Application of Si-strip technology to X-ray diffraction instrumentation Gerndt, E.; Dąbrowski, W.; Brügemann, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2010, Letnik:
624, Številka:
2
Journal Article
Recenzirano
We describe the successful technology transfer of High Energy Physics (HEP) silicon-strip detectors for tracking of minimum ionising particles (MIPS) to industrial X-ray diffraction instruments. In ...our application the detector is used to measure 1-D intensity profiles of low-energy photons. The challenges of such an application are low noise because of the relatively low energy of X-ray photons, from 5 to 22
keV, and high count rate capability. The technical implementation, with a focus on custom designed front-end electronics and optimisation of strip geometry taking into account the charge division effects, is shown and the achieved performance is summarized. The detector was launched several years ago and we report on the in-field experience. Lastly, we describe several scientific applications.
Track finding at 10-MHz hadronic event rate Bruinsma, M.; Fleckenstein, H.; Gerndt, E.K.E. ...
IEEE transactions on nuclear science,
04/2002, Letnik:
49, Številka:
2
Journal Article
Recenzirano
Hera-B is a fixed target experiment using a halo target inside the HERA proton ring to generate B mesons in 920 GeV proton-nucleus interactions. The first-level trigger (FLT) of the experiment has to ...reduce the primary 10-MHz input rate by a factor 200 in less than 10 /spl mu/s to make it acceptable to the second level trigger (SLT). The trigger strategy is based on the tracking of charged particles and on the reconstruction of their kinematic parameters. The combination of track pairs can also be used for the final decision. A parallel and pipelined set of approximately 60 dedicated boards was designed and built to perform this job. In this paper, the working principle of the system and some results obtained by analyzing the data collected during the run in the year 2000 are described.
Concept of the first level trigger for HERA-B Fuljahn, T.; Gerndt, E.; Glass, J. ...
IEEE transactions on nuclear science,
1998-Aug., 1998-8-00, 19980801, Letnik:
45, Številka:
4
Journal Article
Recenzirano
The HERA-B detector aims to measure CP violation in the B meson system. The B mesons under study are produced in interactions of 820 CeV/c protons with the fixed target. Together with the B mesons a ...6 orders of magnitude larger background of minimum bias interactions is produced. A highly selective and efficient trigger system is required and has been designed to acquire a sufficient amount of signal decays. It is able to find lepton and hadron tracks and reconstruct their kinematics on the first level of the trigger chain. The final first level trigger decision is based on the properties of the reconstructed pair of tracks. This is mainly targeting at J//spl psi//spl rarr/l/sup +/l/sup -/ and B/sup 0//spl rarr//spl pi//sup +//spl pi//sup -/ signatures. A parallel and pipelined system of approximately 100 processors is designed to perform this job. It reduces a 10 MHz input rate by a factor of 200 with a latency of 5 to 10 /spl mu/s. A special detailed simulation package was designed to study the system performance and prove the algorithms used. Being a constituent part of the general HERA-B software, it provides not only the possibility of trigger studies but also selects FLT-passing events to be considered as input stream for the studies of the following levels of the HERA-B trigger system.
Measurement of αS from τ decays Sanghera, S.; Skwarnicki, T.; Wei, G. ...
Physics letters. B,
08/1995, Letnik:
356, Številka:
4
Journal Article
Recenzirano
We present measurements of spectral moments extracted from the invariant mass distributions of the final states of hadronic τ decay products recorded in the CLEO detector. From a fit of theoretical ...predictions to the measurements of spectral moments and the total hadronic decay width of the τ, we determine the strong coupling constant and a set of non-perturbative QCD parameters. The strong coupling constant is measured to be
α
s
(
m
τ
) = 0.306 ± 0.024, which when extrapolated to the
Z mass, yields
α
s
(
M
z
) = 0.114 ± 0.003.
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