41 results about "Low dose rate" patented technology

Methods of forming a low-dose-rate (LDR) brachytherapy device include depositing a solution comprising a soluble form of a radioactive material on a substrate. A water-insoluble form of the radioactive material is formed on the substrate by chemical precipitation and/or thermal decomposition.

In order to provide a high accuracy radiation dose rate measurement system by good energy characteristics without deteriorating the original energy characteristics of a low dose rate range due to widening range, the dose rate measurement system is composed of: a radiation detector which sends a discrete current pulse having electric charge proportional to incident radiation energy and a DC voltage in which a DC current proportional to the radiation energy is converted; a high voltage power source which supplies a high voltage that operates the radiation detector; and a measurement unit in which the current pulse and the DC voltage are applied from the radiation detector to be converted to a low range dose rate and a high range dose rate respectively, and the low range dose rate and the high range dose rate are switched to be sent depending on the dose rates.

A system and method is disclosed for providing an integrated circuit that has increased radiation hardness and reliability. A device active area of an integrated circuit is provided and a layer of radiation resistant material is applied to the device active area of the integrated circuit. In one advantageous embodiment the radiation resistant material is silicon carbide. In another advantageous embodiment a passivation layer is placed between the device active area and the layer of radiation resistant material. The integrated circuit of the present invention exhibits minimal sensitivity to (1) enhanced low dose rate sensitivity (ELDRS) effects of radiation, and (2) pre-irradiation elevated temperature stress (PETS) effects of radiation.

The invention discloses a method for an in-situ test of a high-energy electron irradiation effect of an electronic component under a temperature changing condition based on an argon environment, and relates to the field of electronic technologies. The invention aims to solve the problem that during ground irradiation of an electronic component, due to influence of an environmental atmosphere and a temperature, an electrical property in-situ test is not accurate and the evaluating efficiency is low. The method disclosed by the invention adopts the argon environment, so that the influence of oxygen in the air and the influence of a negative pressure in vacuum irradiation in a process of irradiation test in the past can be effectively eliminated, and the accuracy of the in-situ test of the electronic component can be improved. Temperature-changing irradiation is performed during irradiation, and an environmental temperature condition for work of a bipolar transistor is selected in a temperature interval, so that according to the method, a low-dose rate enhancement effect acceleration test method that the in-situ test method has simple steps and is easy to operate. The method disclosed by the invention is suitable for space irradiation effect research and test of a bipolar electronic component.

The invention provides a method for extracting a radiation defect of a linear circuit. The method comprises: step 100, analyzing the linear circuit to determine discrete devices to be separated; step200, cutting and separating the discrete devices to be separated; step 300, testing the electrical properties of the separated discrete devices for screening; step 400, extracting an electrode from the screened discrete devices; step 500, testing the defect on the discrete devices by the extracted electrode. According to the method for extracting the radiation defect of the linear circuit, the discrete devices in the linear circuit are separated for extracting the electrode by the cutting and screening the discrete devices, so that the defect test can be independently performed on the discretedevices in the linear circuit, so that the research of the existing enhancement effect with a low dose rate is enriched, and a better research effect is achieved.

The invention discloses a low-dose-rate irradiation damage enhancement effect judgment method. The method comprises the following steps: 1) obtaining an electrical parameter test result of a to-be-tested object before irradiation; 2) manufacturing a plurality of irradiation test circuit boards, and carrying out ionization irradiation tests with different dose rates and different offsets to obtainelectrical parameter test results of a plurality of irradiation dose points; 3) determining the ratio of the electrical parameter degradation amount of the to-be-tested object and the electrical parameter degradation reliability influence factor of the to-be-tested object; and 4) judging whether the to-be-tested object has low-dose-rate irradiation damage enhancement effect or not according to theratio of the electrical parameter degradation amount and the electrical parameter degradation reliability influence factor. According to the method, high-dose-rate irradiation tests and low-dose-rateirradiation tests are carried out separately, high-dose-rate and low-dose-rate comparison data are obtained, the component parameter degradation factor and the low-dose-rate irradiation damage enhancement factor are considered, and the judgment result about whether an aerospace component has the low-dose-rate irradiation damage enhancement effect or not is obtained.

An X-ray image capturing apparatus includes: scanning and signal lines; an X-ray sensor; detecting elements; a switching element to make charges accumulated in response to an OFF voltage and released in response to an ON voltage; a scan driving unit to switch a voltage applied to the scanning lines between ON and OFF voltages; a readout circuit to read the charges as image data; and a control circuit to detect an irradiation start by a first scheme based on a current increase due to X-ray irradiation or a second scheme based on an output from the X-ray sensor and to turn off the switching element to make charges accumulated if the first or second scheme detects the irradiation start, wherein a detection threshold is set such that the second scheme has a slower response and can detect an X-ray at a lower dose rate than the first scheme.

The invention discloses a small GM counting tube wide-range monitoring instrument. The instrument comprises a high-voltage module used for providing high work voltage for a GM counting tube, the GM counting tube used for monitoring the dose rate level of an environment in real time, AD integral collecting units used for collecting integrals of output signals of the GM counter tube, a high-voltagemeasuring unit used for measuring the output voltage of the high-voltage module, a shaping and pulse counting unit used for monitoring the pulse count number of the output signals of the GM counter tube in real time, and an MCU circuit used for logically judging data of each collecting unit and judging whether the pulse count number of the GM counter tube or a collecting result of the integrals ofthe output signals of the GM counter tube is adopted for measuring a dose rate. On the basis of the calculation of a judgement result, a final dose rate measuring result is obtained; the technical effect of automatic switching between a low dose rate level and a high dose rate level of the output signals of the GM counter tube is achieved.

In an exemplary process for lower dose rate ion implantation of a work piece, an ion beam may be generated using an ion source and an extraction manipulator. The extraction manipulator may be positioned at a gap distance from an exit aperture of the ion source. A current of the ion beam exiting the extraction manipulator may be maximized when the extraction manipulator is positioned at an optimal gap distance from the exit aperture. The gap distance at which the extraction manipulator is positioned from the exit aperture may differ from the optimal gap distance by at least 10 percent. A first potential may be applied to a first set of electrodes. An x-dimension of the ion beam may increase as the ion beam passes through the first set of electrodes. The work piece may be positioned in the ion beam to implant ions into the work piece.

The invention discloses a preparation method of high-performance modified starch. The method comprises the following steps: putting dry starch into a sealed packet, firstly performing positive surfaceirradiation treatment with low dosage rate on the sealed packet, oxygenating the interior of the sealed packet, shaping the oxygenated sealed packet, and finally performing negative surface irradiation treatment with high dosage rate on the sealed packet, so as to obtain the high-performance modified starch. The method has the advantages that comprehensive irradiation technologies, such as oxygenation, alternative irradiation with different dosage rates, packaging and shaping and overturning, are adopted, so that the irradiation dosage unevenness is smaller than 1.1, the viscosity volatilityof the starch subjected to irradiation modification is smaller than 10 percent, the irradiation efficiency is high, and the cost is reduced.

The invention discloses a counting method based on segmentation proportion jump threshold judgment, and the method comprises the following steps: segmenting a counting value of a counter, and determining jump smoothing time, non-jump smoothing time and a jump trigger coefficient of each segmented region; judging a segmented region where a count value of a counter is located during dose rate measurement, and obtaining jump smoothing time, non-jump smoothing time and a jump trigger coefficient corresponding to the count value according to the segmented region; for a count value of a counter during dose rate measurement, if a count of mean smoothing calculation by adopting jump smoothing time is greater than a count of mean smoothing calculation by adopting non-jump smoothing time * a jump trigger coefficient of a segmented region where the count value of the counter is located, adopting the jump smoothing time to perform mean smoothing calculation counting; otherwise, using non-hopping smoothing time to carry out mean smoothing calculation counting. According to the invention, the response time to the dose rate change of the surrounding environment of the counter is short, and the counter can also respond quickly under the condition of low dose rate.

The invention relates to a method for evaluating biological damage caused by low-dose gamma ray irradiation by utilizing isocitrate dehydrogenase 2. According to the dose-effect relationship between the irradiation dose of low-dose gamma rays received by a C57BL/6J mouse and the down-regulation rate of the relative expression quantity of IDH2 in serum, the down-regulation rate of the relative expression level of IDH2 in the serum of a C57BL/6J mouse, biological damage from low-dose gamma radiation was assessed. On the basis of establishing a low dose rate irradiation C57BL/6J mouse model, significant differential expression protein is screened out by using an iTRAQ technology and is verified by using Western blot. The method for evaluating biological damage caused by low-dose gamma ray irradiation by utilizing isocitrate dehydrogenase 2 has the advantages of sensitivity to low-dose radiation, high reliability, strong specificity and the like.