STE #1 Flashcards
(30 cards)
Which of the following is a required pre-operational check?
- Physical condition of the instrument.
2 . Calibration due date
And 3. Battery check
Scintillation detector operate in the G-M region of the gas amplification curve? True or False?
False
Zinc-Sulfide detectors are good for detecting what type of radiation?
Alpha
Sodium Iodine scintillation detector is used for detecting gamma radiation. True or False?
True
You are using an RO-2 survey meter to measure the activity on a smear taken from the refueling canal. The closed window reading is 4 mR/hr and the open window reading is 22.4 mR/hr. Given a beta correction factor of 4.0 what is the dose rate in mrad/hr?
73.6
How does N-16 gamma’s affect G-M type detectors?
Can cause them to over respond
You took an air sample and count it for 10 minutes and it had a reading of 22000 counts. The 60 minute background count on the instrument was 1400 counts.
What is sample net counts per minute (round your answer)?
2177
Entering a high gamma dose rate field with an extendable G-M detector on low range scale could result in which of the following…
Instrument could become saturated which would result in a low reading
Ionizing radiation interacts with phosphor crystalline material to produce light is called scintillation. True or False?
True
In a noble gas atmosphere a vented ion chamber could…
Become saturate giving a false reading
When alpha frisking how close should the detector be to the surface of the object
¼ inch
In a G-M detector, the amount of time from the initial pulse until the detector can produce another pulse is called
Dead time
In a G-M detector, resolving time is the time from the initial measured pulse until another pulse can be measured. True or False?
True
In a G-M detector, saturation is when a detector reads high in a high field of radiation. True or False?
False
Neutron detector use some type of moderator to slow down the fast neutrons so they can measured. The moderator most often used is
Sodium
A contact dose rate taken on a very small point source by a G-M detector, will it be __________ when compared to same dose rate taken by an Ion Chamber?
Higher
Which of the following is not true with a contamination survey instrument
Normally detects neutron activity
A frisker has the ability to detect both fixed and loose contamination at the same time. True or False?
True
Scintillation detectors are used to detect very low levels of radioactivity. True or False?
True
What would the contact beta dose rate be given the following information?
Open window reading 140
Closed window reading 20
Beta Correction Factor is 4
480 mrad/hr
In which region of the Six Region Curve is enough voltage applied where all of the ions produced and be detected.
Ionization chamber
The instrument that is used to determine stay times and assess dose rate is typically which of the following
Ion Chamber
In a proportional counter, due to the amount of voltage being applied, many electrons reach the reach the anode for each primary ion pair produced in the
gas. These secondary ion pairs creates additional secondary ion pairs as it gets closer to the anode. This is called____________.
Townsend Avalanche
In an ion detector, radiation interacts with an atom in the fill gas resulting in the development of an ion pair. The ions will be attracted to the positively charged (+) anode or the negatively charged (-) cathode where they are detected as current flow. The amount of dose is related to the amount of current detected. True or False?
True
