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Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode.

Sakabe N, Ohsawa S, Sugimura T, Ikeda M, Tawada M, Watanabe N, Sasaki K, Ohshima K, Wakatsuki M, Sakabe K - J Synchrotron Radiat (2008)

Bottom Line: When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode.Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life.A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

View Article: PubMed Central - HTML - PubMed

Affiliation: PF, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan. nsakabe@sbsp.jp

ABSTRACT
A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

No MeSH data available.


Related in: MedlinePlus

Design of the new X-ray generator, in which the direction of the electron beam used to irradiate the target is the same direction as the centrifugal force.
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fig1: Design of the new X-ray generator, in which the direction of the electron beam used to irradiate the target is the same direction as the centrifugal force.

Mentions: To overcome such limitations, we have developed a U-shaped rotating-anticathode (Sakabe, 1995 ▶) X-ray generator in which the target is irradiated by the electron beam such that the centrifugal force is in the same direction as the electron beam, as illustrated in Fig. 1 ▶. In this case, (i) the power of the electron beam can be increased to melt the irradiated part of the target, because the melted metal is strongly fixed to the target by the strong centrifugal force, which is at least ∼2000 times stronger than the gravity on the earth when it is calculated by the parameters listed in Table 1 ▶; (ii) when the target surface is melted by the strong electron beam, the surface roughness caused by the thermal stress is reset and the surface is kept very smooth by the strong centrifugal force; (iii) the chances of an irregular electric discharge are extensively reduced, because a high electric field only exists between the cathode and the anode, whose temperature is not high, and the electron beam is bent 180° by the bending magnet (Ohsawa, 2004 ▶), while the metal atoms and/or ions from the target do not have a detrimental effect on the cathode because of the presence of the bending magnet. Therefore the particles do not get into the high electric field region.


Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode.

Sakabe N, Ohsawa S, Sugimura T, Ikeda M, Tawada M, Watanabe N, Sasaki K, Ohshima K, Wakatsuki M, Sakabe K - J Synchrotron Radiat (2008)

Design of the new X-ray generator, in which the direction of the electron beam used to irradiate the target is the same direction as the centrifugal force.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2394780&req=5

fig1: Design of the new X-ray generator, in which the direction of the electron beam used to irradiate the target is the same direction as the centrifugal force.
Mentions: To overcome such limitations, we have developed a U-shaped rotating-anticathode (Sakabe, 1995 ▶) X-ray generator in which the target is irradiated by the electron beam such that the centrifugal force is in the same direction as the electron beam, as illustrated in Fig. 1 ▶. In this case, (i) the power of the electron beam can be increased to melt the irradiated part of the target, because the melted metal is strongly fixed to the target by the strong centrifugal force, which is at least ∼2000 times stronger than the gravity on the earth when it is calculated by the parameters listed in Table 1 ▶; (ii) when the target surface is melted by the strong electron beam, the surface roughness caused by the thermal stress is reset and the surface is kept very smooth by the strong centrifugal force; (iii) the chances of an irregular electric discharge are extensively reduced, because a high electric field only exists between the cathode and the anode, whose temperature is not high, and the electron beam is bent 180° by the bending magnet (Ohsawa, 2004 ▶), while the metal atoms and/or ions from the target do not have a detrimental effect on the cathode because of the presence of the bending magnet. Therefore the particles do not get into the high electric field region.

Bottom Line: When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode.Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life.A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

View Article: PubMed Central - HTML - PubMed

Affiliation: PF, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan. nsakabe@sbsp.jp

ABSTRACT
A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

No MeSH data available.


Related in: MedlinePlus