Why is the central electrode in a G.M. tube positive?

Thread starter Charles W
Start date May 14, 2015
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Alpha Beta Electrode Gamma Positive Radiation Radioactivity Tube

In summary, the central electrode in a G.M. tube is positive because it is connected to the positive terminal of the power supply. Its function is to collect electrons and amplify the signal, contributing to the detection of radiation. The polarity of the electrode can be reversed, but it may not provide accurate measurements. The size of the central electrode can affect the performance of the tube, with a larger electrode producing a stronger signal but potentially leading to false readings, and a smaller electrode reducing background noise and improving accuracy.

May 14, 2015

Charles W

Why is the central electrode in a Geiger-Muller tube always positive (and not negative)?

Many thanks!

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May 14, 2015

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Insights Author

If it would be negative, your electrons would move outwards where the field strength is too low to get charge multiplication.

May 14, 2015

Charles W

Thank you very much! I understand now :)

1. Why is the central electrode in a G.M. tube positive?

The central electrode in a G.M. tube is positive because it is connected to the positive terminal of the power supply. This allows for the flow of electrons from the negative end of the tube to the positive end, creating a current that can be measured.

2. What is the function of the central electrode in a G.M. tube?

The central electrode in a G.M. tube acts as a collector for the electrons that are produced when radiation interacts with the gas inside the tube. It helps to amplify the number of electrons and create a measurable signal.

3. How does the central electrode in a G.M. tube contribute to the detection of radiation?

The central electrode in a G.M. tube is positively charged, which attracts the negatively charged electrons produced by the interaction of radiation with the gas inside the tube. This allows for the creation of a measurable current, which can then be used to detect and measure radiation levels.

4. Can the polarity of the central electrode in a G.M. tube be reversed?

Yes, the polarity of the central electrode in a G.M. tube can be reversed by connecting it to the negative terminal of the power supply. However, this is not the typical configuration and may not provide accurate measurements.

5. How does the size of the central electrode affect the performance of a G.M. tube?

The size of the central electrode in a G.M. tube can affect its performance in a few ways. A larger electrode can collect more electrons and produce a stronger signal, but it may also increase the chance of secondary electron production, leading to false readings. A smaller electrode may produce a weaker signal, but it can also reduce background noise and improve the overall accuracy of the measurements.