Hollow cathode configurations are largely unchanged since their invention over 50 years ago. The plasma discharge from hollow cathodes can also be operated with or without an applied magnetic field and at high currents generates significant self-magnetic fields that affect the plasma dynamics. The cathode plume produces numerous waves and instabilities and can generate ions with energies greatly in excess of the operating discharge voltage. They operate with changes in neutral gas pressure and plasma density from inside to outside of orders of magnitudes, which is challenging to model. Hollow cathodes are also rich in plasma physics and research issues to be investigated and resolved. They can be configured to operate for long time periods, years in some cases. They operate in a variety of different gases and metal vapors, including hydrogen, deuterium, lithium, helium, neon, oxygen, nitrogen, argon, krypton, xenon, mercury, and bismuth. They are straightforward to construct in the laboratory and can be scaled simply to produce different discharge currents from fractions of an ampere to many hundreds of amperes. Once ignited, they self-heat and adjust their voltage drop to provide the internal heating necessary to produce the desired discharge current from a thermionic electron emitter. They are easily started with a momentary heater, RF exciter, or Paschen discharge. They make copious amounts of plasma, highly ionized plasmas in some cases. Hollow cathodes used to generate plasma discharges are remarkable devices. Advances in our understanding and technology in these areas and some of the challenges that still need to be addressed and solved are discussed. In the paper, we describe the status of 2D global simulations of hollow cathode plasmas, hollow cathode plume instabilities, and the development of higher current cathodes and low-current heaterless cathode technologies. While many of the developments have been driven by the demanding requirements of electric propulsion applications, the information provided applies to all thermionic hollow cathodes and their applications. This paper describes perspectives on the progress that has been made in recent years in the capabilities and modeling of hollow cathodes used in plasma discharges. From surface processing and coatings deposition to plasma–surface interaction research and electric propulsion, advances in hollow cathode modeling and performance are critically important to the progress and evolution of these and other areas of technology. PLEASE SEE OUR ADDITIONAL IMAGES TAB FOR FURTHER TECHNICAL INFORMATION AND DIMENSIONAL OUTLINES.Hollow cathode plasma discharges are a fundamental part of a large variety of applications in industry, academia, and space. So, operate at the lamp current specified for the instrument in use. However, instruments using a pulse lighting system may indicate the lamp current value as the mean value. The lamp current values listed above are specified as a peak value. hrs except for the guaranteed life of As, Ga and Hg which are specified as 3000 mA.NOTE: The guaranteed life is defined by the product of the lamp current value (typ.) and the accumulated operating time and is specified as 5000 mA Since each element has two or more spectral emission lines, select the appropriate spectral line for the sample concentration. * Analytical lines marked with an asterisk (*) indicate the maximum absorption wavelength of each element.
#Calcium hollow cathode lamp series#
L733 SERIES (38 mm DIA.): MULTI-ELEMENT HOLLOW CATHODE LAMPS (11 LAMPS) Element Because of that, fabricating cathodes from an optional combination of elements is not possible.
Although multielement lamps offer the advantage of simultaneous determination of multiple elements, their cathode composition must be determined by taking the properties of the metals to combine fully into account. Single-element lamps are usually superior to multi-element lamps in absorption sensitivity and analytical line radiant intensity.
Hollow cathode lamps consist of single-element lamps and multi-element lamps. Please note that Hamamatsu lamps are made to order and have a 2 - 3 month lead time.Īnalysis Lines (Maximum absorption wavelength): L733 SERIES (38 mm DIA.) Multi-element Hollow cathode lampsįor atomic absorption analysis, Metal-vapor discharge lamp, Element : Calcium Magnesium
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