BackgroundRadiation therapy after lumpectomy is a standard part of breast conserving therapy for invasive breast carcinoma. The most frequently used schedule worldwide is 60 Gy in 30 fractions in 6 weeks, a time commitment that sporadically may dissuade some otherwise eligible women from undertaking treatment. The purpose and primary endpoint of this perspective study is to evaluate feasibility ...

May 7, 2008 ... The code shown in brackets { } at the beginning of each section indicates which environment, or acceleration regime, is applicable to the ...

May 7, 2008 ... The code shown in brackets { } at the beginning of each section indicates which environment, or acceleration regime, is applicable to the ...

A hypofractionation treatment protocol for prostate cancer was initiated in our department in December 2003. The treatment regimen consists of a total dose of 36.25 Gy delivered at 7.25 Gy per fraction over 10 days. We discuss the rationale for such a prostate hypofractionation protocol and the need for frequent prostate imaging during treatment. The ...

Radiobiological data suggest that prostate cancer has a low {alpha}/{beta} ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated ...

The longitudinal particle dynamics in a linear accelerator in the acceleration regime of two waves with multiple frequency without regard for space charge is considered. The accelerating structure of a cavity resonator with 100 MeV drift tubes of is chose...

Early breast cancer incidence increases owing to mammography screening. Hypofractionated radiotherapy is more and more proposed in women with low local relapse risk breast cancer, especially accelerated partial breast irradiation. Various irradiation modalities have been reported: brachytherapy, intraoperative irradiation, 3D-conformal ...

Proton beams can provide better dose conformity to the treatment target compared to commonly used photon and electron beams allowing for dose escalation and/or hypofractionation to increase local tumor control, reduce normal tissue complications and/or treatment time/cost. This paper reviews three novel proton accelerator designs that aim at cost-effective ...

Purpose: Dose escalation for prostate cancer improves biological control but with a significant increase in late toxicity. Recent estimates of low {alpha}/{beta} ratio for prostate cancer suggest that hypofractionation may result in biological advantage. Intensity-modulated radiotherapy (IMRT) should enable dose escalation to the prostate while reducing toxicity to local ...

... Accession Number : ADA221755. Title : Stability Regimes in a Helical Quadrupole Focusing Accelerator - Theory and Simulation. ...

BackgroundRecently, the use of hypo-fractionated treatment schemes for the prostate cancer has been encouraged due to the fact that ?/? ratio for prostate cancer should be low. However a major concern on the use of hypofractionation is the late rectal toxicity, it is important to be able to predict the risk of toxicity for alternative treatment schemes, ...

Purpose: To investigate the tumor control rates in locally advanced head-and-neck cancer using accelerated hypofractionated radiotherapy with chemotherapy. Methods and Materials: The data from patients with squamous cell cancer of the larynx, oropharynx, oral cavity, and hypopharynx (International Union Against Cancer Stage II-IV), who received ...

The success of stereotactic radiosurgery has stimulated significant interest in the application of such an approach for the treatment of extracranial tumors. The potential benefits of reduced healthcare costs and improved patient outcomes that could be realized in a high-precision, hypofractionated treatment paradigm are numerous. Image-guidance technologies are eliminating ...

The dosimetric consequences of plans optimized using a commercial treatment planning system (TPS) for hypofractionated radiation therapy are evaluated by re-calculating with Monte Carlo (MC). Planning guidelines were in strict accordance with the Canadian BR25 protocol which is similar to the RTOG 0236 and 0618 protocols in patient eligibility and total dose, but has a ...

The transverse expansion of a thin foil accelerated in the RPDA regime can be exploited in order to increase the ion energy and the acceleration efficiency at the expense of decreasing the number of accelerated particles. In the relativistic regime, the ions become phase-locked with respect to ...

To extend the scope of physics experiments the EhGP-10M accelerator is switched on to pulse operation. Specifications of the nanoseocnd duration pulse shapers are given, so are the results of accelerator pulse regime study. The source of the negatively ch...

A similarity theory is developed for ultra-relativistic laser-plasmas. It is used to compare and optimize possible regimes of three-dimensional wake field acceleration. The optimal scalings for laser wake field electron acceleration are obtained analytically. The main message of the present work is that the bubble ...

Purpose: To evaluate the toxicity of pelvic intensity-modulated radiotherapy (IMRT) with hypofractionated simultaneous integrated boost (SIB) to the prostate for patients with intermediate- to high-risk prostate cancer. Methods and Materials: A retrospective toxicity analysis was performed in 30 consecutive patients treated definitively with pelvic SIB-IMRT, all of whom also ...

A method of hypofractionated accelerated radiotherapy (3 weekly fractions of 6 Gy over 2 weeks to a total tumor dose of 36 Gy) was used as single modality in 14 patients with osteogenic sarcoma for palliative treatment of the primary tumor site (six cases) or skeletal metastases (15 sites). A durable response, radiologically assessed, was obtained in 17 of ...

Intrinsic radioresistance, tumor hypoxia and ability of cancer cells to undergo rapid repopulation during radiotherapy are associated with failure of radiotherapy. Tumors with low alpha/beta-ratio values or hypoxic tumors unable to undergo re-oxygenation, are unlikely to be eradicated with standard radiotherapy. Although the therapeutic efficacy of accelerated regimens based ...

BackgroundAccelerated hypofractionation is an attractive approach for adjuvant whole breast radiotherapy. In this study we evaluated the adverse effects at least 3 years post an accelerated hypofractionated whole breast radiotherapy schedule.MethodsFrom October 2004 to March 2006, 39 consecutive patients aged over ...

This paper reports that to simulate the flight regime of a transatmospheric vehicle such as the National Aero-space Plane, the magnetohydrodynamic accelerator-assisted wind tunnel concept is the most promising technology.

Electron and laser beam interaction in the field of a profiled ondulator is theoretically calculated. Electron capture in the acceleration regime is shown to take place when complying with the conditions of interaction synchronism. Expressions for acceler...

Modern breast cancer radiotherapy aims to increase uncomplicated cure rates. A priority is reduction of late effects which include chronic chest wall or breast pain, poor cosmesis, and cardiac toxicity. As breast screening detects early cancers we may be able to safely restrict irradiation postlumpectomy to the tumour bed with a margin, defining a 'partial breast' target volume for treatment. ...

... a micronozzle orifice (d = 200 micrometers) accelerates nanocrystals through a ... regimes of deposition that depend on the nanocrystal's energy per ...

... accelerated the development of aircraft in this speed regime. At the same time that speed was being improved, so was the carrying capacity of aircraft. ...

The aim is to demonstrate the potential impact of changes in the value of the ? parameter in the linear quadratic (LQ) model on the calculation of clinical relative biological effectiveness (RBE) values used for high linear energy transfer (LET) radiotherapy. The parameter RBEmin is introduced into the LQ formulation to account for possible changes in the ? radiosensitivity coefficient with ...

Hyperfractionation and hypofractionation combined with acceleration have been investigated in stage I-III NSCLC patients. In stage I tumors, hypofractionated radiation schedules given with highly conformal stereotactic body radiotherapy (SBRT) techniques have been proven safe and effective with local control rates > 85% and ...

... Title : Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed after Segmental Mastectomy. Descriptive Note : Final addendum rept. ...

... Title : Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy. Descriptive Note : Final rept. ...

... Title : Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy. Descriptive Note : Final rept. ...

... Title : Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed after Segmental Mastectomy. Descriptive Note : Annual rept. ...

... Title : Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy. Descriptive Note : Annual rept. ...

Proton beams are more advantageous than high-energy photons and electrons for radiation therapy because of their finite penetrating range and the Bragg peak near the end of their range, which have been utilized to achieve better dose conformity to the treatment target allowing for dose escalation and/or hypofractionation to increase local tumor control, reduce normal tissue ...

? Breast conservation is a safe and effective alternative to mastectomy for the majority of women with early-stage breast cancer. Adjuvant radiation therapy lowers the risk of recurrence within the breast and also confers a survival benefit. Although acute side effects of radiation therapy are generally well tolerated; efforts are ongoing to minimize the long-term side effects of radiation, most ...

Theory is developed to estimate the effect of free surface proximity on the initial added mass of a sphere accelerated vertically upward from rest in an ideal fluid. It is assumed that the acceleration regime is sufficiently brief that inertial forces pre...

To provide for designed operating regimes of the EGP-15 accelerator it is necessary that the charging system provided for short circuit current of no lower than 300 (mu)A not appear to be the source of the accelerator high-voltage structure contamination ...

The problem of three-component ring accelerator and the regime choice under the condition of light ion acceleration in a more effective way are considered. The values of the ring loading with nitrogen and hydrogen ions when a heavy component is spilled ou...

Because accelerators, like reactors, can be used to produce special nuclear material, their key components must be controlled. This work identifies the key components of linear accelerators (LINACs) that are critical in the export control regime. The design of LINACs is well documented and easily available to the general public. ...

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 ...

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 ...

Radiotherapy (RT) after tumorectomy in early breast cancer patients is an established treatment modality which conventionally takes 6-7 wk to complete. Shorter RT schedules have been tested in large multicentre randomized trials and have shown equivalent results to that of standard RT (50 Gy in 25 fractions) in terms of local tumor control, patient survival and late post-radiation effects. Some of ...

Radiotherapy (RT) after tumorectomy in early breast cancer patients is an established treatment modality which conventionally takes 6-7 wk to complete. Shorter RT schedules have been tested in large multicentre randomized trials and have shown equivalent results to that of standard RT (50 Gy in 25 fractions) in terms of local tumor control, patient survival and late post-radiation effects. Some of ...

There is a clear dose response for localized prostate cancer radiotherapy and there probably is a radiobiological rationale for hypo-fractionation. Combining the two should maximize tumor control and increase the therapeutic ratio. This study examines the rationale and technical feasibility of CyberKnife radiotherapy (a robotic arm-driven linear ...

Purpose: To evaluate the efficacy and toxicity of hypofractionated conventional conformation radiotherapy (HCCRT) with noninvasive fixation of the skull on patients with single or several brain metastases. Methods and Materials: The subjects were 44 patients who had three or fewer brain metastases (26 solitary, 18 multiple). Treatment was conducted on 65 metastases by ...

Electron acceleration in plasma driven by circular polarized ultraintense laser with asymmetric pulse are investigated analytically and numerically in terms of oscillation-center Hamiltonian formalism. Studies include wakefield acceleration, which dominates in blow-out or bubble regime and snow-plow acceleration ...

Recent clinical trials of hypofractionated radiation treatment have provided critical insights into the safety and efficacy of hypofractionation. However, there remains much controversy in the field, both at the level of clinical practice and in our understanding of the underlying radiobiological mechanisms. In this article, we review the clinical ...

Radiation Pressure Acceleration (RPA) by circularly polarized laser pulses is emerging as a promising way to obtain efficient acceleration of ions. We briefly review theoretical work on the topic, aiming at characterizing suitable experimental scenarios. We discuss the two reference cases of RPA, namely the thick target (�Hole Boring�) and the ...

Purpose: Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with ...

Purpose: To evaluate the acute toxicities of hypofractionated accelerated radiotherapy (RT) using a concomitant intensity-modulated RT boost in conjunction with elective pelvic nodal irradiation for high-risk prostate cancer. Methods and Materials: This report focused on 66 patients entered into this prospective Phase I study. The eligible patients had ...

The dynamics of a quantum particle bound by an accelerating delta-functional potential is investigated. Three cases are considered, using the reference frame moving along with the ?-function, in which the acceleration is converted into the additional linear potential. (i) A stationary regime, which corresponds to a resonance state, ...

Various subgroups of breast tumours have been identified during the last 10 years according to the risk of local relapse. Prognostic factors for local relapse are age, surgical margins, tumour size, Her2 expression and hormonal receptors status. For tumours with a high risk of local relapse, an increased in boost dose or the addition of new drugs (trastuzumab, antiangiogenics, PARP inhibitors) ...

The dynamics of the ions and neutral particles of a multicomponent plasma in an accelerator with closed electron drift orbits and an extended acceleration zone is analyzed in the kinetic approximation. Reactions induced by electron impact are taken into account. The electron temperature is calculated in the hydrodynamic approximation. Boundary conditions ...

INTRODUCTION:: Radiotherapy (RT) for bladder cancer is as an effective alternative of cystectomy. Although rapid cancer clonogen repopulation contributes to radio-resistance, accelerated RT schemes based on ?2 Gy fractions have failed to improve results. We suggest that accelerated hypofractionation (HypoARC) may be more effective, as ...

... a high quality data set in the wave regime where both the velocity and the acceleration-dependent components of the wave forces are important. ...

The relativistic motion of an ensemble of electrons in an intense monochromatic electromagnetic wave

Pool heating of liquid hydrogen, assessing multigravity effects on boiling and supercritical heating

Pool heating of liquid hydrogen, assessing multigravity effects on boiling and supercritical heating

Experimental results on the distribution of radiation fields along the booster injector - linear accelerator with HF-focusing are presented and analysis of secondary radiation parameter connection with accelerator regime is given. A dependence of neutron ...

This note describes a simple model developed to explore some of the properties of the pulse-line ion accelerator, here represented as a series of lumped elements, in the general parameter regime for the 'NDCX-1d' experiments. The goals of this modeling ar...

A number of high current accelerator designs utilize strong focusing in the form of helical quadrupole and axial guide fields. We obtain a linear dispersion relation for an electron beam propagating in a cylindrical waveguide subject to helical quadrupole...

We investigate the conditions required for the production of electron-positron pairs above a pulsar polar cap (PC) and the influence of pair production on the energetics of the primary particle acceleration. Assuming space-charge limited flow acceleration...

In the usual parameter regime of accelerator physics, particle ensembles can be treated as classical. In particular, we have to consider the Pauli exclusion principle, which will limit the minimum achievable emittance for a beam of fermions. We calculate ...

Described are the results of the experiments with the plasma gun used as a source of the atom pulse flow for ion loading of the compressed electron ring in a collective heavy ion accelerator. Two operating regimes of the plasma gun have been studied: with...

New regime of particle acceleration in the central region of the JINR phasotron is generated. The purpose of the investigation was to find parameters of the magnetic and accelerating fields which would increase the longitudinal and transversal stability o...

In conjunction with ongoing high-current experiments on Sandia National Laboratories' Z accelerator we have revisited a problem first described in detail by Heinz Knoepfel. MITLs of previous pulsed power accelerators have been in the 1-Tesla regime. Z's d...

We revise the physics of primary electron acceleration in the 'slot gap' (SG) above the pulsar polar caps (PCs), a regime originally proposed by Arons and Scharlemann (1979) in their electrodynamic model of pulsar PCs. We employ the standard definition of...

Cryogenic linear accelerator structures have high rf efficiency due to reduced resistivity and high heat transfer capability from the boiling heat transfer regime. Finite-element transient heat transfer and thermal stress analysis is used to simulate the ...

Excitation and suppression of zero-frequency cyclotron waves on a relativistic electron beam in a parameter regime appropriate to autoresonant collective ion acceleration are examined through numerical simulation. The excitation mechanism considered is th...

Thermal conditions of foil of axial-symmetrical window for electron accelerator for two current density distributions in a beam were determined. Limiting frequences for different thermal conditions in foil were determined as well as pulse duration value t...

A toroidal trap combined with external time-dependent electric field can be used for implementing different dynamical regimes of matter waves. In particular, we show that dynamical and stochastic acceleration, localization, and implementation of the Kapitza pendulum can be originated by means of proper choice of the external force.

Relativistic electrons can be accelerated by an ultraintense laser pulse in the "supra-bubble" regime, that is, in the blow-out regime ahead of the plasma bubble (as opposed to the conventional method, when particles remain inside the bubble). The acceleration is caused by the ponderomotive force of the pulse, via ...

Relativistic electrons can be accelerated by an ultraintense laser pulse in the "supra-bubble" regime, that is, in the blow-out regime ahead of the plasma bubble (as opposed to the conventional method, when particles remain inside the bubble). The acceleration is caused by the ponderomotive force of the pulse, via ...

Generation of accelerating plasma waves using two counter-propagating laser beams is considered. Colliding-beam accelerator requires two laser pulses: the long pump and the short timing beam. We emphasize the similarities and differences between the conventional laser wakefield accelerator and the colliding-beam ...

Generation of accelerating plasma waves using two counter-propagating laser beams is considered. Colliding-beam accelerator requires two laser pulses: the long pump and the short timing beam. We emphasize the similarities and differences between the conventional laser wakefield accelerator and the colliding-beam ...

We study the quantum dynamics of a material wave packet bouncing off a modulated atomic mirror in the presence of a gravitational field. We find the occurrence of coherent accelerated dynamics for atoms beyond the familiar regime of dynamical localization. The acceleration takes place for certain initial phase-space data and within ...

Waves in plasmas can accelerate particles that are resonant with the wave. A dc electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. Whereas wave-particle acceleration mechanisms have been widely discussed in the literature, ...

Waves in plasmas can accelerate particles that are resonant with the wave. A dc electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. Whereas wave-particle acceleration mechanisms have been widely discussed in the literature, ...

The absorption of an ultra-intense circularly-polarized laser pulse by a near-critical (0.1nc < ne < a0nc) plasma is studied. Previously two regimes of absorption have been suggested: a 'leading edge depletion' (LED) regime and a 'transverse ponderomotive acceleration' regime. Here we seek to describe these ...

It has been pointed out that the Newtonian second law can be tested in the very small acceleration regime by using the combined movement of the Earth and Sun around the Galactic center of mass. It has been shown that there are only two brief intervals during the year in which the experiment can be completed, which correspond to only two specific spots on ...

The current trial tests a regimen of conformal hypo-fractionated radiotherapy (5 fractions) directed to the original tumor bed with margins in a selected subset of post- menopausal women with breast cancer with a very low risk for local recurrence elsewhe...

This IDEA grant proposal tested the feasibility of a regimen of conformal hypo-fractionated radiotherapy (5 fractions in 2 weeks) directed to the original tumor bed with margins in a selected subset of post-menopausal women with breast cancer with a very ...

This trial tests a regimen of prone conformal hypo-fractionated radiotherapy directed to the original tumor bed with margins in a selected subset of post-menopausal women with breast cancer with a very low risk for local recurrence elsewhere in the breast...

The aim is to demonstrate the potential impact of changes in the value of the ? parameter in the linear quadratic (LQ) model on the calculation of clinical relative biological effectiveness (RBE) values used for high linear energy transfer (LET) radiotherapy. The parameter RBE(min) is introduced into the LQ formulation to account for possible changes in the ? radiosensitivity coefficient with ...

Purpose: To investigate predictors for gastrointestinal (GI) and genitourinary (GU) acute toxicity after a short-course hypofractionated radiotherapy regimen for prostate cancer. Materials and Methods: Three institutions included 102 patients with T1-T3N0M0 prostate cancer in a Phase II study. Patients were treated with 56 Gy in 16 fractions over 4 weeks. Acute toxicity was ...

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 ...

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 ...

... Doses to the heart and lungs vere ciinicallv insignificant. ... The lung and heart were spared by reating in the prone position. ...

... of a preexisting physical disability (hemiparesis due to a ... phisms with radiation-induced damage to normal tissues in ...

A disk-loaded waveguide (DLW) is the most common structure for compact linear accelerators working in a traveling wave (TW) regime. Among its advantages are high shunt impedance and manufacturing simplicity. The other popular structure is an on-axis coupled bi-periodical accelerating structure (BAS) that works in standing wave (SW) ...

Purpose: Local tumor recurrence remains a major problem in patients with inoperable non-small-cell lung cancer undergoing radiotherapy. We investigated the theoretical gain in the estimated tumor control probability (TCP) using an individualized maximal tolerable dose (MTD) prescription, for both conventional and accelerated fractionation schemes. Methods and Materials: For 64 ...

Performance in circular accelerators can be limited by some of the same sorts of phenomena described by Miller and Wangler in their lectures on low energy behavior in linear accelerators. In general the strength of the perturbation required to degrade performance is reduced in circular accelerators due to the repetitive nature of the ...

Several accelerator-based neutron capture therapy applications are under development. These applications include boron neutron capture therapy for glioblastoma multiform and boron neutron capture synovectomy (BNCS) for rheumatoid arthritis. These modalities use accelerator-based charged-particle reactions to create a suitable neutron source. Neutrons are ...

A new operating mode of the plasma wakefield accelerator is found at which high efficiency of the driver-to-witness energy exchange can be achieved simultaneously with high transformer ratio and low energy spread. The efficient acceleration is realized in the blowout regime with a high-current moderate-length driver, if most of the ...

Plasma wakefield acceleration of positron beams in the wake of a dense electron beam (in the blowout regime) is numerically analyzed. The acceleration is possible only if the energy content of the wakefield is not very high. This is in contrast to electron acceleration, for which the optimum performance requires ...

The 'four Rs' of radiobiology play an important role in the design of radiation therapy treatment protocol. The purpose of this work is to explore their influence on external beam radiotherapy for fast and slowly proliferating tumors and develop an optimization framework for tumor-biology specific dose-time-fractionation scheme. The linear quadratic model is used to describe ...

The nonlinear evolutions of the Rayleigh-Taylor instability (RTI) with preheat is investigated by numerical simulation (NS). A new phase of the spike deceleration evolution in the nonlinear ablative RTI (ARTI) is discovered. It is found that nonlinear evolution of the RTI can be divided into the weakly nonlinear regime (WNR) and the highly nonlinear regime ...

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 measurements of ...

In the middle of 1980th, the VpxB concept for accelerating electrons are found by Nishida et al, with the use of plasma wave excited by high power microwave in the interaction with weakly magnetized plasma. This acceleration concept was called 'Surfatron effect' in the relativistic regime. However, there is no ...

The ion response to relativistic electron bunches in the so called bubble or blowout regime of a laser-plasma accelerator is discussed. In response to the strong fields of the accelerated electrons the ions form a central filament along the laser axis that can be compressed to densities 2 orders of magnitude higher than the initial ...

Kinetic simulations of break-out-afterburner (BOA) ion acceleration from nm-scale targets are examined in a longer pulse length regime than studied previously. It is shown that when the target becomes relativistically transparent to the laser, an epoch of dramatic acceleration of ions occurs that lasts until the electron density in the ...

Numerical simulations of spontaneous flame acceleration are performed within the problem of flame transition to detonation in two-dimensional channels. The acceleration is studied in the extremely wide range of flame front velocity changing by 3 orders of magnitude during the process. Flame accelerates from realistically small initial ...

Numerical simulations of spontaneous flame acceleration are performed within the problem of flame transition to detonation in two-dimensional channels. The acceleration is studied in the extremely wide range of flame front velocity changing by 3 orders of magnitude during the process. Flame accelerates from realistically small initial ...

The energy of ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced due to a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region resulting in an increase in the ion energy and in the ion longitudinal ...

The energy of ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced due to a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region resulting in an increase in the ion energy and in the ion longitudinal ...

The energy of ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced due to a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region resulting in an increase in the ion energy and in the ion longitudinal ...

The trapping of thermal electrons in a nonlinear plasma wave of arbitrary phase velocity is investigated. The threshold plasma wave amplitude for trapping plasma electrons is calculated, thereby determining the fraction trapped and the expected dark current in a plasma-based accelerator. It is shown that the presence of a laser field (e.g., trapping in the self-modulated ...

The trapping of thermal electrons in a nonlinear plasma wave of arbitrary phase velocity is investigated. The threshold plasma wave amplitude for trapping plasma electrons is calculated, thereby determining the fraction trapped and the expected dark current in a plasma-based accelerator. It is shown that the presence of a laser field (e.g., trapping in the self-modulated ...

Formulas are given which take into account the effect of the electric field component normal to the trajectories on the phase shifts of the ions accelerated in the cyclotron. The region is specified for the applicability of the general solution of the horizontal motion equations. It is shown that at the center of the cyclotron it is possible to turn the direction of ...

The article presents the results of normal and accelerated corrosion tests of zinc and cadmium coatings obtained from cyanous, acid, and urotropin electrolytes. It suggests a classification of climate from the point of view of its effect on the corrosion of metallic materials. It demonstrates the possibility of predicting atmospheric corrosion and establishing the service life ...

Accelerator-driven High-Energy Density Physics (HEDP) experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the 'warm dense matter' regime. Traditional...

The current loading in a bunching section with constant structure is considered, when a strong electron phase space motion occurs during the acceleration process. The beam effect was calculated using a self-consistent description of the particle dynamics in a field representing the superposition of the field of the external generator and those generated by the beam particles. ...

The author looks at instability affects in the magnetopause, when it is acted upon by pressure pulses from the solar wind, which can result in accelerated motion of the magnetopause in either direction. In the time period of this acceleration, assuming its sense is such as to cause instability growth, Kelvin-Helmholz effects can be observed to move into ...

Acceleration of the universe is obtained from a model of non-relativistic particles with a short-range attractive interaction, at low enough temperature to produce a Bose-Einstein condensate. Conditions are derived for negative-pressure behavior. In particular, we show that a phantom-accelerated regime at the beginning of the universe ...

The Pulse Line Ion Accelerator concept was motivated by the desire for an inexpensive way to accelerate intense short pulse heavy ion beams to regimes of interest for studies of High Energy Density Physics and Warm Dense Matter. A pulse power driver applied at one end of a helical pulse line creates a traveling wave pulse that ...

Batteries for solar photovoltaic applications and other terrestrial applications require long life in daily cycling regimes. There is a need to develop testing procedures to accelerate aging of electrochemical cells so that cycle life data can be acquired in less time than real time testing would require. The initial emphasis has been on lead-acid type ...

We review basic constraints on the acceleration of ultra-high-energy (UHE) cosmic rays (CRs) in astrophysical sources, namely, the geometric (Hillas) criterion and the restrictions from radiation losses in different acceleration regimes. Using the latest available astrophysical data, we redraw the Hillas plot and find potential UHECR ...

The authors study the feasibility of and establish the requirements for using an explosive-magnetic generator as a power source for a railgun accelerator. They determine the dependence of the generator inductance on the coordinates such as to provide constant acceleration motion. They construct single and three-element plane MK generators which are able to ...

The RADLAC program encompasses high power electron beam propagation experiments and accelerator development, both for advanced propagation experiments and to develop compact accelerator options for future charged particle beam weapons (CPBW). Propagation experiments include conditioning cell and lead pulse stability (LPS) experiments on RADLAC II, and ...

Waves in plasmas can accelerate particles that are resonant with the wave. A DC electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. We investigate the effect on a Hamiltonian distribution of an accelerating potential ...

The plasma density effect on x-ray characteristics from betatron oscillation in a laser wakefield accelerator was studied via two-dimensional particle-in-cell simulations. Inside an ion cavity, accelerated electrons with betatron oscillatory motion produce synchrotron radiation. As the plasma density increases, both bunch charge and betatron oscillation ...

The authors explore the multidimensional space of beam parameters, looking for preferred regions of operation for a e{sup +}e{sup {minus}} linear collider at 5 TeV center of mass energy. Due to several major constraints such a collider is pushed into certain regime of high beamstrahlung parameters, {Upsilon} regime is examined with IP simulations using the ...

A new laser-plasma ion acceleration mechanism, snowplow ion acceleration, is proposed using an ultra-relativistically intense laser pulse irradiating on a combination target. When the thickness of the foil D is less than the length where the double-layer consisting of electron and ion layers is formed, the relativistic ion beam ...

The kV cone beam CT (CBCT) consists of an X-ray tube and a flat panel detector placed perpendicularly to the treatment beam, allowing the acquisition of hundreds of projections in one rotation of the gantry about the patient. Available in all new linear accelerators, the CBCT provides volumetric imaging in treatment position proving the realization of image- and dose-guided ...

The effect of radiation protraction in step-and-shoot IMRT is investigated for treatment plans created with the help of direct aperture optimization. The latter approach can be used during inverse planning for all clinical linear accelerators with conventional MLC. Direct aperture optimization significantly shortens fraction time for IMRT plans as compared to that for plans ...

The late radiation change observed in 15 patients treated for carcinoma of oral cavity or oropharynx using continuous hyperfractionated accelerated radiotherapy (CHART) was compared to that seen in 15 similar patients treated with conventional radiotherapy. The average follow up was, 31 and 33 months, respectively. A new dictionary for the recording of radiation morbidity, ...

The energy of the ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced by a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region increasing the energy and the longitudinal velocity of the remaining ions. ...

The energy of the ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced by a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region increasing the energy and the longitudinal velocity of the remaining ions. ...

The spin-dependent inertial force in an accelerating system under the presence of electromagnetic fields is derived from the generally covariant Dirac equation. Spin currents are evaluated by the force up to the lowest order of the spin-orbit coupling in both ballistic and diffusive regimes. We give an interpretation of the inertial effect of linear ...

A single quantum system, such as the Unruh-DeWitt detector, can be used to determine absolute acceleration by local measurements on a quantum field. To show this, we consider two kinematically indistinguishable scenarios: an inertial observer, Bob, measuring the field of a uniformly accelerated cavity, and his noninertial twin, Rob, ...

The correlation functions of velocity and magnetic fluctuations in helical developed MHD turbulence driven by random forces with mixed noise correlators are studied in the quantum field model. The exponential increasing of the magnetic fluctuations is stabilized by spontaneous symmetry breaking mechanism which leads to the creation of homogeneous magnetic field B0. It is well known that the ...

The non-scaling Fixed Field Alternating Gradient (FFAG-from now on) accelerator provides few advantages with respect to the other fixed field accelerators like CYCLOTRONS or scaling-FFAG's. One of the advantages is smaller required aperture due to small orbit offsets during acceleration. The large and heavy magnets are ...

Proton trapping and acceleration by an electron bubble-channel structure in laser interaction with high-density plasma is investigated by using three-dimensional particle-in-cell simulations. It is shown that protons can be trapped, bunched, and efficiently accelerated for appropriate laser and plasma parameters, and the proton ...

Purpose: Despite multimodality treatments, the outcome of patients with glioblastoma multiforme remains poor. In an attempt to improve results, we have begun a program of accelerated hypofractionated intensity-modulated radiotherapy (hypo-IMRT) with concomitant and adjuvant temozolomide (TMZ). Methods and Materials: Between March 2004 and June 2006, 35 ...

Laser plasma accelerators are able to produce high quality electron beams from 1 MeV to 1 GeV. The next generation of plasma accelerator experiments will likely use a multi-stage approach where a high quality electron bunch is first produced and then injected into an accelerating structure. In this paper we present scaled ...

Details on the generation of (multiple) quasimonoenergetic electron bunches in the self-modulated laser wakefield acceleration (SMLWFA) regime are presented. This type of laser-plasma interaction can result in pronounced longitudinal laser pulse fragmentation, dependent on plasma density and laser intensity. It is shown by experiments and particle-in-cell ...

The oscillation-center Hamiltonian is derived for a relativistic electron injected with an arbitrary momentum in a linearly polarized laser pulse propagating in tenuous plasma, assuming that the pulse length is smaller than the plasma wavelength. For hot electrons generated by collisions with ions under an intense laser drive, multiple regimes of ponderomotive ...

LBNL is currently pursuing a collider design based on meter-long 10 GeV laser-plasma accelerator stages, and Thomson gamma source designs at �1 GeV, that will operate in the quasi-linear regime. This regime allows symmetric acceleration of electrons and positrons and has the property that the transverse fields ...

Glass beads are placed in the compartments of a horizontal square grid. This grid is then vertically shaken. According to the reduced acceleration ? of the system, the granular material exhibits various behaviours. By counting the number of beads in each compartment after shaking, it is possible to define three regimes. At low ...

The highly nonlinear evolution of the single-mode Rayleigh-Taylor instability (RTI) at the ablation front of an accelerated target is investigated in the parameter range typical of inertial confinement fusion implosions. A new phase of the nonlinear bubble evolution is discovered. After the linear growth phase and a short constant-velocity phase, it is found that the bubble is ...

The highly nonlinear evolution of the single-mode Rayleigh-Taylor instability (RTI) at the ablation front of an accelerated target is investigated in the parameter range typical of inertial confinement fusion implosions. A new phase of the nonlinear bubble evolution is discovered. After the linear growth phase and a short constant-velocity phase, it is found that the bubble is ...

When the Relativistic Heavy Ion Collider (RHIC) at BNL begins operation in the Fall of 1999, heavy ions will be accelerated in collider mode for the first time, and a new energy regime will be entered for Heavy Ion Physics. The Solenoidal Tracker At RHIC ...

extends up near the 25-30 Hz range. T2 (COLBERT). Qualify - Unisolated. PIMS ISS Acceleration Handbook. Date last modified 12/30/10. Regime: Vibratory ...

... 1) particles are settling without acceleration within a fluid dynamic regime where viscosity dominates (i.e., Re < 0. ... Nestler. 2010. A methodological framework for integrating computational fluid dynam...

Mar 1, 2006 ... Appendix G - Acceleration Regime Applicability for Section 6. Paragraph No, All, Orbital Only, Launch/ ReEntry Only, Planetary Only ...

Radiation damage effects at accelerator-based spallation neutron sources correspond to a new regime, distinct from that encountered at fission reactors. We characterize the radiation environment of a spallation neutron source in some detail, and review th...

The phase stability of bunches accelerated by a magnetron-driven microtron-injector of a terahertz Free Electron Laser (FEL) has been studied to optimize the microtron regimes providing good operation of the FEL. The study is based on a simulation of the ...

The main linacs for the proposed Next Linear Collider (NLC) provide acceleration of up to 500 GeV per beam. The linacs operate in a regime where unavoidable imperfections and even natural ground motion cause significant emittance dilutions. In order to ac...

Forcibly annexed to the Soviet Union fifty-one years earlier, the Baltic states-Estonia, Latvia, and Lithuania- regained independence in 1991 after an abortive coup in Moscow that accelerated the collapse of the Soviet regime. Partial contents on each cou...

Medium-energy proton linear accelerators are being studied as drivers for spallation applications requiring large amounts of beam powder. Important design factors for such high-intensity linacs are reviewed, and issues and concerns specific to this unprecedented power regime are discussed.

The Tevatron accelerator at Fermilab incorporates long two-phase helium passages. During magnet design, the generalized flow map of Baker was used to predict homogeneous flow. Longer than expected magnet time constants led to this investigation. The importance of predicting the flow regime has been amplified with the advent of non-horizontal ...

The Air Force and NASA share a common interest in developing advanced propulsion systems for commercial and military aerospace vehicles which require efficient acceleration and cruise operation in the Mach 4 to 6 flight regime. The principle engine of int...

An analytic and numerical scheme is developed to follow the adiabatic evolution of a beam with non-zero transverse pressure in a modified betatron. These calculations are made using improvements to previous zero pressure models in regimes where, as before...

It has long been noted that the nonlinear ``blowout'' regime of the PWFA has certain critical aspects for producing high quality beams that are owed to the elimination of electron density and current inside of the beam-occupied region: time-independent, linear ion-focusing, and acceleration independent of transverse position. Unfortunately, in applying ...

The promise of an abundant energy supply has inspired many approaches to controlling thermal nuclear fusion. One approach to initiating fusion is to use a hypervelocity projectile to impact a deuterium--tritium (DT) pellet. For this purpose, magnetic accelerators have been propsed for accelerating macroparticles to velocities greater than 100 km/s. This ...

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40{+-}20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the {open_quotes}plasma ...

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40 {+-} 20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the plasma shell ...

With intense relativistic electron beams, such as generated by induction linear accelerators, pulsed-transmission-line accelerators or high-current RF linacs, collective effects can play an important role in the FEL process. High-gain FELs are said to operate in the Raman regime when collective effects dominate the usual ponderomotive ...

Plasma wakefield accelerator is examined in the extreme regime of nanometer transverse beam sizes, typical of designs in the multi-TeV range. We find that ion motion, synchrotron radiation, nuclear scattering and particle trapping constrain the design parameters in which high beam quality and efficiency can be maintained. For a particular example relevant ...

Proton acceleration by short-wavelength Alfven (A) waves resonant at the first harmonic of the proton gyrofrequency is reconsidered taking into account nonlinear wave-wave interactions, collisionless wave losses, and wave escape losses in the geometry of a model coronal loop. The loop is semicircular with a uniform axial magnetic field. It is shown that for the A wave levels ...

This book reviews current advances in the physics and technology of free electron lasers (FELs), and reports the results of recent experiments and new trends in theory. It covers such areas as fundamentals, operating in the Compton regime, operating in the Raman regime, optical klystrons, accelerator and magnet technologies related to ...

We discuss the exploration of the newly proposed blowout regime of the plasma wakefield accelerator and advanced photoinjector technology for linear collider applications. The plasma wakefield experiment at ANL produced several ground-breaking results in the physics of the blowout regime. The photoinjector R and D effort produced ...

A modified coaxial gun in the high density regime of 20-70 mT of He restgas, energized by a 1200 HV sinusoidally damped capacitor discharge with peak currents of 86 kA in a potential range of 10-15 kV, was investigated. The acceleration of the current she...

Experiments, and simulations have shown that quasi-monoenergetic electron bunches can be accelerated from the background electron plasma population up to relativistic energies. Theoretical work indicated that with a proper choice of laser, plasma, and injection parameters the acceleration of electron bunches with small energy spread and short bunch length ...

We consider spatially homogeneous and isotropic Friedmann-Robertson-Walker solutions of Milgrom's recently proposed class of bimetric theories of gravity. These theories have two different regimes, corresponding to high and low acceleration. We find simple power-law matter dominated solutions in both, as well as solutions with spatial curvature, ...

Purpose: To quantify the mitigation of geometric uncertainties achieved with the application of various patient setup techniques during the delivery of hypofractionated prostate cancer treatments, using tumor control probability (TCP) and normal tissue complication probability. Methods and Materials: Five prostate cancer patients with {approx}16 treatment CT studies, taken ...

A brief history of the underlying principles of the conventional fractionation in radiation therapy is discussed, followed by the formulation of the hypothesis for hypofractionated stereotactic body radiation therapy (SBRT). Subsequently, consequences of the hypothesis for SBRT dose shaping and dose delivery techniques are sketched. A brief review of the advantages of SBRT ...

PurposeTo improve local control for inoperable non-small cell lung cancer (NSCLC), a phase I dose escalation study for locally advanced and medically inoperable patients was devised to escalate tumor dose while limiting the dose to organs at risk including the esophagus, spinal cord, and residual lung. Helical tomotherapy provided image-guided IMRT, delivered in a 5-week ...

We describe a new regime of electron acceleration in laser plasmas driven by ultrafast pulses of relativistic intensity, in which space-charge separation leads to strongly enhanced laser absorption and the production of 20 MeV (p/m0c approximately = 40) electrons driven outward in vacuum. 1D PIC simulations show that intense attosecond pulses generated ...

Normofractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using ...