摘要:
An apparatus for measuring the concentration of radioactivity in a radioactive fluid discharged from a nuclear power plant. The apparatus comprises a radioactivity concentration measurement pipe arranged to extend vertically, fluid supplying means for supplying the fluid into the measurement pipe in such a manner that the fluid flows down through the measurement pipe along the axis of the measurement pipe without contacting the inner surface of the latter, radioactivity concentration measuring means disposed at the outside of the measurement pipe for measuring the radioactivity concentration in the fluid flowing in the measurement pipe, and means for discharging the radioactive fluid to the outside of the measurement pipe. The apparatus further comprises a gas supply pipe opening at its one end to the atmosphere and communicated at its other end with the inside of the measurement pipe, and a check valve disposed in the gas supply pipe and operated at a pressure higher than the atmospheric pressure. When the pressure in the measurement pipe has come down below the atmospheric pressure, the check valve is operative to always maintain the internal pressure in the measurement pipe at the atmospheric pressure, thereby to prevent the fluid level in the measurement pipe from being raised to reduce the background noise during the measurement of the radioactivity concentration.
摘要:
This invention relates to an apparatus for measuring the radioactive concentration of a radioactive material-containing liquid. In order to improve the measuring sensitivity of and miniaturize the apparatus, it includes a vertically-disposed outer cylinder, an inner cylinder disposed in and concentrically with the outer cylinder, a radiation detector disposed in the inner cylinder, a radioactive liquid feed means for supplying a radioactive material-containing liquid in the form of an annular current into an annular space between the inner and outer cylinders, a first cleaning water feed means for supplying a cleaning liquid along the inner surface of the outer cylinder, and a second cleaning water feed means for supplying a cleaning liquid along the outer surface of the inner cylinder. The cleaning water prevents the radioactive material from being deposited on the inner surface of the outer cylinder and the outer surface of the inner cylinder, and the measuring sensitivity of the apparatus from decreasing.
摘要:
In a radiation measurement apparatus, an analog pulse signal output from a semiconductor radiation detector is converted to a plurality of digital signals by an analog-to-digital converter for each analog pulse signal. A threshold circuit for inputting these digital signals discriminates digital signals exceeding a threshold value. A digital signal integration circuit integrates the plurality of discriminated digital signals for each analog pulse signal and obtains an integrated value for each analog pulse signal. A spectrum generation circuit for inputting the respective integrated values generates a radiation energy spectrum using the integrated values and accurately performs the quantitative analysis and energy analysis of a radioactive nuclide using the radiation energy spectrum. A quantitative analysis and an energy analysis of a radioactive nuclide can be accurately performed while a time resolution of a radiation detector can be maintained.
摘要:
At a worksite of a client, progeny nuclides of radon and thoron are collected into a filter, then making the gross measurement on α-ray amount within an hour from the collection. Next, the filter is sent to an analysis center with information added thereto, such as collection-condition information, gross-measurement information, and sampling-worksite information. At the analysis center, the gross measurement on the filter sent thereto is made again. Also, the radioactive-nuclide analysis is made to perform evaluation of the radioactivity intensity. Moreover, radon amount and thoron amount at the measurement-specimen sampling points-in-time at the worksite are calculated, then reporting the analysis result of the radon and thoron amounts to the client.
摘要:
A radiation imaging system is configured by a collimator 30A including a detector 21 with a discrete detection pixel corresponding with a pixel and a plurality of radiation passages 31 and looks into a plurality of detectors 21 through one radiation passage 31 to set a step width of rotation around a rotation center axis X1 only for an angle θp made by lines provided by connecting a center detector 21 of the radiation passage 31 and the adjacent two detectors 21. In the case of generating a flat plane projection image for one direction, radio-graphing is carried out on a projection image in a plurality of predetermined angle positions (−θp, 0, +θp) in the circumferential direction of the rotation center axis X1 and thereby one plane projection image is obtained.
摘要:
The semiconductor radiological detector 1 minimizes a dead space resulting from the draw-out of a signal line from an electrode and which allows a number of semiconductor devices to be densely arranged to improve sensitivity and spatial resolution. The semiconductor radiological detector 1 comprises a semiconductor device 2, an anode 3 attached to one surface of the semiconductor device 2, and a cathode 4 attached to the other surface of the semiconductor device 2. A signal line 5 is provided on the anode 3; the signal line 5 extends straight from the anode 3 and is connected to an X axis wire 12. Another signal line 13 is provided on the cathode 4; the signal line 13 extends straight from the cathode 4 and is connected to a Y axis wire 14.
摘要:
There are provided a radiation detection module, a printed circuit board, and a radiological imaging apparatus which make it possible to enhance spatial resolution without increasing channel number, and thereby to perform high-accuracy diagnosis. The radiation detection module includes a plurality of radiation detectors, and a wiring board on which the plurality of radiation detectors are mounted in a manner of being arranged in at least a radiation traveling direction. Here, on the wiring board, a pair of the radiation detectors which are adjacent to each other in the radiation traveling direction are electrically connected to each other, thereby configuring one detector structure (i.e., detection channel). Moreover, the radiation detectors are mounted onto the wiring board such that respective connection parts of electrodes, which are to be electrically connected to each other, are in a mutually-facing state.
摘要:
At a worksite of a client, progeny nuclides of radon and thoron are collected into a filter, then making the gross measurement on α-ray amount within an hour from the collection. Next, the filter is sent to an analysis center with information added thereto, such as collection-condition information, gross-measurement information, and sampling-worksite information. At the analysis center, the gross measurement on the filter sent thereto is made again. Also, the radioactive-nuclide analysis is made to perform accurate evaluation of the radioactivity intensity. Moreover, radon amount and thoron amount at the measurement-specimen sampling points-in-time at the worksite are calculated, then reporting the analysis result of the radon and thoron amounts to the client. There are provided an environmental-radioactivity measurement/management system which allows measurement specimens for measuring the environmental radioactivity to be processed at low cost and in large amounts, and the analysis method for the radioactivity intensity.
摘要:
Disclosed herein is a radiation imaging apparatus and radiation-imaging-apparatus-based nuclear medicine diagnosis apparatus having a collimator in which a plurality of rectangular through-holes are arranged in a grid pattern and separated by septa is rotated through a predetermined angle as viewed from above in relation to the layout of a plurality of rectangular detectors that are arranged in a grid pattern. The predetermined angle ranges from 20 to 70 degree and more preferably from 30 deg to 60 deg. With this configuration, the influence of sensitivity variations (moire patterns) that are included in an image picked up due to interference with a collimator when pixel type detectors are used is eliminated.
摘要:
A radiological imaging apparatus of the present invention comprises an image pickup device and a medical examinee holding device that is provided with a bed. The image pickup device includes a large number of radiation detectors and radiation detector support plates. A large number of radiation detectors are mounted around the circumference of a through-hole and arranged in the axial direction of the through-hole. The radiation detectors are arranged in three layers formed radially with respect to the center of the through-hole and mounted on the lateral surfaces of the radiation detector support plates. Since the radiation detectors are not only arranged in the axial direction and circumferential direction of the through-hole but also arrayed in the radial direction, it is possible to obtain accurate information about a γ-ray arrival position in the radial direction of the through-hole (the positional information about a radiation detector from which a γ-ray image pickup signal is output). The use of accurate information about γ-ray arrival increases the tomogram accuracy. As a result, the present invention enhances the tomogram accuracy, that is, the PET examination accuracy.