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Comment: Proceedings for the XXIV Physics in Collisions Conference (PIC04), Boston, USA, June 2004, 3 pages, LaTeX. MONP02
TheBaBar detector has operated over 200 2nd generation Resistive Plate Chambers (RPCs)in the forward end caps ince 2002. Many chambers have increased noise rates and highvoltage currents. These aging symptoms are correlated with the integrated RPC current as expected, but also depend on the rate and direction of the gas flow, indicating that pollutants produced in the gas can accelerate aging of downstream RPC surfaces. HFproduced by decomposition of the Freon 134a component of the BaBar RPC gas inelectric discharges has been proposed as the main pollutant. This paper presents measurements of HFproduction and absorption rates in BaBar RPCs. Since many of the highest rate chambers in the forward end cap were onverted to avalanche mode operation, a comparison of HFproduction in streamer and avalanche mode RPC s is made. Correlations betwe...
$TeO_2$ crystals are used as bolometers in experiments searching for Double Beta Decay without emission of neutrinos. One of the most important issues in this extremely delicate kind of experiments is the characterization of the background. The knowledge of the response to $\alpha$ particles in the energy range where the signal is expected is therefore a must. In this paper we report the results on the response function of a $TeO_2$ bolometer to $\alpha$'s emitted by $^{147}$Sm dissolved in the crystal at the growth phase. A Quenching Factor of ($1.0076\pm 0.0005$) is found, independent of the temperature in the investigated range. The energy resolution on $\alpha$ peaks shows a standard calorimeter energy dependence: $\sigma\; [\rm{keV}] = (0.56 \pm 0.02) \oplus (0.010 \pm 0.002)\sqrt{E[\rm{keV}]} $. Signal pulses show no difference...
Scintillating bolometers of ZnSe are the baseline choice of the LUCIFER experiment, whose aim is to observethe neutrinoless double beta decay of 82Se.The independent read-out of the heat and scintillation signalsallows to identify and reject α particle interactions, the dominant background source for bolometric detectors.In this paper we report the performances of a ZnSe crystal operated within the LUCIFER R&D.We measured the scintillation yield, the energy resolution and the background in the energy region where the signal from 0νDBD decay of 82Se is expectedwith an exposure of 9.4 kg*days.With a newly developed analysis algorithm we improved the rejection of α events,and we estimated the increase in energy resolution obtained by the combination of the heat and light signals.For the first time we measured the light emitted by nuclear ...
Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear $511\ \kilo\electronvolt$ photons produced by positrons annihilation from $\beta^+$ emitters created by the beam. This paper reports rate measurements of the $511\ \kilo\electronvolt$ photons emitted after the interactions of a $80\ \mega\electronvolt / u$ fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a Poly-methyl methacrylate target. The time evolution of the $\beta^+$ rate was parametrized and the dominance of $^{11}C$ emitters over the other species ($^{13}N$, $^{15}O$, $^{14}O$) was observed, measuring the fra...
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