The Karlsruhe Institute of Technology is currently exploring a compact method of longitudinal electron bunch diagnostics with femtosecond resolution that has recently been demonstrated for other parameter ranges. The experimental setup utilizes a THz-based streaking approach with resonator structures, achieving both high compactness and efficiency. In this contribution, we report on the...
Many currently operating and future FELs can generate broadband radiation at MHz repetition rate, requiring a fast diagnostic tool(response time at least on a single-digit ns scale),ultra-broadband, & robustness. We develop ultrafast-operating THz detectors based on Schottky diodes [1,2], and field-effect transistors (FET) [3] operating at room temperature.
This work presents four aspects of...
At the heavy ion LINAC UNILAC at GSI in Darmstadt, longitudinal beam diagnostics were performed using a Bunch Shape Monitor (BSM) and a Fast Faraday Cup (FFC). These diagnostic tools allow for detailed time-resolved measurements of the longitudinal bunch structure of non-relativistic particle beams. The FFC employs a destructive measurement technique to assess the bunch-by-bunch longitudinal...
Virtual diagnostic tools leveraging readily available input data to offer a non-invasive way to optimize Free-Electron Lasers (FEL) operation and delivery, especially when limitations with conventional diagnostics arise. This work presents a novel approach using an artificial neural network to online predict photon pulse pointing at MHz level for both soft and hard x-rays. The model input is...
Cryogenic Current Comparators (CCCs) for beamlines are instruments for the measurement of the intensity of charged particle beam with the following advantages: non-destructive, resolution down to nA, bunched (AC) and un-bunched (DC) beam, metrological traceability to the unit Ampere. This is achieved by exploiting low temperatures (4.2 K) and superconducting/quantum effects.
After a long...
A terahertz (THz) free-electron laser (FEL) is developed at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) to conduct proof-of-principle experiments for the European-XFEL. Narrowband 3 THz pulses with energies up to 100 μJ are generated using a single-pass, high-gain THz FEL driven by high-brightness electron beams. A dedicated diagnostic setup has been implemented for...
Radio-frequency (RF) guns are essential components of accelerator-based light sources. The superconducting continuous-wave RF (SRF) gun at ELBE, operated by Helmholtz-Zentrum Dresden-Rossendorf (HZDR), can drive multiple beamlines, including the THz beamline TELBE. TELBE is typically operated with a 200 pC bunch charge beam. The transverse emittance of the resulting beam is measured using a...
Ultrafast electron diffraction (UED) is a unique technique for for measuring structural and electronic dynamics with femtosecond time resolution when employed in a pump-probe arrangement. In most state-of the-art UED setups, beams with keV electron energy are utilized. The project described here aims to step up to MeV electron beams with the help of an SRF Gun. The higher coherence of the beam...
In 2023 a first demonstrator showed viability of a new pickup structure realized on a printed circuit board (PCB) for a bunch arrival-time monitor (BAM). Measurement shifts at ELBE validated the simulations and motivated the further pursuit of this approach. A few shortcomings were deliberately accepted to simplify production and increase the probability of successful measurement for the first...
In the last few years, we investigated a new type of Fast Faraday Cups (FFC). This type radially couples the bunch to the inner conductor of a coaxial geometry. The main benefit of this FFC is that two methods to suppress secondary electrons (SE) from impacting the output signal can be applied: by a bias potential and geometrically, through hitting the inner conductor only inside a drill hole....
Laser-based electro-optic detection (EOD) has been a valuable method to measure the longitudinal electron bunch shape with sub-ps resolution for almost a decade now, but it has always been a tool for expert use.
At European XFEL and FLASH, we are advancing the EOD from an expert device to a user friendly tool, with new operator interface and automated, server-based procedures for laser...
Femtosecond and sub-femtosecond longitudinal diagnostics are required to accurately characterise the short bunches required by novel acceleration techniques. For femto-second bunch lengths, the coherence of transition radiation starts to reach the near-infrared to optical regime, where the spectrum can be easily detected, rendering information on the form factor and bunch length. The ARES...
The future circular electron-positron collider (FCC-ee) is designed for highest luminosity to enhance the precision of high-energy particle physics experiments, spanning energies from the Z pole to the $\text{t}\bar{\text{t}}$ threshold. As outlined in its conceptual design report, high-precision measurements of the longitudinal bunch profile are required across multiple operation modes, which...
The DESY's Bunch Arrival Time Monitors (BAM) are state-of-the-art sensors based on an electro-optical detection principle, that delivers information on the bunch timing with femtosecond-level precision. Recent developments concerning the device construction and automation resulted in the BAM system stability, that enables year-long participation on standard accelerator operation. Such level of...
In the Karlsruhe Research Accelerator (KARA), electron beams of up to 200 mA are stored with an energy of 2.5 GeV, while injection is performed at 500 MeV. At the injection energy, the beam life time and the injection efficiency depend largely on Touschek scattering. As a counter-measure, the beam size can be enlarged transversally by an excitiing modulation, e.g. applied via a strip-line.
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During recent beamtimes at GSI we have used various diagnostics devices for characterization of the longitudinal properties of the UNILAC beam. Beam Position Monitors (BPM), Secondary Electron Emission Grids (SEM-Grids) - originally developed for the FAIR proton Linac - have been employed as well as a Feschenko Type Bunch Shape Monitor (BSM) to measure beam displacement behind dispersive...
High-power laser system synchronization optimization
Mohammed Salman$^{1,2}$, Dr. Michael Kuntzsch$^2$, Prof. Dr.-Ing. Andreas Penirschke$^1$
$^1$Technische Hochschule Mittelhessen (THM), Friedberg (Hessen), Germany
$^2$Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Sachsen), Germany
Synchronization systems are critical for ensuring precise timing and coordination in...
