16 research outputs found
Customer emotions in service failure and recovery encounters
Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employeeâcustomer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences
Cosmic-Ray Positrons: Are There Primary Sources?
The HEAT instrument has detected cosmic-ray electrons and positrons in two balloon flights, at energies between 1 and ž50 GeV. The combined data set indicates that the positron fraction does not increase with energy above ž10 GeV. However, our results suggest a slight overabundance of positrons at all energies compared with published predictions from secondary production sources, and possibly the hint of a feature in the positron fraction in the energy range 7--20 GeV. We discuss the implications of the observations on the origin and propagation of electrons and positrons, and investigate the possibility that some positrons are from primary, possibly exotic sources. INTRODUCTION The question of the origin and propagation of cosmic-ray electrons and positrons has been an interesting issue in cosmic-ray research for well over 30 years. The all-electron (e + +e \Gamma ) cosmicray flux, amounting to 1-2% of all cosmic rays, is dominated by negative electrons, produced presumably at pri..
The Cosmic Positron Fraction: Implications of a New Measurement
The first balloon flight of the HEAT instrument in 1994 yielded results on the cosmic ray positron fraction with good statistical and systematic accuracy over the range 4.5-50 GeV. These results do not confirm the distinct increase in the positron fraction above 10 GeV that was reported in several other experiments. This seems to rule out a number of models that were proposed to explain the apparent positron excess. In the context of the leaky box model, we conclude from our data that at most 2-3% of the total electron flux (e + + e \Gamma ) arriving near Earth could consist of positrons from primary sources. 1 Introduction Electrons and positrons are distinguished from the nuclear cosmic rays by their low mass and the absence of hadronic interactions. Therefore, at high energies their propagation through the galaxy becomes dominated by radiative energy losses. Different mechanisms may also contribute to the sources of these particles, but are difficult to identify on the basis o..
Monte Carlo Calculations of Atmospheric Electrons Compared with Data from HEAT
The GEANT/FLUKA detector simulation and particle interaction package was used to develop a Monte Carlo program to estimate atmospheric secondary flux produced by primary cosmic rays, as a function of depth in the atmosphere. Of special interest is the calculation of secondary electrons and positrons near the top of the atmosphere. The HEAT instrument measured primary and secondary electrons ranging in energy from 500 MeV to 50 GeV during a high altitude balloon flight during May, 1994 from Ft. Sumner, New Mexico. It is assumed that electrons with rigidities below geomagnetic cutoff consist of both secondary and reentrant albedo electrons. The MC calculations are compared to the flux of secondary electrons as measured by the HEAT instrument. 1 Introduction Despite better measurements of primary cosmic ray spectra and interaction cross sections during the last 30 years, calculations of atmospheric secondaries still differ by as much as a factor of two. In order to correct for atmospheri..
The Cosmic Ray Energetics And Mass (CREAM) timing charge detector
The useofdetectorsbasedonplasticscintillatorwithphotomultipliertubes(PMTs)iscommonin
cosmic-rayexperimentstodifferentiateparticlecharges.However,inthepresenceofacalorimeter,the
standardmethodofpulsechargeintegrationoveratimelongerthanaPMTpulseishamperedby
abundantalbedoparticles.TheCosmicRayEnergeticsandMass(CREAM)instrumentsurmountsthis
problem bymeasuringthepeakvoltageofthePMTpulsewithin 3 nsofathresholdcrossinginthe
readout ofatimingchargedetector(TCD).ThedesignandperformanceoftheTCDispresented.
A chargeresolutionof 0.2e for oxygenand0:4e for ironisobtainedforthrough-goingcosmic-ray
particles
Elemental Spectra from the CREAM-I Flight
The Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to measure the composition and energy spectra of cosmic rays of charge Z = 1 to 26 up to an energy of ~ 10^15 eV. CREAM had two successful flights on long-duration balloons (LDB) launched from Mc- Murdo Station, Antarctica, in December 2004 and December 2005. CREAM-I achieves a substantial measurement redundancy by employing multiple detector systems, namely a Timing Charge Detector and a Silicon Charge Detector (SCD) for particle identification, and a Transition Radiation Detector and a sampling tungsten/scintillating-fiber ionization calorimeter (CAL) for energy measurement. In this paper, preliminary energy spectra of various elements measured with CAL/SCD during the first 42-day flight are presented.The Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to measure the composition and energy spectra of cosmic rays of charge Z = 1 to 26 up to an energy of ~ 10^15 eV. CREAM had two successful flights on long-duration balloons (LDB) launched from Mc- Murdo Station, Antarctica, in December 2004 and December 2005. CREAM-I achieves a substantial measurement redundancy by employing multiple detector systems, namely a Timing Charge Detector and a Silicon Charge Detector (SCD) for particle identification, and a Transition Radiation Detector and a sampling tungsten/scintillating-fiber ionization calorimeter (CAL) for energy measurement. In this paper, preliminary energy spectra of various elements measured with CAL/SCD during the first 42-day flight are presented.The use of detectors based on plastic scintillator with photomultiplier tubes (PMTs) is common in cosmic-ray experiments to differentiate particle charges. However, in the presence of a calorimeter, the standard method of pulse charge integration over a time longer than a PMT pulse is hampered by abundant albedo particles. The Cosmic Ray Energetics and Mass (CREAM) instrument surmounts this problem by measuring the peak voltage of the PMT pulse within ~3ns of a threshold crossing in the readout of a timing charge detector (TCD). The design and performance of the TCD is presented. A charge resolution of 0.2e for oxygen and 0.4e for iron is obtained for through-going cosmic-ray particles
Measurements of cosmic ray secondary nuclei at high energy with the first flight of the CREAM balloon-borne experiment
We present new measurements of heavy cosmic-ray nuclei at high energies performed during the first flight of the balloon-borne cosmic-ray experiment Cosmic-Ray Energetics and Mass (CREAM). This instrument uses multiple charge detectors and a transition radiation detector to provide the first high accuracy measurements of the relative abundances of elements from boron to oxygen up to energies around 1 TeV/n. The data agree with previous measurements at lower energies and show a relatively steep decline (âŒE^â0.6 to E^â0.5) at high energies. They further show the source abundance of nitrogen relative to oxygen is âŒ10% in the TeV/n region