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公开(公告)号：JPH0743471A
公开(公告)日：1995-02-14
申请号：JP18375093
申请日：1993-07-26
Applicant: ALOKA CO LTD
Inventor： MATSUBARA SHOHEI , OSHIMA TOSHINORI , KANAZAWA HIDEO
Abstract: PURPOSE:To realize a structure, which excludes psychological sense of oppression, sense of fear and the like, which are applied on a person under examination, in a whole-body counter for measuring the radioactive amount in the body. CONSTITUTION:A detector 14 is provided at the side surface of a human body 12. The detector 14 is contained in a collimator 16. A shielding wall 24 is provided on the other side. At least the front side of the human body 12 has an open structure. Therefore, sense of oppression, sense of fear and the like do not occur in the person under examination.
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公开(公告)号：JPH0712939A
公开(公告)日：1995-01-17
申请号：JP15666193
申请日：1993-06-28
Applicant: ALOKA CO LTD
Inventor： NAKAOKA HIROSHI , OSHIMA TOSHINORI
Abstract: PURPOSE:To accurately measure dose equivalent in both cases where radiations having a single kind of energy are made incident and radiations having a plurality of kinds of energy are made incident. CONSTITUTION:Detectors 12, 14, and 16 are respectively constituted of sensors having different energy sensitivity and an energy assuming section 22 assumes the energy of incident radiations from the ratios between the count values N1 and N2 of the detectors 12 and 14 and between the count values N1 and N2 of the detectors 12 and 16. A response calculating section 25 finds the response at the assumed energy from the assumed energy. The count values N1, N2, and N3 are also inputted to a first, second, and third weighting section 40, 42, and 44, respectively. Each section 40, 42, and 44 multiplies each count value by a weighting factor and adds multiplied results. Each sum is corrected in sensitivity by means of each correction calculating section 28A, 28B, and 28C. As a result, 1-cm dose equivalent H1, 3-mm dose equivalent H2, and 70-7mum dose equivalent H3 are outputted.
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公开(公告)号：JPH03225293A
公开(公告)日：1991-10-04
申请号：JP2093790
申请日：1990-01-31
Applicant: ALOKA CO LTD
Inventor： KATO TORU , TATEISHI NAOKI , YANAI TOSHIO , OSHIMA TOSHINORI
Abstract: PURPOSE:To improve statistic accuracy with the lapse of time and to obtain a count value whose indication value is not sharply changed by displaying a counting rate value obtained by dividing an integrated value obtained by integrating values by an adder by the time required from detection start up to the current time. CONSTITUTION:When a radiant ray is injected into a detector 12, low pressure vapor (alcohol steam, etc.) is ionized, electric discharge is generated and a discharge current is instantaneously allowed to flow and A/D converted into a digital signal 100. The signal 100 is amplified by an amplifier 14 and the amplified digital signal 101 is counted by a counter 16. A sampling circuit 20 outputs a timing pulse 102 in each previously set time, the count value 103 of the counted signal 101 is outputted to an adder 18 in each timing and the counter 16 is reset by the count signal 103. The adder 18 integrates the count value 103 successively outputted from the counter 16 and outputs the total number 105 of counts from the count starting point up to the current point to a divider 24. The divider 24 calculates the count rate value, which is displayed on a display device 26.
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公开(公告)号：JPS63318060A
公开(公告)日：1988-12-26
申请号：JP15254187
申请日：1987-06-19
Applicant: ALOKA CO LTD
Inventor： KOYANO AKIRA , OSHIMA TOSHINORI , SATO HIROO , MAEKAWA HIROSHI , YANAI TOSHIO , YOSHIZUMI MINORU , SATOU SEIGO
Abstract: PURPOSE:To effectively prevent the incidence of ultraviolet rays or the like and correctly measure radioactive rays by forming a radioactive ray incidence window with titanium foil. CONSTITUTION:A radioactive ray incidence window 20 is formed with a layer of titanium foil, the radioactive ray incidence window 20 has the thickness of about 6-7mu, and its periphery is welded to a cathode cylinder 12. Since the titanium foil has sufficient strength regardless of its thickness of 6-7mu a counter tube 10 is not broken even if its interior is in a decompressed state. It abounds in the light shielding property and can reliably prevent the incidence of ultraviolet rays or the like. The miscount due to the photoelectric effect is thereby prevented, and radioactive rays can be correctly detected.
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公开(公告)号：JP2001042046A
公开(公告)日：2001-02-16
申请号：JP22084999
申请日：1999-08-04
Applicant: KAWADA TSUBAME , ALOKA CO LTD
Inventor： KAWADA TSUBAME , MATSUBARA SHOHEI , OSHIMA TOSHINORI
IPC: G01T1/208
Abstract: PROBLEM TO BE SOLVED: To effectively reduce after pulses being generated immediately after a main pulse in a measuring device using a photomultiplier. SOLUTION: Photomultipliers 22 and 26 are provided with heaters 24 and 28, and are heated at a prescribed temperature (for example, 40 deg.C) by the heaters 24 and 28. A signal-processing circuit 18 reduces thermal noise by so called coincidence counting. Highly accurate measurement can be realized by the reduction of after pulses due to the heating of the photomultipliers and that of thermal noise due to coincidence counting. A cooling mechanism for cooling a light reception surface may be provided.
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Patent Agency Ranking
公开(公告)号：JPH1039027A
公开(公告)日：1998-02-13
申请号：JP19993696
申请日：1996-07-30
Applicant: ALOKA CO LTD
Inventor： TATEISHI NAOKI , OSHIMA TOSHINORI
Abstract: PROBLEM TO BE SOLVED: To provide a personal dosimeter which is used by many people as a shared device and can be used as exclusive use one. SOLUTION: A personal dosimeter consists of a body unit 10 and a cartridge unit 20. The body unit 10 comprises a measuring mechanism that measures radiation dosage and a communication mechanism that communicate data to a managing device. The cartridge unit 20 comprises a secondary battery as well as a memory that stores personal identification information such as an ID number of an owner of the cartridge unit 20. When the cartridge unit 20 is inserted to a slot 100 of the body unit 10, an electric power is supplied to the body unit 10 from the secondary battery so that measurement can be executed. When measured data is transmitted to the managing device, the body unit 10 reads the personal identification information from the memory and transmits it to the managing device. After the device was used, the battery can be charged only by using the cartridge unit 20 so that the body unit 10 can be used soon by a next person.
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公开(公告)号：JPH09257940A
公开(公告)日：1997-10-03
申请号：JP6225896
申请日：1996-03-19
Applicant: ALOKA CO LTD
Inventor： IWAMOTO AKINORI , MATSUBARA SHOHEI , OSHIMA TOSHINORI
Abstract: PROBLEM TO BE SOLVED: To provide a radiation detector, with improved detecting limit, which can specify an incoming zone of radiation on a detecting face. SOLUTION: Four photomultiplier tubes 18-1 to 18-4 are arranged equally and symmetrically on a scintillator plate 12. Each of the photomultiplier tubes 18-1 to 18-4 is connected to pulse-height discriminators 24-1 to 24-4 through corresponding amplifiers 22-1 to 22-4, respectively. An output signal of each of the pulse-height discriminators 24-1 to 24-4 is branched to two signals, each of which is put into each of separate coincidence counters 26-1 to 26-4. Each of the coincidence counters 26-1 to 26-4 puts out an AND result of the two input signals, and each of counters 28-1 to 28-4 counts an output pulse of the corresponding coincidence counters 26-1 to 26-4, respectively. By this constitution, outputs of an adjacent pair of the photomultiplier tubes 18-1 to 18-4 are coincidence-counted, respectively. These pairs cover different zones of the scintillator plate 12, and the zone area is small. Thus, detection limit for each pair is improved, and a main incoming zone of radiation can be estimated from combinations of counting results of the pairs.
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公开(公告)号：JPH0921880A
公开(公告)日：1997-01-21
申请号：JP17320295
申请日：1995-07-10
Applicant: ALOKA CO LTD
Inventor： NAKAOKA HIROSHI , IWAMOTO AKINORI , MATSUBARA SHOHEI , OSHIMA TOSHINORI
Abstract: PROBLEM TO BE SOLVED: To accurately compute dose equivalent of βrays in a mixed field of β, γ rays by subtracting mixed γ counting value from the total counting values of βsensor, and computing only the β counting value of only βrays. SOLUTION: Both β rays and γ rays are detected with a βsensor, and only γrays are detected with γ sensors 14, 16, 18. A preamplifier 30, a discriminator 32, a counter 34 are arranged between each of sensors 12, 14, 16, 18, and a computing part 28. A count value of each sensor is inputted into the computing part 28, and a γ sensitivity table 36 for the β sensor, a βsensitivity memory 38 for the β sensor, a γ sensitivity table 40 for the γ sensor, a γ energy estimation table 42, a dose equivalent conversion factor table 44, a display 46, and a printer 48 are connected to the computing part 28. The counting value of mixed γ rays in the total counting values of the βsensor is estimated by multiplying the amount of γ rays by the γ sensitivity of the β sensor. The mixed γcounting value estimated is subtracted from the total counting values of the βsensor, and true β counting value is found. The dose amount or dose equivalent is computed with the computing part 28 from the true β counting value obtained.
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公开(公告)号：JPH0743472A
公开(公告)日：1995-02-14
申请号：JP18393093
申请日：1993-07-26
Applicant: ALOKA CO LTD
Inventor： MATSUBARA SHOHEI , OSHIMA TOSHINORI
IPC: G01T1/20
Abstract: PURPOSE:To perform the measurement of radiation accurately regardless of the amount of sample liquid. CONSTITUTION:A detecting part is constituted of two detecting parts 30 and 32, which are arranged at the upper and lower sides. The efficiency correcting value is obtained based on the fact that the ratios of the counted values of two detecting parts are different in response to the amount of sample liquid 12. The correcting value is multiplied by the total counted value of the counted values, and the true counted value is obtained. Even if the radioactive material is precipitated in the sample 12, the correction is performed in response to the intrinsic sample amount.
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公开(公告)号：JPH05232239A
公开(公告)日：1993-09-07
申请号：JP3819392
申请日：1992-02-25
Applicant: ALOKA CO LTD
Inventor： NAKAOKA HIROSHI , OSHIMA TOSHINORI
Abstract: PURPOSE:To accurately measure a neutron with high sensitivity. CONSTITUTION:A nuclear reaction substance 12 which emits charged particles by generating a nuclear reaction with neutrons, a semiconductor detector 14 detecting particles emitted by the nuclear reaction substance 12 via a predetermined air layer on the rear side of the neutron flying direction of the nuclear reaction substance and a shield member 18 shielding the nuclear reaction substance 12 and the semiconductor detector 14 from neutrons are provided. When neutrons are made incident, a part thereof passes through the shield member 18 to be directly brought into nuclear reaction with the nuclear reaction substance 12 and the greater part of the neutron incident on a human body 100 from an area other than the shield member 18 is reflected by the human body 100 and a part of the reflected neutron passes through the hole 18a of the shield member 18 to directly generate the nuclear reaction with the nuclear reaction substance 12. Charged particles generated by nuclear reaction are detected by the semiconductor detector 14 and the detection signal of the detector 14 is counted and energy and the number of neutrons are calculated by an operation circuit to be displayed on a display circuit.
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