Results 91 to 100 of about 315 (110)

A Bifocal Ellipsoidal Gregorian Reflector System for THz Imaging Applications

IEEE Transactions on Antennas and Propagation, 2012
Current terahertz imagers rely on reflector systems for the beam quality and imaging speed because the cross-range span that the system can cover is limited by the beam aberrations when the antenna scans. We present the design of a Bifocal reflector system that can rapidly scan a terahertz beam for standoff imaging applications while increasing the ...
Antonio Garcia-Pino, Nuria Llombart, Borja Gonzalez-Valdes, Oscar Rubinos-Lopez   +3 more
openaire   +1 more source

Longitudinal pumping by an ellipsoidal reflector for short-wavelength lasers

Soft-X-Ray Projection Lithography, 1991
We have designed and tested an ellipsoidal reflector to pump short-wavelength lasers by soft x-ray radiation from laser produced plasma. A gaseous medium supplied by a slit nozzle was pumped longitudinally along the optical axis in the region of the second focus. Soft x-ray absorption and VUV emission of gaseous medium have been investigated.
Katsumi Midorikawa, Hideo Tashiro, Toshihisa Watabe, Minoru Obara   +3 more
openaire   +1 more source

Focusing of N waves in air by an ellipsoidal reflector

The Journal of the Acoustical Society of America, 1997
An experimental investigation of the focusing of intense, airborne pressure pulses by an ellipsoidal reflector is reported. Short-duration N waves were generated by weak sparks at the near focus F1 of four different prolate ellipsoidal surfaces. Reflection then concentrated the rays at the far focus F2.
Wayne M. Wright, David T. Blackstock
openaire   +1 more source

Ellipsoidal Reflector for Longitudinal Pumping of Soft X-Ray Lasers

Topical Meeting on Short Wavelength Coherent Radiation: Generation and Applications, 1986
We propose a new geometry for collecting and focusing soft x-ray radiation from a laser-produced plasma which offers collection efficiencies greater than 20% and aspect ratios of more than 50. This combination typically results in (power density) x (length) improvements of 30 relative to present transverse multiple-spot geometries. Longitudinal pumping
J. F. Young, J. J. Macklin, S. E. Harris
openaire   +1 more source

Study on a THz image scanning system with ellipsoidal reflector

2015 8th UK, Europe, China Millimeter Waves and THz Technology Workshop (UCMMT), 2015
This paper presents our study on a reflector system for mechanically scanned imager working at 220 GHz. An ellipsoidal reflector is utilized to replace a paraboloidal reflector to achieve another focus on the target plane under the consideration of better performance in the near field imaging.
Min Zhou, Yasir Alfadhl, Xiaodong Chen
openaire   +1 more source

Ellipsoidal reflector design of the LED vehicle projector type headlamp

SPIE Proceedings, 2016
In this study, the design of the projector type headlamp using LEDs with different structure parameters is proposed. The ellipsoidal reflector with different major and minor axis would contribute different aperture and focal lengths of the ellipsoidal reflector, and then collimate the light to the converging lens.
Shang-Ping Ying, Jhen-Cyun Lyu
openaire   +1 more source

Intensified cavitation produced with pressure release and rigid ellipsoidal reflectors.

The Journal of the Acoustical Society of America, 1996
An underwater bubble is well known to grow in response to a strong negative acoustic pulse and then collapse because of inertial forces. Here it is shown that adding an auxiliary positive pulse after collapse begins intensifies the collapse. The negative-then-positive pulse sequence is produced by two ellipsoidal reflectors, each with an electrical ...
Michael R. Bailey, David T. Blackstock
openaire   +1 more source

The caustic fields of offset ellipsoidal reflectors: a comparative study

International Symposium on Antennas and Propagation Society, Merging Technologies for the 90's, 1990
The conditions under which the GTD (geometrical theory of diffraction) and Gaussian beam solutions are able to specify the phase and magnitude of the fields around the caustics of offset ellipsoidal reflectors are examined. This is done through the comparison of these methods with the near-field physical optics solution (PO).
P.O. Iversen, Y. Rahmat-Samii
openaire   +1 more source

Acoustic and cavitation fields of a pressure release ellipsoidal reflector

The Journal of the Acoustical Society of America, 1997
In an electrohydraulic lithotripter (device to treat kidney stones), an underwater spark at the near focus of a rigid ellipsoidal reflector produces acoustic cavitation at the far focus. A reflector made of pressure release foam, however, dramatically reduces cavitation with little change in acoustic pressure amplitude (∼ +35 MPa, ∼−10 MPa).
openaire   +1 more source

Focusing of shock waves in water by different ellipsoidal reflectors

AIP Conference Proceedings, 1990
Spherical shock waves generated by an underwater sparkgap or an explosive pellet in the first focus of different ellipsoidal segments are focused after reflection in the second focus. Shadowgraphs give an impression of the converging process whereas the field measurement is done by self‐designed piezoelectric pvdf‐needleprobes.Two different series of ...
openaire   +1 more source