Upgrade Project Research Articles

Front end Electronics for SLHC Semiconductor Trackers in CMOS 90 nm and 130 nm Processes

We present the development of a front end amplifier and discriminator circuit implemented in two successive nodes of commercial CMOS process, namely 90 nm and 130 nm. The aim of this work is two-fold, firstly to examine new technology features such as increased transconductance and transit frequency <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$f_{t}$</tex></formula> resulting in higher speed at lower power consumption, and secondly to prototype a novel front end architecture developed to maintain high dynamic range and open loop gain in the presence of the degradation of intrinsic transistor gain and low supply voltage accompanying the scaling of CMOS processes. The circuits are intended to work with silicon strip detectors of moderate length. Although both versions are optimized for 5 pF input capacitance, the input stage of 130 nm front end can be biased with a current allowing for readout of detectors with capacitances of the order of 10 pF. Special attention has been given to the comparison of noise performance and matching of the channel gain and discriminator offsets. Although both versions show good basic analog performance in terms of speed and gain, an appreciable difference in the channel-to-channel matching and the noise figures is measured. The ENC performance of 130 nm version of the amplifier follows theoretical predictions confirming no excess noise for the devices used, whilst the noise performance of the 90 nm version is noticeably worse. Looking at the difference in noise performance between the two designs, the 130 nm process is better understood and is thus a more appropriate choice for the current upgrade project. As a consequence, the presented 130 nm design will form the core of the ABC130 chip for the ATLAS SCT upgrade.

Quality control on planar n-in-n pixel sensors — Recent progress of ATLAS planar pixel sensors

To extend the physics reach of the Large Hadron Collider (LHC), upgrades to the accelerator are planned which will increase the peak luminosity by a factor 5–10. To cope with the increased occupancy and radiation damage, the ATLAS experiment plans to introduce an all-silicon inner tracker with the high luminosity upgrade (HL-LHC). To investigate the suitability of pixel sensors using the proven planar technology for the upgraded tracker, the ATLAS Upgrade Planar Pixel Sensor (PPS) R&D Project was established. Main areas of research are the performance of planar pixel sensors at highest fluences, the exploration of possibilities for cost reduction to enable the instrumentation of large areas, the achievement of slim or active edges to provide low geometric inefficiencies without the need for shingling of modules and the investigation of the operation of highly irradiated sensors at low thresholds to increase the efficiency. The Insertable b-layer (IBL) is the first upgrade project within the ATLAS experiment and will employ a new detector layer consisting of silicon pixel sensors, which were improved and prototyped in the framework of the planar pixel sensor R&D project. A special focus of this paper is the status of the development and testing of planar n-in-n pixel sensors including the quality control of the on-going series production and postprocessing of sensor wafers. A high yield of produced planar sensor wafers and FE-I4 double chip sensors after first steps of post-processing including under bump metallization and dicing is observed.

Development of a 500 MHz high power RF test stand

A flexible high power RF test stand has been designed and constructed at IHEP to test a variety of 500 MHz superconducting RF components for the upgrade project of the Beijing Electron Positron Collider (BEPC II), such as the input coupler, the higher order modes (HOMs) absorber and so on. A high power input coupler has been conditioned and tested with the RF power up to 250 kW in continuous wave (CW), traveling wave (TW) mode and 150 kW CW in standing wave (SW) mode. A prototype of the HOMs absorber has been tested to absorb power of 4.4 kW. An introduction of the test stand design, construction and high power tests is presented in this paper.

Systems usability framework for evaluating tools in safety–critical work

This paper presents a methodology with which evaluation of control rooms in safety---critical industry has been carried out. The results of two cases of evaluation in nuclear power plants (NPP) are presented to elaborate the method thoroughly. The evaluation methodology draws from conventions of human factors and usability evaluation methods but adds an activity theoretical viewpoint by considering different control room functions in a purposeful activity system. A control room has three functions in an activity: instrument, psychological tool, and a communicative tool. The introduced evaluation approach allows understanding of quality of the control room on the level of outcomes it produces, work practices that it consolidates, and the user experience it creates. The evaluation approach is demonstrated by presenting baseline evaluations of two hybrid NPP control rooms that were carried out before major upgrade projects were implemented. Hybrid control room refers to a state in which modern and original hardwired technological solutions are in use simultaneously.

Upgrade of the ALICE Detector

The ALICE experiment is optimized for heavy ion collisions and takes data in proton-proton collisions to obtain comparison data and to study specific measurements exploiting the detector features like the low pT cut-off and the particle identification capabilities. The LHC shutdown foreseen for 2017/18 will allow to address the upgrade of several sub-detectors, in especial the inner tracking system (ITS), the installation of a new forward calorimeter (FOCAL), the extension of the muon spectrometer (MFT -Muon Forward Tracker) and the installation of a detector with enhanced particle identification (VHMPID). An increased rate capability of the largest detector in ALICE, the time projection chamber (TPC), is also under investigation. Furthermore, it is foreseen to improve the data acquisition and high level trigger systems (DAQ and HLT) to achieve more bandwidth and to use more sophisticated and complex triggers. Currently the collaboration is studying the different detector upgrade proposals and prepares a global upgrade plan. This contribution will present the different upgrade projects under study for the ALICE experiment.

The magnet design for the HLS storage ring upgrade project

In order to improve the performance of the Hefei Light Source (HLS), in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices, an upgrade project called HLSII will be launched soon. The storage ring lattice, which has a double bend achromatic structure with four periods, comprises eight dipoles, 32 quadrupoles and 32 combined function sextupoles. The design and analysis of the magnets are shown in this paper, along with the optimization of the multipurpose combined function magnet, which consists of three magnets: skew quadrupole, horizontal dipole and vertical dipole, with the main sextupole magnet. This type of magnet is the first one that has been designed and used in China. The mechanical design and fabrication procedures for the magnets are also presented.

HMI conventions for process control graphics

Process operators supervise and control complex processes. To enable the operator to do an adequate job, instrumentation and process control engineers need to address several related topics, such as console design, information design, navigation, and alarm management. In process control upgrade projects, usually a 1:1 conversion of existing graphics is proposed. This paper suggests another approach, efficiently leading to a reduced number of new powerful process graphics, supported by a permanent process overview displays. In addition a road map for structuring content (process information) and conventions for the presentation of objects, symbols, and so on, has been developed. The impact of the human factors engineering approach on process control upgrade projects is illustrated by several cases.

HLS bunch current measurement system

Bunch current is an important parameter for studying the injection fill-pattern in the storage ring and the instability threshold of the bunch, and the bunch current monitor also is an indispensable tool for the top-up injection. A bunch current measurement (BCM) system has been developed to meet the needs of the upgrade project of Hefei Light Source (HLS). This paper presents the layout of the BCM system. The system based on a high-speed digital oscilloscope can be used to measure the bunch current and synchronous phase shift. To obtain the absolute value of bunch-by-bunch current, the calibration coefficient is measured and analyzed. Error analysis shows that the RMS of bunch current is less than 0.01 mA when bunch current is about 5 mA, which can meet project requirement.

The NA62 Liquid Krypton calorimeter readout module

The NA62 experiment [1] at CERN SPS (Super Proton Synchrotron) accelerator will be focused on precision tests of the Standard Model via studies of ultra-rare decays of charged kaons. The high resolution Liquid Krypton (LKr) calorimeter of the former NA48 experiment [2], together with other detectors, will provide a photon-veto with hermetic coverage from zero out to large angles from the decay region. The old backend electronics [3] does not satisfy the NA62 specifications and the study of a new readout system began in 2008.This paper presents the Calorimeter REAdout Module (CREAM), an upgrade project for the backend part of the LKr data acquisition chain [3]. The CREAMs will provide 40 MHz sampling of 13248 calorimeter channels, data buffering during the SPS spill, zero suppression, and programmable trigger sums for the experiment trigger processor.

MicroTCA-based Global Trigger Upgrade project for the CMS experiment at LHC

The electronics of the first Level Global Trigger (GT) of CMS is the last stage of the Level-1 trigger system [1]. At LHC up to 40 million collisions of proton bunches occur every second, resulting in about 800 million proton collisions. The CMS Level-1 Global Trigger [1], a custom designed electronics system based on FPGA technology and the VMEbus system, performs a quick on-line analysis of each collision every 25 ns and decides whether to reject or to accept it for further analysis. The CMS trigger group of the Institute of High Energy Physics in Vienna (HEPHY) is involved in the Level-1 trigger of the CMS experiment at CERN. As part of the Trigger Upgrade, the Level-1 Global Trigger will be redesigned and implemented in MicroTCA based technology, which allows engineers to detect all possible faults on plug-in boards, in the power supply and in the cooling system. The upgraded Global Trigger will be designed to have the same basic categories of functions as the present GT, but will have more algorithms and more possibilities for combining trigger candidates. Additionally, reconfigurability and testability will be supported based on the next system generation.

ALICE detector upgrades

The LHC with its unprecedented energy offers unique opportunities for groundbreaking measurements in p+p, p+A and A+A collisions even beyond the baseline experimental designs. ALICE is setting up a program of detector upgrades, which could to a large extent be installed in the LHC shutdown planned for 2017/18, to address the new scientific challenges. We will discuss examples of the scientific frontiers and will present the corresponding upgrade projects under study for the ALICE experiment.

Design of Two-Dimention Interferometer for Measuring Electron Beam Transverse Sizes

On electron synchrotron, beam profile and transverse sizes are usually measured by SR (synchrotron radiation) light that is radiated by electron beam at bending magnets of synchrotron. In the upgrade project of HLS (Hefei Light Source), the designed horizontal and vertical beam transverse sizes are 0.127mm and 0.06mm respectively, the SR interferometer must be developed at HLS to measure these smaller electron sizes. To avoid the chromatic aberration of the lens, we designed the reflective SR interferometer based on off axis parabolic mirror instead of objective lens. And we used the quad-aperture instead of the double-aperture to design two-dimention SR interferometer. In this paper, design of the optical configuration of two-dimention SR interferometer and basic theory for the measurement of small beam sizes by two-dimention SR interferometer will be presented firstly, and then the two-dimention interferogram will be simulated. Lastly, processing algorithm of interference image will be introduced, and some factors effect on result will be analyzed.

The Jefferson Lab 12 GeV Upgrade

Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. An overview of this upgrade project is presented, along with highlights of the anticipated experimental program.

Test and Simulation for the Response of PLS-II Button Type Beam Position Monitor

For the upgrade project of the Pohang Light Source (PLS-II), button-type beam position monitors (BPM) have been made and tested. The BPMs have been tested on a test stand using a metallic wire connected to a 500 MHz RF signal generator. During the test of the BPMs, some of the BPMs show a response different from that of the others. The response of these BPMs was usually asymmetric and tilted. In this research, we did simulations to figure out which factors affected the response of BPM. For the simulations, we use the MATLAB code which is made of ALBA-cells and Diamond. Using this code, we studied the effect of defective button geometry on the response of BPM system and made defective BPMs combinations of geometry that minimized the asymmetry and the tilt of the response. From these results, we can use a defective BPM unit with another defective BPM unit that has a complementary button geometry.

Control of Elongated Plasma in Presence of ELMs in the JET Tokamak

Tokamaks are the most promising approach for nuclear fusion on earth. They are toroidal machines where the plasma is heated in a ring-shaped vessel and kept away from the vessel by applied magnetic fields. To achieve high performance in tokamaks, plasmas with elongated poloidal cross-section are needed. Such elongated plasmas are vertically unstable, hence position control on a fast time scale is clearly an essential feature for all tokamak devices. In this context the Plasma Control Upgrade project was aimed at increasing the capabilities of the Vertical Stabilization (VS) of the JET tokamak. This paper introduces the new JET VS system and focuses on how the flexibility of this real-time system has been exploited to enlarge its operational limits in terms of maximum controllable disturbance. Eventually, some experimental results achieved during the last experimental campaigns are presented.

Physics design of a saddle coil system for TCV

Abstract The upgrade project for TCV (Tokamak à Configuration Variable) includes the installation of a set of saddle coils, namely the saddle coil system (SCS), located and powered such as to create a helical magnetic perturbation. Using independent power supplies, the toroidal periodicity of this perturbation is tunable, allowing simultaneously edge localized modes (ELM) control through resonant magnetic perturbation (RMP), error field correction and vertical control. Other experimental applications, like resistive wall mode and rotation control, are also in view. In this article, the adequacy of two SCS designs, an in-vessel one and an ex-vessel one, is assessed with respect to the desired experimental applications. The current requirements and the system performances are also characterized. The conducting vessel wall is accounted for in a model used to determine the coupled response functions of the SCS, the screening of the magnetic perturbation by the wall, the induced voltages and currents during a plasma disruption and the maximal magnetic forces exerted on the SCS. A scaling of the SCS parameters with the number of coil turns is presented and the issue of coil heating and cooling is discussed.

Degrader foils for the CARIBU project

The Californium Rare Ion Breeder Upgrade (CARIBU) project was conceived to provide neutron rich beams originating from the 3% fission decay branch of a 252Cf source to be accelerated by the Argonne Tandem Linear Accelerator System (ATLAS). This 1Ci 252Cf source will be housed in a movable shielded cask, from which it can be directly transferred into a large helium gas stopper cell. Within the gas stopper, the CARIBU 252Cf source is positioned behind an aluminum degrader foil where the radioactive recoils of interest lose most of their energy before being stopped in the helium gas. To stop recoils over the full fission mass range effectively, three degraders of increasing thickness are required, one to cover the light fission peak and two for the isotopes in the heavy fission peak.The geometry of the source within the gas cell would ideally require a hemispherically shaped degrader foil for uniform energy loss of the fission products. The fabrication of a thin foil of such a shape proved to be exceedingly difficult and, therefore, a compromise “top hat” arrangement was designed. In addition, the ultra-high vacuum (UHV) environment necessary for the gas cell to function properly prevented the use of any epoxy due to vacuum outgassing. Handling, assembling of the foils and mounting must be done under clean room conditions. Details of early attempts at producing these foils as well as handling and mounting will be discussed.

A Comparative Case Study of Indonesian and UK Organisational Culture Differences in IS Project Management

Information Systems (IS) Project Management (PM) is fundamental to the modern, constantly changing and upgrading business world and is impacted by culture on many levels. This research shows the extent to which organisational culture in international IS projects is impacted by culture found on a national level. Current data contributing to IS PM knowledge is provided by investigating two Information Technology (IT) firms in the telecommunications sector based in Indonesia and the United Kingdom undergoing system upgrade projects using a survey and interviews. Differing trends between these organisational cultures are identified (and a third international control group) in regard to hierarchical structures and managing conflict employing a version of Hofstede’s cultural survey as a basis.

MAST upgrade closed pumped divertor design and analysis

The design of the Mega Amp Spherical Tokamak (MAST) Upgrade project provides an excellent opportunity for advancements in tokamak physics in support of ITER and DEMO as well as CTF. One of the main areas of contribution is the divertor. MAST Upgrade will be capable of operating with the outer leg of the divertor being either conventional or with the novel Super-X Divertor (SXD) configuration, in which additional shaping of the magnetic field takes the divertor leg out to large radius. A region of low poloidal field in the chamber of the divertor allows the outer leg to traverse a considerable distance toroidally, reaching a large major radius. Cryopumps outboard the divertor targets will provide density control. This paper describes the current design and layout of the closed pumped divertor geometry to meet the configurations envisaged. The assembly supports symmetrical plasmas with both the upper and lower divertor assemblies able to accommodate either the conventional or SXD.

Comprehensive upgrade of the high-resolution small-angle neutron scattering instrument KWS-3 at FRM II

After the KWS-3 instrument was moved from Jülich to Munich (in the first half of 2007), it underwent a fundamental evaluation, with the final result that a major upgrade for the whole instrument became necessary. The main subject of the upgrade project was a general mirror refurbishment,i.e.a new polishing and subsequently a new coating of the mirror surface with the isotope65Cu. In parallel to the mirror refurbishment, comprehensive upgrade activities in the vacuum system, electronics and programming have been performed with the aims of protecting the new mirror coating from aging (degradation of the mirror's surface properties), transforming the instrument into a user-friendly state and introducing conceptual improvements.