Measurement And Study Of The Length And Area Of The Air Kerma Of The Diagnostic X-ray

Since the X-rays was discoveried by Wilhelm Conrad R?ntgen in 1895 and it rapidly applicate in medicine,the measurement of the X rays in medicine also comes with them.In the previous radiation dose measurements,the irradiation dose was used as a representation of the radiation dose,however,with the progress of science and technology,the irradiation dose has been unable to meet the demand of people for dose measurement,the air kerma is also released from it.The air kerma is very important for the dosimetry of ionizing radiation,and acts as the export volume of the international system of units.It is widely used in radiation therapy,radiation diagnosis,radio immunity and many other aspects,while the accurate measurement of air kinetic energy will be the top priority.At the paper thesis,I use the half value layer method to establish the medical diagnosis radiation quality RQR series whose voltage range is(40-150)kV and the radiation quality RQT series whose voltage range is(100-150)kV,basising IEC61627-2005 on the basis of the medium energy X ray standard of Chinese National Institute of Metrology,a total of 12radiations;The beam-defining slits are designed and processed by myself whose gap width can be adjusted and the variation range is(1-10)cm,in addition I also designed and processed the circular beam-defining slits which have different areas,the variation range is(0.79-158.96)cm~2;The theory of the integrated circuit of Labview is studied,and the capacitances and the TNC splices are purchased,I set up the weak current measurement system to measure the current of ionization chamber that is exposured and write the sofPTWare control system of measuring weak current;The absolute measurement and the theoretical calculation of the air kerma length and area is realized,the source of uncertainty in the practical application of this kind of instrument is obtained;The corresponding uncertainty is calculated and it is 2.2%which is meets the requirements of the IEC report within 5%error requirements through the uncertainty evaluation method.This work provides technical support for hospitals,research institutes and other units,and improves the research work of domestic diagnostic X ray air kerma in Chinese,and lays the foundation for international standards.