser machining was used to resolve the electron injection and acceleration processes in a laser wakefield accelerator. It was found that all the electrons in the monoenergetic electron beam are injected at the same location in the plasma column and then accelerated with an ...

the information on the evolution of energy spread of the monoenergetic electron beam with laser propagation after of the machining beam intensity distribution in the region of pump pulse propagation for various knife. After the amplifier chain of the laser system the laser beam with a clear aperture of 4 cm in diameter

Radiation Pressure Acceleration is a regime of laser-driven ion acceleration in which masses of plasma are accelerated by the photon pressure of the laser pulse. For small areal masses and ultra-high intensities (> 10^21Wcm-2) this should permit one to reach ion energies on the order of 100 MeV per nucleon. Since a whole mass of ...

The purpose of this investigation is to study the absolute cross sections for the emission of Balmer radiation from collisions of protons with various gases. When a proton interacts with a neutral gas molecule, an electron from the gas molecule can move to the proton, forming a neutral hydrogen atom and an ionized molecule. If the ...

We are studying the absolute cross sections for the emission of Balmer-alpha and Balmer-beta radiation from collisions of protons with various gases. When a proton interacts with a neutral gas molecule, there is a probability that an electron from the gas molecule will transfer to the proton, forming a neutral hydrogen atom and an ...

When an ultra intense circularly polarized laser pulse irradiates an ultra thin film, a monoenergetic ion beam is produced with characteristics well suited for applications in science and medicine. Upon laser incidence, the electrons in the foil are pushed via the ponderomotive force to the foil rear; the charge separation field then accelerates ions. In ...

... joint planning, national and international ... ACCELERATORS, *PROTON ACCELERATORS, PARTICLE ACCELERATOR TECHNIQUES ...

... The experimental technique, using Yokota-type dosimeter glasses and 28 ... of 239Pu, 237Np and 235U, monoenergetic protons, deuterons and He ...

range is about twice that of the proton: therefore, nu- clear reactions can continue, ... Dosimetry and. Instrumentation for Helium and Heavy Ions. ...

Laser acceleration of protons has drawn vigorous attention due to their application in cancer treatment and other areas. The scheme that has emerged very promising for the generation of mono-energy ions is the Radiation Pressure Acceleration (RPA) of laser illuminated thin foils. A circularly polarized laser impinged on a submicron ...

A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to ...

A new ion radiation-pressure acceleration regime, the �leaky light sail,� is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to ...

Radiative proton capture reactions relevant to rp-process on 46Ti, 64Zn, 114Sn and 116Sn were investigated at the Western Michigan University accelerator facility. Targets were irradiated with a monoenergetic proton beam within the energy range (1-4) MeV. Decay of daughter products was measured using two HPGe ...

A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane ...

A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane ...

Radiation pressure acceleration (RPA) theoretically may have great potential to revolutionize the study of laserdriven ion accelerators due to its high conversion efficiency and ability to produce high-quality monoenergetic ion beams. However, the instability issue of ion acceleration has been appeared to be a ...

an angular divergence much smaller than the other. By using the angularly re- solved electron-energy spectrometer, as shown in Fig. 2(b), it was found that the electron beam with smaller diver- gence containsTomography of Injection and Acceleration of Monoenergetic Electrons in a Laser

More than 15 Japanese laboratories are dedicated to the advanced and compact accelerator development. Some use ultra-intense lasers and others use microwave concepts. As for the laser electron acceleration, the topics are the capillary acceleration and the mono-energetic acceleration. The laser ...

A pulsed high-flux source of nearly monoenergetic atomic oxygen was developed to perform accelerated

Fast coincidence system was constructed and applied to positron annihilation spectrometry (PAS). We studied on the factors that affected the time resolution of the system. Time resolutions were obtained and mutually compared with respect to several factors such as sizes, kinds of scintillators, length dependence of delay lines on the CFD583, and width variations of the windows for 511keV and ...

A new neutron beam line facility with low background has been installed on the TANDEM accelerator facility of CEA/DIF at Bruy�res-le-Ch�tel (France) to allow (n, xn) reactions studies with a new neutron-multiplicity detector. Beam neutrons are produced by nuclear reaction between a proton or deuteron beam and a deuterium or tritium target. The neutron ...

A neutron generator (HIRRAC) for use in radiobiology study has been constructed at the Research Institute for Radiation Biology and Medicine, Hiroshima University (RIRBM). Monoenergetic neutrons of which energy is less than 1.3 MeV are generated by the 7Li(p,n)7 Be reaction at proton energies up to 3 MeV. The protons are ...

This report describes methods and computer programs for calculating absorbed-dose distribution in a water target irradiated by proton beams. The spatial pattern of absorbed dose from monoenergetic pencil beams is calculated as a function of the depth in t...

Considerable improvements in the peak-to-background ratio for the detection of 20 MeV monoenergetic protons were achieved with pulse-shape discrimination techniques by selecting a centain rise time range. A discussion of the results is given. (auth)

... Accession Number : ADA052545. Title : Stochastic Acceleration of Solar Flare Protons. Descriptive Note : Technical rept.,. ...

Some personal recollections are presented that relate to the author's experience developing linear accelerators, particularly for protons. (LEW)

Some personal recollections are presented that relate to the author's experience developing linear accelerators, particularly for protons. (LEW)

Some personal recollections are presented that relate to the author`s experience developing linear accelerators, particularly for protons. (LEW)

... Pagination or Media Count : 9. Descriptors : *ION SOURCES, USSR, TRANSLATIONS, PROTON ACCELERATORS, PATENTS, INJECTORS. ...

Proton-driven fast ignition has been proposed as an alternate FI-scheme shortly after the discovery of high-current, high-energy laser-accelerated protons from the LLNL PW laser [1,2]. The demonstration of other laser-accelerated ion species [2], including mono-energetic light ions, has ...

The Berkeley Accelerator Space Effects (BASE) Facility provides heavy ions and protons for radiation effects testing by government laboratories (Defense, Energy and NASA) and contractors, private U.S. companies and international companies and laboratories. The combination of state-of-the-art ion sources for heavy ion running and relatively high intensities ...

A high-intensity subkilovolt x-ray calibration source utilizing proton-induced inner-shell atomic fluorescence of low-Z elements is described. The high photon yields and low bremsstrahlung background associated with this phenomenon are ideally suited to provide intense, nearly monoenergetic x-ray beams. The proton ...

A Thomson parabola ion spectrometer (TPIS) has been designed and built to study energetic ions accelerated from the rear surface of targets irradiated by ultra-intense laser light from the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE). The device uses a permanent magnet and a pair of electrostatic deflector plates to produce parallel magnetic ...

A method is described for increasing the intensity of accelerated light-nucleus beams in linear proton accelerators. To attain such increase, the fore-injector of the LU-20 linear proton accelerator, which is the injector of the synchrophasotron of the Jo...

The rapid progress in the field of laser particle acceleration has stimulated a debate about the promising perspectives of laser based ion beam sources. For a long time, the beams produced exhibited quasi-thermal spectra. Recent proof-of-principle experiments demonstrated that ion beams with narrow energy distribution can be generated from special target geometries. However, ...

Recent simulations show that an idealized, high intensity, short pulse laser can generate quasi-monoenergetic proton beams with energies over 100 MeV in an interaction with a thin film. However, most short pulse laser facilities with sufficient intensity have difficulty controlling the nanosecond and picosecond contrast necessary to realize such a regime. ...

Recent simulations show that an idealized, high intensity, short pulse laser can generate quasi-monoenergetic proton beams with energies over 100 MeV in an interaction with a thin film [1]. However, most short pulse laser facilities with sufficient intensity have difficulty controlling the nanosecond and picosecond contrast necessary to realize such a ...

The nature of particles producing two visible auroras at Fort Churchill, Canada, was determined with the aid of rocket-borne detectors. Magnetic fields were used to separate the proton and electron components of the particle flux. It was found in each case that a major fraction of the auroral light was produced by electron with energies of less than 10 kev. IGY ...

... MEASUREMENT, PARTICLE ACCELERATOR TARGETS, LIQUEFIED GASES, HELIUM, CARBON, ANTIPARTICLES, PROTON CROSS ...

The usable range of thickness for the solid lithium target in the accelerator-based neutron production for BNCT via the near-threshold (7)Li(p,n)(7)Be reaction was investigated. While the feasibility of using a (7)Li-target with thickness equal to that which is required to slow down a mono-energetic 1.900 MeV incident proton to the ...

The usable range of thickness for the solid lithium target in the accelerator-based neutron production for BNCT via the near-threshold 7Li(p,n)7Be reaction was investigated. While the feasibility of using a 7Li-target with thickness equal to that which is required to slow down a mono-energetic 1.900 MeV incident proton to the 1.881 MeV ...

... The identification of alpha particles with the aid of ... Descriptors : (*PARTICLE ACCELERATORS, OPERATION), (*PROTON ACCELERATORS ...

Self-injection and acceleration of monoenergetic electron beams from laser wakefield accelerators are first investigated in the highly relativistic regime, using 100 TW class, 27fs laser pulses. Quasi-monoenergetic multi-bunched beams with energies as high as multi-hundred MeV are observed with simultaneous ...

Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the ...

The aim of the Radiological Research Accelerator Facility (RARAF) was to provide a source of monoenergetic neutrons for studies in radiation biology, dosimetry and microdosimetry. The research has provided insight into the biological action of radiation a...

Chinese hamster cells (V79) in culture under oxic and hypoxic conditions were irradiated with several neutron beams spanning a wide energy range to determine the oxygen enhancement ratio (OER). Eight essentially monoenergetic neutron beams, ranging from 0.22 to 13.6 MeV and a 0.11-MeV neutron spectrum, were produced at the Radiological Research Accelerator ...

Chinese hamster cells (V79) in culture under oxic and hypoxic conditions were irradiated with several neutron beams spanning a wide energy range. Eight essentially monoenergetic neutron beams, ranging from 0.22 to 13.6 MeV and a 0.11 MeV neutron spectrum, were produced at the Radiological Research Accelerator Facility (RARAF) at Brookhaven National ...

High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser ...

High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 1019Wcm-2 at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and ?-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it ...

A biodosimetry method, based on estimation of an absorbed dose on the basis of assessment of unstable aberration frequency in the lymphocytes of human's peripheral blood is used broadly in ground conditions for analysis of accidental exposure to personal and citizens. A calibration curve giving the relationship between aberration frequency (generally dicentrics and centric rings) and an absorbed ...

Spacecraft observations in the inner heliosphere offer the first opportunity to measure 1-10 MeV solar neutrons. We discuss the cross sections for neutron production in solar flares and calculate the escaping neutron spectra for monoenergetic and power law particle spectra at the Sun and at the distance (0.48 AU) and observation angle of MESSENGER at the time of its reported ...

A derivation is given of an empirical formula for the energy spectrum of protons leaving the surface of a fastneutron-irradiated hydrogenous material, as a function of material constants and the incident neutron spectrum. The result derived is general and includes as a special case the well-known formula by Moyer for total number of protons. A ...

The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a spallation neutron source based on a 500-MeV proton accelerator operating at 30 Hz and with an average proton current of approx. 10 ..mu..A. Neutron-scattering instruments for elastic scattering include two powder diffractometers, a single-crystal ...

Single crystals of sodium chloride were bombarded with 1--2-MeV protons from a Van de Graaff accelerator at low temperature (77 K) and at room temperature. In the case of low temperature, a layered structure was found to be developed within the irradiated part of the crystal. This was indicated by the color-center formation. The color-center distribution ...

The experimental data of neutron transmission through concrete shield of thickness up to 200cm are compiled. The measurements have been conducted by using the quasi-monoenergetic neutron sources of 43- and 68-MeV p-(sup 7)Li reactions at the TIARA Facilit...

Experimental and analytical techniques are described which permitted recalibration of the P-2 chamber's monoenergetic sensitivity based upon combined responses from a set of bremsstrahlung measurements, monoenergetic isotopic source measurements, and a monoenergetic gamma radiation produced by inelastic ...

The Ion Cyclotron Resonance Accelerator (ICRA) uses the operating principles of cyclotrons and gyrotrons. The novel geometry of the ICRA allows an ion beam to drift axially while being accelerated in the azimuthal direction. Previous work on electron cyclotron resonance acceleration used waveguide modes to ...

Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the {sup 11}B(p,{gamma}){sup 12}C reaction to produce 12 MeV gamma-rays which are near the peak of the ...

Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross ...

Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,?)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross ...

A description of an atomic beam formed by vaporizing an electrostatically accelerated high velocity pellet is given. Uniformly sized droplets of neon will be formed by the mechanical disintegration of liquid jet and frozen by adiabatic vaporization in vacuum. The pellets produced will be charged and accelerated by contacting a needle held at high ...

Using multidimensional particle-in-cell simulations we study ion acceleration from a foil irradiated by a circularly polarized laser pulse at 10;{22} W/cm;{2} intensity. When the foil is shaped initially in the transverse direction to match the laser intensity profile, three different regions (acceleration, transparency, and deformation region) are ...

The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of ...

A monoenergetic proton beam is observed from the interaction of a short-pulse infrared (? = 10.6 ?m) laser at intensity I = 6 � 1015 W cm-2 with a gas jet target. The proton beam is found to have narrow energy spread (~ 4% ), high spectral brightness (~ 1012 protons/MeV/sr), low normalized emittance (?n ~ 8 nm ...

pulse propagation Tomography of the transverse laser beam profile along the laser propagation directionx10 cm19 -3 5.5x10 cm19 -3 6x10 cm19 -3 electron beam profile 5 mm plasma density The monoenergetic beampump beam mfocal spot (FWHM) 40 mm40 mmbeam size pulse duration (FWHM) 230 mJenergy laser parameters

/5 of the initial hydrogen atom density. There- FIG. 2. a Setup of the machining beam. b Working principle Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan 2 Department of Physics deceleration is observed for the monoenergetic electron bunch after it reaches the maximum energy. The results

An ultracompact laser-plasma-generated, fs-scale electron double bunch system can be injected into a high-density driver/witness-type plasma wakefield accelerator afterburner stage to boost the witness electrons monoenergetically to energies far beyond twice their initial energy on the GeV scale. The combination of conservation of ...

The cyclotron-based fast neutron source at NPI produces mono-energetic neutron fields up to 35 MeV neutron energy using the p + 7Li(carbon backing) reactions. To be applied for activation cross-section measurements, not only the intensity of neutron peak, but also the contribution of low-energy continuum in the spectra must be well determined. Simulations of the spectral flux ...

In the few-MeV energy range below the (p,n) threshold, gamma rays are produced from proton bombardment of aluminum via the 27Al(p,p'/?)27Al, 27Al(/p,?,?)24Mg, and 27Al(/p,?)28Si reactions. Thick-target /?-ray yield data are important for various applications, including radiation shielding near accelerators and /?-ray background interference in experiments ...

A detailed study of the biological effects of diverse quality radiations, addressing their biophysical interpretation, is presented. Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon and oxygen ions and for CHO cells irradiated by carbon ions have been analysed using the probabilistic two-stage model of cell ...

When the authors first proposed an accelerator-driven reactor, the concept was opposed by physicists who had earlier used the accelerator for their physics experiments. This opposition arose because they had nuisance experiences in that the accelerator was not reliable, and very often disrupted their work as the ...