We developed a 16 k dots × 100 lines Wiener spectrum measurement system using a microscope-television camera system. Heretofore, the granularity of film was evaluated from Wiener spectrum using Wiener spectral value in the spatial-frequency independent region, but this factor is determined by the measurement system and the film emulsion density and there were problems in the evaluation of granularity. We established a new method for evaluating the granularity from Wiener spectral values in the spatial-frequency independent region through Wiener spectrum measurement system that utilized a microscope-television camera system as the input device.

View full abstract

A pulsed x-ray source operated at high repetition rates utilizing a triode for biomedical radiography is described. This source consisted of the following components: a high-voltage generator, a pulse condenser, a repetitive impulse switching system, a turbo molecular pump, and a pulsed x-ray to tube having a cold cathode. The x-ray tube was of the triode type which was connected to the turbo molecular pump. The pulse condenser was charged from 30 to 100kV by the constant voltage generator and was discharged repetitively by an impulse switching system utilizing a frequency control system with a high time resolution. The maximum frequencies varied according to the charging voltage, the condenser capacity, and the current capacity of the high-voltage generator. The frequencies of this generator were less than 100HZ, and the pulse widths of the pulsed x-rays were less than 300ns. The effective focal spot size was determined by the diameter of the anode tip and ranged from 0.1 to 3.0mm in diameter.

View full abstract

A high-intensity single-flash x-ray generator utilizing a triode is described. This generator was constructed in order to obtain the stable flash x-rays at the low operating voltage of about 50kV and consisted of the following components: a high-voltage power supply, a coaxial oil condenser of 100kV-200nF, a gas gap switch having a high-energy trigger device, a low-impedance coaxial transmission line, a turbo molecular pump, and a x-ray tube of the triode type. This generator may be used for condenser charging voltages of 40-100kV and the peak currents of 10-40kA. The pulse widths of the flash x-rays were almost constant and their values were about 300ns. The time integrated x-ray intensity varied according to the charging voltage, anodecathode (A-C) impedance, and the diameter of the anode rod and its maximum value was about 5 x 10^-6 C/kg at 1m per pulse. The effective focal spot was primarily determined by the diameter of the anode tip, and it ranged from 0.5 to 3.0 mm in diameter. The x-ray quality of flash xray source tended to become hard according to increases in the charging voltage and to increases in the A-C impedance.

View full abstract