Healt Physics Laboratory 231

HEALTH PHYSICS LABORATORY

Head of Laboratory: Dr Pawel 01ko Deputy Head: Dr BarbaraMarczewska. Secretary: Irena Lipehska telephone: (48 12) 662-84-11 e-mail: Pawe1.01koifj.edu.p1

PERSONNEL: Research Staff: Pawel Blski, Ph.D. Pawel Olko, Ph.D. Maciej Budzanowski, Ph.D. Michal Walig6rski 1, Prof. Barbara Marczewska, Ph.D. Technical Staff: J6zef Dybel Tomasz Nowak 2,M.Sc., E.Eng. Tomasz Horwacik 3 M.Sc., Nucl.Eng. El2bieta Ryba 4, E.Eng. Irena Lipefiska Katarzyna Zbroja 4 M.Sc., Nucl.Eng. Anna Nowak

OVERVIEW: PLO300145

The activities of the Health Physics Laboratory at the Institute of Nuclear Physics (IFJ) in Krak6w are principally research in the general area of radiation physics, dosimetry and radiation protection of the employees of the Institute. Theoretical research concerns modelling of radiation effects in radiation detectors and studies of concepts in radiation protection. Experimental research, in the general area of solid state dosimetry, is primarily concerned with thermoluminescence (TL) dosimetry, and more specifically: development of LiF:Mg, Ti, CaF2:Tm and CVD diamond detectors for medical applications in conventional and hadron radiotherapy and of LiF:Mg, Cu P and LiF:Mg, Cu, Si, Na for low-level natural external ionising radiation. Environmental radiation measurements (cosmic-rays on aircraft and radon in dwellings and soil) are also performed using track CR-39 and TLD detectors. The Laboratory provides expert advice on radiation protection regulations at national and international levels. Routine work of the Health Physics Laboratory involves design and maintenance of an in-house developed TL-based personnel dosimetry system for over 200 radiation workers at the INP, supervision of radiation safety on IFJ premises, and advising other INP laboratories on all matters pertaining to radiation safety. We provide personal and environmental TLD dosimetry services for several customers outside the IFJ, mainly in hospitals and nuclear research institutes in Poland. We also calibrate radiation protection instruments 400 per year) for customers in the southern region of Poland. The year 2001 was another eventful year for the Health Physics Laboratory. M. Walig6rski has received his Professor of Physics state nomination from A. Kwaniewski, the President of Poland. P. Bilski and M. Budzanowski were granted their Ph.D. degrees by the Scientific Council of the

'Part-Time Consultant, 2Radiation Safety Officer, 3Part-Time Ph.D. Student, 4Chief Radiation Safety Officer at the Institute. 232 Healt Physics Laboratory

Institute of Nuclear Physics. We continued several national and international research projects. Dr Bilski co-ordinates a project on the measurements of radiation doses on board of passenger aircraft of LOT - Polish Airlines and a dose mapping experiment on board of the International Space Station. Dr Marczewska and I develop the application of artificial diamonds for dosimetry of ionising radiation. Dr Budzanowski developed high sensitive LiF:Mg, Na, Si thermolurninescent detectors for personal and environmental dosimetry. We also participated in a project coordinated by Dr J. Swakoh on measuring radon concentration in soil and in houses around different geological structures in Krak6w. In collaboration with the Medical Physics Department of the Centre of Oncology in Krak6w, led by Prof. Walig6rski, we applied our TLD detectors in medical dosimetry. We continued a technical project concerned with the development of the radiotherapy facility for treating eye melanoma with 60 MeV protons from our AIC-144 isochronous cyclotron. On 21 December 2001 our Laboratory for Calibration of Dosimetry Instruments obtained formal accreditation from the Polish Centre of Accreditation, PCA, as the first laboratory at IFJ and the first calibration laboratory in Poland.

Dr Pawel Olko

REPORTS ON RESEARCH: PLO300146

Dosimetry of Cosmic Radiation on Board of Passenger Aircraft and in the Space Laboratory

P. Bilski, M. Budzanowski, T. Horwacik, P.01ko, and G. Reitz'

1DLR, K61n, Germany

A passive dosimetric package for measuring doses from cosmic radiation received by aircrew during passenger flights, is under development. It consists of thermoluminescent detectors and CR-39 track detectors placed in a polyethylene holder. Various types of TLI)s are used in these measurements: MTS (LiF:Mg, Ti), MCP (LiF:Mg, Cu, P) and also specially developed LiF:Mg, Ti with an increased efficiency for high LET radiation. All detectors, developed and produced in our Laboratory, feature different isotopic composition of lithium: natural, 7Li enriched or 6Li enriched, to separate the signal from neutron and non neutron components of the radiation field. Calibration exposures were performed at the high-energy reference field at CERN (CERF) which offers the best on-ground approximation of the radiation spectrum encountered at flight altitudes, particularly in the case of neutrons. The developed dosimeters were used in measurements during a three-month period in all five B-767 and two B-737 airplanes of the LOT Polish Airlines. The highest equivalent dose due to the neutron component measured by CR 39 detectors exceeds 25 mSv during the 3-month period. The measured doses with TLD's and CR-39 were consistent with values obtained by calculations using the CARI-6 computer code, which estimates doses basing on the altitude profile of the flight and takes into account the variation of solar activity (see Table 1). At the end of year 2001 our dosimeters were also exposed on board of a Czech airlines aircraft, in a joint project with the Institute of Nuclear Physics in Prague. Our TL detectors were also used for measurements of radiation doses in space. During the first half of 2001 several packages with MTS and MCP TL detectors were installed on board of the Intepiational Space Station Alpha (ISS) for a period of a few months, within the project "Dose Mapping on ISS . The average dose rate measured in different places of the space station ranged from 17 - 22 tGy/day.