First beam in Linac4 DTL

Following the installation of the Linac4 Drift Tube Linac (DTL) earlier this summer (see here), the first DTL tank saw beams at 12 MeV on 5 August.


Transverse emittance measured at 12 MeV after the DTL tank1
using a temporary slit-and-grid emittance device.

You never forget your first beam. That was especially true for the Linac4 DTL team, as it followed years of design, construction and vigorous testing. "We performed countless measurements of the geometry, vacuum and magnet polarisation of the DTL tanks while we were in the workshop," says Suitbert Ramberger, project engineer for the Linac4 DTL. "Add that preparation to the excellent RF conditioning that we carried out in the weeks before the beam tests and I was confident that the acceleration with beam would fully meet expectations!" Indeed it did. Beam commissioning tests ran until 21 August and found the DTL operating with nominal transmission.

This successful run has confirmed the innovative design of the DTL elements. "The DTL tanks were designed to require very little tuning," explains Alessandra Lombardi, who is heading up Linac4’s commissioning. "This is an excellent feature, but would have left us with little manoeuvrability if it hadn't worked! But this 12 MeV beam has shown that the DTL design is faultless."

With this latest success under their belts, the Linac4 team looks ahead to their next challenge: bringing beams into the next two DTL tanks!

by Katarina Anthony