# The Geiger Counter

In my class, we talked about the GM-counter and we were shown a graph with the voltage on the x-axis and intensity on the y-axis. But I do not understand why the graph has the characteristics it has, such as under a certain voltage it does not work, then it hits a plateau and suddenly it goes up again. I asked my teacher for clarification, but he was rather vague. He said that the particles need a certain voltage to get ionized (I understand this partly), but he also said that there was a continuous discharge above a certain voltage (the part I do not completely understand). I could not find the same graph as in my text book but I found one similar enough, so I have enclosed that picture. I hope someone can help me understand this concept. Thank you in advance.