Search results for "Instrumentation"
showing 10 items of 4914 documents
An integrated calibration system for liquid argon calorimetry
1999
Abstract A novel technical solution for an integrated version of the pulse generator of a calibration system for liquid argon calorimeters is presented. It consists of a differential amplifier with automatic offset compensation, a current mirror and a switching logic. These components are integrated on an ASIC chip in CMOS technology. The technical realisation as well as results on the performance are presented.
Optimizing the operating temperature of a transition edge sensor
2006
We discuss the theory for optimizing the operating temperature of a voltage biased superconducting transition edge sensor (TES) in terms of energy resolution and speed, considering only internal detector noise sources. The noise processes included in the modeling are the unavoidable Johnson and phonon noise. The phonon noise is calculated for the case of ballistic transport. If other external and excess internal noise sources are not dominant, an optimal operating temperature can be found to minimize the energy resolution. The detector slows down by approximately a factor of two at the optimal energy resolution point.
Multi-pixel Geiger-mode avalanche photodiode and wavelength shifting fibre readout of plastic scintillator counters of the EMMA underground experiment
2009
The results of a development of a scintillator counter with wavelength shifting (WLS) fibre and a multi-pixel Geiger-mode avalanche photodiode readout are presented. The photodiode has a metal-resistor-semiconductor layered structure and operates in the limited Geiger mode. The scintillator counter has been developed for the EMMA underground cosmic ray experiment.
A compact 4He cryotarget
1998
Abstract A thin walled cell of 8 cm length and 3 cm diameter has been constructed for liquid 4 He to be used as a target in a tagged photon beam. The target and the housing have been optimised to allow for detection of charged particles emitted on both sides of the beam. A reservoir of 3 l liquid He and good thermal insulation permitted refilling cycles of 12 h.
X-ray fluorescence analysis of yellow pigments in altarpieces by Valencian artists of the XV and XVI centuries
1999
Abstract XRF analysis has allowed a quick and precise detection and identification of the inorganic elements that compose the yellow pigments in altarpieces of the XV and XVI centuries painted by the Valencian artists Miguel Alcaniz, Vicente Macip, Juan de Juanes, Hernando Yanez de la Almedina and Hernando Llanos. The analyses have been carried out with an XRF portable system that consists of a tube of X-rays and detectors of Si(Li) and cadmium zinc telluride. This system has enabled a non-aggressive and non-destructive analysis of many pieces at the Museo de Bellas Artes of Valencia (Spain). Among the yellow pigments we have identified a pigment composed by lead and tin oxides named lead–t…
Experimental review of e + e − →ππh c
2016
We review the recent BESIII measurement of e+e− → ππhc in which its line shape is studied between the center-of-mass energies of 3.9 to 4.42 GeV and an iso-vector charmonium-like state Zc(4020) is observed in the invariant mass of πhc at the BESIII experiment. The charged Zc(4020)± is the second observed Zc state following Zc(3900), while the Zc(4020)0 is the first observed neutral Zc state. The line shape of σ(e+e− → ππhc) is also re-analyzed in view of searching for the Y state and the existence of the Y(4220) state is confirmed and compared with the previous work of the BESIII experiment.
Track finding efficiency in BABAR
2013
Abstract We describe several studies to measure the charged track reconstruction efficiency and asymmetry of the B A B AR detector. The first two studies measure the tracking efficiency of a charged particle using τ and initial state radiation decays. The third uses the τ decays to study the asymmetry in tracking, the fourth measures the tracking efficiency for low momentum tracks, and the last measures the reconstruction efficiency of K S 0 particles. The first section also examines the stability of the measurements vs. B A B AR running periods.
Search for excited neutrinos in Z decay
1990
Excited neutrinos decaying into a neutrino and a photon are searched for in the ALEPH detector at LEP. No evidence is found for Z decay into vv∗ or v∗v∗ final states. Upper limits are derived on excited neutrino couplings up to excited neutrino masses close to the Z mass. Lower limits on the v∗ mass, independent of the v∗ decay modes, are deduced from the total Z width.
$\Lambda_b^0$-baryon production in pp collisions in the general-mass variable-flavour-number scheme and comparison with CMS and LHCb data
2018
We calculate the next-to-leading-order cross section for the inclusive production of $\Lambda_b$ baryons in pp collisions in the general-mass variable-flavor-number scheme. We use realistic evolved non-perturbative fragmentation functions obtained from fits to B-meson production in $e^+ e^-$ annihilation and compare our results for transverse-momentum and rapidity distributions with recent experimental data from the CMS and the LHCb collaborations at the CERN LHC. We find satisfactory agreement in general, with some indication for the need to modify the available fragmentation functions at larger values of the scale variable.
Measurements of cross section of e+e−→pp¯π0 at center-of-mass energies between 4.008 and 4.600 GeV
2017
Based on e(+)e(-) annihilation data samples collected with the BESIII detector at the BEPCII collider at 13 center-of-mass energies from 4.008 to 4.600 GeV, measurements of the Born cross section o ...