William Atkins
Tuesday, 02 September 2008 22:39
Science -
Energy
Page 2 of 3
And, when it is first turned on September 12th, it isn’t like turning on your television set. The preliminary process needed before the LHC is turned on has been ongoing for many months now.
Each of the eight sectors of the LHC is cooled down to an operating temperature of 1.9 Kelvin (which is 1.9 degrees above absolute zero), or -271 degrees Celsius. Over 96 metric tons of liquid helium is used to keep the magnets at their operating temperature of 1.9 Kelvin
Sixteen hundred twenty-four (1,624) superconducting magnets are tested to make sure they are working properly. Many of them weigh over 27 metric tons.
Twelve hundred thirty-two (1,232) of the magnets are “bending” magnets because they are used to “bend” the beams around their circular (ringed) path of approximately 27 kilometers (17 miles).
Another 392 magnets, called “focusing” magnets, are used to “focus” the beams so that the particles within one beam have the maximum chance of colliding (interacting) with particles within a second beam.
After each of these steps is successfully completed, all of the circuits in each sector are turned on and tested. Each of the eight sectors are turned on together so that they work as a single piece of equipment. Synchronization of the LHC with the Super Proton Synchrotron (SPS) accelerator is also performed so that they are “synched” up to less than one nanosecond (one billionth of a second).
On August 25, 2008, the final test of the LHC’s beam synchronization system was performed successfully. This
counterclockwise test, which was conducted after the first test (the
clockwise test), now allows the first beam to be injected into the LHC.
The first injection of a beam into the LHC will be at the injection energy of 450 GeV (giga electron volts), or 0.45 TeV (tera electron volts), where one tera electron volts is equal to one trillion (one thousand billion) electron volts .
According to the National Institute of Standards and Technology, the energy unit of electron volt (eV) is defined as potential difference (1 volt equals 1 joule divided by 1 coulomb) multiplied by electron charge (1.60217653(14) x 10
-19 coulomb). Therefore, 1 eV is equal to 1.60217653(14)×10
−19 joule.
In other words, one electron volt is the amount of energy that is acquired by one unbound electron when it accelerates through an electrostatic potential difference of one volt.
The energy level for the September 12th test is only 0.45 TeV, a far distance from the 5 TeV targeted later in 2008 and the maximum amount of energy able to be generated by the LHC--7 TeV--in 2010.
Read page three for information on why 450 GeV (0.45 TeV) is being used for the September 12th test.
