Readout System for the CMS RPC Muon Trigger
The CMS detector contains the RPC chambersa dedicated trigger subdetectorto identify muons, measure their transverse momenta pT, and determine the bunch crossing from which they originated.The RPC Muon Trigger algorithm is based on muon track search and classification in raw data from the RPC chambers. Large part of the RPC trigger electronics will reside in the control room (approx. 90 meters from the detector) where all trigger data are concentrated. Dedicated synchronous compression decompression algorithm is needed to sent all data for each bunch crossing via optical links. The RPC Readout system uses the same data as Trigger system and will be placed in the Trigger Racks. The idea of readout system and its limitations are discussed below. The paper includes description of prototype boards and tests in the synchronous CERN LHC like test beam H2 in May 2000.
Readout system for CMS RPC Muon Trigger
This paper presents readout for RPC based muon trigger system, part of CMS experiment on LHC collider at CERN (Geneva). All RPC data used to perform trigger algorithm are collected on RPC trigger boards of and send to general CMS data acquisition system. Zero suppression used to transfer data from detector to control room is used to decrease the amount the links and data to be stored.
The Unusual Variability of the Large Magellanic Cloud Planetary Nebula RPJ 053059–683542
We present images and light curves of the bipolar planetary nebula RPJ 053059-683542 that was discovered in the Reid-Parker AAO UKST Hα survey of the Large Magellanic Cloud. The emission from this object appears entirely nebular, with the central star apparently obscured by a central band of absorption that bisects the nebula. The light curves, which were derived from images from the SuperMACHO project at CTIO, showed significant, spatially resolved variability over the period 2002 January through 2005 December. Remarkably, the emission from the two bright lobes of the nebula vary either independently or similarly but with a phase lag of at least 1 yr. The optical spectra show a low level of nebular excitation, and only modest N enrichment. Infrared photometry from the 2MASS and SAGE surveys indicates the presence of a significant quantity of dust. The available data imply that the central star has a close binary companion and that the system has undergone some kind of outburst event that caused the nebular emission to first brighten and then fade. Further monitoring, high-resolution imaging, and detailed IR polarimetry and spectroscopy would uncover the nature of this nebula and the unseen ionizing source.