Abstract
This paper studies the performance of RPCs working with a new family of environment-friendly gases, mainly based on Carbon Dioxide and Hydro-Fluoro-Olefins. The tests are carried out on a 2 ...mm gap RPC and concern the measurement of detection efficiency, avalanche-to-streamer transition probability, prompt and ionic charge delivered. The timing properties of the new gas are also measured.
The intrinsic rate capability and the ageing properties of the Resistive Plate Chambers are closely related to the electrodes material and to the front-end electronics threshold. The development of a ...low noise pre-amplifier led us to improve the intrinsic rate capability of High Pressure Laminate (bakelite) RPCs up to ∼10 kHz/cm2, nevertheless the effective rate is significantly limited by electrodes ageing. To further improve the effective rate capability new materials are investigated. A Resistive Plate Chamber with crystalline semi-insulating Gallium Arsenide electrodes has been characterized with high energy electrons beam at the Beam Test Facility (BTF), (INFN National Laboratory of Frascati, Italy). The response of the Resistive Plate Chamber to multiple bunched electrons was measured operating the detector in avalanche mode. The intrinsic rate capability has been also measured operating the detector in a uniform high energy gamma radiation field at the GIF++ facility (EHN1 of SPS, CERN).
Improving the RPC rate capability Aielli, G.; Camarri, P.; Cardarelli, R. ...
Journal of instrumentation,
07/2016, Letnik:
11, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This paper has the purpose to study the rate capability of the Resistive Plate Chamber, RPC, starting from the basic physics of this detector. The effect of different working parameters determining ...the rate capability is analysed in detail, in order to optimize a new family of RPCs for applications to heavy irradiation environments and in particular to the LHC phase 2. A special emphasis is given to the improvement achievable by minimizing the avalanche charge delivered in the gas. The paper shows experimental results of Cosmic Ray tests, performed to study the avalanche features for different gas gap sizes, with particular attention to the overall delivered charge. For this purpose, the paper studies, in parallel to the prompt electronic signal, also the ionic signal which gives the main contribution to the delivered charge. Whenever possible the test results are interpreted on the basis of the RPC detector physics and are intended to extend and reinforce our physical understanding of this detector.
Fungi are cosmopolitan organisms that grow in and adapt to a vast number of substrates and environments, and that can cause diseases in humans and animals, as well as in crops. The vast area and ...diverse geographical characteristics of Argentina, with the consequent climatic diversity make the country an important source of biological resources suitable for the search of new compounds. The aim of the present study was to describe the antifungal activity of extracts of Parastrephia quadrangularis, a species from northern Argentina, against Fusarium verticillioides M7075. Bio‐guided fractionation and MS/MS studies were conducted to elucidate the chemical structure of active compounds. The extracts exhibited a minimum inhibitory concentration among 118·74 and 250 μg ml−1 and the differences between the treatments and the inoculum control was 12·5–16·5 mm, respectively, in colony growth. Moreover, hyphae treated with the extracts stained blue with Evans blue, showed alterations in permeability of plasma membranes. HLPC‐MS analysis of active fractions revealed the presence of p‐coumaroyloxitremetone, and a derivate structure for another compound is proposed.
Significance and Impact of the Study
In Argentina, Fusarium verticillioides causes ‘ear rot’, a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.
Significance and Impact of the Study: In Argentina, Fusarium verticillioides causes ‘ear rot’, a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.
Further gas mixtures with low environment impact have been tested. For the best RPC performance the main effort was to look for a mixture giving a comfortable avalanche-streamer separation and a gas ...density ensuring sufficient primary ionization. The measurements have been carried out on small size chambers at cosmic ray rates using the waveforms recorded on the oscilloscope. Efficiencies and distributions of amplitude and charge will be presented.
The new high energy high luminosity experiments require an improvement in both the counting rate and the space resolution for the detectors. This improvement can be achieved by reducing the charge ...per count, however this implies a need for a better signal to noise ratio in the signal processing. In this article we will show the performances of diamond detectors and RPCs using a new preamplifier with low noise (500-1000 electrons RMS), fast shaping (about 10 ns) and large input capacitance.
In the last few years, an intense R &D activity on particle detectors for future HEP applications has been carried on with the aim of developing new techniques as well as studying the performance of ...already existing detectors when operated in a high rate environment. As for Resistive Plate Chamber detectors, the main challenges to face are the improvement of their detection capabilities and longevity at very high-rates, and the search for new eco-friendly gasmixtures free from greenhouse components. Results obtained in the framework of the RPC ECOGas@GIF++ Collaboration on a thin-Resistive Plate Chamber exposed at the CERN Gamma Irradiation Facility and operated with eco-friendly gas mixtures based on Tetrafluoropropene and Carbon dioxide will be discussed in this paper.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Results obtained by the RPC ECOgas@GIF++ Collaboration, using Resistive Plate Chambers operated with new, eco-friendly gas mixtures, based on tetrafluoropropene and carbon dioxide, are shown and ...discussed in this paper. Tests aimed to assess the performance of this kind of detectors in high-irradiation conditions, analogous to the ones foreseen for the coming years at the Large Hadron Collider experiments, were performed, and demonstrate a performance basically similar to the one obtained with the gas mixtures currently in use, based on tetrafluoroethane, which is being progressively phased out for its possible contribution to the greenhouse effect. Long term aging tests are also being carried out, with the goal to demonstrate the possibility of using these eco-friendly gas mixtures during the whole High Luminosity phase of the Large Hadron Collider.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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