| dc.date.accessioned |
2015-06-03T08:42:46Z |
und |
| dc.date.accessioned |
2017-11-06T10:58:08Z |
|
| dc.date.available |
2015-06-03 |
fi |
| dc.date.available |
2015-06-03T08:42:46Z |
und |
| dc.date.available |
2017-11-06T10:58:08Z |
|
| dc.date.issued |
2015-06-01 |
|
| dc.identifier.uri |
http://hdl.handle.net/10138/155063 |
|
| dc.publisher |
Helsingin yliopisto |
fi |
| dc.publisher |
Helsingfors universitet |
sv |
| dc.publisher |
University of Helsinki |
en |
| dc.title |
Safety of analytical X-ray appliances |
en |
| ethesis.discipline |
Physics |
en |
| ethesis.discipline |
Fysiikka |
fi |
| ethesis.discipline |
Fysik |
sv |
| ethesis.discipline.URI |
http://data.hulib.helsinki.fi/id/3434818f-62d6-4ad2-9c9b-7a86be9cf8e6 |
|
| ethesis.department.URI |
http://data.hulib.helsinki.fi/id/3acb09b1-e6a2-4faa-b677-1a1b03285b66 |
|
| ethesis.department |
Institutionen för fysik |
sv |
| ethesis.department |
Department of Physics |
en |
| ethesis.department |
Fysiikan laitos |
fi |
| ethesis.faculty |
Matematisk-naturvetenskapliga fakulteten |
sv |
| ethesis.faculty |
Matemaattis-luonnontieteellinen tiedekunta |
fi |
| ethesis.faculty |
Faculty of Science |
en |
| ethesis.faculty.URI |
http://data.hulib.helsinki.fi/id/8d59209f-6614-4edd-9744-1ebdaf1d13ca |
|
| ethesis.university.URI |
http://data.hulib.helsinki.fi/id/50ae46d8-7ba9-4821-877c-c994c78b0d97 |
|
| ethesis.university |
Helsingfors universitet |
sv |
| ethesis.university |
University of Helsinki |
en |
| ethesis.university |
Helsingin yliopisto |
fi |
| dct.creator |
Ahmad, Mian Awais |
|
| dct.issued |
2015 |
|
| dct.language.ISO639-2 |
eng |
|
| dct.abstract |
Analytical X-ray appliances are widely used for materials characterization. The use of X-rays without proper protection can lead to harmful effects. In order to minimize these harmful effects, it is essential to have a proper estimation of the dose rates around the equipment. Moreover, it is important to follow the safety regulations in order to avoid accidental exposure.
This thesis outlines the potential hazards in the use of X-ray analytical instrumentation at the Division of Materials Physics, University of Helsinki. The theoretical part of the thesis introduces to the generally approved fundamental principles of radiation protection and the regulations based on these principles. Also, the production and properties of X-rays, radiation dosimetry and the biological effects of X-rays are discussed.
The experimental part evaluates the actual radiation protection in the X-ray laboratories. Two open X-ray appliances, a powder diffractometer and a Laue setup, were selected for a closer study. A copper anode X-ray tube was used and the tube current was set to 20 mA and the voltage to 45 kV, which are the typical experimental values. The dose rates around the equipment were mapped by an ionization chamber. Based of these measurements, the maximum expected dose rate around the powder diffractometer was estimated to be of the order of 1 µSv/h at the user position. In the case of Laue system, the dose rate around equipment was estimated to be 10-100 times the dose rate around the powder diffractometer. Additionally, for powder diffractometer the theoretical characteristic X-ray flux from the tube was calculated. The characteristic X-ray flux after the monochromator at sample position was measured using a scintillator detector and a copper filter. The dose rate calculated from the flux was as high as 10 mSv/s. In typical powder diffraction experiments the expected dose rates are lower than these estimated maximum values.
In general, the equipment were found to be safe to work with, provided that the users follow the department regulations and safety guidelines. |
en |
| dct.language |
en |
|
| ethesis.language.URI |
http://data.hulib.helsinki.fi/id/languages/eng |
|
| ethesis.language |
English |
en |
| ethesis.language |
englanti |
fi |
| ethesis.language |
engelska |
sv |
| ethesis.supervisor |
Blomberg, Merja |
|
| ethesis.thesistype |
pro gradu-avhandlingar |
sv |
| ethesis.thesistype |
pro gradu -tutkielmat |
fi |
| ethesis.thesistype |
master's thesis |
en |
| ethesis.thesistype.URI |
http://data.hulib.helsinki.fi/id/thesistypes/mastersthesis |
|
| dct.identifier.urn |
URN:NBN:fi-fe201506039994 |
|
| dc.type.dcmitype |
Text |
|
| dct.rights |
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. |
en |
| dct.rights |
Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. |
sv |
| dct.rights |
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. |
fi |
