Fig.1 TK-501 Underwater Gamma Spectrometer
TK-501 Underwater Gamma spectrometer is a highly sensitive underwater radioactive qualitative and quantitative monitoring instruments which has the functions of the measurement of Gamma radiation dose rate, recognition of artificial radionuclide and monitoring activity continuous.
The detector of TK-501 can be selected as a NaI or LaBr3( 4L NaI/2L NaI/φ3”*3” LaBr3/φ2”*2” LaBr3). The detector is encapsulated in a metal shell and carbon phenolic material. So that,it has strong waterproof and anti-pressure ability and little ray absorption
TK-501 can store the data locally and take out data for playback and analysis as time setting, and can analyze the data in real time on the computer which connected with the spectrometer. Data communication links can be customized.
Ⅱ. Main Features
The waterfall map shows radioactive water. The waterfall map shows radioactive water‘soccurrence and disappearance in real time. User can analyze the spectrum of the radioactive material when it appears( Figure 2).
(1) Showing the the dose rate curve changes by over time.
(2) It has a highly sensitive nuclide recognition function. Fuzzy clustering, particle time series analysis and energy spectrum analysis technology are appliedintegrally to make the sensitivity of nuclide identification much higher than other similar kind of the production. When the dose rate of artificial radionuclides exceeds 5% of the background, it can be identified in 10 seconds.The false recognition rate is very low.
(3) Activity calculation. A special multi peak analysis algorithm is specially designed to calculate the net counting rate of the multi peak as the poor energy resolution of the scintillation detector. The built-in efficiency scale factor curve varies with the energy change, which is specially designed for the calculation of the saturated water volume of different energy rays.
(4) Natural background deduction technology.Artificial radionuclide alarm is designed by natural background deduction technology.
(5) Data transmission. Store the data locally,transmit the data in real time,wireless remote transmissioncustomizable.
(6) Continuous monitoring and alarm of artificial radionuclides. Data terminal display water dose rate curve, count rate curve, spectrum waterfall chart, and cumulativespectrum change over time. It is alarmed, when the identification of artificial radionuclides, counting rate area integral counting balance is broken,andthe dose rate exceeds the preset threshold.
(7) Continuous display the changes of radioactive activity over time (Fig3).
(8) The built-in temperature control device can heat the spectrometer at low temperature to ensure that the detector works in suitabletemperature.
(9) Spectra-stabilize automatically.
Fig 2 TK-501 software interface（waterfall plot、energy spectrum analysis、dose rate changing curve over time）
Fig 3 TK-501 software interface(artificial radioactive nuclide changing curve over time)
Fig4 Comparison efficiency of underwater detectionof different shape 4 - liter NaI detectors.
l MCA：1024 or 4096
l Energy resolution：＜8%（NaI,@661.7keV），＜3%（Labr3@661.6keV）
l Casing：Stainless steel ，Aluminum alloy，Carbon phenolics
l Maximum depth：50m( can reach 100m)
l Sensitivity:5Bq/m3 in 10 minutes(Fuzzy clustering, particle time series analysis and energy spectrum analysis technology)
l Automatic energy spectrum analysis , built-in efficiency calibration factor, automatic activity calculation.
l Display by waterfallplot. The artificial radionuclide abnormality is displayed intuitively.
l Alarming:Artificial radioactivity alarm,NNBR
l TK-501 Underwater Gamma spectrometer is applied to water radioactivity monitoring form Water plant, environmental protection Department, fought of army , nuclear emergency.