Traveling wave cathode tube

traveling wave cathode tube

image of a wave tube Photo: Sue Tallon Tubes in Space: The cold- cathode traveling - wave tube would make it possible to equip even very.
Abstract: We have constructed cathode - ray tubes utilizing traveling waves, whose deflection sensitivity can be made independent of frequency by equalizing the.
The Traveling - Wave Tube (TWT) is an amplifier of microwave energy. TWTs manufactured at the Williamsport operation utilize the oxide cathode and have..

Traveling wave cathode tube - tour

RF wave velocity as it travels down the circuit is much less. The walls of a modern tube are made not of glass but of heat- and corrosion-resistant metals like tungsten and molybdenum, as well as iron, high-purity copper, and high-temperature ceramics. La résistance tungstène du filament est dépendante de la température et présente un coefficient positif. For more than a decade, my colleague David Whaley and I, working with the SRI team, have been trying to turn this laboratory device into something more practical. In medium-power tubes, the helix is often supported on a beryllia or alumina substrate, but for high-power TWTS, alternative slow-wave structures are employed eg coupled cavities , though usually at the expense of bandwidth. The lower the work function, the lower the temperature you need to emit electrons, the lower the evaporation rate of the barium, and the longer the cathode lasts. Les tubes les plus performants emploient même une double variation de la périodicité: d'abord une augmentation du pas donc de la vitesse de l'onde vue par les électrons pour améliorer la formation des paquets d'électrons, suivie d'une réduction du pas pour un freinage plus efficace. The electrons in solid-state devices, by contrast, suffer a multitude of collisions as they drift through the semiconductor, and so produce waste heat right at the transistor junction, inside the device itself.

traveling wave cathode tube

The walls of traveling wave cathode tube modern tube are made not of glass but of heat- and corrosion-resistant metals like tungsten and molybdenum, as well as iron, high-purity copper, and high-temperature ceramics. This is usually achieved using the helix electrode, which is simply a spiral of wire around the electron beam. The essential features of a typical travelling wave tube. The beam current is controlled by the grid-cathode voltage. TWTs manufactured at the Williamsport operation utilize. Operation is similar to that of a klystronexcept that coupled-cavity TWTs are designed with attenuation between the slow-wave structure instead of a drift tube. Their cathode consists of tens of thousands of travel leisure saint ignace molybdenum cones deposited on a circular silicon substrate with an area of about one square millimeter. These tubes are known as backward wave oscillators BWOs and have the advantage of a very wide tunable range an octave or more, traveling wave cathode tube. The beam current therefore becomes modulated by the RF signal, and the bunches react with the RF fields associated with the slow wave travelling down the helix, resulting in a net transfer of energy from the beam to the signal, and consequent amplification. Higher powered helix TWTs usually contain beryllium oxide ceramic as both a helix support rod and in some cases, as an electron collector for the TWT because of its special electrical, mechanical, and thermal properties. As the helix is fragile and will not dissipate more than a certain power without damage, the helix current should be metered, and a current trip incorporated to cut the power supplies to the tube if the helix current becomes excessive.

Traveling wave cathode tube - - traveling

The tube also has fins attached to the collector to radiate heat from the tube and the satellite into the cold surroundings of space. The features of a typical TWT are shown in the top diagram. And in contrast to TWTs, their performance is much more sensitive to variations in operating temperature. Traveller Education Information Project. The transfer characteristic is essentially linear, which permits the tube to be used to amplify ssb-one of its great advantages in an amateur context. And in an extension of a MEMS technique, researchers at the U. Naval Research Laboratory are using a process that combines UV lithography and electroplating to make extremely accurate, all-metal structures for use in millimeter-wave traveling-wave tubes. What can I access?