ترغب بنشر مسار تعليمي؟ اضغط هنا

Compact single-shot electro-optic detection system for THz pulses with femtosecond time resolution at MHz repetition rates

121   0   0.0 ( 0 )
 نشر من قبل Bernd Steffen
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Electro-optical detection has proven to be a valuable technique to study temporal profiles of THz pulses with pulse durations down to femtoseconds. As the Coulomb field around a relativistic electron bunch resembles the current profile, electro-optical detection can be exploited for non-invasive bunch length measurements at accelerators. We have developed a very compact and robust electro-optical detection system based on spectral decoding for bunch length monitoring at the European XFEL with single-shot resolution better than 200~fs. Apart from the GaP crystal and the corresponding laser optics at the electron beamline, all components are housed in 19 chassis for rack mount and remote operation inside the accelerator tunnel. An advanced laser synchronization scheme based on radio-frequency down-conversion has been developed for locking a custom-made Yb-fiber laser to the radio-frequency of the European XFEL accelerator. In order to cope with the high bunch repetition rate of the superconducting accelerator, a novel linear array detector (KALYPSO) has been employed for spectral measurements of the Yb-fiber laser pulses at frame rates of up to 2.26~MHz. In this paper, we describe all sub-systems of the electro-optical detection system as well as the measurement procedure in detail, and discuss first measurement results of longitudinal bunch profiles of around 400~fs (rms) with an arrival-time jitter of 35~fs (rms).

قيم البحث

اقرأ أيضاً

One of the optimization goals of a particle accelerator is to reach the highest possible beam peak current. For that to happen the electron bunch propagating through the accelerator should be kept relatively short along the direction of its travel. I n order to obtain a better understanding of the beam composition it is crucial to evaluate the electric charge distribution along the micrometer-scale packets. The task of the Electro-Optic Detector (EOD) is to imprint the beam charge profile on the spectrum of light of a laser pulse. The actual measurement of charge distribution is then extracted with a spectrometer based on a diffraction grating. The article focuses on developed data acquisition and processing system called the High-speed Optical Line Detector (HOLD). It is a 1D image acquisition system which solves several challenges related to capturing, buffering, processing and transmitting large data streams with use of the FPGA device. It implements a latency-optimized custom architecture based on the AXI interfaces. The HOLD device is realized as an FPGA Mezzanine Card (FMC) carrier with single High Pin-Count connector hosting the KIT KALYPSO detector. The solution presented in the paper is probably one of the world fastest line cameras. Thanks to its custom architecture it is capable of capturing at least 10 times more frames per second than fastest comparable commercially available devices.
Although ultraviolet (UV) light is important in many areas of science and technology, there are very few if any lasers capable of delivering wavelength-tunable ultrashort UV pulses at MHz repetition rates. Here we report the generation of deep-UV las er pulses at MHz repetition rates and mu J-energies by means of dispersive wave (DW) emission from self-compressed solitons in gas-filled single-ring hollow-core photonic crystal fiber (SR-PCF). Pulses from an ytterbium fiber laser (~300 fs) are first compressed to ~25 fs in a SR-PCF-based nonlinear compression stage, and subsequently used to pump a second SR-PCF stage for broadband DW generation in the deep UV. The UV wavelength is tunable by selecting the gas species and the pressure. At 100 kHz repetition rate, a pulse energy of 1.05 mu J was obtained at 205 nm (average power 0.1 W), and at 1.92 MHz, a pulse energy of 0.54 mu J was obtained at 275 nm (average power 1.03 W).
In the past decade, the bunch lengths of electrons in accelerators have decreased dramatically to the range of a few picoseconds cite{Uesaka94,Trotz97}. Measurement of the length as well as the longitudinal profile of these short bunches have been a topic of research in a number of institutions cite{Uesaka97,Liu97,Hutchins00}. One of the techniques uses the electric field induced by the passage of electrons in the vicinity of a birefringent crystal to change its optical characteristics. Well-established electro-optic techniques can then be used to measure the temporal characteristics of the electron bunch. In this paper we present a novel, non-invasive, single-shot approach to improve the resolution to tens of femtoseconds so that sub-millimeter bunch length can be measured.
Based on a paper published in 2019 by the FCAL Collaboration, this talk is giving an update of the Collaborations effort to design prototype of highly compact calorimeter to instrument the very forward region of a detector at future $e^+e^-$ collider s. A luminometer prototype, based on sub-millimeter thick detector planes, is tested with an electron-beam of energy 1-5 GeV. The effective Moliere radius of the prototype comprising eight detector planes was measured to be (8.1 +/- 0.1 (stat.) +/- 0.3 (syst.))mm, and the result is well reproduced by the Monte Carlo simulation.
A large RICH detector is used in NA62 to suppress the muon contamination in the charged pion sample by a factor of 100 in the momentum range between 15 and 35 GeV/c. Cherenkov light is collected by 1952 photomultipliers placed at the upstream end. In this paper the characterization of the photomultipliers and the dedicated Frontend and Data Acquisition electronics are described, the time resolution and the light detection efficiency measurement are presented.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا