As the intensity of x-ray exposure of the air volume increases, the number of electron–ion pairs produced:
increases
Units that specify dose area product (DAP)
mGy-cm2
Types of ionizing radiation that produce virtually the same biologic effect in body tissue for equal absorbed doses
X-rays; beta particles; gamma rays
Theory that relates to the ionization produced in a small cavity within an irradiated medium or object to the energy absorbed in that medium as a result of its radiation exposure
Bragg-Gray
Alpha particles have a radiation weighting factor (WR) that is numerically equal to
20
First American radiation worker to die from radiation-induced cancer in October of 1904
Clarence Madison Dally
An energy absorption of 1 J/kg of matter in the irradiated object equals which of the following
1 Gy
Formula used to calculate effective dose
EfD = D × WR × WT
1 gray equals
100 cGy (centigray)
Beta particles are:
Protons
The sum total of air kerma over the exposed area of the patient’s body surface:
Dose area product
Radiation quantities that may be defined as the measure of the total electric charge of one sign, either all pluses or all minuses, per unit mass that these two types of radiation generate in dry air at standard temperature and pressure (760 mm Hg or 1 atmosphere at sea level and 22° C)
Exposure
Physicians cancer deaths attributed to x-ray exposure were reported as early as what year?
1910
The total kinetic energy released in a unit mass (kilogram) of air and expressed in metric units of joules per kilogram is
Air kerma
Early tissue reactions of ionizing radiation that were experienced by early radiation workers
Diffuse redness of skin
Blood disorders
Intestinal disorders
SI unit of electric current
Ampere
What do radiation weighting factors primarily take into consideration?
Some types of radiation are more efficient at causing biologic damage than other types of radiation for a given dose
Cataract formation, fibrosis, reduced fertility and sterility are classified as
Late tissue reactions of ionizing radiation
Discovered x-rays on November 8, 1895
Wilhelm Conrad Roentgen
Whole-body TEDE regulatory limit for exposed personnel is __ and __ for the general public
- 05 Sv
0. 001 Sv
If 200 people receive an average effective dose of 0.25 Sv, what is the collective effective dose
50 person-Sv
0.1 Gy equals
100 mGy
Instrument that can be calibrated to read air kerma
Ionization chamber
SI units used to specify absorbed dose
Gray or centigray
The front of the white paper packet may be color coded to facilitate correct usage and placement of the dosimeter on the body of occupationally exposed personnel in what type of dosimeter?
Optically stimulated luminescence (OSL) dosimeter
physicists use ionization chambers connected to electrometers to perform the annual standard measurements required by state, federal, and health care accreditation organizations for radiographic and fluoroscopic devices. These annual measurements could include:
X-ray output in Gy or mGy Fluoroscopic radiation entrance rates in mSv/min kVp setting accuracy Exposure time exactness Half-value layers, or beam quality
Maximum period of time that a thermoluminescent dosimeter (TLD) may be worn as a personnel device
3 months
Whenever the letter “M” appears under the current monitoring period or in the cumulative columns of a personnel monitoring report, it signifies:
Equivalent dose below the minimum measurable radiation quantity was recorded
The optically stimulated luminescence (OSL) dosimeter is “read out” by:
A laser light
Personal monitoring device that contains an aluminum oxide detector
Optically stimulated luminescence dosimeter
Because of the OSL dosimeter’s sensitivity down to as low as 10 μSv for x-ray and gamma ray photons in the energy range 5 keV to 40 MeV, it is an excellent and practical monitoring device for:
Employees working in low-radiation environments
Pregnant workers
An ionization chamber connected to an electrometer is a device that can measure:
Small electric currents with high precision and accuracy
Advantages of the optically stimulated luminescence (OSL) dosimeter:
Can be used for up to 1 year
Light weight, durable, and easy to carry
Contains integrated, self-contained, preloaded packet
Disadvantages of using pocket ionization chambers as personnel dosimeters:
They can discharge if they are subjected to mechanical shock
Health care facilities that use this method to record personnel exposure must delegate someone to keep such a record
The dosimeter may give an inaccurate reading because the electric charge tends to escape
Occurs when the sensing crystals contained in the thermoluminescent dosimeter are irradiated.
Electrons in the crystalline lattice structure absorb Energy and are excited to higher energy levels or bands
Component(s) of the Geiger-Muller survey meter that alert the operator to the presence of ionizing radiation:
Audio amplifier
Speaker
Personnel dosimeter that resembles an ordinary fountain pen externally.
Pocket ionization chamber
Personnel monitoring devices can be used to provide an immediate exposure readout for a radiation worker:
Personnel digital ionization dosimeter
Pocket ionization chamber
Filters incorporated into the detector packet of the optically stimulated luminescence dosimeter are made of:
Aluminum
Tin
Copper
Radiation survey instruments must do the following:
Detect all common types of ionizing radiation
Be calibrated annually to ensure accurate operation
Interact with ionizing radiation similarly to the way human tissue reacts
Advantages of the personnel digital ionization dosimeter:
Instant access to reports
No waiting time for mailing dosimeters
Lightweight and durable
Can be dropped or scratched with little chance of harm to the device
Cutie pie
Ionization chamber-type survey meter
What do optically stimulated luminescence dosimeters, thermoluminescent dosimeters, pocket ionization chambers, and digital ionization dosimeters have in common?
The devices are all used for personnel monitoring
Three different filters are incorporated into the detector packet of the optically stimulated luminescence (OSL) dosimeter:
Aluminum
Copper
Tin
Disadvantage of the optically stimulated dosimeter:
Exposure not determinable on the day of occurrence
An instrument that generally has a check source of a weak, long-lived radioisotope located on one side of its external surface to verify its constancy daily:
Geiger-Muller survey meter
