Taking a closer look at LHC

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MAGNETISM (I)

(more at the bottom of the page)

1232 magnetic dipoles (14,3 m long and weighs around 35 tons) placed along the beam path will produce the force which will permanently bend the protons trajectory.

An ingenious design of the magnetic field in every dipole generates a vector B on each pipe opposite in direction to that of the other pipe.

This configuration is called:

2-in-1

Curving the beam's path is achieved by the magnetic field of dipole magnets. This is because the magnetic force (Lorentz Force) exerted on charged particles is always perpendicular to their velocity, perfect for curving the trajectory.

The magnetic field in every dipole generates a vector B on each pipe opposite in direction to that of the other pipe. This makes the forces over both proton beams act in the same direction towards the centre of the ring.

From the previous calculations of the centripetal force we can now get the magnetic field B.

Since the centripetal force F_c is the Lorentz Force: F_c = q·v·B

F = 2.64·10^-10 N , q = 1,602·10^-19 C and v ~ c

B ~ 5,50 Tesla

Taking a closer look, we need to consider the fact that the dipoles do not fill all of the 26659 m of the ring, but only a fraction of it. A lot of other devices are necessary: injectors, vacuum pumps, multipole magnets, radio-frequency cavities, high voltage instruments, measurement equipment, and obviously the enormous detectors.

There are 1232 dipoles, each one having a magnetic length of 14,3 m, giving a total of 17618 m.

Precisely, we can calculate the "bending radius": 17618/(2π) = 2804 m

So now we can get other important accelerator parameter:

B = 5.50·26659/17618

B ~ 8.33 T

(100000 times Earth’s magnetic field)

If the LHC had been made of conventional magnets, it would have needed to be 120 km long to achieve the same energies and its electricity consumption would have been phenomenal.

The dipole magnet is wound of a special cable superconductives, containing 28 and 36 strands on the inner and outer coil layers, respectively.

The strands of the cable are made of Nb-Ti filaments of 6 and 7 mm in diameter (inner and outer layer of the coil) and are embedded in a copper matrix. During the LHC operation at 1.9 K, the two counter-rotating beams follow flat circular trajectories along the 14.3 m long active part of each dipole.

The two orbits are separated by 194 mm which is the nominal distance between the coil axes.

That distance is 420 mm in RF cavities, whereas both beams use a unique pipe when going through detectors.

1232 magnetic dipoles (14,3 m long and weighs around 35 tons) placed along the beam path will produce the force which will permanently bend the protons trajectory.
An ingenious design of the magnetic field in every dipole generates a vector B on each pipe opposite in direction to that of the other pipe. This configuration is called: 2-in-1

	KINEMATICS
	FORCES
	MOMENTUM
	ENERGY
	LOW TEMPERATURE
	MAGNETISM
	ELECTRICITY
	SUPERCONDUCTIVITY
	LUMINOSITY
	CROSS SECTION
	RELATIVITY
	SYNCHROTRON RADIATION
	IONIZING RADIATION
	BLACK HOLES?

Curving the beam's path is achieved by the magnetic field of dipole magnets. This is because the magnetic force (Lorentz Force) exerted on charged particles is always perpendicular to their velocity, perfect for curving the trajectory. The magnetic field in every dipole generates a vector B on each pipe opposite in direction to that of the other pipe. This makes the forces over both proton beams act in the same direction towards the centre of the ring.



From the previous calculations of the centripetal force we can now get the magnetic field B. Since the centripetal force F_c is the Lorentz Force: F_c = q·v·B F = 2.64·10^-10 N , q = 1,602·10^-19 C and v ~ c B ~ 5,50 Tesla Taking a closer look, we need to consider the fact that the dipoles do not fill all of the 26659 m of the ring, but only a fraction of it. A lot of other devices are necessary: injectors, vacuum pumps, multipole magnets, radio-frequency cavities, high voltage instruments, measurement equipment, and obviously the enormous detectors. There are 1232 dipoles, each one having a magnetic length of 14,3 m, giving a total of 17618 m. Precisely, we can calculate the "bending radius": 17618/(2π) = 2804 m So now we can get other important accelerator parameter: B = 5.50·26659/17618 B ~ 8.33 T (100000 times Earth’s magnetic field) If the LHC had been made of conventional magnets, it would have needed to be 120 km long to achieve the same energies and its electricity consumption would have been phenomenal.

The dipole magnet is wound of a special cable superconductives, containing 28 and 36 strands on the inner and outer coil layers, respectively. The strands of the cable are made of Nb-Ti filaments of 6 and 7 mm in diameter (inner and outer layer of the coil) and are embedded in a copper matrix. During the LHC operation at 1.9 K, the two counter-rotating beams follow flat circular trajectories along the 14.3 m long active part of each dipole. The two orbits are separated by 194 mm which is the nominal distance between the coil axes. That distance is 420 mm in RF cavities, whereas both beams use a unique pipe when going through detectors.