Backstage Science: Powerful magnets
17 Aug 2011



Martyn Bull shows us around the powerful magnets that control ISIS's beam of neutrons




The ISIS facility produces neutrons by bombarding a target with a beam of high energy protons.

But controlling a beam of neutrons requires so​​me powerful magnets  

Martyn Bull:  "This is a collection of magnets from the proton beam. They’re spares that can be replaced if needed. They’re made all around Europe and their job is to guide and focus the proton beam as it comes from the accelerator and travels down the target.

These copper coils are where you put the electrical current that generates the magnetic field. The beam of particles travels through the centre here, usually in a tube with all the air sucked out. This is called a quadrapole. This effectively acts as a lense. It squeezes the beam and helps to focus it. We have different ones here; this blue one has just two big coils, one at the top and one at the bottom. This is a dipole magnet and its job is to bend the beam and in this case it’s bent in the horizontal direction. So, combinations of the two types of magnets allow you to control how the beam is transported to the target".