scholarly journals Local reconstruction algorithms in the cathode strip chambers of CMS

2019 ◽  
Vol 214 ◽  
pp. 02014
Author(s):  
Mirena Paneva

The design of the CMS detector is optimized for muon measurements. The muon system consists of gas ionization detector technologies. Cathode Strip Chambers (CSC) with both tracking and triggering capabilities are installed in the forward region. The first stage of muon reconstruction uses information from individual muon chambers and is thus called local reconstruction, in contrast to a subsequent global reconstruction where the information from all detectors is combined. First, 2-dimensional spatial points (rechits) describing where a muon crosses the CSC layers are built from the electrical signals induced by the charged particle traversing the chamber. Next, from the reconstructed hits, straight-line track segments are built within each chamber. Local reconstruction becomes particularly challenging at high instantaneous luminosities, which are expected at the HL-LHC. The high rate of particles traversing the detectors leads to increased rate of spurious rechits and segments thus increasing the combinatorial backgrounds. In this respect, work on improving the current and developing new algorithms is essential and is in progress. This document presents the existing local reconstruction algorithms used in the CMS cathode strip chambers. Their performance as well as ongoing efforts towards HL-LHC improvements are discussed.

1985 ◽  
Vol 63 (12) ◽  
pp. 2817-2824 ◽  
Author(s):  
Richard M. P. Ward ◽  
Charles J. Krebs

The behavioural responses of lynx (Lynx canadensis) to declines in snowshoe hare (Lepus americanus) abundance were examined in the southwestern Yukon. Between April 1982 and June 1984, 11 lynx were radio tagged and monitored in and near the Kluane Game Sanctuary. Lynx home range size increased from 13.2 to 39.2 km2 concurrent with a decline in snowshoe hare abundance from 14.7 to 0.2 hares/ha. Below about 0.5 hares/ha, several lynx abandoned their home ranges and became nomadic, although they remained within the general study area. Lynx concentrated their foraging efforts in areas of relatively high snowshoe hare abundance and abandoned these areas after hares declined. Straight-line daily travel distance remained constant at 2.2−2.7 km/day above 1.0 hare/ha. Below 1.0 hares/ha, straight-line daily travel distances increased rapidly, reaching 5.5 km/day at 0.2 hares/ha. Three of seven radio-tagged lynx dispersed 250 km or more from the study area during the 1982 period of rapid hare decline. No similar long-distance emigrations were recorded after hare densities stabilized at less than 1.0 hares/ha. Trapping mortality was responsible for the loss of seven of nine radio-tagged lynx that travelled outside the game sanctuary. One lynx probably starved during the winter or spring of 1984. The high rate of trapping mortality outside the game sanctuary suggests that refugia in wilderness areas are important in maintaining lynx populations during periods of low recruitment.


Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 83-88 ◽  
Author(s):  
L Wacker ◽  
M Grajcar ◽  
S Ivy-Ochs ◽  
PW Kubik ◽  
M Suter

The injection of 10BeF- instead of 10BeO- into a compact accelerator mass spectrometry system with a terminal voltage of 0.58 MV was investigated, because BF- molecules are unstable and isobaric interference of 10B with 10Be can thus be significantly reduced. We describe the method we developed to prepare BeF2 samples. 10Be was measured in a segmented gas ionization detector. Separation of 10Be from 10B could be achieved both for ions in the 1+ charge state with an energy of 0.8 MeV and in the 2+ charge state with an energy of 1.4 MeV. The 2+ ions are better separated, whereas the 1+ charge state has a higher transmission. 10Be/9Be ratios (~10-12) in a suite of rock samples were successfully determined for exposure dating in either charge state and compared with measurements made on the 6MV tandem.


2021 ◽  
Vol 11 (10) ◽  
pp. 4556
Author(s):  
Milan Džunda ◽  
Peter Dzurovčin ◽  
Peter Kaľavský ◽  
Peter Korba ◽  
Zoltán Cséfalvay ◽  
...  

In the process of our research, we have identified new methods of processing ultra-wide-band (UWB) radar signals and possibilities of the UWB radar use in aviation security systems. We paid our main attention to finding new algorithms for tracking the movement of a person behind an obstacle using the UWB radar. Such UWB radar application is typical for tracking the movement of people behind obstacles in case of security forces intervention at an airport. In the research process, we used methods of analysis, synthesis, and measured data from the performed experiment. The main contribution of the paper is the development of new algorithms for locating the movement of a person behind an obstacle using a straight- line method in the case of using two independent UWB radar systems. The article did not examine the accuracy of determining the position of a person behind the obstacle. We found that when applying the Kalman filter after signal processing by the straight-line method, the trajectory of the person’s movement behind the obstacle was smoother. The results of processing the measurement signals of UWB radar by the linear method have shown that this method is applicable to tracking a person behind an obstacle and can be used in aviation security systems.


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