Raphex 2000 Flashcards
the f factor is
- the R to cGy conversion factor
- greatest for high Z materials & low E photons
- is 0.873 in air
exposure is
-the charge liberated by photons in a given mass of air
1 mSv is equivalent to
- 100 mrem
- 1 mSv=0.001 Sv= 0.1 rem= 100 mrem
dose equivalent is greater than absorbed dose for
neutrons
an e- is electrostatically ? by an alpha particle
attracted
an e- is electrostatically ? by an e-
repelled
an e- is electrostatically ? by a positron
attracted
an e- is electrostatically ? by a proton
attracted
an e- is electrostatically ? by a neutron
not affected
charge of a neutrino
- no charge
- negligible mass
charge of an alpha particle
- charge of 2
- mass of 4 amu
charge of a positron
- charge of +1
- mass of 9.1 x 10^-31 kg
charge of a neutron
- no charge
- mass of 1.6 x 10^-27 kg
elements which have the same Z but different A are
isotopes
the mass # (A) of an atom is equal to the sum of
nucleons
when an e- is removed from an atom, the atom is said to be
ionized
the t1/2 of a radioisotope is ? than the avg life
less
the E absorbed by a mass of air from x or gamma rays per R is
-a constant, 8.7 mGy/R
quality factor of 1.25 MeV gamma rays is
1
quality factor of 100 keV of x-rays is
1
quality factor of 200 keV of neutrons is
20
which is not an SI unit: m, kg, sec, rad, Bq?
rad
nucleus of a H atom?
proton
is emitted during pure beta minus decay?
- antineutrino
- in beta minus decay, a n chgs into a p+, with the emission of a beta minus particle (e-) & antineutrino
is created during pair production?
- positron
- pp occurs in the electric fld of the nucleus when a photon of E at least 1.022 MeV disappears & an e- & positron are created
initiated fission in U-235?
- neutron
- when a n is absorbed by the nucleus of a U-235 atom, fission occurs
charge of an alpha particle?
+2
-consist of 2 p+ & 2 n
charge of a neutron?
0
charge of an e-?
-1
charge of a positron?
+1
charge of a photon?
0
-photon carries E but no charge
a neutral atom has 6 e- & A f 13. # of n is?
7
-# of e = # of p+, so 13-6=7
of e- per gram for H is ? x 10^23
6
e- binding E:
- decr with incr distance from nucleus
- is a few eV for the outer e- of an atom
- must be overcome if ioniz is to take place
- binding E incr approx as the square of Z
the max # of e- in a shell =
2n^2, where n is the principle quantum #
after 10 half lives, the fraction of activity remaining in a source is?
- (1/2)^n
- (1/2)^10
effective half life approx equals
physical half life
alpha decay most likely occurs in atoms with Z ?
- greater than 82
- A changes by 4
- Z changes by 2
an alternative to emission of a characteristic x-ray is
- Auger process
- characteristice xray emitted and undergoes photoelec interaction w/another orbital e-
- E of Auger e- is = to E of characteristic xray less binding E of e-
