111218928
Missing bunches and sextupoles in the Booster
45001182
Modern operators' consoles for accelerator control at Fermilab
Since the construction of the Tevatron, the Fermilab accelerator complex has been controlled from operators' consoles based on PDP-11 computers and interaction with display hardware via CAMAC. In addition, the linac has been controllable from microprocessor-based local consoles. The new generation of console devices is based on VAXstation computers, networked by Ethernet and Token Ring, and utilizes the X-Windows protocol. Under X, the physical display (server) can be driven by any network node, and need not be part of the console computer (client). This allows great flexibility in configuring display devices, with X-terminals, UNIX workstations, and Macintoshes all having been utilized. Over half of the 800 application programs on the system have been demonstrated to work properly in the new environment. The modern version of a linac local console runs in a Macintosh. These are networked via Token Ring to linac local control stations. They provide color graphics and a hard copy capability which was previously lacking.<<ETX>>
42275095
Magnetization Effects in Superconducting Dipole Magnets
Magnetization effect of superconductor on the field quality has been investigated for some of the typical Energy Doubler bending magnets. Calculations were made using the computor program GFUN2D and compared with some measured results. Agreement between them is good. The field quality at low excitation is mainly determined by the magnetization effect. A similar effect due to a stainless collar mechanical support was also calculated, although it is not as big as the first one.
110416727
Synchronous Transfer of Beam from the NAL Fast Cycling Booster Synchrotron to the NAL Main Ring System
Beam from successive cycles of the 15-Hz booster synchrotron is stacked end to end in the main synchrotron with constant magnetic field. Beam already injected into the main ring is held in stationary rf buckets, and the rest field is determined by the circulating beam. To capture beam from subsequent booster cycles into the empty buckets in the main ring, the phase and frequency of the rf beam bunches in the booster are locked to the main ring rf system before beam is transferred. The magnetic fields in the booster and the main ring are regulated separately and tuned for the correct orbit radii and particle momentum. The azimuth of the beam circulating in the main ring is monitored by counting main ring rf cycles, and the beam transfer system is timed to inject beam from successive booster cycles in the correct sequence around the main-ring circumference.
113758813
Operational Test and Field Measurement of E5-1 Magnet. 1.
12403529
Coil Extension, Deformation and Compression during Excitation in Superconducting Accelerator Dipole Magnets
The measurement of conductor motion, caused by exciting a superconducting dipole magnet, is compared to the measured field quality.
118747225
V+jets Background and Systematic Uncertainties in Top Quark Analyses
Vector boson production in association with jets is an important process to test perturbative quantum chromodynamics and also a background process in top quark analyses. Measurements on vector boson production in association with light and heavy flavour jets are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at LHC. Techniques applied in top quark analyses to estimate the vector boson+jets background are also discussed.
210002512
Top Quark Mass Measurements at the Tevatron
Since the discovery of the top quark in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron proton antiproton collider, precise measurements of its mass are ongoing. Using data recorded by the D0 and CDF experiment, corresponding to up to the full Tevatron data sample, top quark mass measurements performed in different final states using various extraction techniques are presented in this article. The recent Tevatron top quark mass combination yields m_t=173.20 +-0.87 GeV. Furthermore, measurements of the top antitop quark mass difference from the Tevatron are discussed.
122117796
Measurements and searches with top quarks
In dieser Dissertation wird die Produktion und der Zerfall von Topquarks 
untersucht. Insbesondere wird neben dem 
Topquarkpaarproduktions-Wirkungsquerschnitt s_ttbar das Verzweigungsverhaltnis R=Br(t->Wb)/Br(t->Wq) 
mit q= d-,s- oder b-Quark gemessen, nach geladenen Higgs Bosonen im 
Zerfall t->H^+b und nach neutralen Higgs Bosonen im ttH Prozess gesucht. 
Die Analysen wurden grosstenteils im Lepton plus Jets, dileptonischen und Tau plus Lepton Kanal durchgefuhrt. Der gesamte analysierte Datensatz entspricht etwa einem inversen 
Femtobarn und wurde mit dem D0 Detektor am Tevatron 
Proton-Antiproton-Beschleuniger zwischen 2002 und 2006 aufgenommen. 
Die Anzahl von identifizierten b-Jets wurde fur die simultane Messung von R 
und s_ttbar im Lepton plus Jets Kanal verwendet, wobei eine bessere 
Signifikanz durch die Ausnutzung topologischer Variablen erreicht werden konnte. Mit dem gemessenen 
Wert von R=0.968+0.092-0.083 konnten Werte des CKM Matrixelementes V_tb>0.884 mit 95% 
Wahrscheinlichkeit ausgeschlossen werden. 
 
 Das unterschiedliche Verhalten von Topquarkpaar-Ereignissen in verschiedenen 
Kanalen bei Prasenz eines geladenen Higgs Bosones liefert die Sensitivitat fur die Suche 
nach geladenen Higgs Bosonen im Topquark Zerfall. Neben der kombinierten 
Messung von s_ttbar konnte die zur Zeit 
beste obere 
Schranke auf Br(t->H^+b) in verschiedenen Modellen gesetzt werden. Weiterhin 
wurde die erste simultane Messung von s_ttbar und Br(t->H^+b) durchgefuhrt.