The outstanding characteristics of EA-FEL and on the other hand its large dimensions and cost determine the range of applications that can be ascribed to this unique radiation source. The high average power capability of the device makes it naturally fitt ing for energy related applications. A number of attractive future applications were identified, and are briefly described in this section. Most of them require long range development programs and international cooperation.
Potential Applications:
Material Processing
EA-FELs would operate predominantly at long wavelengths - IR-mm waves and therefore their interaction with matter will be usually based on termal processes. Two major applications were identified for mm wavelength FEM:
This is expected to produce very strong ceramics because the fast and uniform bulk heating by mm waves - microwaves deeps the fine grain structure of the ceramics. Such ceramics are expected to have important applications in high efficiency engines, medical applications.
EA-FEM can produce very high power densities (1-10kW/cm2) over large areas of material. Such power levels can melt the surface instantaneously without affecting the bulk. This will give rise to differentsurface processing treatments as production of wear resistant or corrosion resistant surfaces by incorporation of different materials (e.g. Ni in Steel), glazing processes attachment of ceramics thin films (e.g. high temperature superconductors) to metal and vice versa.
Thermonuclear power reactors are the "environmentally clean" future power reactors, which like "little suns" use Hydrogen isotopes as the fuel for power production instead of the radioactive heavy elements used in nuclear reactors. A continuos engineering, technological and scientific d evelopment effort for tens of years is still required to achieve commercial realization of this concept. To ignite the plasma in the fusion reactor, it has to be heated to high temperatures which only exist in the sun.
One of the schemes, suggested for heating the plasma and controlling its density profile, requires radiation sources with total power of 20 MWatt which operate quasi-CW at wavelength 1-2mm and are tuneable. A battery of a few Free Electon Masers (FEM) seems to be an excellent candidate to perform this function.
A development project of a 1MWatt FEM for fusion research application is now under way in FOM Institute for Plasma Physics in Nieuweigen, Nederlands. The Dutch project relies on wide international collaboration, and the Israeli FEL group collaborated and contributed to its conceptual design.
The high average power and high energy conversion efficiency of FEL gives hope to an old dream of energy transmission by means of "radiation beams" propagating freely in the open atmosphere or in outer space. Options of microwave and optical energy beamin g from ground to satellite and vice versa were considered for various schemes like solar energy utilization, satellite powering and energy redistribution on land. More easily applicable schemes may be short range wireless energy transmission links to inaccessible energy consumers beyond natural obstacles, or catastrophy zones (e.g. earthquake or pollution striken areas). State of the art of large transmitting and r eceiving mirrors permits transmission of collimated laser beams to distances of kms to hundred thousands kms depending on the wavelength. For atmospheric transmission the tunability of FEL is an advantage, making it possible to choose an atmospheric trans mission window in the frequency domain.
An important application of radiative energy transmission seems to be now the powering of Unmanned Airborve Vehicles (UAV) as aerostats and drones at stratospheric heights (20-30 km). Such UAVs are expected to have very important application in high volume cellular voice, video and computer communications.
| See: | Efficient Electrostatic-Accelerator Free-Electron Masers for Atmospheric Power Beaming. |
The high spectral purity and tunability of EA-FELs are their most important property in isotope separation schemes which rely on the small difference in the IR absorption lines of molecules composed of different isotopes.
Several photochemical manufacturing processes also require fine tuning of the laser to perform radiative electronic or vibrational transitions which excite atoms or molecules to higher energy level, ionizes them or break moleculae bonds.
This, combined with the high average power and energy efficiency of EA-FEL makes it a well fitted source for that chemical manufacturing and molecular laser isotop separation schemes for efficient production of. In these applications the cost per photon is a major consideration. EA-FELs have a distinct advantage hare because of their potential high energy conversion efficiency, high average power and proven high reliability in continuous round operation.
In the combustion process of fossil fuel, various polluting by-products (as SOx and NOx gaseous compounds) are released into the air. The molecules of these gases have characteristic vibrational resonances whi ch determine their IR absorption spectrum.
As in the previous application, the high spectral purity and tuneability of EA-FEL make it a good tool for investigating and monitoring the combustion products. If efficient schemes will be developed for breaking the molecular bonds of undesirable combus tion gases by resonant multiphoton excitation, then EA-FEL will have the advantages of high fluence (average power) and high energy efficiency necessary for this application.