111000899
Operational experience and performance of the CDFII silicon detector
The CDFII silicon detector consists of 8 layers of double-sided silicon micro-strip sensors totaling 722,432 readout channels, making it one of the largest silicon detectors in present use by an HEP experiment. After nearly 2 years of data taking, we report on our experience operating the complex device. The performance of the CDFII silicon detector is presented and its effect on physics analyses is discussed. The CDFII silicon detector has begun to show measurable effects of radiation damage. These results and their impact on the expected lifetime of the detector are briefly reviewed.
112091395
Power Distribution in a CMS Tracker for the SLHC
An upgraded tracker for CMS will need a new architecture for powering to keep the power dissipated in the power cables to acceptable levels. Inductor topologies to reduce the stray magnetic field are discussed together with measurements of the magnetic field produced by prototype inductors. A transformer based DC-DC converter has the potential to produce a high stepdown ratio whilst producing a low stray field and retaining high efficiency. The relative merits of buck configuration and transformer based DC-DC converters are discussed.
14475053
EXPERIENCE WITH THE GTS-LHC ION SOURCE
For the heavy ion programme of the LHC a new ECRIS type heavy ion source had to be designed and built for Linac3 to fullfill the intensity requirements. Experience acquired during the installation and commissioning of the source and during operation for the LEIR ring commissioning will be presented. The performance of the source and its reliability are evaluated. Further requirements for high reliability, low down time, easy maintenance and for future physics needs will be discussed.
120114220
The trace anomaly and low energy phenomenological implications of wormholes
Abstract In Coleman's wormhole scenario it is the trace anomaly on S 4 that controls the behavior of fundamental coupling constants, particle masses, mixing angles, etc. We indicate how low energy phenomenology may be derivable from very general properties of wormhole physics and calculable β-functions, etc.
969079
Anomaly mediated neutrino-photon interactions at finite baryon density.
We propose new physical processes based on the axial vector anomaly and described by the Wess-Zumino-Witten term that couples the photon, Z-boson, and the omega-meson. The interaction takes the form of a pseudo-Chern-Simons term, approximately E(munurhosigma)omega(mu)ZnuFrhosigma. This term induces neutrino-photon interactions at finite baryon density via the coupling of the Z-boson to neutrinos. These interactions may be detectable in various laboratory and astrophysical arenas. The new interactions may account for the excess observed at the Fermilab Booster Neutrino Experiment MiniBooNE. They also produce a competitive contribution to neutron star cooling at temperatures greater, similar10(9) K. These processes and related axion-photon interactions at finite baryon density appear to be relevant in many astrophysical regimes.
117629294
Broken Symmetry and the Accelerated Observer
Spontaneous symmetry breaking affords an interesting probe of the phenomenon of “acceleration radiation” in general relativistic quantum field theory and raises a peculiar paradox. Accelerated observers infer the presence of particles in the vacuum in a thermal distribution with a temperature proportional to the proper acceleration. Nonetheless, by ever increasing the temperature (acceleration) a broken symmetry cannot be restored without violating general covariance. How does the accelerated observer interpret this outcome dynamically?
92814731
Performance of the ECR ion source of CERN's heavy ion injector
In fall 1994 the new heavy ion injector at CERN was brought into operation successfully and a lead beam of 2.9 ×10 ions per pulse was accelerated in the SPS up to an energy of 157 GeV/u. The ion source, whi h was supplied by GANIL (France) was in operation almost continuously over a period of about one year and proved to be very reliable. It produces a current of more than 100 μA of Pb 27+ (after the first spectrometer) during the afterglow of the pulsed discharge. The current stays within 5% of the maximum value for a time of about 1 ms, which is more than required by the accelerators. Measurements of the charge state distribution, emittance and energy spread, which were made during this time window, are presented together with other operating data. Presented at the 12th International Workshop on ECR Ion Sources, April 25-27, 1995, RIKEN, Japan