- E of photon beam - material/medium (type of absorber) - mass E absorption of the coef of absorber

Radiation Detectors Flashcards by Jennifer Montoya

standard free air ionization chamber is ? measuring device

Roentgen measuring device

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thimble ion chamber & stem capacitor made up of ?

air cavity w/Al rod in center

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condenser chamber brand

victoreen R

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stem effect occurs when

ioniz occurs @ the stem rather than pt of measurement

- innacurate

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baldwin farmer chamber kind

thimble ion chamber

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extrapolation chamber measures

surface dose

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pancake chamber what kind

parallel plate

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pocket ioniz chamber used for ? periods

used for short periods

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cutie pie size

portable

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proportional counters more sensitive than

ion chamber

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geiger mueller used to measure

sealed/unsealed low gamma rays & unsealed beta

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ion recombination region ? voltage

low voltage

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ion chamber region/ionization saturation point voltage

300V

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in proportional counter region neg ions get enough E to cause

more add’l e- to be liberated

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if add voltage in Geiger counter region

no effect

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kerma stands for

kinetic E released in matter

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f-med or f-factor relates dose in air to

dose in tissue

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f-med depends on (3)

E of photon beam
material/medium (type of absorber)
mass E absorption of the coef of absorber

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bragg-cavity theory used to determine

absorbed dose from ioniz chamber reading

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bragg cavity smaller than range of

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chemical dosimetry uses

fricke or ferrous sulfate=ferrous sulfate, sodium chloride, sulfuric acid

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TLD is solid ?

state

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OSL stands for

optical stimulating luminescence

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calorimetry measures in form of

heat based on temp chg

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silicon dosimetry type

n-type & p-type

dose equivalent units

- SI unit= Sv | - traditional= rem

film badges price

cheap, inexpensive

Ngas

cavity-gas calibration factor introduced by the TG21 protocol for dose determination

degree of blackening is related to

optical density

possible leakage from package surface rate exceeds

6600 dpm

scintillation counter most sensitive for detection of

gamma ray

air kerma measured by

R, expressed in Gy

calibrate chambers temp/pressure

- 22degC | - 760 mm Hg

ionization type survey meter reads amount of ? in room

scatter

finger badge given if receive greater than ? annual effective dose equivalent limit

10%

penetrometer designed by

Benoist

chromoradiometer designed by

Holzknecht

methods of dose determiniation (3)

- ion chamber - tld - film

film made of

transparent base coated w/emulsion w/silver bromide crystals

dose rates w/o phantom measured with

buildup cap of a thickness equal to depth of dmax

dose rate in tissue measured where

cax @ ssd @ dmax

standard free air ionization chamber measures in ?

air

standard free air ionization chamber only for ? instruments

secondary

standard free air ionization chamber used where?

not used in department

standard free air ionization chamber made up of

lead box with 2 parallel plates

thimble ion chamber & stem capacitor for ? Z

low

thimble ion chamber & stem capacitor composed up

thin wall (plexiglass, plastic)

thimble ion chamber & stem capacitor uses buildup cap for?

high E & TAR

thimble ion chamber & stem capacitor does not use build up cap for?

low E, TMR/TPR

condenser chamber kind

thimble ion chamber

condenser chamber connected to ?

condenser

condenser chamber used with ? E

low

condenser chamber shows ? effect

stem

baldwin farmer chamber connected to

electrometer for instant readout

baldwin farmer chamber used with ? E

high

baldwin farmer chamber reduces stem effect ? %

< 1%

pancake chamber has ? spaced 2 mm apart

electrodes

pancake chamber measures what depth

superficial

pancake chamber useful in circumstances where ?

cylindrical chambers cannot be used

pocket ioniz chamber needs to be

zeroed out

pocket ioniz chamber can give false reading because of

leakage

pocket ioniz chamber requires how freq attn?

daily & recordings

pocket ioniz chamber is how sensitive

most sensitive personnel measuring device

proportional counters discriminate b/n

alpha & beta

proportional counters used to measure in

radioactive spills

geiger mueller filled with

gas

geiger mueller detects

lost sources

geiger mueller used to survey

room, personnel, instruments, implants

geiger mueller disadvantage

can have dead time

ion chamber region/ionization saturation point is region

where ionization chamber should fxn

in proportional counter region causes

over read

cutie pie use for surveying

area for exposure, testing console

kerma is E per unit mass transferred from

photon to charged particles

f-med or f-factor is what conversion

R to rad

f-med or f-factor relates E released in matter to

E absorbed in matter

f-med or f-factor for water is

0.971

f-med or f-factor only for what kind of E beam

monoenergetic

f-med or f-factor not defined beyone ? MeV

f-med or f-factor ? must exist

equilibrium

bragg-cavity theory filled with

gas

bragg-cavity theory measured using

water phantom

bragg-cavity theory phantom made of

polysterene, plexiglass, parafin, solid water

bragg-cavity absorbing material greater than

range of e- equilibrium

bragg-cavity absorbing material must be

homogenous

bragg-cavity beam must be

homogenous

TLD made of

LiF

TLD measured how

heated & emitted light measured

TLD dose related to

light given off

TLD can be used how many times?

reusable

size of TLD

small

TLD is equivalent to

tissue

OSL measures what kind of radiation

x-ray, gamma, beta

OSL similar to

TLD

OSL uses

laser lights

OSL made of

aluminum oxide

OSL cost

less expensive

OSL can be used how many times

reusable

OSL how long for reading

instant

silicon dosimetry sensitivity

more sensitive than gas

silicon dosimetry- how long for reading

instantly

film badges how long reading lasts

permanent recording

film badges accurate within

10 mrem

film badges filters

detect different E levels

film badges provide info concerning

beam quality

penetrometer measures

quality of x-rays; kVp

Ngas depends on ? of walls

composition

Ngas depends on ? of chamber

volume

film darkening is related to

absorbed dose