Patent Number: 050142917
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION In the following description, and in the claims, the term "X-ray reflection" has been used to indicate the phenomenon of induced emission of X-rays by an electrode of "reflection". It will be noted, however, that in a purely technical sense this term is not perfectly accurate, as it regards phenomena of diffraction, diffusion, scattering, etc. The term "reflection" has, nevertheless, been adopted as (a) its significance is immediately comprehensible, and (b) on the practical side, for the purpose for which the invention is intended, the effect that ensues is identical. The method in conformity with the invention foresees firstly, exploitation of X-ray diffraction on the crystal lattice, so that the incidental X-rays of fixed frequency are reflected at a characteristic angle dependent on both the frequency of the incidental rays on the structural properties of the material making up the reflective surfaces. Secondly, advantage is taken of the strength of the incidental X-rays to induce, in a target material, an emission of X-rays (of equal or greater wave length). A part of these X-rays will most certainly be emitted in the direction of the reflected rays increasing the overall intensity. The reflective surface, furthermore, is maintained in a suitably excited state for emission of X-rays. By virtue of this measure, the assumption is that the incidental X-rays induce emission of new X-rays through the target surface, without substantial loss of intensity, becoming fortified following reflection, due to the superposition of the rays emitted by induction in the direction of reflection. A preferred embodiment of an amplifying device for the practice of this method consists, basically, of two circular metal rings 1, 2 arranged concentrically so as to create a space or channel 3 between them. These circular rings 1, 2 can be made of any metallic material suitable, to reflect or to emit X-rays, and to the frequency of the incidental rays, to obtain the desired effect of amplification. This is achieved if the two circular rings are of a metal having an atomic number equal or lower to that of the anti-cathode of the tube producing the primary X-rays. For example, for one incidental X-ray obtained from a tungsten anti-cathode, the circular rings 1, 2 can be made, advantageously, of silver or tin or antimony, because these elements are of an atomic number inferior to that of tungsten, and also because their electronic levels are favourable to induced X-rays. In the space 3, there is an entrance channel 4, and an exit channel 5, both basically tangent to the inside circular rings 2, and at a proper angle so that the incidental X-rays, coming from the source 6, penetrate the space 3, through the entrance channel 4, and after several reflections leave the aforesaid space through the exit channel 5. The complete amplifying device is housed in a casing (not shown), such as a glass container, which can be emptied of air. In order to put the reflective surface 1, into a state of excitation it is sufficient to apply an appropriate difference of potential to the metallic rings 1, 2. Thus each metallic ring 1, 2 can be connected respectively to one pole of an electric mean 7, for example a suitable power supply. The applied potential difference must be superior to the highest typical potential of ionization of the metallic material of the rings 1, 2, to ensure a sufficient excitation of the electronic states in the metallic rings 1, 2. Nevertheless, to increase the excitation of the reflective surface, i.e., of the metallic ring 1, thus obtaining a greater amplification of the incident X-rays, an exciting gas can be introduced inside the space 3. The atomic number of the exciting gas must be higher than the atomic number of the metallic material of the rings 1, 2. As an exciting gas it is possible to use for example Xenon at pressures which vary i.e., from 10.sup.-3 to 10.sup.-5 mbar. It is assumed that the difference of potential applied, for example, 50 kvolts, ionizes the exciting gas accelerating the ions and electrons against the metal rings 1, 2 and inducing, in particular the circular ring 1 in a state of excitation fitting for X-ray emission. In this particular case the metallic rings 1, 2 work also as accelerating electrodes for the exciting gas particles. It is presumed that this state of excitation of the reflective metal also permits induction of X-ray emission without causing virtually any excessive weakening of the incidental X-rays and permitting therefore their amplification, as the electrons of the most internal strata have been blown up to a superior energy level obtaining an inversion of the electonic ambient favorable induction of new X-rays. Realization of the reflective and emission surfaces in the form of circular metallic rings (best if buffed to a high lustre) means that the problem, related to the precise direction of the subsequent surfaces of reflection and emission, is eliminated, rendering construction of the device, pertinent to the invention, particularly simple and efficaceous. In fact, because of the feature of the geometrical circular form of the external ring, with any angle of incidence whatsoever the reflection will be similar. According to their angle of incidence, the primary X-rays can also fall on and be reflected by the inner surface of the inner metallic ring 2. The dimensions of the X-ray amplifier, according to this illustrative example, must be established so that the number of reflections and emissions are sufficient to ensure a good amplification of primary ray intensity, with possible exploitation of any reflections on inside ring 2. Using, for example, circular rings of silver (or silver coloured metal), with the primary rays of inferior wave length to lambda=0.561 .ANG. typical of silver, emitted by an anticathode of tungsten, a reflection angle equal to approximately 3.degree.55', typical both for such a wavelength as well as the silver lattice (d=4.077 .ANG.), therefore along one circumference about 46 subsequent reflections can be observed. A practical embodiment for realization of the device according to the invention is made up of a glass ring fitted with two tangential channels for entrance and exit (as per FIGS. 1 and 2 in the attached drawing), housing inside it the two circular electrodes 1, 2 made from silvered tin and distant one from the other 2 cms, with V=50 kv. The outside diameter of the glass ring is 32.5 cms. and an inside diameter of 29.5 cms, it is closed at the two extremities, is vacuum and is filled with Xenon. In a further improvement of the invention, the two circular concentric rings 1, 2 can be made of any element suitable for X-rays emission, having in all cases either the same atomic number or a lower atomic number than that of the metallic anti-cathode of the tube producing the primary X-rays. Preferably the surfaces of the concentric rings or electrodes 1, 2 are buffed to a higher lustre in order to ensure very high reflections coefficients.