I want to know how much time it takes to accelerate the electrons to such energy. I wish an answer from one who knows the experimental details of LEP.
Hi Sadeem,
First of all you need to know the injection energy of electrons into the LEP and the energy gain during each turn. Then you can continue finding out how many turns needed to reach the required energy. You might then calculate the relativistic Lorentz factors for each turn which will stop increasing in some point - basically due to the speed of light being a constant. By knowing gamma factors for each turn, you can calculate the velocity and having known the circumference of LEP you can calculate how long would it take for electrons to go around. Add up times required for each turn and here you go...
Regards, Oznur
Dear Öznur Mete
Thank you, but the problem I don't have these information so I can do the required calculations. I really need it because the time is one of the variables in a model that I'm working on.
I reckon you can find the required info and more in LEP design report. Here you go: http://cds.cern.ch/record/102083/files/cm-p00047694.pdf
Regards, Oznur
Nevertheless I want an experimental data not calculated one. Because I want to compare with it.
Hello Sadeem,
I will try to find out the requested information for you in a few days.
Cheers
Massimo
Hello Sadeem,
some more details concernign your question.
Normally, a circular collider is filled with the two beams and then the energy ramp occurs. At the end of the ramp, i.e., once the collision energy is reached, the optics of the collider is changes (the so-called beta-squeeze) to the situation in which the counter-rotating beams have the smallest size at the interaction point. Finally, the beams are brought into collision at the interaction points.
In LEP things were done with a different procedure. After filling, the two beams were accleelrated from 22 GeV to 102 GeV. Then, changing the optics and putting the beams in collisions were performed while continuing the acceleration to 104 GeV. In reality, the beams were in collision already at about 102.5 GeV. Typical times from 22 GeV to 104 GeV were 15-20 mins.
I think, these details might be helpful for you in order to see whether your question is still the appropriate one.
BTW...H. Burkhardt and J. Wenninger were really helpful in providing me with these details.
Cheers
Massimo
Dear Professor M. Giovannozzi
I would like to thank you so much for your valuable information. I'm really grateful to you and to all the Professors and researchers that participate or helped in getting these information. Lastly one think to ask how much time it takes to finish the filling process . That is how much time it takes from the starting of acceleration process until the energy of 22 GeV is reached?
I ask this because the variable used represents time from the starting of acceleration.
Sorry for asking much and taking much of your time.
Thank you so much
Dear Sadeem,
The total time from filling at low energy to collisions at high energy was about 15 minutes (when all went very well) to half an hour or more.
The actual 'ramping' time for acceleration of the electrons from the 22 GeV up to 102 GeV was less than a minute, most of the remaining time being spent in various corrections and tunings. This resulted from several years of tuning! (see reference attached) What ultimately limits this "ramping" time is that all the magnets (dipoles, quadrupoles, sextupoles,etc) need to be ramped in good synchronization.
I hope this is useful.
Alain Blondel
http://cds.cern.ch/record/702981/files/sl-note-95-195.pdf
Dear Prof. Alain Blondel
Thank you so much for your valuable comment and link.
So as you said the whole process takes between 15 min to 30 min or more .
Thank you so much for these information. Actually I was looking for the real experiment time for the LEP experiment that accomplished at 104. GeVand the information that you and Prof M Giovannozzi have given were valuable to me
thanks
Hello Sadeem,
the injection process takes a variable time. The time I specified in my answer are already the time from the end of the injection, at 22 GeV, to 104 GeV.
I hope this helps.
Cheers
Massimo
Hello Prof. M Giovannozzi
Thanks a lot Professor your answers are really
helpful to me. Now the matter is clear to me.
Thank you again I'm grateful to you and to all
the participants of this question.
Best regards
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