Search results for " Detectors"
showing 10 items of 2027 documents
High Energy Nuclear Collisions
1999
Highlights of the results from ultrarelativistic heavy ion collisions at CERN-SPS are reviewed. In particular, I discuss how the experimental results indicate that a collective strongly interacting system has been produced, and what are the implications towards the Quark Gluon Plasma. The physical ideas behind measuring certain observables are introduced. The future program of high energy nuclear collisions at BNL-RHIC and CERN-LHC/ALICE is also briefly discussed.
Searching for Axion Dark Matter in Atoms: ~Oscillating Electric Dipole Moments and Spin-Precession Effects
2015
Roberts, Benjamin M. "Searching for Axion Dark Matter in Atoms: ~Oscillating Electric Dipole Moments and Spin-Precession Effects" in Proceedings, 11th Patras Workshop on Axions, WIMPs and WISPs (Axion-WIMP 2015) / Irastorza, Igor G., Redondo, Javier, Carmona, José Manuel, Cebrian, Susana, Dafni, Theopisti, Iguaz, Francisco J., Luzon, Gloria (eds.), Verlag Deutsches Elektronen-Synchrotron : 2015 ; AXION-WIMP 2015 : 11th Patras Workshop on Axions, WIMPs and WISPs, 2015-06-22 - 2015-06-26, Zaragoza 11th Patras Workshop on Axions, WIMPs and WISPs, AXION-WIMP 2015, Zaragoza, Spain, 22 Jun 2015 - 26 Jun 2015 ; DESY-PROC 120-123(2015). doi:10.3204/DESY-PROC-2015-02/roberts_benjamin_axions
Real-time measurements of solar $pp$ neutrinos using $^{131}$Xe
2020
Various large-scale experiments for double beta decay or dark matter are based on xenon. Current experiments are on the tonne scale but there are also ideas to aim for even larger sizes in the future. Here we study the potential of the isotope $^{131}$Xe to allow to make real-time measurements of solar $pp$ neutrinos, besides classical neutrino-electron scattering. Improved nuclear models are used to determine the cross-section of neutrinos on $^{131}$Xe. The present calculations deviate significantly from the previous ones due to updated estimates for the excited-state contributions. The updated capture-rate estimate for $pp$ neutrinos is $(4.47\pm 0.09)\ \rm SNU$ and for all solar neutrin…
Measurement of the $^{229}$Th isomer energy with a magnetic micro-calorimeter
2020
We present a measurement of the low-energy (0--60$\,$keV) $\gamma$ ray spectrum produced in the $\alpha$-decay of $^{233}$U using a dedicated cryogenic magnetic micro-calorimeter. The energy resolution of $\sim$$10\,$eV, together with exceptional gain linearity, allow us to measure the energy of the low-lying isomeric state in $^{229}$Th using four complementary evaluation schemes. The most accurate scheme determines the $^{229}$Th isomer energy to be $8.10(17)\,$eV, corresponding to 153.1(37)$\,$nm, superseding in precision previous values based on $\gamma$ spectroscopy, and agreeing with a recent measurement based on internal conversion electrons. We also measure branching ratios of the r…
First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment
2018
We present first results on the scalar coupling of weakly interacting massive particles (WIMPs) to pions from 1 t yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most nonrelativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, …
Position sensitive plastic scintillator for beta particle detection
2022
A new segmented plastic scintillator detector Tuike has been developed for recoil-beta tagging experiments at the Accelerator Laboratory of the University of Jyväskylä. The detector consists of individual plastic scintillator bars arranged in two orthogonal layers, and the scintillation light is detected using silicon photomultipliers. Performance of the new detector was tested using fusion-evaporation reaction 40Ca(36Ar, pn)74Rb, and the results are discussed here. It was found that for beta particles seen in the main silicon detector, Tuike can tag high-energy beta particles with a 48(10)% efficiency. An energy calibration method using Compton edges of gamma ray transitions is described i…
Radiation Tolerance Tests of Small-Sized CsI(Tl) Scintillators Coupled to Photodiodes
2009
Radiation tolerance of small-sized CsI (Tl) crystals coupled to silicon photodiodes was studied by using protons. Irradiations up to the fluence of 1012 protons/cm2 were used. Degradation of light output by less than 5% was achieved.
Large-angle production of charged pions with incident pion beams on nuclear targets
2009
Measurements of the double-differential pi(+/-) production cross section in the range of momentum 100 <= p <= 800 MeV/c and angle 0.35 <=theta <= 2.15 rad using pi(+/-) beams incident on beryllium, aluminum, carbon, copper, tin, tantalum, and lead targets are presented. The data were taken with the large-acceptance hadron production (HARP) detector in the T9 beam line of the CERN Proton Synchrotron. The secondary pions were produced by beams in a momentum range from 3 to 12.9GeV/c hitting a solid target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber place…
First Muon-Neutrino Disappearance Study with an Off-Axis Beam
2012
We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 × 10(20) protons on target, we observe 31 fully-contained single μ-like ring events in Super-Kamiokande, compared with an expectation of 104 ± 14(syst) events without neutrino oscillations. The best-fit point for two-flavor νμ → ντ oscillations is sin 2(2θ(23)) = 0.98 and |Δm(2)(32)| = 2.65 × 10(−3) eV2. The boundary of the 90% confidence region includes the points (sin2 (2θ(23)), |Δm(2)(32)|) = (1.0, 3.1 × 10(−3) eV2), (0.84, …
Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source @ LISOL
2012
The Leuven Isotope Separator On-Line (LISOL) facility at the Cyclotron Research Center (CRC) Louvain-la-Neuve; The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63Cu. A final run under on-line conditions in which the ra…