Studies of Nonlinear QED in Collisions of 46.6 Electrons with Intense LaserPulses PDF Download

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
We report on measurements of quantum electrodynamic processes in an intense electromagnetic wave, where nonlinear effects (both multiphoton and vacuum polarization) are prominent. Nonlinear Compton scattering and electron-positron pair production have been observed in collisions of 46.6 GeV and 49.1 GeV electrons of the Final Focus Test Beam at SLAC with terawatt pulses of 1053 nm and 527 nm wavelengths from a Nd:glass laser. Peak laser intensities of approximately 0.5 x 10[sup 18] W/cm[sup 2] have been achieved, corresponding to a value of approximately 0.4 for the parameter[eta]= eE[sub rms]/m[omega][sub 0]c, and to a value of approximately 0.25 for the parameter[Upsilon][sub e]= E[sub rms]/E[sub crit]= eE[sub rms][h-bar]/m[sup 2]c[sup 3], where E[sub rms] is the rms electric field strength of the laser in the electron rest frame. We present data on the scattered electron spectra arising from nonlinear Compton scattering with up to four photons absorbed from the field. A convolved spectrum of the forward high energy photons is also given. The observed positron production rate depends on the fifth power of the laser intensity, as expected for a process where five photons are absorbed from the field. The positrons are interpreted as arising from the collision of a high-energy Compton scattered photon with the laser beam. The results are found to be in agreement with theoretical predictions.

Author: K. Felix Mackenroth
Publisher: Springer
ISBN: 3319077406
Category : Science
Languages : en
Pages : 183

View

Book Description
Scientific advances and several technical breakthroughs have led to a remarkable increase in available laser intensities over the past decades. In available ultra-intense laser fields, photon fluxes may become so high that free charge carriers interact coherently with several of the field's photons. In this thesis such nonlinear interactions are investigated for the prime example of radiation emission by electrons scattered from intense laser pulses of arbitrary temporal structure. To this end, nonlinear quantum field theory is employed taking the interaction with the laser into account exactly. After an in-depth introduction to classical particle dynamics as well as quantum field theory in nonlinearly intense laser fields the emission of one and two photons is explicitly analyzed. The results are then translated to viable technical applications, such as a scheme for the determination of the carrier-envelope phase of ultra-intense laser pulses and a proposal for detecting the strongly suppressed two-photon signal.

Author: Konstantin Dmitrievich Shmakov
Publisher:
ISBN:
Category :
Languages : en
Pages : 458

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 205

View

Book Description
An experiment is described which studied quantum electrodynamic interactions under conditions of extremely high fields, along with a review of the relevant theory. The high fields were created by an intense, tightly-focused pulse of laser light at green or infrared wavelengths, into which was sent an ultra-relativistic electron beam of 46.6-GeV energy. The relevant theory is that of an electron in an electromagnetic wave so intense that the electron's mass is effectively shifted by the transverse momentum imparted to it by the wave, and the electron encounters field strengths comparable to the Schwinger critical field strength of 511 kV per Compton wavelength. An electron in the intense wave may radiate a photon and balance 4-momentum by absorbing multiple photons from the laser, which can lead to real photons with energies above the kinematic limit for conventional Compton scattering. All particles have significant probability of scattering multiple times while in the focus of the laser, including the photons radiated by the electrons, which may convert into electron-positron pairs, again with absorption of multiple photons from the laser. This experiment was able to measure the rates and spectra of positrons, electrons, and photons emerging from the interaction region. Results from both experiment and theoretical simulations are presented and compared. The results from the electron and positron measurements are compatible with the accepted theory, within experimental uncertainties due mainly to the laser intensity measurement. The photon spectrum shows the correct shape, but the ratio of rates in the linear and two-absorbed-photon portions of the spectrum does not vary as expected with the laser intensity, suggesting a disagreement with the accepted theory, with a significance of roughly two standard deviations. A follow-up experiment would be in order.

Author: Chantal Sundqvist
Publisher:
ISBN:
Category :
Languages : de
Pages : 0

View

Book Description
One of the many astonishing predictions of quantum field theory is the nonlinear nature of the quantum vacuum. In the context of quantum electrodynamics this enables classically forbidden, nonlinear interactions between electromagnetic fields in the vacuum. One much pursued idea to test this prediction is to excite the quantum vacuum with high-intensity laser pulses to emit signal photons that can be distinguished from the driving laser photons, for example, by their polarization or photon energy. A major experimental challenge is the small number of signal photons compared to the background photons. With the aim of identifying a potential discovery experiment of quantum vacuum nonlinearity, we provide theoretically firm predictions for two different quantum vacuum signatures with an emphasize on experimentally feasible setups. This covers on the one side the much studied effect of vacuum birefringence, for which we analyze an innovative setup using a single X-ray free-electron laser. Special attention is paid to the influence of the optical components in the setup on the laser pulse properties. On the other side, we perform an in-depth study of a signature of quantum vacuum nonlinearity that has received less attention so far, namely laser photon merging. The signal photons here have the outstanding property that they differ in photon energy from the background photons and can thus be isolated efficiently. We show that, using state-of-the-art technology, the merging signal can compete with the vacuum birefringence signal in terms of its suitability for a potential discovery experiment of quantum vacuum nonlinearity.

Author: Anthony Hartin
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description

Author: Kaoru Yamanouchi
Publisher: Springer
ISBN: 3319648403
Category : Science
Languages : en
Pages : 234

View

Book Description
This thirteenth volume in the PUILS series covers a broad range of topics from this interdisciplinary research field, focusing on atoms, molecules, and clusters interacting in intense laser field and high-order harmonics generation and their applications. The series delivers up-to-date reviews of progress in ultrafast intense laser science, the interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Typically, each chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries.

Author: Dimitri Batani
Publisher: Springer Science & Business Media
ISBN: 9780306466151
Category : Science
Languages : en
Pages : 434

View

Book Description
Proceedings of the 30th Course of the International School of Quantum Electronics on Atoms, Solids and Plasmas in Super-Intense Laser Fields, held 8-14 July, in Erice, Sicily

Author: Jun Ye
Publisher: Springer Science & Business Media
ISBN: 0387237917
Category : Science
Languages : en
Pages : 373

View

Book Description
Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.

Author: Hartmut Figger
Publisher: Springer Science & Business Media
ISBN: 3662048973
Category : Science
Languages : en
Pages : 525

View

Book Description
Published on the occasion of Theodor Hänsch's 60th Birthday emphasis is placed on precision related to results in a variety of fields, such as atomic clocks, frequency standards, and the measurement of physical constants in atomic physics. Furthermore, illustrations and engineering applications of the fundamentals of quantum mechanics are widely covered. It has contributions by Nobel prize winners Norman F. Ramsey, Steven Chu, and Carl E. Wieman.