摘要:
An apparatus for engagement with a LINAC head of a LINAC machine, the LINAC machine generating radiation for intensity modulated radiation therapy of a cancer patient. The apparatus is a member incorporating separately a beam shaping material and a beam sculpting material. The member typically includes a tray and the tray is designed to fit into or adjacent the head of a LINAC machine. When radiation passes through the tray mounted member, it will be modulated and shaped to conform to the tumor of the cancer patient, which patient is radiated by the modified radiation beam.
摘要:
An apparatus for engagement with a LINAC head of a LINAC machine, the LINAC machine generating radiation for intensity modulated radiation therapy of a cancer patient. The apparatus is a member incorporating separately a beam shaping material and a beam sculpting material. The member typically includes a tray and the tray is designed to fit into or adjacent the head of a LINAC machine. When radiation passes through the tray mounted member, it will be modulated and shaped to conform to the tumor of the cancer patient, which patient is radiated by the modified radiation beam.
摘要:
In order to eliminate the day-to-day gyro drift phenomena which result from interaction of the magnetic pole position of the synchronous motor typically used to drive the gyro and the gyro wheel, an induction motor controlled by a phase locked loop referenced to an appropriate control frequency is utilized to drive the gyro.
摘要:
A device for compensating for gyro wheel frequency inaccuracies wherein a reference oscillator feeds a square wave signal to a first and second counter. The second counter also has an input of plus or minus the spin axis angular rate. The first counter scales down the reference signal and the second counter generates a signal having a frequency proportionately higher than the first counter. The output of the second counter provides a signal indicative of angular spin rate displaced from the input gyro axis. The outputs from the first and second counters are fed to an up/down counter which combines the two signals to provide for gyro wheel compensation.In a second embodiment of the invention a computer having spin rate axis signal from two gyros, control two settable counters to obtain compensation of the gyro wheel of a first and second gyro.
摘要:
A computer system is provided for reconstructing a word, which is altered during cycling of the computer memory when a nuclear event occurs. The computer system includes a nuclear event detector, a circuit for setting flags in response to the detection of an event, a generating circuit for generating a random variable time interval in response to the flags, a circuit for performing block parity on the data in the memory in response to the flags, and correcting circuit for correcting the altered word in the memory in response to the block parity circuit. The computer system further includes a circuit for correcting multiple memory word upsets in response to the block parity circuit and an updating circuit for performing block parity during sequential storage or random storage of the data words before or after an event.
摘要:
An electro-static capacitive accelerometer is a square law device and includes two fixed plates and an intermediary movable plate. A control circuit detects unbalances in the accelerometer, due to acceleration, and generates a signal which induces a corresponding electro-static corrective torque on the accelerometer thus forcing it toward a null condition. The signal is proportional to the acceleration. The invention eliminates prior art summing amplifiers in the control circuit for linearizing the torque of the accelerometer.
摘要:
A ring laser gyro is electromechanically oscillated so that oppositely moving light beams in the gyro do not exhibit an undesirable lock-in effect. A piezoelectric transducer mounted in the gyro measures the dither. Analog/digital circuitry converts the measurement to digital dither signals. A non-compensated beam combiner and photodetector assembly are integrally mounted to the gyro for producing beam frequency outputs from the light beams, indicative of inertial rotation of the gyro. The beat frequency outputs and dither signal are input to logic circuitry which eliminates the effect of the dither signal on the beam frequency output signals.
摘要:
A piezo-electric crystal vibrating in several modes controls several frequencies generated by voltage controlled oscillators simultaneously. The output of each voltage controlled oscillator is fed to a summing amplifier which drives the crystal. The output of the crystal is fed to individual phase detectors; each phase detector is also supplied with the output of a voltage controlled oscillator and generates a voltage proportional to the phase difference between the voltage controlled oscillator and the crystal output for correcting the output frequency of each oscillator.
摘要:
An error correction system is provided for a random access memory system of the magnetic core or plated wire type, and which serves to render the memory system immune to the effects of nuclear radiation, and the like. The system of the invention includes circumvent circuitry which serves to limit all currents in the memory access network to safe values during a radiation event, so as to pevent burn-out of the memory and of its associated components. The system of the invention also serves to correct single word errors which can occur to words being written or read during the radiation pulse. The single word error correction is achieved in a first embodiment of the invention by partitioning the fixed data program words in the memory into blocks; by providing an error correction word for each such block, and by reconstructing from the error correction word, the word being read or written during the radiation pulse. This is achieved in the first embodiment of the error correction system by first accessing the affected word, then loading all zeros into the memory address of the affected word, and then reconstructing the effected word by the provision of an "exclusive or" summing means which forms a computed error correction word for the entire block, including the affected word (which is now zeros), plus the original error correction word. The computed error correction word is a reconstruction of the affected data word. A second embodiment of the invention achieves the same correction in the case of the variable data storage portion of the memory, by means of a system which continuously up-dates the error correction word as the variable data in the memory is up-dated. Further embodiments of the invention provide error correction to the variable data words without the use of error correction words.