P + W | Opdrachtsbeschrijving
Door: Martijn
Blijf op de hoogte en volg Martijn
21 Februari 2008 | Zwitserland, Genève
Hieronder vind je de opdrachtsbeschrijving. Dit is inmiddels de definitieve versie. Voor de mensen die het nog niet opgevallen is. Ik heb foto’s online gezet op een andere site: zie het bericht “Introductie” voor de link.
CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works.
LHC, the Large Hadron Collider, is a gigantic scientific instrument. It is a particle accelerator used by physicists to study the smallest known particles, the fundamental building blocks of all things. One detector of the LHC is the ATLAS.
ATLAS, A Toroidal LHC ApparatuS, is a particle physics experiment that will explore the fundamental nature of matter and the basic forces that shape our universe. The ATLAS detector will search for new discoveries in the collisions of protons of extraordinary high energy.
The magnet system of the ATLAS detector consists of 4 parts: the Central Solenoid, the Barrel Toroid and 2 End-Cap Toroids.
In the Barrel toroid, eight 25m long superconducting coils are connected in serie. 20.000 A of operating current induce a magnetic field in the very large volume of the ATLAS detector with a peak value around 4T. The energy stored in the Barrel Toroid is more than 1 GJ. By the use of liquid Helium the coils are kept cold at 5 K.
The magnet control system is made so, that when something is wrong, the current is cut off and all the energy is withdrawn from the system into an external dump resistor. This process is called the slow-dump. Depending on the emergency, a slow-dump or a fast-dump can be started. Basically the fast-dump is the same as the slow dump, but in addition internal heaters are used to dissipate the energy of the magnet internally. The fast dump causes the interruption of the entire experiment for a few days, as the coils are getting warm and have to be cooled again. For the Barrel Toroid, the time of the slow-dump is 130 minutes and in case of the fast-dump, the duration is only 80 seconds.
The Barrel Toroid has been tested separately. At slow dump, the control system gave an alarm that the differences in the voltages over the conductors were too high and the fast-dump had to be started. The main reason of this unbalance is due to resistance of the normal zone. This was not correct, because of some sort of phenomenon, which was observed in the first few seconds after start of the discharge. The sensitivity of the magnet quench detection system has been modified to make the safety system reliable. But the level of detection remains desensitized.
One of possible explanation of this effect is that the changing current through the magnets may cause induced currents in the structure around. These currents are not necessarily similar to each other. The goal of the assignment is to find an explanation and make a simulation of the start phenomenon of the slow-dump of the ATLAS detector.
CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works.
LHC, the Large Hadron Collider, is a gigantic scientific instrument. It is a particle accelerator used by physicists to study the smallest known particles, the fundamental building blocks of all things. One detector of the LHC is the ATLAS.
ATLAS, A Toroidal LHC ApparatuS, is a particle physics experiment that will explore the fundamental nature of matter and the basic forces that shape our universe. The ATLAS detector will search for new discoveries in the collisions of protons of extraordinary high energy.
The magnet system of the ATLAS detector consists of 4 parts: the Central Solenoid, the Barrel Toroid and 2 End-Cap Toroids.
In the Barrel toroid, eight 25m long superconducting coils are connected in serie. 20.000 A of operating current induce a magnetic field in the very large volume of the ATLAS detector with a peak value around 4T. The energy stored in the Barrel Toroid is more than 1 GJ. By the use of liquid Helium the coils are kept cold at 5 K.
The magnet control system is made so, that when something is wrong, the current is cut off and all the energy is withdrawn from the system into an external dump resistor. This process is called the slow-dump. Depending on the emergency, a slow-dump or a fast-dump can be started. Basically the fast-dump is the same as the slow dump, but in addition internal heaters are used to dissipate the energy of the magnet internally. The fast dump causes the interruption of the entire experiment for a few days, as the coils are getting warm and have to be cooled again. For the Barrel Toroid, the time of the slow-dump is 130 minutes and in case of the fast-dump, the duration is only 80 seconds.
The Barrel Toroid has been tested separately. At slow dump, the control system gave an alarm that the differences in the voltages over the conductors were too high and the fast-dump had to be started. The main reason of this unbalance is due to resistance of the normal zone. This was not correct, because of some sort of phenomenon, which was observed in the first few seconds after start of the discharge. The sensitivity of the magnet quench detection system has been modified to make the safety system reliable. But the level of detection remains desensitized.
One of possible explanation of this effect is that the changing current through the magnets may cause induced currents in the structure around. These currents are not necessarily similar to each other. The goal of the assignment is to find an explanation and make a simulation of the start phenomenon of the slow-dump of the ATLAS detector.
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21 Februari 2008 - 22:41
Liesbeth:
Klinkt indrukwekkend!
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22 Februari 2008 - 12:31
Marloes:
Zolang jij maar weet wat je aan het doen bent! :)
Succes!
Is Alexey trouwens een Rus, of is dat ook een gebruikelijke Zwitserse naam? -
22 Februari 2008 - 17:12
Martijn:
Alexey is inderdaad een rus en niet de enigste. Ik geloof dat er van onze groep toch wel ongeveer de helft rus is. In de gangetjes hoor ik geregeld een Russisch gesprek. Ik versta er echt niets van.
En indrukwekkend is het zeker ! Vandaag ben ik in de cavern geweest... Wat is dat een groot ding, en dat allemaal voor die minuscule deeltjes. Ik kreeg een korte rondleiding (weinig tijd) waarbij we met allemaal kleine trappetjes onder, boven, langs en over het ATLAS hebben gelopen. -
24 Februari 2008 - 10:24
Sieuwe:
Ook al wat Nederlanders tegengekomen? -
26 Februari 2008 - 12:58
Merijn:
Heej Martijn,
Kijk die opdracht snap ik toch nog een beetje, als in ik snap wat de opdracht is. Krijg je daar ook punten voor :P.
Ik wil wel graag weten hoe jij dat gaat oplossen. Ben wel benieuwd. -
03 April 2008 - 11:21
Karien:
Eej grappig,
Ik snap hem ook :D.
Alleen niet wat 4T en 1GJ is.
Groetjes
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