Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

A Data Acquisition Middle Layer Server with Python Support for Linac Ooperation and Experiments Monitoring and Control

This paper presents online anomaly detection on low-level radio frequency (LLRF) cavities running on FLASH/XFEL DAQ [1] system. The code is run by a DAQ Middle Layer (ML) server, which has access to all collected data, via executing a Python script that runs a pre-trained machine learning model on every shot in the FLASH/XFEL machine. We discuss the challenges associated with real-time anomaly detection due to high data rates generated by RF cavities, and introduce a DAQ system pipeline and algorithms used for online detection on arbitrary channels in our control system. The system's performance is evaluated using real data from operational RF cavities. We also focus on the DAQ monitor server's features and its implementation

Subsystem Level Data Acquisition for the Optical Synchronization System at European XFEL

The optical synchronization system for the European X-Ray Free-Electron Laser provides sub-10 femtosecond timing precision * for the accelerator subsystems and experiments. This is achieved by phase locking a mode-locked laser oscillator to the main RF reference and distributing the optical pulse train carrying the time information via actively propagation-time stabilized optical fibers to multiple end-stations. Making up roughly one percent of the entire European XFEL, it is the first subsystem to receive a large-scale data acquisition system [2] for storing not just hand-selected information, but in fact all diagnostic, monitoring, and configuration data relevant to the optical synchronization available from the distributed control system infrastructure. A minimum of 100 TB per year may be stored in a persistent archive for long-term health monitoring and data mining whereas excess data is stored in a short-term ring buffer for high-resolution fault analysis and feature extraction algorithm development. This paper describes scale, challenges and first experiences from the optical synchronization data acquisition system

First Realization and Performance Study of a Single-Shot Longitudinal Bunch Profile Monitor Utilizing a Transverse Deflecting Structure

For the control and optimization of electron beam parameters at modern free-electron lasers (FEL), transverse deflecting structures (TDS) in combination with imaging screens have been widely used as robust longitudinal diagnostics with single-shot capability, high resolution and large dynamic range. At the free-electron laser in Hamburg (FLASH), a longitudinal bunch profile monitor utilizing a TDS has been realized. In combined use with a fast kicker magnet and an off-axis imaging screen, selection and measurement of a single bunch out of the bunch train with bunch spacing down to 1us can be achieved without affecting the remaining bunches which continue to generate FEL radiation during user operation. Technical obstacles have been overcome such as suppression of coherent transition radiation from the imaging screen, the continuous image acquisition and processing with the bunch train repetition rate of 10Hz. The monitor, which provides the longitudinal bunch profile and length, has been used routinely at FLASH. In this paper, we present the setup and operation of the longitudinal bunch profile monitor as well as the performance during user operation

The Virtual European XFEL Accelerator

The ambitious commissioning plans for the European XFEL require that many of the high-level controls are ready from the beginning. The idea arose to create a virtual environment to carry out such developments and tests in advance, to test interfaces, software in general and the visualisation of the variety of components. Based on the experiences and on the systems that are already in operation at the FLASH facility for several years, such a virtual environment is being created. The system can already simulate most of the key components of the upcoming accelerator. Core of the system is an event synchronized data acquisition system (DAQ). The interfaces of the DAQ system towards the device level, as well as to the high-level side is utilising the same software stack as the production system does. Thus, the software can be developed and used interchangeably between the virtual and the real machine. This allows to test concepts, interfaces and identify problems and errors at an early stage. In this paper the opportunities arising from the operation of such a virtual machine will be presented. The limits in terms of the resulting complexity and physical relationships will also be shown

Linear Array Detector for Online Diagnostics of Spectral Distributions at MHz Repetition Rates

Free-electron lasers (FELs) based on superconducting accelerator technology and storage ring facilities operate with bunch repetition rates in the MHz range, and the need arises for bunch-by-bunch electron and photon diagnostics. For photon-pulse-resolved measurements of spectral distributions, fast one-dimensional profile monitors are required. The linear array detector KALYPSO (KArlsruhe Linear arraY detector for MHz-rePetition rate SpectrOscopy) has been developed for electron bunch or photon pulse synchronous read-out with frame rates of up to 2.7 MHz. At the FLASH facility at DESY, a current version of KALYPSO with 256 pixels has been installed at a grating spectrometer as online diagnostics to monitor the pulse-resolved spectra of the high-repetition-rate FEL pulses. Application-specific front-end electronics based on MicroTCA standard have been developed for data acquisition and processing. Continuous data read-out with low latency in the microsecond range enables the integration into fast feedback applications. In this paper, pulse-resolved FEL spectra recorded at 1.0 MHz repetition rate for various operation conditions at FLASH are presented, and the first application of an adaptive feedback for accelerator control based on photon beam diagnostics is demonstrated

The Evolution of the DOOCS C++ Code Base

This contribution traces the development of DESY's control system DOOCS from its origins in 1992 to its current state as the backbone of the European XFEL and FLASH accelerators and of the future Petra IV light source. Some details of the continual modernization and refactoring efforts on the 1.5 million line C++ code base are highlighted

First Experience with the Standard Diagnostics at the European XFEL Injector

International audienceThe injector of the European XFEL is in operation since December 2015. It includes, beside the gun and the accelerating section, containing 1.3 and a 3.9 GHz accelerating module, a variety of standard diagnostics systems specially designed for this facility. With very few exceptions, all types of diagnostics systems are installed in the injector. Therefore the operation of the injector is served to validate and prove the diagnostics characteristics for the complete European XFEL. Most of the standard diagnostics has been available for the start of beam operation and showed the evidence of first beam along the beam line. In the following months the diagnostics has been optimized and used for improvements of beam quality. First operational experiences and results from the standard beam diagnostics in the injector of the European XFEL will be reported in this contribution