caption: Numbers indicate potential difference near the cup in kV
exif: {"Image DocumentName": "Numbers indicate potential difference near the cup in kV", "Image ImageDescription": "5.3 X-RAY TUBES Cathode. Biasing the focusing cup leads to a compression of the trajectories giving a smaller focus. With an increasing negative bias voltage at the focusing cup the focus size will decrease and finally the electron current will be pinched Off. Effect is sometimes used to electronically control the focus size or for a fast switching of the anode current (Grid Controlled Tubes) when short radiation pulses are required as in pulsed fluoroscopy. Numbers indicate potential difference near the cup in kV. IAEA. Review of Radiology Physics: A Handbook for Teachers and Students.", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}