 Low atomic number also makes beryllium relatively transparent to energetic particles . Therefore , it is used to build the beam pipe around the collision region in particle physics setups , such as all four main detector experiments at the Large Hadron Collider ( ALICE , <unk> , CMS , <unk> ) , the <unk> and the SLAC . The low density of beryllium allows collision products to reach the surrounding detectors without significant interaction , its stiffness allows a powerful vacuum to be produced within the pipe to minimize interaction with gases , its thermal stability allows it to function correctly at temperatures of only a few degrees above absolute zero , and its diamagnetic nature keeps it from interfering with the complex <unk> magnet systems used to steer and focus the particle beams . 
