Abstract: A chopper for a particle beam comprises an annular guiding element and an element for controlling the intensity of the particle beam. The control element is supported on the guiding element so that at least one point under consideration on the control element can revolve along the circumference of the guiding element. Mounting along a circumference allows for accommodation of considerably higher disturbance torque than mounting on a rotational axle, using the same bearing force. Furthermore, it is possible to dispense with the entire rotational axle, and the control element can be designed, for example, as a ring. This brings about considerable weight savings as compared to chopper wheels according to the prior art, which accordingly enables higher circumferential speeds and therefore higher modulation frequencies for the particle beam, while at the same time increasing operational safety.

Abstract: Bradbury-Nielson gates for the modulation of beams of charged particles, particularly ion beams in mass spectrometry, have been produced with an adjustable wire spacing down to 0.075 mm or a smaller spacing. The gates are robust, they can be fabricated in less than 3 hours, and the method of production is reproducible. In time-of-flight mass spectrometers, fine wire spacing leads to improvements in mass resolution and modulation rates. Gates that were produced using this new method have been installed in a Hadamard transform time-of-flight mass spectrometer in order to demonstrate their utility.

Abstract: A device for providing a hologram of an object which may be converted to an optical image in real time. The device is part of an acoustical holographic system which uses a source of coherent acoustic radiation to irradiate the object which reflects the acoustic radiation on to a piezoelectric transducer to provide a rapidly varying sinusoidal electronic charge pattern corresponding to the reflected acoustic radiation. Electrons are released from a photocathode, illuminated by a radiation source, in a spatial distribution of electron energies corresponding in space and time to the electronic charge pattern. A first grid positioned adjacent the photocathode is maintained at a potential to provide a modulated electron current which varies in space and time linearly in accordance with the acoustic input. The electron current is modulated by a second grid energized by a coherent reference voltage of fixed phase to function as a reference signal as used in holography.

Abstract: A face plate suitable for use with an acoustical-optical image tube is disclosed and its method of manufacture. A fused glass capillary array which constitutes a disk having a large number of smooth parallel passages or pores therethrough is metalized, preferably by an electroless plating process, whereby the inside surfaces of all the pores are coated. The resulting layer of gold, silver or platinum may then be increased, if desired, by further plating, after which the disk is cleaned, heated to approximately 470.degree. C. and the pores filled with a sealant such as silver chloride. One or both surfaces may then be lapped to provide a disk having a glass surface but with many conducting cylinders extending therethrough which then appear as rings on the surfaces.

Abstract: A target for ultrasonic camera comprising, applied to a substrate, a pyroelectric retina covered, in the present example, with a layer which absorbs incident ultrasonic waves; the temperature rise due to said absorption produces in the retina a charge relief read out by means which depend upon the selected device, for example an electron beam as in the case of the known pyroelectric targets.

Abstract: Apparatus for the detection of an acoustic image by means of an election tube including a face plate and an electronically scanned transducer made of a thin foil of polymer material whose acoustic wave velocity of propagation is less than 1.8 that of a liquid imaging medium. The face plate also is made of a polymer material having a velocity of propagation less than 1.8 that of said liquid. Preferably, the transducer foil is much thinner than the face plate and has a thickness approximately 0.5 times the acoustic wavelength.