A laser-based method to generate ultrashort pulses of synchrotron radiation in electron storage rings is coherent harmonic generation (CHG) using two undulators to produce coherent radiation at harmonics of the initial laser wavelength by microbunching. The bunching factor and thus the pulse intensity, however, decreases exponentially with increasing harmonic order. Echo-enabled harmonic genera...

We investigate quantum radiation reaction in laser-electron interactions across different energy and intensity regimes. Using a fully quantum approach which also accounts exactly for the effect of the strong laser pulse on the electron motion, we identify in particular a regime in which radiation reaction is dominated by quantum interference. We find signatures of quantum radiation reaction in ...

Aperture-based inverse planning (ABIP) for intensity modulated radiation therapy (IMRT) treatment planning starts with external radiation fields (beams) that fully conform to the target(s) and then superimposes sub-fields called segments to achieve complex shaping of 3D dose distributions. The segments’ intensities are determined by solving a feasibility problem. The least-intensity feasible (L...

We demonstrate that external noise can play a constructive role in a laser diode, inducing coherent mid-infrared radiation. Depending on noise intensity, the induced lasing can be either unimode or mulitimode. The coherence of the radiation in each mode reaches its maximum at an optimal noise intensity that differs depending on the mode. The phenomenon can therefore be classified as a multiple ...

Roger Carr Stanford Synchrotron Radiation Laboratory, Palo Alto, California 94304 (Received 29 April 1998) We report measurements of very large output intensities corresponding to a gain larger than 105 for a single pass free-electron laser operating in the self-amplified spontaneous emission (SASE) mode at 12 mm. We also report the observation and analysis of intensity fluctuations of the SASE...

Introduction: Ultraviolet (UV) radiation affects human organs such as skin, eyes and immune system, as well as animals and plants. The main natural source of UV radiation is the Sun. To study the effects of solar UV radiation there is a need to quantify variations of solar energy received on the earth surface at different intervals. Materials and Methods: To measure UV radiation a broadband fib...

OBJECTIVE Our survey assessed the use of advanced radiotherapy technologies at the designated cancer care hospitals in Japan, and we identified several issues to be addressed. METHODS We collected the data of 397 designated cancer care hospitals, including information on staffing in the department of radiation oncology (e.g. radiation oncologists, medical physicists and radiation therapists),...