First Experience with the LHC Cryogenic Instrumentation

The LHC under commissioning at CERN will be the world's largest superconducting accelerator and therefore makes extensive use of cryogenic instruments. These instruments are installed in the tunnel and therefore have to withstand the LHC environment that imposes radiation-tolerant design and construction. Most of the instruments require individual calibration; some of them exhibit several variants as concerns measuring span; all relevant data are therefore stored in an Oracle® database. Those data are used for the various quality assurance procedures defined for installation and commissioning, as well as for generating tables used by the control system to configure automatically the input/output channels. This paper describes the commissioning of the sensors and the corresponding electronics, the first measurement results during the cool-down of one machine sector; it discusses the different encountered problems and their corresponding solutions

The Integration Of The LHC Cryogenics Control System Data Into The CERN Layout Database

The Large Hadron Collider’s Cryogenic Control System makes extensive use of several databases to manage data appertaining to over 34,000 cryogenic instrumentation channels. This data is essential for populating the software of the PLCs which are responsible for maintaining the LHC at the appropriate temperature. In order to reduce the number of data sources and the overall complexity of the system, the databases have been rationalised and the automatic tool, that extracts data for the control software, has been simplified. This paper describes the main improvements that have been made and considers the success of the project

Accuracy of the Approximation Function Deduced from the Fixed 3-Points Calibration Delivered with the Cernox™ Sensor

The cernox™ sensor is delivered with a 3-point resistance versus temperature cal-ibration that permits the construction of an individual interpolation table by using the data in the CERN thermometer database. For instance at the 4.2 K point, the individual calibration and the manufacturer data are within +/-0.1 K for 99.39% of a sample population of about 5700 sensors. Preliminary results also indicate that accuracies of 0.1 K and 1 K can be obtained below respectively 5 K and 77 K

Validation of the Data Consolidation in Layout Database for the LHC Tunnel Cryogenics Controls Package

The control system of the Large Hadron Collider cryogenics manages over 34’000 instrumentation and actuator channels

Quality Management of CERN Vacuum Controls

The vacuum controls Section (TE-VSC-ICM) is in charge of the monitoring, maintenance and consolidation of the control systems of all accelerators and detectors in CERN; this represents 6 000 instruments distributed along 128 km of vacuum chambers, often of heterogeneous architectures and of diverse technical generations. In order to improve the efficiency of the services provided by ICM, to vacuum experts and to accelerator operators, a Quality Management Plan is being put into place. The first step was the standardization of the naming convention across different accelerators. The traceability of problems, requests, repairs, and other actions, has also been put into place (VTL). This was combined with the effort to identify each individual device by a coded label, and register it in a central database (MTF). Occurring in parallel, was the gathering of old documents and the centralization of information concerning architectures, procedures, equipment and settings (EDMS). To describe the topology of control components, the data structure is being defined, for later implementation (Layout-DB). Once complete, the quality and efficiency of ICM services can only improve, and appropriate performance indicators will be in place to display them

Validation of the Data Consolidation in Layout Database for the LHC Tunnel Cryogenics Controls Upgrade

The control system of the Large Hadron Collider cryogenics manages over 34’000 instrumentation and actuator channels. The complete information on their characteristics and parameters can be extracted from a set of views on the Layout database, to generate the specifications of the control system; from these, the code to populate PLCs (Programmable Logic Controller) and SCADA (Supervisory Control & Data Acquisition) is automatically produced, within the UNICOS framework (Unified Industrial Control System). The Layout database is, since 2003, progressively integrating and centralizing information on the whole CERN Accelerator complex. It models topographical organization (layouts) as functional positions and relationships. After three years of machine operation, many parameters have been manually adjusted in SCADA and PLCs; they now differ from their original values in the Layout database. Furthermore, to accommodate the upgrade of the UNICOS Continuous Process Control package to version 6, some data structures and values have been modified. This paper describes the methodology to update and validate the new data, and the software tools developed for that purpose

First experience with the lhc cryogenic instrumentation

The LHC under commissioning at CERN will be the world's largest superconducting accelerator and therefore makes extensive use of cryogenic instruments. These instruments are installed in the tunnel and therefore have to withstand the LHC environment that imposes radiation-tolerant design and construction. Most of the instruments require individual calibration; some of them exhibit several variants as concerns measuring span; all relevant data are therefore stored in an Oracle® database. Those data are used for the various quality assurance procedures defined for installation and commissioning, as well as for generating tables used by the control system to configure automatically the input/output channels. This paper describes the commissioning of the sensors and the corresponding electronics, the first measurement results during the cool-down of one machine sector; it discusses the different encountered problems and their corresponding solutions