The construction of the European Spallation Source (ESS) is advancing at a high pace with the support of many laboratories and institutions all over Europe. Prototyping and manufacturing for the accelerator are in full swing in more than 23 laboratories distributed over 12 European partner countries. The origin and goals of the ESS will be briefly outlined in this paper. The milestones achieved, both in Lund and at the partner labs will be described as well as the plans up to operations. DESCRIPTION History The ESS [1] is the materialization of a long-standing request of the community of neutron physicists in Europe. Following the selection of the green-field site of Lund (Sweden) in 2009, the host countries, Sweden and Denmark, invested resources recruiting specialists worldwide to update the design and refine the planning. Construction formally started in 2013, with the goal of being in operation in 2025 with a set of 16 instruments. The European Spallation Source was set-up as a European Research Infrastructure Consortium (ERIC) by decision of the European Commission in August 2015 [2]. ESS facility The ESS [3] consists of a ~500 m long 2 GeV superconducting proton linac [4, 5] sending beam on a tungsten target with moderators from which beam lines guide neutrons to instruments (see site layout in Fig. 1). It differs from most existing or planned neutron spallation sources by being a long pulse source with significantly higher performance, with a record beam power of 5 MW, a high number of beam ports (42) and a novel type of moderator providing much brighter neutrons beams. The main parameters are summarized in Table 1. Availability is another important requirement with the ultimate goal of 95 %. Table 1: ESS Main Characteristics Parameter Value Unit Average proton beam power 5 MW Proton kinetic energy 2 GeV Pulse repetition rate 14 Hz Pulse length 2.86 ms Average current during pulse 65 mA Number of moderators 2 Number of neutron beam ports 42 Specificities State-of-the-art technology from European institutes and industry in the partner countries is key to reaching the required performances in a green-field site (Table 2). Table 2: In-kind Partners to the ESS Machine

Progress on the ESS Project Construction

The control system is the central control unit of the radio telescope. It is used to monitor, control, coordinate, and manage software and hardware systems so as to satisfy the requirements of high-precision control in astronomical observation of radio telescope. The control system architecture is the foundation for the implementation of the control system, which determines the stability, scalability, and maintainability of the control system. Furthermore, the architecture design of the control system is closely geared towards the technological development of radio telescope and computer software architecture. In this article, we analyze the characteristic of the control system of a radio telescope in various steps and discuss the development of their architecture and middleware framework. System architecture and middleware framework of control system also serve as a useful reference for the design of other radio telescope control systems.

/pdf/trends-in-architecture-and-middleware-of-radio-telescope-534o0fpgp1.pdf

Trends in Architecture and Middleware of Radio Telescope Control System

The open standard EtherCAT is well established as a real-time fieldbus for largely distributed and synchronised systems. Using EtherCAT hardware for digital and analogue I/Os, Diamond Light Source (DLS) and the Paul Scherrer Institut (PSI) introduced open source solutions for the bus master in scientific installations. The European Spallation Source (ESS) decided to use EtherCAT systems for mid-performance data acquisition and motion control on accelerator applications. In this contribution we present the motion control software package ECMC developed at the ESS using the open source Etherlab master to control the EtherCAT bus. The motion control interfaces to the EPICS Motor Record with a model 3 driver. It supports functionalities like positioning, jogging, homing and soft/hard limits. Advanced features of the ECMC package include full servoloop feedback, a scripting language for custom synchronisation of different axes, virtual axes, externally triggered position capture and interlocking. We will illustrate the synchronisation feature on the example of a 2-axis slit set and present different CPU hardware platforms and EtherCAT slave modules for the ECMC framework.

ECMC, the Open Source Motion Control Package for EtherCAT Hardware at the ESS

The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 13 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on the control system design for the different cryogenic subsystems, hardware and software selected, industry and in-house development, advantages and disadvantages of the chosen setup and operational experience. There is also a lessons learned, feedback from providers and stakeholders and an outlook for further development described.

/pdf/ess-cryogenic-controls-design-5d7oeqhg2m.pdf

ESS Cryogenic Controls Design

EPICS version 4 is a set of software modules that add to the base of the EPICS toolkit for advanced control systems. Version 4 adds the possibility of process variable values of structured data, an introspection interface for dynamic typing plus some standard types, highperformance streaming, and a new front-end processing database for managing complex data I/O. A synchronous RPC-style facility has also been added so that the EPICS environment supports service-oriented architecture. We introduce EPICS and the new features of version 4. Then we describe selected deployments, particularly for highthroughput experiment data transport, experiment data management, beam dynamics and infrastructure data. EPICS BASE AND EPICS VERSION 4 The Experimental Physics and Industrial Control System (EPICS), is a software framework for highperformance distributed control and data acquisition in large scientific instruments, such as accelerators and telescopes. The "base" of EPICS is software for supervisory control, closed loop control, archiving, alarm management, timing and other aspects of front-end processors and device facing hardware. Typically hosted in an embedded system processor such as RTEMS or VME, this software and its host are collectively known as the IOC (Input/Output Controller) in an EPICS control system. IOCs are optimized for low-latency I/O. They control and/or monitor a collection of devices such as actuators and measurement diagnostics. Each IOC node contains a memory resident real-time database. The IOC database is a set of "smart" records, which are interconnected in a data flow pattern. They're smart in that their field values may come directly from hardware, or a result of processing that was dependent on the type of record. The records may contain "device support" code, to interface the processing to physical devices through device drivers. Much more information can be found on the EPICS base at [1, 2]. EPICS base and the software extensions built on top of it have proven very successful for the control aspects of scientific instruments, providing excellent low level I/O, DAQ and optimal control. Figure 1: The basic architecture of EPICS version 4, showing the classic “base” components of EPICS in green, and components added by version 4 in blue. A new protocol, pvAccess, transports potentially complex data types encoded by pvData. pvAccess connects clients to IOCs, which may include a new database type, pvDatabase to support complex data processing services (and is the basis of the high-performance detector streaming applications described here), and to middleware services that can themselves connect to enterprise data stores, the web, etc. Note that hardware device I/O remains under the IOC database. EPICS Version 4 for New Controls Problems Modern control systems of large instruments call for more science to be done in the control system itself, than is possible with the EPICS base software alone. High output detectors call for pipelined data processing; physics applications deal with systems of process variables and their values rather than one process variable (PV) at a time; process variables may be structured, multi-modal, or require significant metadata associated with values in order to be understandable (such as images, or timing related metadata to give context when reviewing archives). Proceedings of ICALEPCS2015, Melbourne, Australia Pre-Press Release 23-Oct-2015 11:00WEA3O02 Software Technology Evolution ISBN 978-3-95450-148-9 1 Co py rig ht © 20 15 CC -B Y3. 0 an d by th er es pe ct iv ea ut ho rs Pr ePr es sR ele as e2 3O ct -2 01 5 11 :0 0 EPICS version 4 is a system of software modules that extend EPICS base to address these emerging requirements. Core Modules of EPICS Version 4 Apart from EPICS base, the two core modules of EPICS version 4 are “pvData” and “pvAccess.” The pvData module is the high-performance structured data backbone of EPICS version 4. It provides an introspection interface for the dynamic creation and management of structured data types and arrays. Although types can be created on the fly, EPICS version 4 also defines a standard set of data types oriented towards scientific controls data (called “Normative Types” [3]). The types there defined include matrices, key-value sets, tables, histograms, continua, and images, among others both generic and application specific. pvAccess is the network protocol of EPICS v4. Like the equivalent protocol in version 3, “Channel Access”, named endpoints (PVs) are discovered by broadcast, while data I/O is by TCP. In addition to the expected get, put, and put/get methods one would expect, pvAccess supplies a Remote Procedure Call (RPC) method, and a method to deal efficiently with exchanging only the changed elements of large arrays. Working in concert with pvData, the two include memory management and efficient encoding and deserialization, to minimise copy and wire transactions for even large complex data I/O. For instance, in the case of a PV defined by a complex structure, a client can subscribe only to the fields of the structure of interest to that client [4]. The RPC channel method enables a client to pass arguments along with a PV value request, in which case the value is computed with respect to the arguments. Notably, the same PV may be accessed by either an asynchronous get method, or an RPC method. In this way, a get-value operation on one PV, can be either the familiar “monitor”, or the “compute value subject to given parameters and return result.” In either case, the processing path (and so potentially the PV’s value) would be different. This RPC facility is being used extensively at SLAC, and is being adopted also at ESS, for beam dynamics (see Figure 2), infrastructure, and directory service data. RECENT ADDITIONS TO EPICS VERSION 4 The pvAccess system is now codec based; the communication layer is decoupled from the transport layer, allowing alternative transport layer protocols such as one using zeroMQ. A codec for the former transport layer of pvAccess is provided. Array handling has been greatly enhanced in the C++ implementations of the core modules. Reference counted shared vectors help minimize copy operations. Fixed and bounded arrays have been added in order to more easily facilitate high-performance array management. These complement the existing unbounded arrays. Stride length can be specified in put and get operations. The Normative Types have been extended to include full dynamic typing (essentially an “Any” in the CORBA sense). A plug-in architecture for implementing security schemes has been added, along with the plugin for Channel Access security. The command line tools have been extended to better support time stamp, alarms, and correct display of enumerated types. All of the command line tools now support both pvAccess and Channel Access operations. A new tool, pvlist gives information about pvAccess servers on the network, including lists of the PVs they host. Extensive API changes have been made to give greater flexibility for channel callbacks and converting from one introspection data type to another. New Data Processing Database The new “pvDatabase” module of EPICS v4 implements a framework for a memory resident database of records defined in terms of pvData structures. Like the IOC database of classic EPICS, the records of pvDatabase can process on I/O events; unlike the IOC the records may be of any structure the engineer wishes, and may pull in data from any pvAccess-ible data source, plus Channel Access. pvDatabase images may be standalone, or hosted within an IOC, where they might interface directly to base records, asynchronous device driver support (asynDriver), or detector control (areaDetector). pvDatabase is then useful for complex optimal control tasks, data assembly, $ eget -s XCOR:IN20:491:RMAT -a b BPMS:IN20:525 0.669544 0.694654 0 0 0 0 -0.57085 0.901274 0 0 0 0 0 0 1.333434 0.966896 0 0 0 0 0.358411 1.009578 0 0

Recent Advancements and Deployments of EPICS Version 4

The European Spallation Source (ESS) is a collaboration of 17 European countries to build the world’s most powerful neutron source for research [1]. ESS has entered the construction phase and the plan is to produce first neutrons by the year 2019 and to complete the construction with 22 neutron instruments and reach the target 5 MW beam power by 2025. The Integrated Control System Division (ICS) is responsible to provide control systems for the whole facility. The unprecedented beam power and the construction of the facility as a collaboration of the member countries, with many components delivered in-kind presents a number of challenges to the control system. The Integrated Control System Division has to prepare systems and specifications so that the work can be effectively shared between the contributors and staff onsite. The systems need to provide sufficient performance for successful operation of the facility, be standardized to a level that allows easy integration into the facility during a short installation period and have to be maintainable by the in-house staff after the construction has finished.

Status of the European Spallation Source Control System

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Nick Levchenko

Author Tools

Chat about Author

Papers

Status of the European Spallation Source Control System