Abstract: The present invention is a method of joining two materials by single pulse electron radiation. The method comprises the step of disposing a first material layer adjacent to a second material layer such that an interface is disposed therebetween. Then there is the step of irradiating the interface with a pulsed electron beam such that energy of the pulsed electron beam is selectively deposited in a narrow spatial region and localized at the interface to produce an effective joint between the first and second material layers in a single pulse. Preferably, before the irradiating step, there is the step of calculating an optimum temperature profile across the interface depending on electron energy, beam current density and pulse length of the pulsed electron beam. The electron energy of the pulsed electron beam is preferably in the range of 100 keV to 10 MeV. The pulsed electron beam current density is preferably in the range of 1-1000 A/cm.sup.2.

Abstract: The present invention is based on a relatively simple mechanism which heretofore has not been tried before. The mechanism depends on modulation of a collimated beam transverse to the beam direction rather than the usual longitudinal modulation. Conversion of the transverse motion into longitudinal bunching in an output cavity is accomplished by means of the difference in path length in a bending magnet. Since the present invention does not depend on longitudinal modulation, it is suitable for pulsed superpower (1 GW) applications, but it can be equally suited for multi-megawatt cw applications. The present invention pertains to an apparatus for bunching relativistic electrons. The apparatus comprises means for imparting a periodic velocity in a first direction in a first region to electrons of an electron beam moving in a second direction.

Abstract: The present invention is an apparatus for examining a body part of a patient. The apparatus is comprised of a first detector module for detecting radiotracer emissions from the body part and a second detector module for detecting radiotracer emissions from the body part. The first and second detector modules are disposed adjacent to each other with the body part disposed therebetween. The apparatus also comprises means for backprojecting detected coincident events with respect to the first and second detector modules onto a plurality of imaging planes between the first and second detecting modules. Preferably, the backprojecting means comprises means for defining a line between a point on the first sensor array and a point on the second sensor array associated with a coincident event and means for determining the intersection of the line with each imaging plane.

Abstract: A microwave calorimeter is disclosed for substantially measuring the total icrowave energy in an applied microwave pulse. The microwave calorimeter includes: a housing having a highly reflective interior surface, a microwave absorbing device disposed in the housing for substantially absorbing microwave energy transmitted into the housing and for producing a thermal response proportional to the amount of microwave energy being absorbed, and a measurement device responsive to the thermal response for determining the amount of microwave energy being absorbed by the microwave absorbing device.

Abstract: A spectrum analyzer for analyzing electromagnetic radiation which may be utilized to determine the radiation wavelength and power. The analyzer includes a gas filled chamber which has a collimating lens through which radiation is injected, and a reflective plate that reflects the radiation back toward the lens. A standing wave is created within the chamber having spatially periodic peaks. The chamber gas pressure is regulated to a pressure such that gas breakdown occurs, thereby generating a light pattern at each standing wave peak. The patterns are then photographed, and the patterns' diameters and spacing are measured from the resulting photograph. From the spacing and diameter obtained, wavelength and power may be calculated.