Message boards : LHC@home Science : Measured speed of the particle beam?
Message board moderation

To post messages, you must log in.

AuthorMessage
Simplex0

Send message
Joined: 26 Aug 05
Posts: 68
Credit: 545,660
RAC: 0
Message 17965 - Posted: 23 Sep 2007, 9:27:00 UTC

Has there ben made any measurement of the speed on the particle beam in accelerators and if so, how is it done?
ID: 17965 · Report as offensive     Reply Quote
Profile CoM

Send message
Joined: 29 Sep 04
Posts: 42
Credit: 11,295,036
RAC: 52
Message 17966 - Posted: 23 Sep 2007, 15:01:03 UTC - in response to Message 17965.  

Has there ben made any measurement of the speed on the particle beam in accelerators and if so, how is it done?

the speed is c=3*10^8 m/s (speed of light)!!
ID: 17966 · Report as offensive     Reply Quote
Simplex0

Send message
Joined: 26 Aug 05
Posts: 68
Credit: 545,660
RAC: 0
Message 17967 - Posted: 23 Sep 2007, 15:25:28 UTC - in response to Message 17966.  

Has there ben made any measurement of the speed on the particle beam in accelerators and if so, how is it done?

the speed is c=3*10^8 m/s (speed of light)!!


1. On a particle with a rest mas > zero?
2. How was the measurement made?

ID: 17967 · Report as offensive     Reply Quote
Profile CoM

Send message
Joined: 29 Sep 04
Posts: 42
Credit: 11,295,036
RAC: 52
Message 17974 - Posted: 24 Sep 2007, 7:21:43 UTC

OK, my answer was quite sensational. You are right that particle with mass will not reach the speed of light, but they come very close 95% up to 99,999...%.
Todays accelerators like the LHC or SPS, Tevatron, RHIC, SLAC, KEK, ... are all power full enough.

How to measure, well thats easy. You measure the time t the particle takes to travel the distance s and you calculate the speed v = s/t. You should use a very precise stopwatch (TDC with time resolution down to some 100ps).
ID: 17974 · Report as offensive     Reply Quote
Simplex0

Send message
Joined: 26 Aug 05
Posts: 68
Credit: 545,660
RAC: 0
Message 17979 - Posted: 24 Sep 2007, 15:15:59 UTC - in response to Message 17974.  

OK, my answer was quite sensational. You are right that particle with mass will not reach the speed of light, but they come very close 95% up to 99,999...%.
Todays accelerators like the LHC or SPS, Tevatron, RHIC, SLAC, KEK, ... are all power full enough.

How to measure, well thats easy. You measure the time t the particle takes to travel the distance s and you calculate the speed v = s/t. You should use a very precise stopwatch (TDC with time resolution down to some 100ps).


Ok. let's assume that you measure the speed by determine the time it takes for a particle to travel from A to B. What method do they use to verify when the particle is at location A and location B and how do they actually do it.

ID: 17979 · Report as offensive     Reply Quote
Profile CoM

Send message
Joined: 29 Sep 04
Posts: 42
Credit: 11,295,036
RAC: 52
Message 17981 - Posted: 24 Sep 2007, 20:11:26 UTC

There are charged particles in the accelerators (mainly electrons and protons). And these charged particles induce a signal when they flight cross a capacitance like system. This system is named schottky pick up (if i am right), so you measure the revolution frequency and one know the circumference of the synchrotron, so one can calculate the speed.
There are also other possibilities: Taking some detectors like scintillators. But that disturbs the beam.
ID: 17981 · Report as offensive     Reply Quote
Simplex0

Send message
Joined: 26 Aug 05
Posts: 68
Credit: 545,660
RAC: 0
Message 17982 - Posted: 25 Sep 2007, 2:49:18 UTC

Thank you CoM.
ID: 17982 · Report as offensive     Reply Quote

Message boards : LHC@home Science : Measured speed of the particle beam?


©2021 CERN