The invention relates to targets for an X-ray transmission tube ( 9 ); to a high efficiency, high excitation energy X-ray transmission tube; to combinations of the targets and high efficiency X-ray transmission tubes; and applications for utilizing such X-ray tubes. The target comprises two or more different thin foils ( 1 ) or at least two foils of the same material but different foil thickness on separate areas of a substantially planar substrate which is substantially transparent to X-rays. The target may also comprise at least two different foils ( 2, 3 ) layered sequentially one of the other, wherein X-rays are produced when an electron beam impinges the foil closest to the source fo the electron beam; wherein the energy of the electron beam is selectively changed to produce X-rays of a least one preselected energy characteristic of at least one of the foils.

High quantum energy efficiency X-ray tube and targets

A current sensor provides a voltage signal which is proportional to the average current flowing through a semiconductor device junction. This voltage signal is applied to a first analogue circuit which produces an output voltage indicative of the average power dissipated at the junction. The output of the first analogue circuit is applied to a second analogue circuit which outputs a voltage signal indicative of the temperature difference between the junction and a heat sink associated with the semiconductor device and to a third analogue circuit which outputs a voltage signal indicative of the temperature difference between the heat sink and ambient. The ambient temperature is sensed by an ambient temperature sensor which outputs a voltage signal indicative of the ambient temperature. A voltage summing circuit sums the output voltages from the second and third analogue circuits and from the ambient temperature sensor, and produces an output voltage indicative of the junction temperature.

Temperature monitoring of semiconductors

A simulator, in particular for simulating thermal batteries, the simulator delivering an output voltage Ubat across output terminals thereof, said output voltage being a function of a current Iout delivered, into a load connected to said terminals, and of an e.m.f. parameter. Eg and of an internal resistance parameter Rg that are determined from simulation profiles that give successive values taken by said parameters under real battery operating conditions during an active life cycle of a given battery. The simulator includes computer equipment delivering the simulation profiles in the form of e.m.f. references CEg and internal resistance references CRg to a battery simulation card which, in order to generate the output voltage Ubat of the simulator at the output of said voltage programmable power supply feeds said power supply with a battery voltage reference CUbat determined on the basis of a measurement of the current delivered by said power supply and on the basis of the e.m.f. reference and the internal resistance reference as received from the computer equipment.

Simulator, in particular of thermal batteries

For hybrid digital subtraction angiography mask x-ray images are made at low and high x-ray tube anode kVp. Both exposures are terminated by AEC and the exposure times are calculated and stored and used to govern the times of a subsequent run sequence of alternate low and high energy pre-contrast and post-contrast exposure images. The data for the mask and subsequent images are stored individually on magnetic disk. A TV camera receives optical versions of the images. Its target is scanned or read out during a TV frame time between the end of a low energy exposure and the start of a high energy exposure. After the low energy mask exposure time is determined an anticipation or delay time is calculated and the low energy exposures in the run sequence are shifted from the vertical blank pulse preceding the frame in which the exposure starts by the delay time so all low energy exposures terminate coincident with the blanking pulse that precedes the read out frame. Since the high energy exposures are started at the end of the readout, minimum time between low and high exposures is achieved. High kVp is fixed. Low kVp and tube MA are selectable. High MA that the tube target can withstand thermally is calculated and adjusted so it will not result in excessive tube target bulk or focal spot temperature.

Dual energy rapid switching imaging system

In an X-ray tube with a hydrodynamic slide bearing, an electron beam is caused to strike the focal point track area F on its rotary anode, which then emits X rays. An X-ray emission control device that sets the conditions for emitting the X rays stores as data the rises and drops in the temperature at the electron beam incident point and the other part on the focal point track surface of the anode. On the basis of the data, the input permission or inhibition conditions for the X-ray tube at every moment are calculated and the resulting conditions are displayed on a display unit. As a result, it is possible to perform a computing process in advance to determine whether or not X rays can be emitted under specific conditions without a permitting the rotary anode in the X-ray tube with a hydrodynamic slide bearing to melt and then display the results, thereby enabling a safe, efficient photographing control.

X-ray apparatus having a control device for preventing damaging X-ray emissions

PATENT APPLICATION For HEAT UNIT INTEGRATOR FOR X-RAY TUBES By John T. Perry Joel J. Schmutzer ABSTRACT Apparatus to indicate the temperature of an X-ray tube target includes an analog storage circuit to simulate the heat energy stored. Input signals representing the current and the voltage of the electron beam in the tube are multiplied to give a signal representing the instantaneous power input. The power signal is integrated in the storage circuit to give a temperature signal representing the total heat. input. The temperature signal is dissipated by a cooling curve circuit representing the heat loss with time.An indicator reads the temperature signal. Input voltage and current signals are processed to refer them to ground before multiplication. The current signal is corrected to set its zero value. The voltage signal derived from a transformer primary is corrected for transformer regulation. To eliminate spurious inputs the power signal is gated to the storage circuit only when a measured current is flowing. Multiple storage circuits indicating a number of tubes remember the temperature of their own targets while the power signal and the temperature indicator are being used with another storage circuit.

Joel John Schmutzer

Papers

Heat unit integrator for x-ray tubes