(THz based) advanced electron bunch diagnostic

THZ based diagnostic - headlinefigure

Figure: (a) Electro-optic measurement of a THz pulse from the TELBE undulator utilizing the developed high-reprate pulse-resolved detection scheme which allows to correct for arrivaltime jitter and intensity fluctuations at repetition rates of presently up to 100 kHz [1] A demonstrator device for the European XFEL is under construction . This detection scheme opens up  characterize the superradiant THz sources at TELBE, (b) undulator and (c) diffraction radiator, with a time resolution of better than 13 fs (rms) and a dynamic range of up to 1000000. 

The main focus of the actual research activities at the HZDR within the program topic accelerator-research and development: subtopic 3 ps - fs photon and electron beams (ARD - ST3) is in the development of versatile (THz-based) diagnostic for electron bunches and superradiant THz sources. To this end (T)ELBE serves within ARD-ST3  as a testfacilitiy for diagnostics on quasi-cw electron and photon beams. Two Examples for recent breakthroughs are the first demonstration of pulse-resolved arrivaltime monitoring at high repetition rate [1], as well as the development of an integrated THz spectrometer chip for advanced bunch compression monitoring [3,4]. Other activities within ARD-ST3 are the characterization and development of compact superradiant THz sources [2,5,6,7]. (T)ELBE also serves as a test field for the implementation of existing diagnostics such as Bunch-Arrival-Time (BAM) Monitors of the XFEL type at high-current quasi-cw accelerators [8] or electro-optic sampling based bunch duration monitors [9]. This research is performed in close collaboration with colleagues from DESY, KIT and SLAC and also extends to the development of diagnostics suitable for 4th Generation X-ray lightsources such as FLASH [10,11], the European XFEL or LCLS.

The research activities are funded through the HGF (program topic ARD), the BMBF (projects INSeL and SAMoS) as well as the European Union (EUCALL).

[1] S. Kovalev et al., "Probing ultra-fast processes with high dynamic range at 4th-generation light sources: Arrival time and intensity binning at unprecedented repetition rates", Struct. Dyn. 4 (2017), 024301.

[2] B. Green et al., "High-Field High-Repetition-Rate Sources for the Coherent THz Control of Matter", Sci. Rep. 6 (2016), 22256. 

[3] M. Schiselski et al., "Integrated Schottky Diode Detector for THz Spectrometer", Proceedings of 2015 GERMAN MICROWAVE CONFERENCE, (2015), 272.

[4] M. Schiselski et al., "A planar Schottky diode based integrated THz detector for fast electron pulse diagnostics", 2016 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS), (2016). 

[5] M. Gensch et al., "SUPER-RADIANT LINAC-BASED THz SOURCES IN 2013", Proceedings of FEL2013, New York, NY, USA, (2013), WEIBNO01.

[6] V. Asgekar et al., "Interference effects in super-radiant THz sources", Infrared Phys. Technol. 64 (2014), 26.

[7] S.S. Dhillon et al., "The 2017 terahertz science and technology roadmap", Journ. Phys. D 50 (2017), 043001.

[8] A. Angelovski et al., "Evaluation of the cone-shaped pickup performance for low charge sub-10 fs arrival-time measurements at free electron laser facilities", Phys. Rev. Spec. Top. 18 (2015).

[9] C. Kaya et al., Phase sensitive monitoring of electron bunch form and arrival time in superconducting linear accelerators, Appl. Phys. Lett. 100 (2012), 141143.

[10] F. Tavella, N. Stojanovic, G. Geloni & M. Gensch, Few Femtosecond Timing at Fourth Generation X-ray Lightsources, Nat. Photon. 5 (2011), 162.

[11] R. Riedel et al., "Single-shot pulse duration monitor for extreme ultraviolet and X-ray free-electron lasers", Nature Comm. 4 (2013), 1731.