BAK earned after a year of inactivity
On November 20, for the first time after 14 months of repair and modernization, CERN specialists sent a proton beam along a large 27 km radius in one direction. This bundle was extinguished and on November 21 the bundle was launched in the opposite direction. The experiment, according to representatives of CERN in his microblog , passed in the normal mode. After several million test turns in each direction, the collider was launched to accelerate the beams in opposite directions simultaneously. All four detectors installed at the LHC successfully register the proton flux.
Now the LHC accelerates protons to energies of the order of 450 GeV (without using accelerators-magnets of a large radius, because the proton synchrotron accelerates to this energy the previous stage). The next stages of CERN's work will be experiments on the collision of protons with an energy of 450 GeV and a trial increase in energy up to 1.1 TeV, which is likely to be somewhere in the middle of December ( source 1 , slide number 3; source 2 ). The energy increase to 3.5 TeV in 2009 will not be made, in order to secure the collider launch process as much as possible. Around December 17, the collider will be stopped for the Christmas holidays (yes, scientists also have holidays).
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In 2010, it is planned to launch the collider again (January 7). And after the preparatory work and checks to bring it to the power of 3.5 TeV. After that, 3 months of experiments with 3.5 TeV protons (February-May), output to 4-5 TeV and 5 months of experiments with 4-5 TeV energies (June-October) are planned. At the end of the year, the proton beam will be switched off, setting up work with beams of lead ions and 1 month of operation in the mode of ion-ion collisions (November-December).
Starting from 3.5 TeV (when two protons collide with such energy, the total interaction energy is 7 TeV) scientists expect the most “tasty” results of the experiment. Namely, they expect to find new particles involved in the strong interaction (including the Higgs boson). It is expected that the first data to be accumulated by the detectors will be processed no earlier than mid-2010. So with the discoveries of new particles, which will have to be repeated and carefully checked, we will have to wait a long time.
One of the problems that exists now and which will need to be solved by CERN specialists is the lifetime of one proton beam. Now it is about 30 minutes. To carry out experiments at maximum energies of 7 TeV, it is necessary to bring it to about 10–12 hours.
But there is good news. The QPS (Quench Protection System) particle detection and prevention system, which has been installed 14 months since the last accident in September 2008, has been working successfully. During the test run, a proton beam touched one of the magnets. QPS immediately disconnected its power supply and removed it from its superconducting state in order to prevent damage. A similar incident delayed scheduled work for about half an hour. However, he showed that the security system is now more perfect, and it will not allow the magnets to be disabled, as was the case in September 2008 (recall that this accident resulted in the failure of one of the magnets and a ton of liquid helium spilled into the tunnel).
So we will cross our fingers for good luck, and wait for what will happen next.
Plans for the rest of 2009
Now the LHC accelerates protons to energies of the order of 450 GeV (without using accelerators-magnets of a large radius, because the proton synchrotron accelerates to this energy the previous stage). The next stages of CERN's work will be experiments on the collision of protons with an energy of 450 GeV and a trial increase in energy up to 1.1 TeV, which is likely to be somewhere in the middle of December ( source 1 , slide number 3; source 2 ). The energy increase to 3.5 TeV in 2009 will not be made, in order to secure the collider launch process as much as possible. Around December 17, the collider will be stopped for the Christmas holidays (yes, scientists also have holidays).
')
Plans for 2010
In 2010, it is planned to launch the collider again (January 7). And after the preparatory work and checks to bring it to the power of 3.5 TeV. After that, 3 months of experiments with 3.5 TeV protons (February-May), output to 4-5 TeV and 5 months of experiments with 4-5 TeV energies (June-October) are planned. At the end of the year, the proton beam will be switched off, setting up work with beams of lead ions and 1 month of operation in the mode of ion-ion collisions (November-December).
Starting from 3.5 TeV (when two protons collide with such energy, the total interaction energy is 7 TeV) scientists expect the most “tasty” results of the experiment. Namely, they expect to find new particles involved in the strong interaction (including the Higgs boson). It is expected that the first data to be accumulated by the detectors will be processed no earlier than mid-2010. So with the discoveries of new particles, which will have to be repeated and carefully checked, we will have to wait a long time.
Details
One of the problems that exists now and which will need to be solved by CERN specialists is the lifetime of one proton beam. Now it is about 30 minutes. To carry out experiments at maximum energies of 7 TeV, it is necessary to bring it to about 10–12 hours.
But there is good news. The QPS (Quench Protection System) particle detection and prevention system, which has been installed 14 months since the last accident in September 2008, has been working successfully. During the test run, a proton beam touched one of the magnets. QPS immediately disconnected its power supply and removed it from its superconducting state in order to prevent damage. A similar incident delayed scheduled work for about half an hour. However, he showed that the security system is now more perfect, and it will not allow the magnets to be disabled, as was the case in September 2008 (recall that this accident resulted in the failure of one of the magnets and a ton of liquid helium spilled into the tunnel).
So we will cross our fingers for good luck, and wait for what will happen next.
Source: https://habr.com/ru/post/76062/
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