# How is the alternating electric potential produced in cyclotrons?

1. Apr 20, 2013

### tachyon_man

If the cyclotron frequency is f = (q B)/(2 pi m) this gives a very large frequency for a relatively large magnetic field and for an alpha particle say. If the acceleration of the charged particle across the "dees" is cause by an alternating electric potential (usually in the form of a square wave), how would one go about producing this alternating electric potential?
Title should say alternating electric potential... I cannot type today.

Last edited: Apr 20, 2013
2. Apr 21, 2013

### technician

When you put in the numbers you will find that the cyclotron frequency is high frequency radio frequencies.
This is tens of MHz. So a radio frequency generator is used

3. Apr 21, 2013

### sophiecentaur

The sort of device that would be used to produce the alternating current would be the same as is used in low power radio transmitters. Afaik, the power is in the order of tens of Watts (?).

4. Apr 23, 2013

### Pseudo Epsilon

does the frequency change with time or radius. Or can it posibly stay stationary, ever?

5. Apr 23, 2013

### Pseudo Epsilon

constant sorry, not stationary. Im stupid tonight.

6. Apr 23, 2013

### Staff: Mentor

In the original "classical" cyclotrons, the frequency was constant. When the particle energy gets high enough, relativistic effects become significant. The particles' frequency of revolution decreases and gets out of step with the driving frequency. The next step was the synchrocyclotron which varied the driving frequency to keep in step with the relativistic effects.

7. Apr 23, 2013

### Pseudo Epsilon

what would the maximum particle energy be before we woule have to use the relativistic cyclntron frequency for a) electron b) proton? If you dont mind me borrowing your intellect.