Experiment for transient effects of sudden catastrophic loss of vacuum on a scaled superconducting radio frequency cryomodule

Safe operation of superconducting radio frequency (SRF) cavities require design consideration of a sudden catastrophic loss of vacuum (SCLV) adjacent with liquid helium (LHe) vessels and subsequent dangers. An experiment is discussed to test the longitudinal effects of SCLV along the beam line of a string of scaled SRF cavities. Each scaled cavity includes one segment of beam tube within a LHe vessel containing 2 K saturated LHe, and a riser pipe connecting the LHe vessel to a common gas header. At the beam tube inlet is a fast acting solenoid valve to simulate SCLV and a high/low range orifice plate flow-meter to measure air influx to the cavity. The gas header exit also has an orifice plate flow-meter to measure helium venting the system at the relief pressure of 0.4 MPa. Each cavity is instrumented with Validyne pressure transducers and Cernox thermometers. The purpose of this experiment is to quantify the time required to spoil the beam vacuum and the effects of transient heat and mass transfer on the helium system. Heat transfer data is expected to reveal a longitudinal effect due to the geometry of the experiment. Details of the experimental design criteria and objectives are presented.Comment: 8 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference CEC-ICMC. 13-17 June 2011. Spokane, Washingto

Cryogenic Testing and Analysis Associated with Tevatron Lower Temperature Operation

An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics at the previous energy of 900 GeV. This has allowed us to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which has taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, our new satellite refrigerator controls system is capable of the expansion necessary to reach our goal. New features are being added to the control system which will allow for more intelligent control and better diagnostics for component monitoring and trending

Dynamic PID loop control

The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters' oscillation.Comment: 7 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference CEC-ICMC 2011, 13-17 June 2011. Spokane, Washingto

O excesso de confiança e o caso prático dos alunos do CSE

TCC (graduação) - Universidade Federal de Santa Catarina. Centro Sócio-Econômico. Economia.Por longa data a tomada de decisão dos indivíduos do ponto de vista das finanças e economia neoclássica foi tratada segundo um modelo que julga os investidores racionais, detentores da informação completa que maximiza a utilidade esperada. Essa corrente é contraposta pelas Finanças Comportamentais, cujas teorias ganham cada vez mais espaço nos estudos econômicos. Segunda ela, o indivíduo não é totalmente racional na tomada de sua decisão e está exposto a diversos vieses psicológicos, levando à incerteza das escolhas humanas diante de condições incertas. Será que as pessoas pensam que sabem mais do que realmente sabem? Está é a pergunta base de um dos vieses psicológicos mais debatidos: o excesso de confiança. Através de pesquisa de campo foram avaliados 187 alunos de Administração, Economia e Ciências Contábeis da Universidade Federal de Santa Catarina (UFSC) no intuito de verificar e analisar a ocorrência do excesso de confiança nas decisões propostas. Há determinadas características comuns no perfil dos entrevistados superconfiantes que sobressaltam aos olhos. Todos os alunos envolvidos na pesquisa foram submetidos a estudos do seu nível de confiança, que correlatos a suas características de gênero, idade, estado civil, ocupação, grau de familiaridade com a Bolsa de Valores, nível de conhecimento e rapidez nas decisões trazem importantes apontamentos no que diz respeito ao comportamento humano na tomada de suas decisões econômicas

Entwicklung eines partikelbasierten Verfahrens für den parallelen Nachweis von Proteinen

In dieser Arbeit wurde ein auf fluoreszenzkodierten Mikropartikeln basiertes Multiplex-Verfahren für den gleichzeitigen Nachweis mehrerer Krankheitsmarker entwickelt. Die Krankheitsmarker werden mittels fluoreszenzmarkierter Antikörper detektiert. Dekodierung der Partikel und Quantifizierung der Proteine erfolgen fluoreszenzmikroskopisch. Es wurde gezeigt, dass mindestens 4 Krankheitsmarker im klinisch relevanten Bereich nachgewiesen werden können

Cryogenic testing and analysis associated with Tevatron lower temperature operation

An upgrade of the Tevatron cryogenic system was installed and commissioned in 1993 to allow lower temperature operation. As a result, higher energy operation is possible. Following the installation and initial commissioning, it was decided to continue the current colliding beam physics at the previous energy of 900 GeV. This has allowed us to perform parasitic lower temperature tests in the Tevatron over the last year and a half. This paper presents the results of operational experiences and thermal and hydraulic testing which has taken place. The primary goal of the testing is to better understand the operation of the cold compressor system, associated instrumentation, and the performance of the existing magnet system during lower temperature operation. This will lead to a tentatively scheduled higher energy test run in the fall of 1995. The test results have shown that more elaborate controlling methods are necessary in order to achieve reliable system operation. Fortunately, our new satellite refrigerator controls system is capable of the expansion necessary to reach our goal. New features are being added to the control system which will allow for more intelligent control and better diagnostics for component monitoring and trending

Initial Performance of Upgraded Tevatron Cryogenic Systems

Fermilab began operating a re-designed satellite refrigerator systems in November 1993. Upgrades were installed to operate the Tevatron at a magnet temperature of 3.5 K, approximately 1K lower than the original design. Refrigerator upgrades included new valve boxes, larger reciprocating expanders, the installation of cold vapor compressors, new sub-atmospheric instrumentation and an entirely new distributed controls system. Cryogenic system reliability data for Colliding Physics Run 1B is presented emphasizing a failure analysis for each aspect of the upgrade. Comparison to data for Colliding Physics Run 1A (previous to upgrade) is presented to show the impact of a major system overhaul. New operational problems and their solutions are presented in detail