Performance of the BACCUS Transition Radiation Detector

International audienceThe Boron And Carbon Cosmic rays in the Upper Stratosphere (BACCUS) balloon-borne exper-iment flew for 30 days over Antarctica in December 2016. It is the successor of the CREAMballoon program in Antarctica which recorded a total cumulative exposure of 161 days. BAC-CUS is primarily aimed to measure cosmic-ray boron and carbon fluxes at the highest energiesreachable with a balloon or satellite experiment, in order to provide essential information for abetter understanding of cosmic-ray propagation in the Galaxy. The payload is made of multipleparticle physics detectors which measure the charge up to Z=26 and energy of incident particlesfrom a few hundred GeV to a few PeV. The newly designed Transition Radiation Detector (TRD)measures signals that are a function of the charge and Lorentz factor. In April 2016, BACCUSwas taken to CERN in its flight configuration to characterize its detectors’ response to beams ofelectrons and pions. The performance of the TRD using beam test data are reported in this paper

Measurements of the Proton and Helium Spectra from CREAM-V

International audienceThe Cosmic Rays Energy And Mass (CREAM) balloon payload directly measures the composition and elemental spectra of cosmic rays in the upper stratosphere. It is designed to probe the acceleration mechanism and propagation history of cosmic rays at energies from 10$^{12}$ up to 10$^{15}$ eV. Being the fifth flight in a series of seven, CREAM-V took data above Antarctica for 39 days from December 1$^{st}$ 2009 to January 8$^{th}$ 2010. The instrument comprises a tungsten/scintillating fiber calorimeter using graphite as a target for the energy measurement which had been calibrated at CERN (European Organization for Nuclear Research). The charge measurement of the incident particles is performed by means of a Silicon Charge Detector (SCD), a Cherenkov Detector, a Cherenkov Camera (Cher-Cam) and a Timing Charge Detector (TCD). In this paper we present results from the on-going data analysis and compare them to data collected by the previous CREAM_III flight

Measurement of Cosmic-Ray Nuclei with the Third Flight of the CREAM Balloon-Borne Experiment

International audienceThe balloon-borne Cosmic Ray Energetics And Mass experiment had its third flight (CREAM-III) over Antarctica for 29 days from December 17, 2007 to January 19, 2008. CREAM-III was designed to directly measure the elemental spectra of cosmic-ray nuclei from Hydrogen to Iron in the energy range from 10^12 to 10^15 eV. Energy of incident cosmic rays was measured with a calorimeter that consisted of a densified carbon target directly above a stack of 20 alternating layers of tungsten and scintillating fiber ribbons. Multiple charge measurements were independently made with the silicon charge detector (SCD), Cherenkov Camera (CherCam), and a Timing Charge Detector (TCD) in order to identify particles and minimize backscattering effects from the calorimeter. Compared to previous CREAM flights, the electronic noise of CREAM-III was reduced, significantly lowering the energy threshold. Results from on-going analysis of the energy spectra will be presented

Simulation Status of the Top and Bottom Counting Detectors for the ISS-CREAM Experiment

International audienceThe Cosmic-Ray Energetics And Mass (CREAM) instrument for the International Space Station (ISS) is a detector for studying the origin, acceleration and propagation mechanism of high-energy cosmic rays. The ISS-CREAM instrument is scheduled to launch in 2017 to the ISS. The Top and Bottom Counting Detectors (TCD/BCD) are designed for studying electron and gamma-ray physics. The TCD/BCD are composed of a plastic scintillator and an array of photodiodes The active detection areas of the TCD/BCD are 500 $\times$ 500 mm$^2$ and 600 $\times$ 600 mm$^2$, respectively. The TCD/BCD were completed in 2015 and passed the environmental tests for safety in a space environment. After finishing these tests, the TCD/BCD were integrated with the payload. The TCD is located between the carbon target of the ISS-CREAM instrument and the calorimeter, and the BCD is located below the calorimeter. The TCD/BCD can distinguish between electrons and protons by using the different shapes between electromagnetic and hadronic showers in the high-energy region. We study the TCD/BCD performance in various energy ranges by using GEANT3 simulation data. Here, we present the status of the electron and proton separation study with the TCD/BCD simulation

The ISS-CREAM Silicon Charge Detector for identification of the charge of cosmic rays up to Z = 26: Design, fabrication and ground-test performance

International audienceThe Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is a space-borne mission designed for the precision measurement of the energy and elemental composition of cosmic rays. The Silicon Charge Detector (SCD), placed at the top of the ISS-CREAM payload, consists of 4 layers. Each layer has 2688 silicon pixels and associated electronics arranged in such a fashion that its active detection area of 78.2  ×  73.6 cm 2 is free of dead area. The foremost goal of the SCD is to efficiently and precisely measure the charge of cosmic rays passing through it. The 4-layer configuration was chosen to achieve the best precision in measuring the charge of cosmic rays within the constraints on the mass, volume and power allotted to it. The amount of material used for its support structure was minimized as well to reduce the chance of interactions of the cosmic ray within the structure. Given the placement of the SCD, its 4-layer configuration and the minimal amount of material in the cosmic-ray trajectory, the SCD is designed to measure the charge of cosmic rays ranging from protons to iron nuclei with excellent detection efficiency and charge resolution. We present the design and fabrication of the SCD as well as its performance during space environment tests which it underwent successfully. We also present its performance in charge measurement using heavy ions in a beam test at CERN, the European Organization for Nuclear Research

Performance of the ISS-CREAM Calorimeter

International audienceThe Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is scheduled for launch in 2017. It is designed to directly measure and identify theelemental composition of incident Galactic cosmic rays from a few hundred GeV to PeV energies.Such large energy range sensitivity is reached by using an electromagnetic sampling calorimeter(CAL) which measures the energy deposit of particle-induced showers. The CAL is composedof twenty layers of tungsten plates interleaved with scintillating fibers, and glued together usingepoxy-coated fiberglass to comply with space launch requirements. In August 2015, beam testmeasurements were performed at CERN to verify the performance of the CAL using layers ofepoxy-coated fiberglass placed between tungsten plates. The CAL response to electron and pionbeams and its performance are reported and compared with previous beam test configurations

Charge resolution of the ISS-CREAM SCD measured with a heavy-ion beam

International audienceThe Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is scheduled to be launched and installed on the ISS in August 2017, and will carry out a measurement of the energy and composition of energetic cosmic rays in space. The Silicon Charge Detector (SCD) will identify the charge of through-going cosmic rays. It consists of four layers, each with 2688 silicon pixels and associated electronics. The ISS-CREAM payload was delivered to the launch site, Kennedy Space Center, in August 2015 after the successful completion of integration and space environment tests. A heavy-ion beam, required to verify the capability of precision charge measurement of the SCD, became available at the European Organization for Nuclear Research (CERN) in November 2016. A prototype instrument using the same types of silicon pixel sensors and electronics installed in the SCD was placed in a heavy-ion beam composed of secondary ions ranging from helium to zinc. We present the charge resolution for each ion as a function of the number of layers used for charge measurement so that the improvement in charge resolution is clearly demonstrated as the number of layers for charge measurement increases

The boronated scintillator detector of the ISS-CREAM experiment

International audienceThe Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) instrument is a next-generation experiment for the direct detection and study of cosmic-ray nuclei and electrons. With a long exposure in low Earth orbit, the experiment will determine the particle fluxes and spectral details of cosmic-ray nuclei from hydrogen to iron, over an energy range of about 1012 eV to > 1015 eV, and of cosmic-ray electrons over an energy range of about 5 × 1010 eV to > 1013 eV. The instrument was deployed to the ISS in August 2017 on the SpaceX CRS-12 mission. We review the design, implementation and performance of one of the ISS-CREAM detector systems: a boron loaded scintillation detector used in discriminating electron-induced events from the much more abundant cosmic-ray nuclei

Measurement of delayed fluorescence in plastic scintillator from 1 to 10 μ\mus

International audienceThe time dependence of the relative light emission of Eljen Technology EJ-200 polyvinyltoluene-based plastic scintillator was measured between 1 and 10μs after the passage of a particle shower, a singly charged particle (atmospheric muon), and with a UV LED exciting the fluor. This was compared in magnitude to the integrated response for the prompt light (within 500 ns of excitation). A model with a time-dependent yield consisting of three exponentially decaying components (fast, medium, and slow) was developed to fit the data. Note that the exact time structure of early (< 1μs ) light emission was not measured for individual components, only for all three components together This model assumes all three components share the same rise time. The decay time constants of the fast, medium and slow components are, respectively, 7.8 ns, 490 ns, and 2370 ns. The relative total normalized yields for each component are: fast 95.8%, medium 2.2%, and slow 2.0%