PITZ 3.0 Beamline

 

The main components of the PITZ setup are a photocathode laser system, an RF photo-electron gun as accelerating structure, which is surrounded by focussing solenoid magnets, and a post-accelerating cavity, the Cut Disk Structure (CDS) – also called booster cavity.

Several diagnostic devices are used between the gun and the booster cavity: two Faraday Cups (FCs) for detailed (and low-charge) bunch charge measurements; a Cherenkov radiator with streak camera readout for bunch length measurements (in the straight as well as in the first dispersive section); the low-energy spectrometer (Low Energy Dispersive Arm – LEDA) for momentum characterization of the ~6.5 MeV electron bunches.

Steering magnets together with Beam Position Monitors (BPMs) allow for realizing and controlling the proper beam positioning along the complete electron's trajectory. Screen stations with YAG screens are used for beam transverse position and transverse size measurements. Along the complete beamline, there are several ICTs for bunch charge measurements.

Downstream the booster cavity, the beamline consists of different types of diagnostic devices for detailed electron bunch characterization at the final beam energy (~25 MeV). Three dedicated screen stations can be used for beam position and beam size measurements as well as for transverse emittance measurements utilizing the slit scan technique (Emittance Measurement Stations – EMSYs). A Phase Space Tomography module (PST) located further downstream the booster is used for measurements of the transverse phase space and can simultaneously restore the horizontal and vertical transverse planes in contrast to the slit scan technique. The two high-energy spectrometers allow for detailed momentum characterization: one directly downstream the booster cavity (the first High Energy Dispersive Arm – HEDA1), and one at the end of the PITZ beamline (the second High Energy Dispersive Arm – HEDA2). Quadrupole magnets are used for beam focussing and enable slice emittance measurements using streak camera enhanced quadrupole scan technique in HEDA1. They are also necessary for matching of the electron beam to the subsequently following Phase Space Tomography module (PST) . The Transverse Deflecting Structure (TDS) enables slice measurements of the electron bunches and is a adequate tool for high-resolution longitudinal phase space measurements.

The PITZ 3.0 beamline contains in addition a Plasma cell for the planned plasma self-modulation experiments.