Browse Prior Art Database

MULTILAYER MATERIALS FOR X-RAY TARGET

IP.com Disclosure Number: IPCOM000198293D
Publication Date: 2010-Aug-03
Document File: 5 page(s) / 104K

Publishing Venue

The IP.com Prior Art Database

Abstract

A technique relating to a high power X-ray target with multilayer materials is disclosed. This technique proposes the use of a multiple layer material design for the X-ray target includes a high atomic number material and a good heat conduction material.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 5

RP13452

BRIEF ABSTRACT

    A technique relating to a high power X-ray target with multilayer materials is disclosed. This technique proposes the use of a multiple layer material design for the X-ray target includes a high atomic number material and a good heat conduction material.

KEYWORDS

    X-ray target, multilayer materials, Z number, Coefficient of thermal expansion (CTE), cathode, anode, tungsten, molybdenum, copper.

DETAILED DESCRIPTION

    Generally, an X-ray tube comprises a cathode which emits electrons into the vacuum and an anode to collect the electrons. Due to the flow of electrons from cathode to anode an electrical current/beam is flowing through the tube is established. A high voltage power source, for example 30 to 150 kilovolts (kV), is connected across the cathode and anode to accelerate the electrons. The X-ray spectrum depends on the anode material and the accelerating voltage.

    Electrons from the cathode collide with the anode material, which is usually tungsten, molybdenum or copper. Further, these electrons accelerate electrons, ions and nuclei within the anode material. About one percent of the

1

MULTILAYER MATERIALS FOR X-RAY TARGET

Page 2 of 5

RP13452

energy generated is emitted/radiated, usually perpendicular to the path of the electron beam, as X-rays. The rest of the energy is released as heat.

    Conventional X-ray targets face a problem of Coefficient of thermal expansion (CTE) mismatch of the material, Conventional X-ray targets include a rotating anode made of tungsten (W) and Titanium Zirconium Molybdenum (TZM) alloy. Such a target is generally used in medical x-ray tubes and relies on radiation to cool down. Another conventional X-ray target is made of W and Cu in industrial tubes. The CTE mismatch between W and Cu makes its joint interface vulnerable to thermal cycles during operation due to the thermal stress that the CTE mismatch causes.. CTE leads to cracking and X-ray target failure during thermal cycling. Further, transient layer material is used in conventional X-ray tubes to bind top and bottom layer material together. However such binding is very difficult for materials used in stationary X-ray tube. Examples of such materials are tungsten (W) and Copper (Cu). A similar solution is used in glass- envelope X-ray tubes in which a transition piece of glass with a graded C...