MDCB UPDATED EXAMS SCRIPT QUESTIONS AND
ANSWERS MARKED A+
✔✔Wt; bladder, breast, liver esophagus, thyroid - ✔✔0.05
✔✔Wt; skin, bone surfaces - ✔✔0.01
✔✔Wt; remainder - ✔✔0.05
✔✔Low Level Rad Effects <10 cGy - ✔✔genetic effects
neoplastic disease
growth and development for a fetus or young child
cataracts
✔✔Occupational Exposure - ✔✔50 mSv
5 rem
✔✔Occupational Cumulative - ✔✔10 mSv x age in years
1 rem x age in years
✔✔Public: frequent exposure - ✔✔1 mSv
0.1 rem
✔✔Public: infrequent exposure - ✔✔5 mSv
0.5 rem
✔✔Education (<18 yrs) - ✔✔1 mSv
0.1 rem
✔✔Fetus - ✔✔5 mSv over gestation
0.5 rem
0.5 mSv per month
0.05 rem per month
✔✔Skin/Hand/Feet - ✔✔100 mSv
50 rem
✔✔Lens - ✔✔150 mSv
15 rem
✔✔Annual Background Radiation - ✔✔360 mrem
✔✔Controlled Areas goal - ✔✔5 mSv/yr
0.1 mSv/week
,✔✔Uncontrolled Area goal - ✔✔1 mSv/yr
0.02 mSv/wk
✔✔Occupancy Factors (T) - ✔✔Control Area=1
Adjacent tx Area=1/2
Employee=1/4
✔✔Definition of Medical Event - ✔✔>20% (brachytherapy)
wrong pt
wrong tx site
wrong isotope
failure to remove sources
leaking source
✔✔Keep Fetal dose
AAPM and Jacobson hammer rule - ✔✔<0.1 Gy
✔✔H(rem)= - ✔✔Dose (rad or cGy) x Quality Factor
✔✔H(Sv)= - ✔✔Does (Gy) x Quality Factor
✔✔NCRP - ✔✔National Council on Radiation Protection and Measurement
primary standard setting body for the US
✔✔Waveguides - ✔✔Electron beam accelerated
Traveling wave
Standing wave
Electrons accelerated in "bunches"
✔✔Waveguides use _____ waves in ____ range - ✔✔Electromagnetic waves about
3000 MHz
✔✔Traveling Waveguide - ✔✔longer
"heat sink"
surfer
less complex
Dummy load Req'd
MW fed at gun end
✔✔Standing WG - ✔✔MW reflected back and forth and uses side cavities
2 traveling waves
shorter
twice as much energy
, ✔✔Klystron/magnetron - ✔✔generate MW energy
✔✔Electron gun - ✔✔injects e into accelerator
thorium with tung filament
copper anode
control grid
✔✔Bending Magnet - ✔✔directs electron to head
✔✔Modulator - ✔✔Pulse forming Network and Pulse Repetition Frequency
Thyratron Switch
Pulsed DC provided to e gun
Pulsed DC provided to MW generator
✔✔Magnetron - ✔✔GENERATE high power microwaves
lower energy beams up to 6MeV
Used in traveling wave linacs
High power Oscillator
Circular cavities
Unstable
✔✔Klystron - ✔✔AMPLIFIY microwaves DOES NOT GENERATE microwaves
Higher Power
standing wave linacs
Oil cooled
also needs low energy microwave source
bigger and more expensive than magnetrons
electrons travel in bunches in drift tube
Stable
✔✔"chromatic" or 90 degree bending magnet - ✔✔create an oval shape focal spot
✔✔270 degree bending magnet "achromatic" - ✔✔sharper focal spot
refocused
1-2 mm spot
✔✔Circulators - ✔✔one way stop for MW power to acc quide
prevents damage
✔✔Order of Head of Machine
photon mode - ✔✔etcfdc
electron, target, pri coll., flat filter, dose chamber, sec coll.
✔✔Target - ✔✔Tungsten
1-2 mm focal spot
ANSWERS MARKED A+
✔✔Wt; bladder, breast, liver esophagus, thyroid - ✔✔0.05
✔✔Wt; skin, bone surfaces - ✔✔0.01
✔✔Wt; remainder - ✔✔0.05
✔✔Low Level Rad Effects <10 cGy - ✔✔genetic effects
neoplastic disease
growth and development for a fetus or young child
cataracts
✔✔Occupational Exposure - ✔✔50 mSv
5 rem
✔✔Occupational Cumulative - ✔✔10 mSv x age in years
1 rem x age in years
✔✔Public: frequent exposure - ✔✔1 mSv
0.1 rem
✔✔Public: infrequent exposure - ✔✔5 mSv
0.5 rem
✔✔Education (<18 yrs) - ✔✔1 mSv
0.1 rem
✔✔Fetus - ✔✔5 mSv over gestation
0.5 rem
0.5 mSv per month
0.05 rem per month
✔✔Skin/Hand/Feet - ✔✔100 mSv
50 rem
✔✔Lens - ✔✔150 mSv
15 rem
✔✔Annual Background Radiation - ✔✔360 mrem
✔✔Controlled Areas goal - ✔✔5 mSv/yr
0.1 mSv/week
,✔✔Uncontrolled Area goal - ✔✔1 mSv/yr
0.02 mSv/wk
✔✔Occupancy Factors (T) - ✔✔Control Area=1
Adjacent tx Area=1/2
Employee=1/4
✔✔Definition of Medical Event - ✔✔>20% (brachytherapy)
wrong pt
wrong tx site
wrong isotope
failure to remove sources
leaking source
✔✔Keep Fetal dose
AAPM and Jacobson hammer rule - ✔✔<0.1 Gy
✔✔H(rem)= - ✔✔Dose (rad or cGy) x Quality Factor
✔✔H(Sv)= - ✔✔Does (Gy) x Quality Factor
✔✔NCRP - ✔✔National Council on Radiation Protection and Measurement
primary standard setting body for the US
✔✔Waveguides - ✔✔Electron beam accelerated
Traveling wave
Standing wave
Electrons accelerated in "bunches"
✔✔Waveguides use _____ waves in ____ range - ✔✔Electromagnetic waves about
3000 MHz
✔✔Traveling Waveguide - ✔✔longer
"heat sink"
surfer
less complex
Dummy load Req'd
MW fed at gun end
✔✔Standing WG - ✔✔MW reflected back and forth and uses side cavities
2 traveling waves
shorter
twice as much energy
, ✔✔Klystron/magnetron - ✔✔generate MW energy
✔✔Electron gun - ✔✔injects e into accelerator
thorium with tung filament
copper anode
control grid
✔✔Bending Magnet - ✔✔directs electron to head
✔✔Modulator - ✔✔Pulse forming Network and Pulse Repetition Frequency
Thyratron Switch
Pulsed DC provided to e gun
Pulsed DC provided to MW generator
✔✔Magnetron - ✔✔GENERATE high power microwaves
lower energy beams up to 6MeV
Used in traveling wave linacs
High power Oscillator
Circular cavities
Unstable
✔✔Klystron - ✔✔AMPLIFIY microwaves DOES NOT GENERATE microwaves
Higher Power
standing wave linacs
Oil cooled
also needs low energy microwave source
bigger and more expensive than magnetrons
electrons travel in bunches in drift tube
Stable
✔✔"chromatic" or 90 degree bending magnet - ✔✔create an oval shape focal spot
✔✔270 degree bending magnet "achromatic" - ✔✔sharper focal spot
refocused
1-2 mm spot
✔✔Circulators - ✔✔one way stop for MW power to acc quide
prevents damage
✔✔Order of Head of Machine
photon mode - ✔✔etcfdc
electron, target, pri coll., flat filter, dose chamber, sec coll.
✔✔Target - ✔✔Tungsten
1-2 mm focal spot
