Abstract: Ion getter pumps (IGPs) are particularly appropriate for use in modern accelerator facilities because of their high reliability, cleanliness and the absence of vibration that could disturb the trajectory of the beam. Normally, T-pieces are used to connect the pumps to the beam tube. These reduce the effective pumping speed and require the use of radiofrequency (RF) shielding which is complicated and expensive. Moreover, very often the accelerated particles are sensitive to stray magnetic fields and the impedance of the surrounding vacuum tube. Magnetic fields generated by the ion pump magnets, which are asymmetrically oriented to the beam tube, can be a major drawback. To overcome these problems, we have developed, in collaboration with the Deutsche Elektronen -Synchrotron (DESY), an innovative in -line ion getter pump which can be mounted directly into a beam line without a T -piece and which has a symmetrical arrangement of the magnets around the beam tube. Additionally, RF shielding can be easily integrated inside the in-line pump. Using this innovative in-line concept (Patent EP2 431996A1) ion pumps will become an integral part of the beam tube for the first time when installed on the X -FEL system at DESY. The arrangement of the magnets and the geometry of the pole piece, used to guide the magnetic field lines, were designed to minimize any disturbance on the beam trajectory. Moreover, the element location inside the pump has been optimized to“selfshield”the beam, without requiring the addition of expensive and complex optical shields. Finally, thanks to the in-line solution, a simple RF shield (a copper coated tube with pumping slits) can now be easily installed directly inside the pump at the accelerator site installed directly inside the pump at the accelerator site.

Key words: particle accelerator, vacuum system, inline, high-conductance, ion pump