Physics Coursework-1

VISIT TO ASHFORD HOSPITAL

In a group of 12, our physics group went to the Ashford hospital on the 1st February 08. We were guided by radiologists, who illustrated the process of Nuclear Medicine: gamma camera, x-ray machine: x-ray production and about the CAT scanner.

Identification of purpose of physics

The two aspects of physics that I am focusing on are the production of X-rays and the operation of Gamma camera.

X-ray is a highly penetrating electromagnetic radiation that contains a short-wavelength from a range 10-8m-10-11 m and frequency a higher than visible light. The main uses of x-ray are for diagnosis (the process that identified diseases in the human body) and therapy (detecting cancer and tumours n human body).  In both cases X-ray machine is used to penetrate the x-rays to the body and produce an image.

The gamma camera is a nuclear medicine devise that is used to view and analyse images of human body parts by injections or inhaling. This camera has large crystal detectors that detects the radiation signal and which then converts to faint light. This is then converted to electric signal and been reformed as an image by a computer (The images come sin grey scale).

Production of x-ray

The x-ray machine consists of an x-ray tube that contains two essential electrodes: the anode (target) made out of tungsten or any heavy metal and the cathode, which is used for the emission of electrons. The typical potential difference (kilo electrons kV) needed is the force that makes the electrons to accelerate.

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When the electrons are emitted from a heated filament, it accelerates at a high voltage. This allows the electrons to collide with the metal target. The kinetic energy is transferred into electromagnetic energy. Suddenly the collision slows down and then x-rays are produced in all direction of the target.  The projectile electron (electron travelling from the cathode to the anode) interact with the outer shell of the target atom, however sufficient energy is not been transferred to the outer shell, instead they are just raised to an exited level. During the process, about 99% of the kinetic energy is ...

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