Novel Control System for the LHCb Scintillating Fibre Tracker Detector Infrastructure

During the Long Shutdown 2 of the LHC at CERN, the LHCb detector is upgraded to cope with higher instantaneous luminosities. The largest of the new trackers is based on the scintillating fibres (SciFi) read out by SIlicon PhotoMultipliers (SiPMs). The SiPMs will be cooled down to -40°C to minimize noise. For performance and space reasons, the cooling lines are vacuum insulated. Ionizing radiation requires detaching and displace the readout electronics from Pirani gauges to a lower radiation area. To avoid condensation inside the SiPM boxes, the atmosphere inside must have a dew point of at most -45°C. The low dew point will be achieved by flushing a dry gas through the box. 576 flowmeters devices will be installed to monitor the gas flow continuously. A Condensation Prevention System (CPS) has been introduced as condensation was observed. The CPS powers heating wires installed around the SiPM boxes and the vacuum bellows isolating the cooling lines. The CPS also includes 672 temperature sensors to monitor that all parts are warmer than the cavern dew point. The temperature readout systems are based on multiplexing technology at the in the front-end and a PLC in the back-end

Fifteen Years of Operation of the Compact Muon Solenoid Detector Superconducting Magnet

The Compact Muon Solenoid (CMS) detector magnet has been in operation since 2008 at CERN's Large Hadron Collider (LHC). It will have to operate until the end of the High-Luminosity LHC run, beyond 2040. The CMS magnet comprises a large superconducting solenoid coil providing a magnetic field of 3.8 T with a free bore of 6 m in diameter and a length of 12.5 m. The coil is constructed with an aluminium stabilized Rutherford Nb-Ti/Cu cable and operates at 4 K with indirect conduction cooling in thermosiphon mode with boiling helium. The magnet reached 4 T and a record stored energy of 2.6 GJ when it was commissioned in 2006 in the surface hall at CERN Point 5. It was then transferred in 2007 to the underground experimental area, where it was recommissioned and successfully operated at a nominal field of 3.8 T since then. A summary of the magnet operating data is presented in this paper along with the observed progressive change of the Residual Resistivity Ratio (RRR) of the pure aluminium conductor stabilizer as a function of operating cycles and magnet warm-ups. The technical problems encountered, and the solutions implemented with the cryogenics and the vacuum pumping of the cryostat are described, as well as the upgrades carried out during the LHC shutdown periods on the control system, the cryogenics and the powering circuit where a freewheel thyristor system has been implemented

UNICOS framework and EPICS: A possible integration

UNICOS (UNified Industrial Control System) is a CERN-made framework to develop industrial control applications. It follows a methodology based on ISA-88 and provides components in two layers of a control system: control and supervision. The control logic is running in the first layer, in a PLC (Programmable Logic Controller), and, in the second layer, a SCADA (Supervisory Control and Data Acquisition) system is used to interface with the operators and numerous other features (e.g. alarms, archiving, etc.). UNICOS supports SIEMENS WinCC OA as the SCADA system. In this paper, we propose to use EPICS (Experimental Physics and Industrial Control System) as the supervision component of the UNICOS framework. The use case is the control system of a CO$_{2}$ cooling plant developed at CERN following the UNICOS methodology, which had to be integrated in a control system based on EPICS. The paper describes the methods and actions taken to make this integration feasible, including automatic EPICS database generation, PLC communications, visualization widgets, faceplates and synoptics and their integration into CSS and EPICS, as well as the integration with the BEAST alarm system

Development, commissioning and operation of the large scale CO2_2 detector cooling systems for CMS pixel phase I upgrade

During the 2017 Year-end Technical Stop of the Large Hadron Collider at CERN, the CMS experiment has successfully installed a new pixel detector in the frame of Phase I upgrade. This new detector will operate using evaporative CO$_{2}$ technology as its cooling system. Carbon Dioxide, as state of the art technology for current and future tracking detectors, allows for significant material budget saving that is critical for the tracking performance. The road towards operation of the final CO$_{2}$ cooling system in the experiment passed through intensive prototype phase at the CMS Tracker Integration Facility (TIF) for both cooling process hardware and its control system. This paper briefly describes the general design of both the CMS and TIF CO$_{2}$ detector cooling systems, and focuses on control system architecture, operation and safety philosophy, commissioning results and operation experience. Additionally, experience in using the Ethernet IP industrial fieldbus as distributed IO is presented. Various pros and cons of using this technology are discussed, based on the solutions developed for Schneider Premium PLCs, WAGO and FESTO IOs using the UNICOS CPC 6 framework of CERN

First Steps in Automated Software Development Approach for LHC Phase II Upgrades CO₂ Detector Cooling Systems

With refrigerating power of the order of 1.5 kW at -35 °C and full compatibility with Detector Control System standards, Light Use Cooling Appliance for Surface Zones (LUCASZ) is the first movable medium size evaporative CO₂ detector cooling system. By 2018 a series of 4 LUCASZ units has been fully deployed by the EP-DT group at CERN. LUCASZ is capable to provide CO₂ cooling for various needs of detector development and testing required for Phase Iⅈ upgrades of LHC experiments. This paper describes selected software and controls hardware ideas used to develop the LUCASZ control system as baseline solutions for CO₂ cooling systems for Phase II upgrade of ATLAS and CMS trackers. The main challenges for future control system development will come from the number of cooling plants, the modularity, operation, and the implementation of backup philosophy. The introduction of automated software generation for both PLC and SCADA is expected to bring major improvement on the efficiency of control system implementation. In this respect, a unification step between experiments is highly required without neglecting specific needs of ATLAS and CMS