T-wave alternans predicts mortality in a population undergoing a clinically indicated exercise test.

Eur Heart J. 2007 Oct;28(19):2332-7. Epub 2007 Jul 25.

Muon detector link system test set-up

CERNin tutkimuskeskuksen rakenteilla olevan hadronikiihdyttimen eräs tarkoitus on todistaa Higgsin bosonin olemassaolo. Higgsin bosonin löytyminen yhtenäistäisi nykyisen hiukkasfysiikan teorian ja antaisi selityksen sille kuinka hiukkaset saavat massansa. Kiihdyttimen CMS koeasema on tarkoitettu erityisesti myonien ilmaisuun. Tämä työ liittyy CMS koeaseman RPC-ilmaisintyypin linkkijärjestelmään, jonka tarkoituksena on käsitellä ilmaisimelta tulevia myonien aiheuttamia signaaleja ja lähettää tiedot tärkeäksi katsotuista törmäystapahtumista tallennettavaksi analysointia varten. Työssä on toteutettu linkkijärjestelmän ohjaus- ja linkkikorteille testiympäristö, jolla voidaan todeta järjestelmän eri osien keskinäinen yhteensopivuus ja toimivuus. Työn alkuosassa esitellään ilmaisimen linkkijärjestelmän eri osat ja niiden merkitykset. Työn loppuosassa käydään läpi eri testimenetelmiä ja analysoidaan niiden antamia tuloksia.

Muon Detector Link System Test Setup Software

Euroopan hiukkastutkimuslaitoksen CERNin rakenteilla olevan LHC-hiukkaskiihdyttimen CMS-koeasema on tarkoitettu erityisesti myonin ilmaisuun. Tässä työssä on esitelty CMS-koeaseman RPC-ilmaisintyypin linkkijärjestelmä ja sen testaamiseen tarkoitetut laitteet sekä laitteiden testaamiseen tarvittavat ohjelmistot. Työssä on selvitetty ohjelmien toimivuus ja keskinäinen yhteensopivuus.

Isentropic Exergy and Pressure of the Shock Wave Caused by the Explosion of a Pressure Vessel

An accidental burst of a pressure vessel is an uncontrollable and explosion-like batch process. In this study it is called an explosion. The destructive effectof a pressure vessel explosion is relative to the amount of energy released in it. However, in the field of pressure vessel safety, a mutual understanding concerning the definition of explosion energy has not yet been achieved. In this study the definition of isentropic exergy is presented. Isentropic exergy is the greatest possible destructive energy which can be obtained from a pressure vessel explosion when its state changes in an isentropic way from the initial to the final state. Finally, after the change process, the gas has similar pressure and flow velocity as the environment. Isentropic exergy differs from common exergy inthat the process is assumed to be isentropic and the final gas temperature usually differs from the ambient temperature. The explosion process is so fast that there is no time for the significant heat exchange needed for the common exergy.Therefore an explosion is better characterized by isentropic exergy. Isentropicexergy is a characteristic of a pressure vessel and it is simple to calculate. Isentropic exergy can be defined also for any thermodynamic system, such as the shock wave system developing around an exploding pressure vessel. At the beginning of the explosion process the shock wave system has the same isentropic exergyas the pressure vessel. When the system expands to the environment, its isentropic exergy decreases because of the increase of entropy in the shock wave. The shock wave system contains the pressure vessel gas and a growing amount of ambient gas. The destructive effect of the shock wave on the ambient structures decreases when its distance from the starting point increases. This arises firstly from the fact that the shock wave system is distributed to a larger space. Secondly, the increase of entropy in the shock waves reduces the amount of isentropic exergy. Equations concerning the change of isentropic exergy in shock waves are derived. By means of isentropic exergy and the known flow theories, equations illustrating the pressure of the shock wave as a function of distance are derived. Amethod is proposed as an application of the equations. The method is applicablefor all shapes of pressure vessels in general use, such as spheres, cylinders and tubes. The results of this method are compared to measurements made by various researchers and to accident reports on pressure vessel explosions. The test measurements are found to be analogous with the proposed method and the findings in the accident reports are not controversial to it.

Particle detector link system modifications in RE1/1 sector

The large hadron collider constructed at the European organization for nuclear research, CERN, is the world’s largest single measuring instrument ever built, and also currently the most powerful particle accelerator that exists. The large hadron collider includes six different experiment stations, one of which is called the compact muon solenoid, or the CMS. The main purpose of the CMS is to track and study residue particles from proton-proton collisions. The primary detectors utilized in the CMS are resistive plate chambers (RPCs). To obtain data from these detectors, a link system has been designed. The main idea of the link system is to receive data from the detector front-end electronics in parallel form, and to transmit it onwards in serial form, via an optical fiber. The system is mostly ready and in place. However, a problem has occurred with innermost RPC detectors, located in sector labeled RE1/1; transmission lines for parallel data suffer from signal integrity issues over long distances. As a solution to this, a new version of the link system has been devised, a one that fits in smaller space and can be located within the CMS, closer to the detectors. This RE1/1 link system has been so far completed only partially, with just the mechanical design and casing being done. In this thesis, link system electronics for RE1/1 sector has been designed, by modifying the existing link system concept to better meet the requirements of the RE1/1 sector. In addition to completion of the prototype of the RE1/1 link system electronics, some testing for the system has also been done, to ensure functionality of the design.

Electric field distribution in silicon edgeless detector

This Master’s Thesis work reports about electric field distribution in recently developed silicon edgeless detector with a new current terminating structure. This structure enables the essential reduction of insensitive detector area as well as allows separation of the current flowing through the active area from the current flowing at the cut edge. The reliable operation of this detector is strongly needed due to the installation inside LHC. In accordance with formulated problems SEM was used as an investigation tool for collecting the data about electric field distribution.

The Detector Control Systems for the CMS Resistive Plate Chamber at LHC

The RPC Detector Control System (RCS) is the main subject of this PhD work. The project, involving the Lappeenranta University of Technology, the Warsaw University and INFN of Naples, is aimed to integrate the different subsystems for the RPC detector and its trigger chain in order to develop a common framework to control and monitoring the different parts. In this project, I have been strongly involved during the last three years on the hardware and software development, construction and commissioning as main responsible and coordinator. The CMS Resistive Plate Chambers (RPC) system consists of 912 double-gap chambers at its start-up in middle of 2008. A continuous control and monitoring of the detector, the trigger and all the ancillary sub-systems (high voltages, low voltages, environmental, gas, and cooling), is required to achieve the operational stability and reliability of a so large and complex detector and trigger system. Role of the RPC Detector Control System is to monitor the detector conditions and performance, control and monitor all subsystems related to RPC and their electronics and store all the information in a dedicated database, called Condition DB. Therefore the RPC DCS system has to assure the safe and correct operation of the sub-detectors during all CMS life time (more than 10 year), detect abnormal and harmful situations and take protective and automatic actions to minimize consequential damages. The analysis of the requirements and project challenges, the architecture design and its development as well as the calibration and commissioning phases represent themain tasks of the work developed for this PhD thesis. Different technologies, middleware and solutions has been studied and adopted in the design and development of the different components and a big challenging consisted in the integration of these different parts each other and in the general CMS control system and data acquisition framework. Therefore, the RCS installation and commissioning phase as well as its performance and the first results, obtained during the last three years CMS cosmic runs, will be

Method and arrangement for collecting wave energy

US-patentti nro: US 7,908,854 B2