Developments of the TEUFEL injector racetrack microtron

In this paper we report on developments of the 25 MeV racetrack microtron (RTM) that will be the electron source for the second phase of the TEUFEL project, to generate radiation of 10 µm in a 2.5 cm period hybrid undulator. The theoretical understanding of this unconventional, azimuthally varying field type of RTM has been extended. A comparison of analytically calculated orbit stability with that based on measured data will be presented; orbit calculations using measured field data show the designed performance. Construction and tuning of the 1300 MHz, 2.2 MV microwave cavity have been completed, and signal level measurements have been performed. The overall assembly of the microtron is nearing completion. At present a vacuum pressure better than 5 × 10-7 Torr is achieved

The injector microtron for the TEUFEL infrared laser

Progress is reported on a 25 MeV injector racetrack microtron for a 10 ¿m radiation free electron laser (TEUFEL project). The accelerator exhibits transverse focusing in 180° inhomogeneous two-sector dipole magnets which are slightly rotated with respect to each other in the bending plane. This provides closed orbits, isochronism and a large transverse acceptance. Details on this unconventional microtron focusing system will be given. An analytical treatment, based on conformal mapping, of the field near pole boundaries and at the hill-valley boundaries in the microtron dipole is compared with Poisson calculated results and with field measurements. The design of a model accelerating cavity is presented together with field measurements based on the perturbation ball method

Electron-optical properties of the Eindhoven race-track microtron

The Eindhoven Race-track microtron contains two inhomogeneous bending magnets to obtain sufficient transverse focusing. For the design of these magnets we have used a first-order matrix theory to describe particle trajectories. Recently, higher-order terms of the magnetic field have been taken into account and the effects on the transverse motions have been studied. Here, we have used the numerical code COSY INFINITY [1] as well as numerical orbit integrations through the measured field maps

Beam positioning and monitoring in the racetrack microtron Eindhoven

A scheme to compensate for the effect of misalignments in the racetrack microtron Eindhoven is presented. An array of small dipole magnets will be employed to obtain closed orbits. These dipoles are located at the symmetry axis of the microtron, in the drift space between the two bending magnets. For each orbit a radial stripline beam position monitor (BPM) will be installed in the field free region. The strength of the corrector dipole magnet in the nth orbit is adjusted with the BPM signal in the (n+1)th orbit. The design of the BPM's is described. It will be shown that a rectangular geometry has a distinct advantage over a conventional circular geometry since it is less dependent on vertical displacements of the beam. Expressions for the difference-over-sum signal are given and compared with that for a circular geometry. Results of measurements performed in a test bench on prototype BPM's are discusse

A 10MeV injection beam transport line for a racetrack microtron

The ion optical design of a beam transport line from a 10 MeV injector linac to a 10-75 MeV racetrack microtron is given. The bending section in the beam line consists of a two step doubly achromatic system to bring the beam down from the linac axis to the median plane of the mi crotron. This achromatic system comprises four identical 50 degree dipole magnets. A quadrupole triplet between linac and bend section and a quadrupole doublet with elec tron steering capability downstream the bends are also in corporated