GM Counter Not Useful for Measuring Gas Absorbed Energy

  • I
  • Thread starter Mason Smith
  • Start date
  • Tags
    Tube
In summary, a GM counter is not useful for determining the absorbed energy in a gas because it only counts events and does not measure energy. This is because the ionizing radiation in the tube produces ion pairs, which causes an "avalanche" of ions and creates a pulse of charge at the anode. The counter also does not discriminate between types of radiation, and the output becomes independent of energy at lower tube voltages. Other types of detectors, such as proportional counters and ionization chambers, are better suited for measuring absorbed energy in gas.
  • #1
Mason Smith
21
2
Why is a GM counter not useful for determining the absorbed energy in a gas?
 
Physics news on Phys.org
  • #2
Because it only counts events, not energy.
 
  • #3
To put it another way the event is an all or nothing processes. The ionizing radiation ( charged particles or photon) produces ion pairs in the tube.The high voltage between the anode and cathode accelerated the electrons in the gas of the tube which in tern causes more ionization which can initiate an "avalanche" of ions creating pulse of charge at the anode. GM counter do not discriminate between type of radiation. A pulse is created every time enough ion pairs are left behind in the tube.

If the tube voltage is reduce enough you get a range of voltages where you can get a pulse created that is proportional to the energy deposited in the gas. This is the basis of the proportional counter. Reducing the tube voltage further the the output of the chamber again becomes independent of the energy for the most part. This then becomes and ionization chamber.

Each of the three types of detectors above are basically the same with a conducting cylinder enclosing a wire on the axis with a positive voltage on the wire. However the actual construction, size, and gas used varies with the chambers and use.
 
  • #4
Mason Smith said:
Why is a GM counter not useful for determining the absorbed energy in a gas?

Why should it? What exactly is in the mechanism of a Geiger tube that makes you think that it can measure the "... absorbed energy in a gas.. "?

Zz.
 

1. Why is a GM counter not useful for measuring gas absorbed energy?

A GM counter, or Geiger-Muller counter, is primarily used for detecting and measuring ionizing radiation. It works by detecting the ionization of gas molecules in a chamber, which is then converted into an electrical signal. However, it is not sensitive to non-ionizing radiation, such as the energy absorbed by gas molecules. Therefore, it is not an appropriate tool for measuring gas absorbed energy.

2. What is the difference between ionizing and non-ionizing radiation?

Ionizing radiation has enough energy to remove electrons from atoms or molecules, creating ions. This type of radiation includes gamma rays, X-rays, and particles such as alpha and beta particles. Non-ionizing radiation, on the other hand, does not have enough energy to create ions. This includes radio waves, microwaves, and infrared and ultraviolet light.

3. Can a GM counter be used to measure any type of radiation?

No, a GM counter is only useful for measuring ionizing radiation. It is not sensitive to non-ionizing radiation, such as the energy absorbed by gas molecules.

4. What are some other methods for measuring gas absorbed energy?

One method for measuring gas absorbed energy is through the use of a calorimeter. This instrument measures the temperature change of a gas when it absorbs energy. Another method is spectroscopy, which uses the absorption of specific wavelengths of light to determine the energy absorbed by gas molecules.

5. Are there any situations where a GM counter might be useful for measuring gas absorbed energy?

In general, a GM counter is not a suitable tool for measuring gas absorbed energy. However, in some cases, it may provide a rough estimation of absorbed energy if the gas is being exposed to high levels of ionizing radiation. This is because the ionization of gas molecules can indirectly indicate the amount of energy absorbed by the gas.

Similar threads

B Radiation detector types/physics
    • High Energy, Nuclear, Particle Physics
Replies
24
Views
2K
GM counter and alpha particles
    • Nuclear Engineering
Replies
7
Views
2K
A Understanding Proportional Counter Circuit
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
812
I GM tube and dual probe scintillator
    • High Energy, Nuclear, Particle Physics
Replies
2
Views
964
B Source radioactivity estimate from a radiation detector
    • High Energy, Nuclear, Particle Physics
Replies
2
Views
835
Can GM gamma meter be sensitive for neutron radiation?
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
3K
Exit velocity of gas through two orifices
    • Mechanical Engineering
Replies
12
Views
845
I Why Bremsstrahlung <20keV for Tungsten?
    • High Energy, Nuclear, Particle Physics
Replies
17
Views
2K
Simulated voltage gain in Multisim differs very much from calculated
    • Electrical Engineering
Replies
8
Views
511
B Using Compton Scattering to Determine Interaction Depth in Materials
    • High Energy, Nuclear, Particle Physics
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top