Centre for Ionizing Radiation
Ing. Norman Durny
riaditeľ centra
tel.: 02/60294 672
fax.: 02/60294 670
e-mail: durny@smu.gov.sk
Johana Vašeková
sekretariát
el.: 02/60294 672
fax.: 02/60294 670
e-mail: vasekova@smu.gov.sk
DOSIMETRY LABORATORY
1. DOSIMETRY OF GAMMA RADIATION
Quantity - air kerma, dose equivalent and their rates.
Unit - Gy (gray), Sv (sievert), Gy·h-1, Sv·h-1.
Tasks
The main tasks are realisation and transfer to the user's instruments of the scale of dosimetry quantities from low dose rates (background level) througth the medium dose rates (radiation protection leveles) to the high dose rate (therapy level). The instrument type tests and personal certification in dosimetry field is a further activity of the Laboratory.
International comparisons
- 2000 - 2002 : BIPM.RI(I)-K1 key comparison o fair kerma for 60Co
- 2005-2008 : No. 813 (EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4) key comparison of air kerma and absorbed dose to water
- 2005-2006 : COOMET 318 regional key comparison of air kerma for 60Co
- 2000 - 2003 : EA IR3 comparison - radiation protection dosemeters
- 2000 - 2003 : EA IR4 comparison - personal dose equivalent
- 2007 : multilateral intercomparison in radiation protection (H*(10) a Hp(10))
Available metrological services
Radiation protection - photon rays:
- calibration of dosimeters and reference standards,
- calibration of personal dosimeters,
- calibration of users reference fields, -
Therapy level - photon rays:
- calibration of dosimeters and reference standards.
tests and verification of dosimeters, personal dosimetry services.
Methods of measurement:
- calibration against the calibrated reference photon field is the main method used. Also the substitution method is available. The reference beams are produced in accordance with ISO 4037-1 and ISO 4037-2;
- calibration and tests are performed in accordance with the working procedures of SMU based on ISO and IEC standards (ISO 4037-3, STN IEC 61017-1, STN IEC 61017-2, IEC 61526, ISO 14146);
- for determination of absorbed dose in water the conversion procedure from air kerma based on IAEA TRS 277 code of practice is used. The calibration itself is done in water phantom.
Instruments in use
Radiation protection range is covered by the set of secondary standard ionising chambers Two TEMA irradiators with 137Cs and 60Co radiation sources are used for generating of calibrated photon fields. 3-D positionings variation of source to detector distance in wide range from 0.5 m to 7 m. The PMMA slab phantom is used for personal dose equivalent Hp(10) measurement. In the gamma therapy range, the calibrations are performed in collimated 60Co reference photon field. The photon field is calibrated against the primary standard graphite cavity ionising chamber and Keithley 6517A electrometer.
Contact
Dr. Jozef Dobrovodský
phone: + 421 2 60294 671
e-mail: dobrovodsky@smu.gov.sk
Mr. Norman Durný
phone: + 421 2 60294 668
e-mail: durny@smu.gov.sk
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2. DOSIMETRY OF NEUTRON RADIATION
Quantity - absorbed dose, absorb dose rate, dose equivalent and their rates.
Unit - Gy (gray), Sv (sievert), Gy·h-1, Sv·h-1.
Tasks
Main tasks are realisation and transfer to the user's instruments of dosimetry quantities of neutron.
International comparisons
2001: EUROMET/DUNAMET D28 - Comparison of the National Standard of the Neutron Dose Equivalent.
Available metrological services
Radiation protection - neutron:
- calibration of dosimeters and reference standards;
- calibration of personal dosimeters;
- tests and verification of dosimeters, personal dosimetry services.
Methods of measurement:
neutron reference fields in accordance with the ISO 8529 standard are generated in a centre of 10 x 10 x 8 m large room by the underground installed set of 241AmBe, 239PuBe and 252Cf radionuclide neutron sources and the neutron generator by 1011 s-1 output is under the construction.
Instruments in use
Neutron dose equivalent rate standard - consists of tree substandards:
- the set of different volume tissue eqivalent proportional counters with related electronics;
- the set of paired ionising chambers with electrometer;
- the Bonner sphere spectrometer with the spherical 3He counter and electronics.
Contact
Mr. Valent Jenis
phone: + 421 2 60294 664
e-mail: jenis@smu.gov.sk
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3. X-RAY KERMA
Quantity - air kerma, dose equivalent and their rates.
Unit - Gy (gray), SV (sievert), Gy·h-1, Sv·h-1.
Tasks
The main tasks are realisation and transfer to the user's instruments of dosimetry quantities of X-rays of the following quantities: ISO 4037-1 Narrow spectra, ISO 4037-1 Wide spectra and IEC 61267 RQA. The quality of the X-ray beams in Mammography diagnostic level is a further activity of the Laboratory.
International comparisons
2001: EUROMET 526 - Calibration of dosimeters used in mammography with different X-ray qualities.
Available metrological services
Air kerma and air kerma rate, ambient dose equivalent and ambient dose equivalent rate:
- calibration of dosimeters and reference standards.
Personal dose equivalent and personal dose equivalent rate:
- calibration of personal dosimeters and personal dosimemeter systems.
Quality beams measurement: air kerma and air kerma rate:
- calibration of dosimeters and reference beams.
Instruments in use
Instrument for quality beams measurement Norimex, PTW: absorbed dose 300 nGy ÷ 500 mGy; dose rate is 50 nGy·s-1 ÷ 5 mGy·s-1; kV range is 50 kV ÷ 150 kV; mAs range is 0.5 mAs ÷ 999.9 mAs.
Set of IC: OMH ND 1000; ND 1001; Xradin A4.
Electrometers: DPI2; Keithley 6517A.
X-ray generator: MG324, Philips: continuous, kV range is 14 kV ÷ 320 kV, current range is 0.05 mA ÷ 22.5 mA; XHF 30R, Creos: pilsed 100 kHz, kV range is 50 kV ÷ 120 kV, mAs range is max 640 mAs.
Contact
Mr. Jaroslav Compel
phone: + 421 2 60294 665
e-mail:compel@smu.gov.sk
ACTIVITY OF RADIONUCLIDES LABORATORY
Quantity - activity.
Unit - Bq (becquerel).
Tasks of the laboratory
The main task of the Laboratory is the realisation of the unit of radionuclide activities and its transfer to user's instruments. Derived quantities used are mass activity, volume activity and surface activity in corresponding units.
International comparisons
CCRI (II) comparison of 152Eu activity measurement (BIPM 1999-2000). DUNAMET D29 common calibration of ionizing chambers (CMI 2001).
Available metrological services
Radionuclides calibrators verification (mainly to nuclear medicine laboratories). Instruments are tested to fulfill STN 40 4014 standard requirements of 10 % expanded uncertainty in the range from 1 MBq up to 100 GBq.
Gammaspectrometers verification. Semiconductor detectors used in gammaspectrometry are verified in according with IEC 973 standard.
Verification of monitoring equipment in liquid effluents. tests of calibration and linearity are made in according with IEC 861 standard (15 % expanded uncertainty).
Verification of surface contamination monitors. Alpha and/or beta surface contamination monitors are tested for 14C, 60Co, 90Sr, 137Cs, 204Tl and 241Am calibration in according with STN 35 6566 standard (25 % expanded uncertainty).
Sealed sources standardization and certification. Sealed sources activity can be by 4 ionizing chamber measurement. The chamber has bee traced directly to some PTB standards.
Methods of measurement:
- radionuclide calibrators are verified in situ with a travelling standard ionization chamber using radionuclides provided by users. Standard measurement conditions are given using standard containers (injection ampoules or peniciline vials) filled by 2 - 5 ml of radionuclide solution;
- gammaspectrometers are verified by calibrated water solutions of several radionuclides sent to users. Liquid effluent monitors are verified by calibrated 137Cs low-activity water solutions and a set of 137Cs solid standards. Contamination monitors are tested by certified large area sources checked by a standard instrument.
Instruments in use
Basic instrument for activity measurement is calibrated 4∏ (re-entrant) pressurized ionizing chamber. Low gama activity measurements and radionuclide purity testing are made by calibrated gammaspectrometric system with HPGe detector. set of large area (110 x 150) sources is available together with a verification instrument with two thin-window proportional counters.
Contact
Dr. Anton Švec
phone: + 421 2 60294 657
e-mail: svec@smu.gov.sk
