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.

The Energy of X-ray

All radiant energy, including X-ray, has its origin in a disturbance of electrical charge. Consider a point charge — an electron — surrounded by a symmetrical electromagnetic field and moving through space at constant velocity. What happens to the motion of the field if the central charge is speeded up or slowed down? Experiments indicate that the field reacts much like a mass of jelly. When the central charge is accelerated, the disturbance is communicated radially through the field as a wave motion — the outside parts of the field requiring an appreciable time interval to catch up with the center. Work expended in accelerating the central charge is carried away by the wave as radiant energy, at a velocity which depends on the nature of the “jelly.”

Tungsten alloy is a suitable material for radiation protection, for more details, you could visit: http://www.tungsten-alloy.com/en/alloy07.htm.

X-ray Tungsten Alloy Radiation Protection for Bone Study

X-ray has a science function on bone study in medical field, and it tends to flow through the skin and away from vital organs such as the heart.

In this case, instead of filling with a lavender glow, like the quartz bulb, the inside of the tungsten alloy tube remained dark but the glass in contact with the magnesium lighted with a pale greenish fluorescence that reminded me of the glow emitted by old style X-ray tubes of the gas type, which is of tungsten alloy radiation protection.

Like visible light, X-rays are a form of radiant energy. Exports have solved the problem of equipment cost. Protection against exposure to the rays is not difficult to arrange. With these two considerations out of the way, X-rays open a range of experiments equaled by few other phenomena of physics. In addition to providing a source of X-rays for radiographs, a generator of X-rays in combination with accessories enables you to measure the charge of the electron, to study the structure of crystals, to observe the wave-particle duality of matter and radiation, and to probe other microcosmic corners. During this process, tungsten alloy material will be a suitable material for radiation protection. For more details, you could visit http://www.tungsten-alloy.com/en/alloy07.htm.

The Substituation of Tungsten Plastic to Lead in Molded Products

There is a technique of tungsten plastic to develop tungsten-filled plastics that can replace lead for radiation protection. 

This technique has converted more than 50 lead-shielding parts with a proprietary non-lead, polymer shielding material. Tungsten plastic technique is more and more popular for radiation protection now. Lead may be the asbestos of the 21 Century, but tungsten material superior in its high specific density and denser gravity. Medical device manufacturers in the United States also expect to face stiff regulations on use of lead. Tungsten in a nylon 6 base offers equivalent X-ray shielding and can be molded on standard equipment. However, as a new type technique applied on tungsten plastic, the manufacture cost will be expensive but it has an effective function to absorb radiation better than lead. For more details, you could visit http://www.tungsten-alloy.com/tungsten-plastic.html.