Wyniki wyszukiwania - Biblioteka Nauki

1

Basic features of the laser acceleration of charged particles

100%

Małachowski M. J. , Dubik A.

|

tom Vol. 49, nr 2

412--420

EN

Purpose: of this paper is to study the acceleration of the charged particles by the laser beam in the range outside the resonance conditions. The studies have been limited in the subresonance region since in order to achieve the resonance acceleration a very high constant magnetic field is needed. Design/methodology/approach: The studies are carried out using the analytical derivations of the particles dynamics and its kinetic energy. The evolution of the acceleration process in time has been studied. The presented illustrations enabled interpretation of the obtained equations. Findings: The kinetic energy of the particle periodically achieves the maximal energy. Its value and the distance between the subsequent maxima rise with the increasing magnetic field or the laser beam intensity. However, these parameters of oscillating energy decrease with the decreasing wavelength. Research limitations/implications: Limits in the energy of accelerated particles are caused by the limits of the available at present the laser beam energy and the static magnetic field intensity. Practical implications: The authors of this paper believe that the presented results of the studies will help the designing of the experimental studies. It has been shown the way of achieving the high energy particles without the application of a very high magnetic field. Originality/value: The value of the paper is the analytical derivation of the parameters describing the oscillatory shape of the particles energy and numerical analysis its course. According to the authors best knowledge there are no performed such analysis of the acceleration process.

2

Impact of the chirping effect on charged particle acceleration in laser radiation

88%

Małachowski M. J. , Dubik A.

|

2011

|

tom Vol. 48, nr 1

87--96

EN

Purpose: The aim of this paper is to find in a numerical way the trajectories and kinetic energies gained by electrons, protons and deuterons accelerated in the laser or maser chirped radiation propagating in a vacuum, with an additionally applied external static axial magnetic field. The accelerated particles to the well defined energies are of interest in many applications, among others in medicine or in processing of different materials. Design/methodology/approach: The acceleration processes of electrons, protons and deuterons were found to be strongly depending on the way the frequency of the laser or maser radiation changes in time. In order to design the realistic acceleration processes the appropriate parameters of a laser or maser and a static magnetic field were used. Findings: The quantitative illustrations of the calculation results in a graphical form enable to discuss the impacts of the chirping effect on the acceleration process of electrons, protons and deuterons. It was found that the rate at which a particle gains the energy depends not only on the particle’s mass but also on the laser radiation frequency variation rate. Due to the different rate at which a relativistic mass of an electron, proton or deuteron increases during the acceleration process the rate at which chirped frequency decreases in time should be different. Research limitations/implications: Limits in the gained energy by the accelerated particles are a consequence of the limits in the available at present the laser or maser beam energy and the static magnetic field intensity. Originality/value: The authors have found, in an exact numerical way, the values of the acceleration equipment parameters which should be applied to obtain the desired energy of the accelerated particles. It is explained why the rate at which a particle gains the energy depends on the way the radiation frequency varies in time.

3

Impact of the mass and other parameters of charged particles on the results of laser resonance acceleration

44%

Dubik A. , Małachowski M. J.

|

tom Vol. 63, nr 1

13-42

EN

Theoretical and numerical analyses are presented concerning the conditions at which the charged particles of different masses can be accelerated to significant kinetic energy in the circularly polarized laser or maser beams and a static magnetic field. The studies are carried out using the analytical derivations of the particles dynamics and theirs kinetic energy. The presented illustrations enabled interpretation of the complex motion of particles and the possibilities of their acceleration. At the examples of an electron, proton and deuteron, the velocity, kinetic energy and trajectory as a function of the acceleration time at the resonance condition are illustrated in the appropriate graphs. The particles with larger masses require the application of enhanced magnetic field intensity at the resonance condition. However, this field intensity can be significantly reduced if the particles are preaccelerated.

PL

Stosując metody teoretyczną i numeryczną przebadano warunki, w których naładowane cząstki o rożnych masach można przyspieszać do znacznej energii w kołowo spolaryzowanej laserowej bądź maserowej wiązce z dodatkowym statycznym polem magnetycznym. Badania przeprowadzono za pomocą wyprowadzonych analitycznych relacji dotyczących dynamiki i kinetycznej energii cząstek. Dzięki stosunkowo licznym wykresom stała się możliwa interpretacja dość złożonego ruchu cząstek oraz przebiegu ich akceleracji. Na przykładach elektronu, protonu i deuteronu zostały zilustrowane zależności od czasu trwania akceleracji takich wielkości jak kształt trajektorii oraz kinetyczna energia. Wszystkie ilustracje dotyczą warunku rezonansu, czyli synchronizacji ruchów obrotowych cząstki i wektora natężenia pola elektrycznego. Czym większa masa cząstki, tym większe natężenie stałego pola magnetycznego jest niezbędne do uzyskania warunku synchronizacji. Jednak to natężenie można znacznie zredukować, jeśli cząstka będzie posiadała prędkość początkową.