4,408 research outputs found
Resistive plate chambers for time-of-flight measurements
The applications of Resistive Plate Chambers (RPCs) have recently been
extended by the development of counters with time resolution below 100 ps sigma
for minimum ionising particles. Applications to HEP experiments have already
taken place and many further applications are under study. In this work we
address the operating principles of such counters along with some present
challenges, with emphasis on counter aging.Comment: Presented at "PSD6 - 6th International Conference on Position
Sensitive Detectors", 9-13 September 2002, Leicester, UK. Submitted to
Nuclear Instruments and Methods
A Novel UV Photon Detector with Resistive Electrodes
In this study we present first results from a new detector of UV photons: a
thick gaseous electron multiplier (GEM) with resistive electrodes, combined
with CsI or CsTe/CsI photocathodes. The hole type structure considerably
suppresses the photon and ion feedback, whereas the resistive electrodes
protect the detector and the readout electronics from damage by any eventual
discharges. This device reaches higher gains than a previously developed
photosensitive RPC and could be used not only for the imaging of UV sources,
flames or Cherenkov light, for example, but also for the detection of X-rays
and charged particles.Comment: Presented at the International Workshop on Resistive Plate Chambers,
Korea, October 200
Introduction: food relocalisation and knowledge dynamics for sustainability in rural areas
The chapter presents the literature on local food and local knowledge and introduces the case studies analysed in the volum
Novel Single Photon Detectors for UV Imaging
There are several applications which require high position resolution UV
imaging. For these applications we have developed and successfully tested a new
version of a 2D UV single photon imaging detector based on a microgap RPC. The
main features of such a detectors is the high position resolution - 30 micron
in digital form and the high quantum efficiency (1-8% in the spectral interval
of 220-140 nm). Additionally, they are spark- protected and can operate without
any feedback problems at high gains, close to a streamer mode. In attempts to
extend the sensitivity of RPCs to longer wavelengths we have successfully
tested the operation of the first sealed parallel-plate gaseous detectors with
CsTe photocathodes. Finally, the comparison with other types of photosensitive
detectors is given and possible fields of applications are identified.Comment: Presented at the 5th International Workshop on RICH detectors Playa
del Carmen, Mexico, November 200
Gain, Rate and Position Resolution Limits of Micropattern Gaseous Detectors
In this study we report the results of a systematic study of the gain, rate
and the position resolution limits of various micropattern gaseous detectors.
It was found that at low rates (<1 Hz/mm^2) each detector has it own gain
limit, which depends on the size and design features, as well as on gas
composition and pressure. However, in all cases the maximum achievable gain is
less than or equal to the classical Raether limit. It also was found that for
all detectors tested the maximum achievable gain drops sharply with the
counting rate. The position resolution of micropattern detectors for detection
of X-rays (6 to 35 kV) was also studied, being demonstrated that with solid
converters one could reach a position resolution better than 30 micrometers at
1 atm in a simple counting mode.Comment: 10 pages, 3 figures, Presented at the PSD99-5th International
Conference on Position-Sensitive Detectors, 13-17 th September 1999,
University College, Londo
High Resolution RPC's for Large TOF Systems
Here we report on a particular type of RPC that presents up to 99% efficiency
for minimum ionizing particles and a very sharp time resolution, below 50 ps
sigma in the most optimized conditions. Our 9 cm2 cells, made with glass and
metal electrodes that form accurately spaced gaps of a few hundred micrometers,
are operated at atmospheric pressure in non-flammable gases and can be
economically produced in large quantities, opening perspectives for the
construction of large area time of flight systems.Comment: 10 pages, 8 figure
Advances in the Development of Micropattern Gaseous Detectors with Resistive Electrodes
We describe the most recent efforts made by various groups in implementing
resistive electrodes in micropattern gaseous detectors with the aim to combine
in the same design the best features of RPCs (for the example, their robustness
and spark protection property) with the high granularity and thus the good
position resolution offered by microelectronic technology. In the stream of
this activity, we have recently developed two novel detectors with resistive
electrodes: one was based on resistive micromeshes and the second one is a MSGC
with resistive electrodes. We have demonstrated that the resistive meshes are a
convenient construction element for various designs of spark protective
detectors: RPCs type, GEM type and MICROMEGAS type. These new detectors enable
to considerably enhance the RPC and micropattern detectors applications since
they feature not only a high position resolution but also a relatively good
energy resolution (25-30 persent FWHM at 6 keV) and, if necessary, they can
operate in cascaded mode allowing the achievement of a high overall gas gain.
The main conclusion from these studies is that the implementation of resistive
electrodes in micropattern detectors makes them fully spark protected; on this
basis we consider this direction very promising
- …