CREAM for high energy composition measurements

Ground-based indirect measurements have shown that the cosmic-ray all- particle spectrum extends many orders of magnitude beyond the energy thought possible for supernova acceleration. Our balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment is capable of extending direct measurements of cosmic-rays to the supernova energy scale of 1015 eV in a series of Ultra Long Duration Balloon (ULDB) flights. Identification of Z = 1 - 26 particles will be made with a timing-based charge detector and a pixelated silicon charge detector. Energy measurements will be made with a transition radiation detector and a tungsten/scintillating fiber calorimeter. The instrument has been tested with various particles in accelerated beams at the CERN SPS. The first flight is planned to be launched from Antarctica in December 2004

Preliminary measurements of carbon and oxygen energy spectra from the second flight of CREAM

The Cosmic Ray Energetics and Mass (CREAM) experiment was successfully flown twice on long-duration balloons from McMurdo, Antarctica, in 2004/05 and 2005/06. During the second flight, the redundant charge identification system of the instrument (based on scintillators and silicon detectors) was upgraded with the addition of a second layer of pixelated silicon sensors. A measurement of the particle energy was provided by an ionization calorimeter. From the on-going analysis of the data of the second flight, preliminary results on Carbon and Oxygen spectra up to a few TeV/n will be presented

Relative abundance of heavy ions measured by the CREAM Silicon Charge Detector

The Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed for direct measurement of high energy cosmic rays with energy up to 10^15 eV. CREAM incorporates a sampling tungsten/scintillating-fiber calorimeter for energy measurements and a dual-layer Silicon Charge Detector (SCD) and Timing-based Charge Detector (TCD) to measure the charge of incident particles. CREAM has had two successful flights in 2004/5 and 2005/6, with a combined duration of 70 days of data. Preliminary results on the relative abundances of heavy ions measured by the SCD will be presented

Elemental Spectra from the CREAM-I flight

The Cosmic Ray Energetics And Mass (CREAM) instrument 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 McMurdo Station, Antarctica, in December 2004 (CREAM-I) 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, spectra of various elements measured with SCD/CAL during the first 42-day flight are presented, along with spectral shapes and relative abundances

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

H and He spectra from the 2004/05 CREAM-I flight

The balloon-borne Cosmic Ray Energetics And Mass (CREAM) payload flew for a record-breaking 42 days during the 2004/05 Antarctic season. The instrument incorporates a tungsten/scintillating-fiber sampling calorimeter and graphite targets to measure energies of nuclei. A finely segmented Silicon Charge detector (SCD) located above the targets is used for charge measurements. The position of the primary particle in the SCD is determined by backward extrapolation of the reconstructed shower axis in the calorimeter. The flight data have been analyzed using the latest calibration of the calorimeter. The energy spectra of proton, helium and their ratios will be presented in this paper

GEANT4-Based Model of the CREAM Timing Charge Scintillation Detector

The CREAM instrument is a balloon-borne detector designed to measure the cosmic-ray spectrum in the 1-1000TeV energy range, with good charge resolution from protons to iron (Z = 1 to 26). The CREAM instrument has had two successful flights, both from McMurdo Station, Antarctica. CREAM-I was flown in the 2004-2005 Antarctic summer campaign and CREAM-II in 2005-2006, with a combined flight duration of approximately 70 days. The CREAM-I instrument consisted of a fast scintillation-based Timing Charge Detector (TCD), a Transition Radiation Detector and a sampling calorimeter. Here we describe a GEANT4-based model for a CREAM TCD scintillation counter, used in characterizing the charge and timing response of the counters to various incident particles. The model incorporates all counter components, including the scintillator, light guides and an approximation of the PMT readout. We compare the simulated output results to actual event signals

Elemental energy spectra of cosmic rays measured by CREAM-II

We present new measurements of the energy spectra of cosmic-ray (CR) nuclei from the second flight of the balloon-borne experiment CREAM (Cosmic Ray Energetics And Mass). The instrument (CREAM-II) was comprised of detectors based on different techniques (Cherenkov light, specific ionization in scintillators and silicon sensors) to provide a redundant charge identification and a thin ionization calorimeter capable of measuring the energy of cosmic rays up to several hundreds of TeV. The data analysis is described and the individual energy spectra of C, O, Ne, Mg, Si and Fe are reported up to 1014 eV. The spectral shape looks nearly the same for all the primary elements and can be expressed as a power law in energy E−2.66±0.04. The nitrogen absolute intensity in the energy range 100-800 GeV/n is also measured