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Co-ballin' Out
Straight Outta Compton
Mega 6 (photons and e-)
All Thumbs (rules of)
Hodge Podge
100
This is the half life of Cobalt 60 (within 0.25 yrs)
What is 5.27yrs
100
Compton scattering is an example of this type of scattering...
What is inelastic
100
Tomotherapy units only have this energy of photons for treatment
What is 6MV
100
The n/p ratio for atomic numbers <20 is ___
What is 1
100
The average half life is obtained by multiplying the half life by this amount
What is 1.44 (
200
This is the Dmax for Co-60 in cm
What is 0.5cm
200
The difference between the max energy of the scattered photon in a compton interaction and the scattered photon in the photoelectric reaction is ____
Trick Question: Photoelectric effect has complete absorption of the incoming photon
200
Attenuation for 6MV photons is ____ percent per centimeter in tissue
What is 3.5%
200
Alpha decay generally occurs only for atomic numbers greater than ____
What is 82
200
Within an EPID system, xray swill strike a metal plate to generate xrays which are then converted to visible light in this layer
What is phosphor screen
300
Cobalt undergoes this type of decay
What is Beta minus
300
The incoming photon energy range for which Compton interaction is most likely is from 25 keV to ____
What is 15 MeV
300
PDD for a 6MV photon beam at 100cm SSD, 10x10cm field at 10cm depth is ____.
What is 67%
300
When Xrays are generated by a mixture of brehmstralung and characteristic xrays, a broad spectrum is produced. the AVERAGE/MEAN energy of the photon beam is given by this equation
What is Emax/3
300
This type of wedge is described by collimator jaws moved across the field, blocking portions of the field to create and angled wedge without presence of a physical wedge
What is dynamic wedge
400
Cobalt-60 undergoes decay to this material
What is NICKEL
400
During a compton interaction, this is the approximate energy of a scattered photon emitted at 90 degrees.
What is 0.511 MeV
400
The max range for a 6MeV electron beam is this amount
What is 3cm (E/2)
400
When shielding electrons with a LEAD cutout, the thickness (in mm) needed to reduce the dose to < 5% is given by dividing the Energy (E) of the electron beam by ____
What is 2
400
one atomic mass unit is equal to ___ MeV
What is 931 MeV
500
Cobalt decay emits gamma rays of an average of 1.25 MeV. This average is obtained from gamma rays of these two energies
What is 1.17 MeV and 1.33 MeV
500
During a compton interaction, this is the approximate energy of a scattered photon emitted at 180 degrees.
What is 0.255 MeV
500
Neutron contamination can be a concern with photon beam treatment, particular at increasing energies. For a 6MV photon beam, neutrons contribute to this percent of out of field dose.
What is ZERO. Neutron contamination doesn't occur at 6MV photons.
500
Sensitivity of an ion chamber is related to its volume. If you want a chamber to be 4 times more sensitive, you would need to increase the size of the chamber by
What is 4
500
The conformality index is described by this ratio
What is volume getting Rx Dose/ Volume of target