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12. Röntgen. Radiation Measurement Units. Rad. Rem. Curie. SI Units. 13. Röntgen. unit of exposure Does not equate energy deposited to biological damage No longer addressed by 10CFR20. 14. Rad. unit of absorbed dose Applies to all radiation types in all absorbers
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12 • Röntgen Radiation Measurement Units • Rad • Rem • Curie • SI Units HPT001.007 Revision 3 Page of 21
HPT001.007 Revision 3 Page of 21 13 Röntgen • unit of exposure • Does not equate energy deposited to biological damage • No longer addressed by 10CFR20
HPT001.007 Revision 3 Page of 21 14 Rad • unit of absorbed dose • Applies to all radiation types in all absorbers • Does NOT account for RBE
HPT001.007 Revision 3 Page of 21 15 Relative Biological Effectiveness(RBE) • RBE = Dose of 250 kVp X-rays to produce effect • Different radiation types are more effective at causing biological damage • The Rad does not account for RBE Dose of other radiation for same effect
HPT001.007 Revision 3 Page of 21 16 Linear Energy Transfer(LET) • Avg. energy deposited per unit distance traveled • Quality Factor calculated from LET • Relates to biological damage induced by radiation!
HPT001.007 Revision 3 Page of 21 17 LET vs. QFs LET (kev/µmeter) Q ≤ 3.5 1 7 2 53 10 ≥175 20
HPT001.007 Revision 3 Page of 21 18 Röntgen Equivalent Man(Rem) • Equates energy deposited to biological damage done • Rem = Rad X Quality Factor • Does account for RBE
HPT001.007 Revision 3 Page of 21 19 QFs from 10CFR20 Radiation Type Q X-ray or gamma/Beta particles 1 Thermal Neutrons 2 Neutrons of unknown energy 10 Alpha particles/FFs 20
HPT001.007 Revision 3 Page of 21 20 Curie • unit of radioactivity • Amount of material decaying at a rate of 3.7 X 1010 dps • Basis is decay rate of Ra-226
HPT001.007 Revision 3 Page of 21 21 SI Units • 1 Gray = 100 Rads • 1 Sievert = 100 Rem • 1 Becquerel = 1 dps