This is for HIPPI cable connections betzeen 25 Metres and 50 Metres. This repeater was developped at Los Alamos National Laboratories.
NEDDI (Never Ending Destination Interface). It was used for test purposes. It handles the HIPPI hardware handshake regardless of Data. The NEDDI was developed at CERN and manufactured at CES in Geneva.
Slice through an LHC superconducting quadrupole (focusing) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. Bringing beams into collision requires a precision comparable to making two knitting needles collide, launched from either side of the Atlantic Ocean.
A short test version of coil of wire used for the LHC dipole magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair.
3 accelerating cavities.
Particles are accelerated using radio-frequency cavities. These contain an electric field which oscillates at just the right frequency to give a kick to the charged particles passing through.
Sem títuloA short section of the LHC beam-pipe including beam screen. In the LHC, particles circulate under vacuum. The vacuum chamber can be at room temperature (for example, in the experimental areas), or at cryogenic temperature, in the superconductive magnets. This piece is located in the superconductive magnets. The outer pipe is the vacuum chamber, which is in contact with the magnets, at cryogenic temperature (1.9K). It is called the “cold bore”. The inner tube is the beam screen. Its main goal is to protect the magnets from the heat load coming from the synchrotron radiation. Indeed, when high energy protons’ trajectory is bent, photons are emitted by the beam. They are intercepted by the beam screen. The temperature of the beam screen is kept between 5 and 20K by a circulation of gaseous helium in the small pipes on both sides of the beam screen. As those surfaces are at cryogenic temperature. The residual gas present in the accelerator is sticking on the surfaces. This phenomenon called “adsorption” is used to maintain a very low pressure in the vacuum chamber of the accelerator. About materials: The cold bore is in stainless steel. The beam screen is in stainless steel with colaminated copper. Both those material have a low outgassing rates, which means that they release few molecules in the vacuum chamber. About beam and impedance: The goal of the copper, which has a good electrical conductivity, is to facilitate the circulation of the image current. The beam is composed of charged particules circulating: it is an electric current. When it is circulating, an image current is produced. It is called induction. If the image current cannot circulate properly, the beam is slowed down. About adsorption process: When the beam circulates, photons from synchrotron radiation are emitted and hit the beam screen. By doing so, they desorb molecules from the walls. The molecules are then pumped down on the outer pipe (where they cannot be reached by the photons anymore), through the small holes in the beam screen.
If all molecules in this bottle could be used, this hydrogen bottle contains enough protons to feed the Large Hadron Collider for 200’000 years of continuous operation! But since there are losses inside the source, in and between the accelerators, such a bottle only lasted for 4 to 6 months of operations and needed then to be replaced.
42 modules like this one surround the collision point inside the LHCb detector. Their role is to measure the tracks of short-lived particles spraying out from the collision and to pinpoint the exact spots where they decay into secondary particles. Some exist for just trillionths of a second before decaying! The silicon modules operate so close to the collision point, they can only be moved into position once the circling particle beams are at their most focused. Otherwise, peripheral particles on the outside of the finer-than-a-hair beam would bore a hole right through them.