Tungsten Alloy Shielding for Gamma Sources of Cesium 137

A new technology for gamma shielding is already used as tungsten alloy material radiation protection. There is a research for special tungsten alloy material for gamma sources of Cesium 137, which is a lead-free radiation protective fabric in a form of a blanket created with nanotechnology. It could reduce emission from high energy gamma sources such as Cesium 137. Such material might be hidden beneath the silicon ceramic or inside of the cylindrical body of E-cat HT where the heaters are placed.
As its high density, good machinability, high hardness, excellent elongation, wear resistance, tungsten alloy material is more and more popular for gamma sources shielding and protection. For more details, you could visit http://www.tungsten-alloy.com/tungsten-alloy-radiation-shielding.html.

Tungsten Alloy Shielding for Gamma Radiation

Gamma rays emitted from the nickel nanopowder that is closer to the cylindrical enclosure will be stronger. From the publicly released information by Focardi and Rossi it is known that a small gamma radiation exists. For this purpose the E-cat described in the Rossi patent contains a lead jacket. For the E-cat HT reactors that were tested by G. Levi et al., however, a lead jacket was not noticed. This does not mean that there is not any radiation shield. With the advancement of nanotechnology a new way of effective gamma radiation shield is developed. This has been in focus of NASA research for years.
Tungsten alloy material is suitable for gamma radiation protection, for more details, you could visit http://www.tungsten-alloy.com/tungsten-alloy-radiation-shielding.html.

Gamma Radiation from the Nickel Nanopowder

For gamma energy in the order of 6 MeV, the wavelength is about 0.2 pm. This wavelength is a few orders smaller than the gaps between the nanopowder particles. The gas occupying the gaps has a refractive index close to one, while the refractive index of the nanoparticle material for the wavelength of 0.2 pm is much higher. Then the emitted gamma rays from the nickel nanopowder in the bulk will undergo multiple reflections, refractions and absorption, so the energy they loose will be converted to heat. Some proper attenuated gamma rays will produce Rydberg hydrogen that is useful for the cold fusion. Only not absorbed attenuated gamma rays may escape the fuel powder, so they must be shielded.
Tungsten alloy material is suitable for gamma radiation protection, for more details, you could visit http://www.tungsten-alloy.com/tungsten-alloy-radiation-shielding.html.

X-ray Output & Tungsten Alloy Anode

The area over which the electrons from the cathode strike tungsten alloy anode is referred to as the focal spot. The cooler the anode can be kept, the smaller the focal spot can be and the greater the image detail that is possible. If a high X-ray output is required, a larger focal spot would be needed to mitigate the temperature increase.

In the early tubes the angle of the target was usually 45 degrees (see figure below left). Later tubes often employed the so-called line-focus principle in which the target angle was closer to 20 degrees (see figure below right). This reduced the effective area of the focal spot (as viewed from the perspective of the object being x-rayed permitted) without significantly affecting the area of the anode bombarded by the electron beam from the cathode. In other words, it permitted high loading (x-ray intensity) without having to sacrifice image details.

Tungsten Alloy Anode for X-ray Radiation

Tungsten alloy anode is the most commonly used target material because it has a high atomic number which increases the intensity of the x-rays, and because it has a sufficiently high melting point that it can be allowed to become white hot.

During operation, the tungsten alloy anode can get as high as 2,700 degrees centigrade. In many cases, it is surrounded by copper - the high heat capacity of copper improves the dissipation of heat. It is very suitable for X-ray radiation.

X-rays Shielding Calculation

Like gamma rays, X-rays have no definite range - the intensity of radiation transmitted through a material falls exponentially with the thickness of the material. Tungsten alloy X-rays shielding become more and more popular for radiation protection. Following is the calculation:

I = Io e-ux

where u is the linear attenuation coefficient of the material

For typical 50 KeV X-rays the half value thicknesses, H1/2 = 0.69/u, for some common materials are

         Air                     H1/2 ~ 10m

        Body tissue          H1/2 ~ 3 cm

        Lead (Pb)             H1/2 ~ 0.1 mm

        Steel                    H1/2   ~ 0.5 mm

An attenuation of I/Io = 10-10 is achieved by lead of thickness 3.3 mm or by steel of thickness 16.6 mm.

What is X-ray Spectrum

Most of the X-ray output of rotating anode sources has a continuous energy range that extends up to a value, Emax that, measured in electron volts, is equal to the acceleration voltage applied to the tube.. This Bremsstrahlung ("braking radiation") arises from the accelerations suffered by the electrons during collision with the atoms of the anode, then that is the X-ray spectrum, superimposed on the Bremsstrahlung background there are intense narrow line emissions that are characteristic of the material of the anode. These characteristic lines are important for crystallography but since they amount to only a few percent of the total X-ray output they are of little radiological importance. For the radiation during this whole process, tungsten alloy shielding will be the ideal material for radiation protection, for more details, you could visit our website: http://www.tungsten-alloy.com/X-ray-target-collimator.htm.