Search

Abstract A transverse deflecting structure (TDS) is a well-known device for characterizing the longitudinal properties of an electron bunch in a linear accelerator. The standard use of such a cavity involves streaking the bunch along a transverse axis and analysing the image on a screen downstream to find the bunch length and slice properties along the other transverse axis. A novel X-band deflecting structure, which will allow the polarization of the deflecting field to be adjusted, is currently being designed as part of a collaboration between CERN, DESY and PSI. This new design will allow bunches to be streaked at any transverse angle within the cavity, which will open up the possibility of new measurement techniques, which could be combined to characterize the 6D phase space distribution of bunches. In this paper, a method is presented for reconstructing the longitudinal phase space distribution of bunches by using the TDS in combination with a dipole. Simulations of this technique for the SINBAD-ARES beamline are presented and the key limitations related to temporal resolution and induced energy spread are discussed. Highlights • Longitudinal phase space reconstruction using a transverse deflector simulated. • Induced energy spread makes the reconstruction of femtosecond bunches challenging. • Nevertheless, reconstruction possible for 5 fs bunch from SINBAD-ARES linac at DESY. [ABSTRACT FROM AUTHOR]

Abstract: Laser WakeField Accelerators (LWFA) feature short bunch lengths and high peak currents, combined with a small facility footprint. This makes them very interesting as injectors for Synchrotron light sources. Using the ANKA Synchrotron as an example, we investigate the possibility to inject a LWFA bunch into an electron storage ring. Particular emphasis is put on the longitudinal evolution of the bunch. [Copyright &y& Elsevier]

At present, the beam-based alignment of the LHC collimators is performed by touching the beam halo with both jaws of each collimator. This method requires dedicated fills at low intensities that are done infrequently and makes this procedure time consuming. This limits the operational flexibility, in particular in the case of changes of optics and orbit configuration in the experimental regions. The performance of the LHC collimation system relies on the machine reproducibility and regular loss maps to validate the settings of the collimator jaws. To overcome these limitations and to allow a continuous monitoring of the beam position at the collimators, a design with jaw-integrated Beam Position Monitors (BPMs) was proposed and successfully tested with a prototype (mock-up) collimator in the CERN SPS. Extensive beam experiments allowed to determine the achievable accuracy of the jaw alignment for single and multi-turn operation. In this paper, the results of these experiments are discussed. The non-linear response of the BPMs is compared to the predictions from electromagnetic simulations. Finally, the measured alignment accuracy is compared to the one achieved with the present collimators in the LHC. [ABSTRACT FROM AUTHOR]