Influence of aerosol concentration and multivariate processing on the indication of radon progeny concentration in air

• Autorzy: Machaj B. , Urbański P.
• Języki publikacji: EN

Abstrakty

EN

Measurements of radon progeny concentration in air by a radon progeny monitor are sensitive to the concentration of particles suspended in air. Minimum detectable concentration and accuracy of the measurement are determined by random errors of the monitor. Multivariate data processing can be used to decrease these random errors. Influence of aerosol concentration on the measured results of radon progeny concentration in air, by an RGR-30 mining radiometer, operating on the principle of alpha radiation detection from radon progeny deposited on an air filter, were determined in a radon chamber experiment. The air suspended particle concentration and the radon concentration in the radon chamber were controlled and the corresponding radon progeny concentration was measured by the radon progeny monitor. Additionally, count rate from the monitor detector, originating from the alpha activity deposited on the air filter, was measured at intervals of one minute and was then used for the three-interval, and Principal Component Regression (PCR) data processing. It was found that for the aerosol concentration in air from 40 p/cm3 to approximately 9,000 p/cm3 indications of the radon progeny monitor depends considerably on the aerosol concentration. Radon daughter concentration normalized to the radon concentration against aerosol concentration varied from 0.3 to 0.9. In mines, where the aerosol concentration generally is high, this phenomenon has little effect on the indication of the radon progeny monitor. At low aerosols concentration, appropriate correction of radon progeny concentration has to be taken. Comparison of random errors when measured signal of the monitor (count rate against time) was processed employing the three-interval method and PCR data processing shows that PCR ensures a lower random error.

Słowa kluczowe

EN

radon progeny; measurement; data processing

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2004
• Tom: Vol. 49, nr 3
• Strony: 123--129
• Opis fizyczny: Bibliogr. 19 poz., rys.

Twórcy

autor

Machaj B.

• Department of Radioisotope Instruments and Methods, Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland, Tel.: [phone], Fax: [phone]

autor

Urbański P.

• Department of Radioisotope Instruments and Methods, Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland, Tel.: [phone], Fax: [phone]

Bibliografia

• 1. Cheung TK, Yu KN, Nikezic D, Haque AKMM, Vucic D Bronchial dosimeter for radon progeny, www.irpa.net/irpa10/cdrom/00109.pdf
• 2. Duggan NJ, Howell DM (1969) The measurement of the unattached fraction of airborne RaA. Health Phys 17:423−427
• 3. George AC (1996) State-of-the-art instruments for measuring radon/thoron and their progeny in dwellings – a review. Health Phys 70:451−463
• 4. George AC, Hinchliffe L (1972) Measurement of uncombined radon daughters in uranium mines. Health Phys 23:791−803
• 5. Gierdalski J, Bartak J, Urbanski P (1993) New generation of the mining radiometers for determination of radon and its decay products in the air of underground mines. Nukleonika 38;4:27−32
• 6. International Atomic Energy Agency (1989) Radiation monitoring in the mining and milling of radioactive ores. Safety Series No 95. IAEA, Vienna
• 7. Jacobi W (1972) Activity and potential α-energy of 222radon and 220radon-daughters in different air atmospheres. Health Phys 22:441−450
• 8. Machaj B (1999) Modification of the RGR monitor of radon daughters in air. Nukleonika 44:478−490
• 9. Machaj B, Bartak J (1998) Simulation of the activities of radon daughters on RGR monitor air filter. Nukleonika 43:175−184
• 10. Machaj B, Urbanski P (2002) Principal component data processing in radon metrology. Nukleonika 47:39−42
• 11. Markov KP, Ryabov NW, Stas KN (1962) Express-method of radiation hazard assessment related with radon progeny in air. Atomnaja Energija 12:315−319
• 12. Martens H, Naes T (1991) Multivariate calibration. Wiley & Sons, Chichester
• 13. Morawska L, Jamriska M (1996) Deposition of radon progeny on indoor surfaces. J Aerosol Sci 27:305−312
• 14. Nazaroff WW, Nero AV (1988) Radon and its decay products in indoor air. John Willey and Sons, New York
• 15. Rolle R (1972) Rapid working level monitoring. Health Phys 22:233−238
• 16. Sarad EQF 3120 Radon/radon progeny monitor, www.saradgermany.com
• 17. Thien-Chi, Ho-Ling Liu (1996) Simulated equilibrium factor studies in radon chamber. Appl Radiat Isot 47:543−550
• 18. Thomas JW (1972) Measurement of radon daughters in air. Health Phys 23:783−789
• 19. Yu KN (2001) Theoretical foundation for simultaneous measurement of the unattached fraction and activity median diameter of attached radon progeny. Appl Radiat Isot 54:961−965