PLAZMA-Sk Co. Ltd.
No 1120211 in Skolkovo project
The project devoted to development of universal method of preventing secondary breakdown at the satellites radio-frequency (RF) systems for communication and navigation payloads. We propose new original method for diminishing secondary emission effects at the RF satellites systems. At the base of new technology we developed special carbon nanostructured covers and appropriate device for coating.
PAPER PRESENTED AT MULCOPIM-11
CLADDING METALLIC SURFACE WITH THIN FILM NANO-DIMENSIONAL CARBON FOR DIMINISHING OF SECONDARY ELECTRON EMISSION YIELD
During the past 20-30 years, multipactor phenomena has mainly been studied due to the adverse effect it can have on microwave systems operating in a vacuum environment. It can disturb the operation of high power microwave generators, and electron accelerators, but, above all, it can cause severe system degradation and failure of satellites, which are difficult or impossible to repair after launch. Satellites operate under vacuum conditions and the most common means of communication with the Earth is microwave transmission. Many microwave components are hollow metallic structures that guide the electromagnetic power. A free electron inside the device will experience a force due to the electric field and since there is no gas or other material stopping the electron can knock out other electrons and under certain circumstances this procedure is repeated continuously until the electron density is large enough to counter-act the effect of the applied electric field and a steady state is achieved. This is the physics of a multipactor discharge excitation in the microwave apparatus on the board of satellite applicable for communication purposes.
Development of means dedicated to the suppression of multipactor excitation is one among the most urgent problems of modern microwave techniques. Feasible solution of this problem is processing of metallic components surface by such a means that it leads to the significant diminishing of multipactor excitation probability without any visible change radio-physical properties of units.
In this report results of developed in the GPI techniques for such a kind of metallic components treatment are presented. Method is based on the coating of surface of metal by thin film composed of nano-dimensional carbon. Original principles of nano-structural carbon production have been elaborated. Setup in which nano-dimensional carbon has been produced is presented.
Full text presented at MULCOPIM-11 Conference
2. Problem actuality.
Look for example at paper at Aerospace Corporation www.aero.org site:
Preventing Radio-Frequency Breakdown in Satellite Components
Both military and commercial satellites rely on radio-frequency (RF) systems for communication and navigation payloads. The RF power demand for these systems has continued to grow with increasing user needs and higher available satellite power. Global Positioning System (GPS) III and the Mobile User Objective System (MUOS) are just two examples of satellites with unparalleled RF power requirements at multiple frequencies.
With increasing power levels comes increasing risk for RF breakdown within high-power components. RF breakdown is an electrical discharge—such as a plasma or multipactor discharge—that can degrade high-fidelity communication signals and cause physical damage to susceptible components. These discharges can lead to complete loss of essential communication or navigation signals and prevent proper satellite operation. As such, preventing RF breakdown is essential.
In response to this growing risk, The Aerospace Corporation is leading new research into plasma and multipactor breakdown. This program, led by Timothy Graves, Space Materials Laboratory, is pursuing basic research into the underlying phenomenology while helping contractors develop better hardware and testing requirements.
Multipactor breakdown is one of the highest concerns for high-power RF component designers today. Also referred to as multipaction, this discharge type can occur when electrons impact material surfaces in resonance with the RF electric field. This resonance depends primarily on three components: the RF voltage (how fast the electron is accelerated), the RF frequency (how long before the electric field changes direction), and the geometry (how far the electron travels before hitting a surface).
As electrons resonantly impact electrode surfaces, the electron density grows through secondary electron emission. The secondary electron yield, defined as the number of emitted electrons per incoming electron, is a fourth parameter for multipactor breakdown, such that the secondary electron yield is greater than 1 to develop the discharge. When these conditions are met, the formation of a large electron density can perturb the RF system and substantially increase the risk of plasma breakdown and component damage.
3. ALTERNATIVE TECHNOLOGIES & COMPANIES
AND ADVANTAGES OF OUR TECHNOLOGY
We can mention follows companies & institutes which develops alternative technology platforms for solving problem of Radio-Frequency Breakdown in the Satellite Components:
a) High Power RF Laboratory, ESA, Valencia, Spain.
b) Tesat Spacecom GmbH&Co. KG, Gerberstr 49, D-71522, Backnang, Germany.
c) Hubert+Sulner: Exellence in Connectivity Solutions.
d) Instituto de Cienua de Materiales de Madrid, Spain.
For solving the problem the above mentioned groups propose traditional Au, Ag and Cu coatings. Sizes of coated samples are now less than 100 microns. Such coatings soon degrades at the air and lost their properties. Prize of such technologies is very expensive and complex in compare with our nano-carbon coating technology. We can also coat large area several square centimeters size and much more. Our coating has excellent wear resistance properties.