Monday, March 11, 2002 - DPG-Tagungen

More documents

Recommendations

Info

Nuclear Physics Tuesday ung polarisierter Elektronen an unpolarisiertem Wasserstoff ist seit Inbetriebnahme im Sommer 2000 erfolgreich im Einsatz. Seither wurden viele Hundert Stunden Daten am Strahl genommen. Um im Meßbetrieb eine schnelle Qualitätsprüfung vornehmen zu können, wurde ein Online-Datenanalysesystem entwickelt, das die Energiespektren des Kalorimeters auswertet und graphisch darstellt. Die Zusammenführung mit weiteren Daten (Strahlmonitorierung etc.) bildet die Basis für die spätere Offline-Analyse. Datenaufbereitung und -analyse für einen ersten Datenpunkt werden vorgestellt. HK 14.9 Tue 10:30 Foyer Chemie Monitorierung strahlbedingter Asymmetrien für das A4- Experiment an MAMI — •Thorsten Hammel für die A4-Kollaboration — Institut für Kernphysik, Johannes-Gutenberg- Universität Mainz, 55099 Mainz Die Kollaboration A4 an MAMI strebt die Vermessung eines möglichen Beitrags der Strangeness zu den Pauli-Formfaktoren des Nukleons an. Die experimentelle Methode besteht in der Bestimmung der paritätsverletzenden Asymmetrie in der Zählrate der elastischen Streuung von rechts- und linkshändig polarisierten Elektronen an einem unpolarisiertem Flüssig-Wasserstoff-Target. Während des Experiments ist eine Messung von allen Größen, die im Falle einer Korrelation mit der Polarisationsumschaltung eine systematische Veränderung der gemessenen Asymmetrie bewirken können, erforderlich. Hierzu werden Strahlparameter, wie Strom, Intensität, Energie, Strahllage, Strahlwinkel, sowie die Targetdichte während der gesamten Messzeit gleichzeitig zum laufenden Experiment überwacht. Das hierzu entwickelte Detektorsystem ist seit 1999 aufgebaut und erfolgreich im Einsatz. Es werden das Detektorsystem sowie Messungen mit dem vollständigen Aufbau und Ergebnisse vorgestellt und diskutiert. HK 14.10 Tue 10:30 Foyer Chemie Aufbau der Ausleseelektronik für das A4-Experiment an MAMI — •Rainer Kothe für die A4-Kollaboration — Institut für Kernphysik, Johannes-Gutenberg-Universität Mainz, 55099 Mainz Die Kollaboration A4 an MAMI strebt die Vermessung des Beitrags der Strangeness zu den Pauli-Formfaktoren des Nukleons an. Die experimentelle Methode besteht in der Bestimmung der paritätsverletzenden Asymmetrie in der Zählrate der elastischen Streuung rechts- und linkshändig polarisierter Elektronen an einem unpolarisiertem Flüssig- Wasserstoff-Target. Die gestreuten Elektronen werden mit 1022 Bleifluoridkristallen nachgewiesen. Die Energie der Einzelereignisse wird mittels der nachgeschalteten Ausleseelektronik bestimmt und kanalweise histogrammiert. Vorgestellt wird diese Ausleseelektronik, im Hinblick auf deren Aufbau,Test und Weiterentwicklung, sowie Ergebnisse bisheriger Messungen. HK 14.<strong>11</strong> Tue 10:30 Foyer Chemie Investigation of Parametric X–Radiation under small Bragg angles at MAMI — •G. Kube, C. Ay, H. Backe, N. Clawiter, M. El Ghazaly, F. Hagenbuck, K.-H. Kaiser, W. Lauth, H. Mannweiler, H. Rochholz, andT. Weber — Institut für Kernphysik, Universität Mainz, J.-J. Becher Weg 45, 55099 Mainz When a charged ultrarelativistic particle passes through a perfect crystal the particle field can be diffracted in the vicinity of the Bragg angle. The emitted radiation is called quasi– Čerenkov radiation or parametric X–radiation. The energy ¯hω of the X–ray photons which are most efficiently radiated is predicted for silicon with plasma frequency ωp =31eV/¯hand a Lorentz factor γ = 1672, as for the Mainz Microtron MAMI, to be ¯hω = γ ¯hωp = 51.8 keV [1]. Angular distributions of (<strong>11</strong>1), (333) and (444) reflections for silicon single crystals of various thicknesses between 100 and 500 µm have been investigated at MAMI for Bragg angles θB ≤ 5◦ . The measured intensity distributions will be compared with theoretical calculations. [1] A. Caticha, Phys.Rev. B45 (1992) 9541 Work supported by the DFG under contract BA 1336/1-3 HK 14.12 Tue 10:30 Foyer Chemie Stabilization system for the A4-Compton-Polarimeter — •Jürgen Diefenbach for the A4 collaboration — Institut für Kernphysik, Universität Mainz The A4-Collaboration at the University of Mainz measures parity violation in electron proton scattering. The longitudinal polarization of the electron beam is to be measured with a compton backscattering polarimeter. The intracavity design requires long laser resonator arms. It is therefore important to properly stabilize the optics. First an overview of the stabilization requirements is given, then implementation methods using analog and digital filters are presented. The effects on the measuring accuracy are discussed. HK 14.13 Tue 10:30 Foyer Chemie Elemental Analysis of Soil Samples from Toshki in Upper Egypt by using Instrumental Neutron Activation Analysis Techniques — •Atef Eltaher 1,2 , K. L. Kratz 1 , A. Nosser 2 ,andA. Azzam 3 — 1 Institut für Kernchemie, J. Gutenberg-Universität, D-55128 Mainz, Germany — 2 Physics Department, Faculty of science, Al-Azher University, Assiut Egypt — 3 Nuclear Physics Deparment, Atomic Energy Authority, Cairo Egypt Instrumental neutron activation analysis techniques (INAA) were applied for elemental analysis of soil samples collected from Toshki area 280 km from Aswan city in Upper Egypt. The samples were irradiated with thermal neutrons at the TRIGA Mainz research reactor. Gamma-ray spectra were recorded using a HPGe detector to determine the contents of major, minor and trace elements in these samples. As a result of the analysis, altogether 32 elements were identified qualitatively and quantitatively. These elements are: Na, Mg, Al, Cl, K, Sc, Ca, Cr, Ti, V, Mn, Fe,Co,Zn,Rb,Zr,As,Nb,Sn,Ba,Cs,La,Ce,Nd,Eu,Sm,Yb,Lu,Hf, Ta, Th and U. In several cases, X-ray fluorescence analysis (XRF) was used for comparison. Furthermore delayed neutron activation analysis (DNAA) was used to determine the uranium content from these samples. The results from different analysis techniques will be compared and discussed. HK 14.14 Tue 10:30 Foyer Chemie Implementation of a RISC CPU in FPGA — •A. Danasino, H. Fischer, J. Franz, A. Grünemaier, S. Hedicke, F.H. Heinsius, M. von Hodenberg, F. Karstens, W. Kastaun, K. Königsmann, J. Reymann, T. Schmidt, H. Schmitt, and J. Worch for the COMPASS collaboration — Fakultät für Physik, Universität Freiburg The CATCH modules are the central building blocks of the readout system of the COMPASS experiment. The CATCH acts as a local event builder, adding information useful for the localization of the signals sent from the detectors. The CATCH is designed with several programmable logic devices (FPGA and CPLD). For monitoring and control of the data flow a complete system-on-a-chip design is implemented in one FPGA. It includes a 16 bit RISC processor which is clocked with 10 MHz. The microprocessor core is derived from the XSOC project developed by Jan Gray of Gray Research LLC. Very flexible programming can be done in integer C which is translated to the MIPSbased instruction set of the microprocessor. It can communicate to all other FPGAs on the CATCH, reset and monitor mezzanine cards and send serial initialization data to the front end boards. It can drive a four character display on the front panel of the CATCH module. For further information: http://hpfr02.physik.uni-freiburg.de/projects/compass/electronics This project is supported by the BMBF. HK 14.15 Tue 10:30 Foyer Chemie X-ray diagnostics and calibration of the COMPASS straw detectors — •Klaus Platzer 1 , Wolfgang Duennweber 1 ,andHermann Wellenstein 2 — 1 Sektion Physik der LMU, Am Coulombwall 1, 85748 Garching — 2 Physics Department, Brandeis University, Waltham MA 02454 A scanning device consisting of a continuous beam, 50kV X-ray tube and a 20mm x 30mm CCD has been installed for the inspection of the straw tracking system of the COMPASS experiment at CERN. One double layer of about 800 straws, covering an area of 3.2m x 2.7m, is scanned in about 30 hours. The result is a grid of 5000 wire positions. The control of wire and wall spacing is possible with a local resolution better than 5 µm. The absolute wire positions are determined with an accuracy of about 50 µm, wich is sufficient as compared with the particle tracking resolution of about 200 µm of a single straw.
Nuclear Physics Tuesday HK 14.16 Tue 10:30 Foyer Chemie Tracking Capabilities of COMPASS GEM Detectors † — •Frank Simon 1 , Jan Friedrich 2 , Boris Grube 2 , Bernhard Ketzer 3 , Igor Konorov 2 , Stephan Paul 2 ,andFabio Sauli 3 for the COM- PASS collaboration — 1 Max–Plank–Institut für Physik, München, Germany — 2 Physik–Department E18 TU München, Garching, Germany — 3 CERN, Geneva, Switzerland For the small angle tracking of the COMPASS Experiment at CERN’s SPS accelerator, a total of 20 triple–GEM detectors, each with an active area of 31×31 cm 2 , are used. Prior to their successful operation in the COMPASS physics run in 2001, the detectors were tested in various particle beams to determine their tracking capabilities. The spatial resolution was shown to be better than 50 µm and an efficiency of 99% was reached for minimum–ionizing particles. The GEM detectors are equipped with an orthogonal two–dimensional projective readout that leads to a correlation between the charge collected on both readout coordinates. The charge ratio has a mean value close to unity and a width σ
Page 1 and 2: Nuclear Physics Sectional Programme
Page 7 and 8: Nuclear Physics Monday sition form
Page 9 and 10: Nuclear Physics Monday imental meas
Page 11 and 12: Nuclear Physics Monday HK 5.6 Mon 1
Page 13 and 14: Nuclear Physics Monday HK7 Instrume
Page 15 and 16: Nuclear Physics Tuesday however lar
Page 17 and 18: Nuclear Physics Tuesday tion prescr
Page 19 and 20: Nuclear Physics Tuesday HK10 Poster
Page 21 and 22: Nuclear Physics Tuesday Recent expe
Page 23 and 24: Nuclear Physics Tuesday HK 10.26 Tu
Page 25 and 26: Nuclear Physics Tuesday ground even
Page 27 and 28: Nuclear Physics Tuesday bution desc
Page 29 and 30: Nuclear Physics Tuesday HK 12.30 Tu
Page 31: Nuclear Physics Tuesday A set of fu
Page 35 and 36: Nuclear Physics Tuesday the hydroge
Page 37 and 38: Nuclear Physics Tuesday HK 16.3 Tue
Page 39 and 40: Nuclear Physics Tuesday ∗ support
Page 41 and 42: Nuclear Physics Tuesday capability
Page 43 and 44: Nuclear Physics Wednesday Group Rep
Page 45 and 46: Nuclear Physics Wednesday HK 25.2 W
Page 47 and 48: Nuclear Physics Wednesday S/A ≈ 3
Page 49 and 50: Nuclear Physics Wednesday meson exc
Page 51 and 52: Nuclear Physics Wednesday of so-cal
Page 53 and 54: Nuclear Physics Wednesday HK 34.4 W
Page 55 and 56: Nuclear Physics Thursday The effect
Page 57 and 58: Nuclear Physics Thursday HK40 Elect
Page 59 and 60: Nuclear Physics Thursday pretation
Page 61 and 62: Nuclear Physics Thursday HK45 Nucle
Page 63 and 64: Nuclear Physics Thursday HK47 Heavy
Page 65 and 66: Nuclear Physics Friday HK49 Plenary
Page 67 and 68: M. Ding3 , M.O. Distler3 , P. Drago
Page 69 and 70: 4 Institut for Fysik og Astronomi,
Page 71 and 72: 8Gesellschaft für Schwerionenforsc
Page 73 and 74: den Brand 2,4 , Henk Bulten 2,4 , L
Page 75 and 76: Friese, J. . HK 14.1, HK 14.3, HK 4
Page 77 and 78: Rusev, G. ..................HK 10.1

Monday, March 11, 2002 - DPG-Tagungen

Create successful ePaper yourself

Delete template?

Save as template?