More about the technical side of Q2P1

As part of the USLHC accelerator project, Fermilab is responsible for delivering 1/2 of the final focusing high gradient quadrupole magnets used for the LHC interaction regions.

After a very successful program of 2 meter long model magnets (1998-2000), we have built our first full-scale prototype. This magnet is called Q2P1. Q2P1 was recently tested in our new facility built especially for these magnets.

Our goal: Make a full length prototype magnet that will perform as well as the model magnets in three areas:
1. Quench performance: Can it reach a quadrupole field gradient of 230 Tesla/meter?
2. Magnetic field quality: Does the magnetic field quality meet or exceed the accelerator requirements?
3. Quench Protection: Will the magnet survive the quench process without damage?

The answer to all three questions is "yes". The magnet trained in superfluid helium to 230 Tesla/meter in 10 quenches. It started out around 210 Telsa/meter, above the nominal LHC operating gradient, and improved to 230 Tesla/meter in 10 quenches. This training is typical of magnets in the model program.

The field quality is of a sufficiently high quality that it could be used in the LHC accelerator. And finally, the magnet is still operating properly after all of those training quenches.

However, we are not quite through with this magnet. A good magnet has to perform well after several cool down and warm up cycles. So our plan is to warm the magnet up to room temperature and cool it down again and run the same tests. We expect the magnet to "remember" its quench training (it has to operate in the LHC at 215 T/m without quenching) and continue to have good field quality.

- Mike Lamm, Technical Division -