| Автор | I A Brezovich |
| Автор | G T Barnes |
| Дата выпуска | 1980-03-01 |
| dc.description | It was observed that the radiation output of X-ray tubes falls off exponentially during an exposure with a time constant of about 120 ms. The equilibrium value is approximately 15% lower than that at the beginning of the exposure. The clinically noticeable consequences are discrepancies in X-ray generator calibration, the loss of the strict mA s (tube current*exposure time) linearity, and, in scanning devices, the possibility of artefact generation. A systematic investigation of the phenomenon revealed that it is caused by the cooling of the cathode due to evaporation of electrons. Theoretical expressions for the magnitude and time constant of the fall-off derived from basic thermodynamics are in good agreement with the observations. A simple mA stabilisation circuit which prevents the fall-off is described. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | An investigation and explanation of the fall-off of X-ray tube current during an exposure |
| Тип | paper |
| DOI | 10.1088/0031-9155/25/2/004 |
| Electronic ISSN | 1361-6560 |
| Print ISSN | 0031-9155 |
| Журнал | Physics in Medicine and Biology |
| Том | 25 |
| Первая страница | 241 |
| Последняя страница | 249 |
| Аффилиация | I A Brezovich; Univ. of Alabama School of Medicine, Birmingham, AL, USA |
| Аффилиация | G T Barnes; Univ. of Alabama School of Medicine, Birmingham, AL, USA |
| Выпуск | 2 |
