If your application involves any of the following, we may be able to assist you:

Brazing Technology: Associated with electron tubes, it provides a means of joining metal parts and metal to ceramic.

Cataphoretic Deposition: A means for depositing small particles onto a surface. Our experience includes depositing heater coatings, oxide cathodes, and phosphor coatings.

Cathode Ray Tubes: These are still the primary information displays in televisions and computers over much of the world. We have extensive background in both color and monochrome tubes. They have been around for about 100 years, and their extinction has been confidently predicted for at least 50 of those years. Their remarkable flexibility and low cost accounts for their longevity. Recently, flat panel displays have started to replace CRT's in the U.S. computer monitor market. And it looks like rear projection televisions are finally switching to non-CRT alternatives. But what an amazing success story the cathode ray tube has been. A monochrome monitor is shown at right. Just below it, one of the many attempts to make a flat CRT. This device was taken from a Sony Watchman, one of the earliest and most successful hand-held televisions. For research applications, cathode ray tubes are very good at capturing pictures of single, high-speed events. If you have such a need, we can help. In fact, we can help you with almost any other need involving cathode ray tubes.

Cathodes: primarily thermionic, including oxide, impregnated, and reservoir dispenser cathodes. We can help in all phases of cathode development and use. Our smallest cathode is shown below.


Ceramics: These provide electrical insulation and containment for electron tubes. They can withstand high temperatures and can be metalized and brazed. They have a high modulus of elasticity and are dimensionally stable.

Depositions, Evaporated and Sputtered: We are familiar with deposits such as black chrome, gold and chromium, and indium tin oxide used in display tubes. We can provide most of these.

Electrical Test: We can help you test your device and design the electronics for doing so.

Electron Bombarded Semiconductors: These are diodes that provide high current gain when back-biased and struck by energetic electrons. They can be used as distributed microwave amplifiers, and to downshift impedance from an electron beam.

Electron Guns: generate, form and shape the electron beam prior to its use. We can help with many kinds, including Wehnelt, multibeam, CRT cross-over guns, and Pierce electron guns that are used in microwave tubes.

Feedthrus, Vacuum: These are the metal electrodes that pass through a glass or ceramic envelope and transmit electrical currents while maintaining the vacuum seal. Careful design is required to avoid vacuum leaks, electrolysis, etc.

Field Emission Cathodes: A hot topic these days because of advances in making and patterning carbon nanotubes. These tiny filaments of carbon emit electrons if sufficient electric field is placed in front of them. Their drawback is that they don't produce as much electron current as thermionic cathodes unless very high voltages are used. These high voltages can cause arcs which, in turn, destroy the cathodes. For modest current densities, they offer the prospect of large area emission, which thermionic cathodes can never do because the cost to heat them becomes prohibitive. Carbon nanotube technology is a revolutionary development that will change vacuum electronics, and indeed, electronics in general.

Field Emission Display (FED): Flat, thin CRTs. We can build the glass structures and do the phosphor screening for these.

Free Electrons: Electrons in vacuum as opposed to electrons imprisoned in a material. We, of course, support the free electron cause.

Frits and Solder Glass: These are used to join pieces of glass and glass to metal. We can fabricate glass assemblies using these.

Getters: Devices used to maintain vacuum in a vacuum electron device after it has been removed from an external pump. We can help you select the getter that is right for your application.

Glass: This is a primary material used in electron tube construction for electrical insulation and for vacuum envelopes. We have experience with many types of glass.

Grids and Metal Meshes: These are materials used to control and shape electron beams while allowing the electrons to pass through.

Heat Transfer: Energetic electrons produce heat when they strike objects. The management and transfer of this heat away from critical elements in the device is an important subject. We have modeling tools and years of experience in this area.

High Voltage: We can design and fix problems associated with high voltage circuits such as ones used to drive vacuum electron devices.

Klystrons: convert electron beam energy into radio frequency waves, often with significant amplification. They can be oscillators, like the circa 1950 reflex klystron shown at right, or they can be amplifiers, in some cases monster amplifiers producing hundreds of megawatts of radio frequency power. They are also very efficient, as high as 80%. But they have narrow bandwidth, i.e., they amplify only over a narrow frequency range. We can help design and build your klystron.

Life Test: when an electron tube or cathode is operated under controlled conditions until it fails. We can life test your cathodes and electron tubes under a wide range of conditions.

Magnetic Fields: Electron beams are often focused by magnetic fields.

Magnetrons: produce radio frequency waves, usually at high power. They are single-frequency, so they are not used in communications, but are still used for radar. For raw, efficient, low-cost RF power to heat things up, nothing surpasses them. The most common use today is in microwave ovens. These magnetrons produce up to 1500 watts at about 2 GHz and cost about $5 to make. So much for the argument that vacuum electronics is too expensive. A magnetron, circa 1950, used in a military radar is shown at right.

Metal Forming: The precision rings, barrels, cups, bushings and wafers used in vacuum electron devices must be formed, cut, drawn, swaged, etc. They are sometimes polished to a mirror finish to prevent high voltage breakdown. Only certain materials are vacuum compatible and the processes are exacting to prevent contaminants or gasses from being occluded in the grain structure of the metals.

Metalization: This is the coating that is deposited on glass or ceramic to allow brazing or joining to other components.

Micro-Channel Plates: These provide high current gain via secondary emission of electrons in an area array. They allow very fast events to be captured on the screen of a cathode ray tube.

Microwave Windows: These block air but allow microwaves to freely pass. We can help with both ceramic and glass, and waveguide and coaxial types.

Modeling: The various computer codes that we employ to predict the path of the electrons and thereby predict the performance of the vacuum electron device. We have an extensive suite of tools for modeling electron beams and their interaction with microwaves.

Phase Measurement: Traveling wave tubes are yoked together to increase antenna power. It is important that the phase relationships remain fixed as frequency is varied. We can provide equipment and expertise if you have a phase problem.

Phosphors and Phosphor Screens: Phosphors are materials that emit light of various colors when struck by energetic electrons. They are used in CRTs to display pictures and information. We have expertise in this area.

Photocathodes: These release free electrons when light strikes them. They are used in streak tubes, where very fast signals are to be imposed on the electron beam.

Resonant Ring: provides microwave power amplification in a passive device. That means you don't need an active amplifier. It consists of a waveguide that closes back on itself. There is a coupler to feed power into the ring, and tuners to adjust the impedance match and phase. The flow of power will build up as the microwaves reinforce each other around the loop. It can be used to test transmissive devices that don't dissipate much power. Of special interest is the testing of high power microwave windows. We can design and build both microwave windows and resonant rings.

Standard Test Vehicle: a standardized glass electron tube that is inexpensive to build that can be constructed in large quantities so as to generate statistically useful performance data.

Streak Tubes: These are devices in which a high-speed signal is impressed onto an electron beam. The beam is deflected very fast across a diode array and varying levels of charge are captured. Out of these charges the waveform of the signal can be reconstructed. A streak tube built by Tektronix is shown at right.

Thermionic: refers to cathodes that emit electrons when heated and require only a modest voltage in front of them to coax electrons into the vacuum.

Traveling Wave Tubes (TWTs): These convert electron beam energy into radio frequency waves, but with broader bandwidth than klystrons. We have expertise with helix, coupled cavity, and ring-loop TWTs.

Tube: The old, short term for a vacuum electron device. It is shunned now in some quarters, because it is said to call up old-technology images – fathers on Saturday mornings carrying tubes in paper bags to the drug store, wherein resided "tube testers". But “tube” people are a traditional bunch, and the word refuses to depart. A "tube" is shown here for the benefit of those born after 1970.

Vacuum Electron Device (VED): The new age, high-tech term for electron tube. It replaces the word "tube"because that word is said to be bad for business due to its unsexy, old-technology image. VEDs encompass power tubes (triodes, rectifiers, pentodes, tetrodes, etc.), microwave tubes (klystrons, traveling wave tubes, magnetrons, etc.), display tubes (cathode ray tubes, vacuum fluorescent displays, etc.), and X-ray tubes.

Vacuum Envelopes: the bottle, funnel, cylinder, etc. that provides the vacuum barrier for an electron tube. We can build both glass and ceramic in many shapes and sizes.

Vacuum Technology: All the processes and wisdom that go into pumping, baking, and sealing vacuum electron devices.

Vacuum Tube: another term for electron tube, but usually referring to low-frequency amplifier tubes such as triodes, tetrodes and pentodes.

Welding Technology: Associated with electron tubes, it provides a means of joining metal parts. Our expertise includes spot welding, heliarc, and laser welding.

Window:  we refer here to any interface which transmits microwaves through a vacuum envelope.  We have done much work on these, both waveguide and coaxial, and both low power and high power.

X-Rays: X-rays are generated by x-ray tubes, which are also vacuum electron devices. They require the same sort of modeling, vacuum processing, etc., that other electron tubes require. Recently, x-rays for imaging applications have assumed prominence. These often require very small, well-focused electron beams to create small X-Ray sources. We can help with design and prototypes.

Copyright 2005, ebeam, Inc.