Innovative applications in light signal sensing require flexibility, lightweight, low-cost and low temperature processability, as well as high sensitivity and quantitative photoresponse. We report on ...flexible organic phototransistors (OPTs) with excellent reproducibility in the detection of outstandingly low light intensities of few nW cm−2. The optical response of the phototransistor was thoroughly characterized as a function of the wavelength, the incident optical intensity and the electrical polarizations. The photodetectors work reliably under bending and pulse cycling in different environmental conditions, at low polarizations down to the range 0.1–5 V. Based on these outcomes, arrays for broadband or multiple wavelength detection were implemented and successfully tested. The proposed device structure, derived from a layered p-p heterojunction, was developed to be easily implementable in each wavelength of interest. These results show a prospect of highly sensitive flexible OPT arrays for both experimental research and innovative optoelectronic systems.
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•Organic phototransistor for detection of weak light intensities of few nW/cm2•Full characterization and analysis of the optical response of the developed OPTs•Photodetector with high electrical stability and excellent reliability•OPTs with layered p-p heterojunction for broad/multiple wavelength detection arrays•Highly sensitive bendable photodetector array for innovative optoelectronics
A general purpose FPGA based DAQ module has been developed based on a Virtex-4 FPGA. It is able to acquire up to 1024 different channels distributed over 10 slave cards. The module has an optical ...interface a RS-232 a USB and a Gigabit Interface. The KLOE-2 experiment is going to use it to collect data from the Inner tracker and the QCALT. An embedded processor (power pc 604) is present on the FPGA and a telnet server has been developed and installed. A new general purpose data taking system has been based on this module to acquire the Inner Tracker. The system is at the moment working at LNF (Laboratori Nazionali di Frascati).
We present a global time fit to determine the reference time event-by-event in an array of drift cells. The method is applied to the monitored drift tube tracking chambers (MDT) of the muon ...spectrometer of the ATLAS experiment at the large hadron collider (LHC). During operation with proton-proton collisions, the muon trigger is based on dedicated fast detectors and the readout is clocked at the beam crossing frequency of 40 MHz. A method has been developed for tracking particles through the MDT chambers which works without a precisely timed external trigger. This study was conceived to exploit the MDT tracking capabilities in non standard operation of the ATLAS detector, e.g., during commissioning with cosmic rays when there is no time correlation with the LHC clock frequency. Results obtained using an asynchronous trigger, with a high energy muon beam from the CERN SPS, and with cosmic rays are reported.
Detectors for absolute luminosity measurement at DAFNE Valente, P.; Boscolo, M.; Bossi, F. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Since the second half of year 2007, the Frascati
Φ
- factory DAFNE has been running with an upgraded interaction region in order to test the crabbed waist collision scheme. The aim is to reach a ...large improvement of the specific luminosity of the accelerator. We describe the various detectors realized to have a reliable and fast absolute luminosity measurement, the on-line analysis in order to get rid of the machine background contribution, and the performances of the system.
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAΦNE. This boson, called U, has been searched for in the decay ϕ→ηU, U→e+e−, analyzing the decay ...η→π0π0π0 in a data sample of 1.7 fb−1. No structures are observed in the e+e− invariant mass distribution over the background. This search is combined with a previous result obtained from the decay η→π+π−π0, increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of α′/α<1.7×10−5 for 30<MU<400 MeV and α′/α⩽8×10−6 for the sub-region 50<MU<210 MeV. This result assumes the Vector Meson Dominance expectations for the ϕηγ⁎ transition form factor. The dependence of this limit on the transition form factor has also been studied.
We describe the realization and performance of a prototype high granularity calorimeter built with lead and scintillating fibers. We describe the calorimeter construction and show cosmic ray and ...electron test beam results obtained with a custom-designed trigger.
The trigger system of the ARGO-YBJ experiment Aloisio, A.; Branchini, P.; Catalanotti, S. ...
IEEE transactions on nuclear science,
2004-Aug., 2004-08-00, 20040801, Letnik:
51, Številka:
4
Journal Article
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Astrophysical radiation with ground-based observatory at YangBaJing (ARGO-YBJ) is a ground-based cosmic ray detector presently under construction at the Yangbajing High Altitude Cosmic Ray Laboratory ...(4300 m a.s.l.), Lhasa, Tibet. The apparatus has been designed to detect air showers with an energy threshold of a few hundred GeV and it has a total active area of 6400 m/sup 2/. The full-coverage central carpet of 5772 m/sup 2/ is equipped with an array of resistive plate counters. This array is surrounded by a partially instrumented guard ring to improve the reconstruction of showers with the core falling outside the carpet. The ARGO trigger logic implements simple yet robust algorithms, based on the timing distribution of the hits and their multiplicity on the central carpet. In this paper, we describe the hardware architecture and the main features of the trigger system.
The neutron detection efficiency of a sampling calorimeter made of 1
mm diameter scintillating fibers embedded in a lead/bismuth structure has been measured at the neutron beam of The Svedberg ...Laboratory at Uppsala. A significant enhancement of the detection efficiency with respect to a bulk organic scintillator detector with the same thickness is observed.
A
bstract
The quantum interference between the decays of entangled neutral kaons is studied in the process
ϕ
→ K
S
K
L
→
π
+
π
−
π
+
π
−
, which exhibits the characteristic Einstein-Podolsky-Rosen ...correlations that prevent both kaons to decay into
π
+
π
−
at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and
CPT
violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, and corresponds to an integrated luminosity of about 1.7 fb
−
1
, i.e. to about 1
.
7 × 10
9
ϕ
→ K
S
K
L
decays produced. From the fit of the observed ∆
t
distribution, being ∆
t
the difference of the kaon decay times, the decoherence and
CPT
violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and
CPT
symmetry, while for some parameters the precision reaches the interesting level at which — in the most optimistic scenarios — quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
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