Session S14: Missions and Instruments II (Cosmic Rays and Neutrinos)

Final Preparation of the CALorimetric Electron Telescope (CALET) for Launch to the International Space Station

CALET has been delivered to the JAXA Tsukuba Space Center and is undergoing final preflight testing for launch to the ISS on HTV5 for installation on the Japanese Experiment Module - Exposed Facility (JEM-EF) with a target date in 2015. This Japanese-Italian-US astroparticle observatory consists of a main calorimeter (CAL) and a Gamma-ray Burst Monitor (CGBM) subsystem. The CAL is comprised from top to bottom of a charge detector (CHD) with two crossed layers of scintillator paddles, an imaging calorimeter (IMC) with planes of scintillating fibers interleaved with a total of 3 radiation lengths ($X_{0}$) of tungsten, and a 27 $X_{0}$ deep total absorption calorimeter (TASC) made of lead tungstate logs, which has the excellent energy resolution and imaging capabilities to resolve electrons, hadrons and photons. In a planned 5 year mission CALET will measure the combined cosmic ray electron and positron spectrum to 20 TeV, gamma rays to 10 TeV, nuclei $1 \leq Z \leq 40$ to 1,000 TeV, and gamma-ray bursts between 7 keV and 20 MeV. CALET will look for signs of possible local astrophysical sources of cosmic ray electrons, search for dark matter signatures and probe the environment through which cosmic rays propagate from their source(s) to Earth.   

Proton - Electron discrimination capabilities with CALET

The CALorimetric Electron Telescope (CALET) is a space--borne observatory set to be deployed on the ISS-JEM (aka Kibo) by a Japanese led collaboration with Italy and the United States. The primary objective of the mission is to provide precise measurements of the flux of photons, electrons and nuclei in the cosmic radiation, with energies in excess of several TeV. The instrument consists of the three sub-detectors: The Charge Detector (CHD), Imaging Calorimeter (IMC), and Total Absorption Calorimeter (TASC); totaling 30 $X_0$ and 1.3 $\lambda$ on axis. The imaging capabilities and depth of the apparatus produces precise longitudinal and lateral profiles, as well as the energy loss of the electromagnetic particles, allowing for a discrimination factor of about $10^5$ between electromagnetic and hadronic particles. We demonstrate the separation capabilities of the instrument and present a multivariate technique developed from both Monte Carlo simulations and test beam data \textbf{to aid in the electron/hadron separation while maintaining a very high detection efficiency.}   

On-orbit instrument calibration of CALET

The CALorimetric Electron Telescope (CALET) is a high-energy cosmic ray experiment which will be placed on the International Space Station in 2015. Primary goals of CALET are measurement of cosmic ray electron spectra from 1 GeV to 20 TeV, gamma rays from 10 GeV to 10 TeV, and protons and nuclei from 10 GeV up to 1000 TeV. The detector consists of three main components: a Charge Detector (CHD), Imaging Calorimeter (IMC), and Total Absorption Calorimeter (TASC). As CALET is going to work in the ISS orbit space environment, it needs to be calibrated while it is in orbit. Penetrating non-showering protons and helium nuclei are prime candidates for instrument calibration, as they provide a known energy signal for calibrating the detector response. In the present paper, we discuss estimation of CALET's detector efficiency to protons and helium nuclei. Included is a discussion of different galactic cosmic ray and trapped proton models used for flux calculation and simulations performed for detector geometric area and trigger rate calculation. This paper also discusses the importance of the albedo proton flux for the CALET detector calibration.   

The Heavy Nuclei eXplorer (HNX) Small Explorer Mission

The Heavy Nuclei eXplorer (HNX) will investigate the nature of the reservoirs of nuclei at the cosmic-ray sources, the mechanisms by which nuclei are removed from the reservoirs and injected into the cosmic accelerators, and the acceleration mechanism. HNX will use two large high-precision instruments, the Extremely-heavy Cosmic-ray Composition Observer (ECCO) and the Cosmic-ray Trans-Iron Galactic Element Recorder (CosmicTIGER), flying in the SpaceX DragonLab, to measure, for the first time, the abundance of every individual element in the periodic table from carbon through the actinides, providing the first measurement of many of these elements. HNX will measure several thousand ultra-heavy galactic cosmic ray (UHGCR) nuclei Z$\ge $30, including about 50 actinides, and will: determine whether GCRs are accelerated from new or old material, and find their age; measure the mix of nucleosynthesis processes responsible for the UHGCRs; determine how UHGCR elements are selected for acceleration, and measure the mean integrated pathlength traversed by UHGCRs before observation. The scientific motivation and instrument complement of HNX will be discussed.   

From CREAM to ISS-CREAM: A Next Step in the Direct Measurement of Cosmic Rays

The balloon-borne Cosmic Ray Energetics and Mass (CREAM) Experiment has carried out six successful ?ights around the continent of Antarctica for a total exposure of over 160 days. The CREAM Data Acquisition (CDAQ) software system, utilized on all six balloon missions, is a crucial component of the CREAM instrument that facilitates data-taking, monitoring, commanding and calibration of the entire apparatus. Currently, a CREAM payload is being developed for integration on the International Space Station (ISS) in the spring of 2015. The shift from a balloon-borne experiment to a space mission required numerous hardware modifications and introduces a new command and data handling environment. New operational considerations are also needed to accommodate a multi-year mission. These hardware, environmental and operational modifications must be accommodated in CDAQ. The nature of these modifications and how they are reflected in the CDAQ software are discussed here.   

The Askaryan Radio Array (ARA): status and initial results

Ultra-high energy (UHE) cosmogenic neutrinos are expected through photohadronic interactions of UHE cosmic rays with CMB photons. The Askaryan Radio Array (ARA) is a neutrino observatory located near the South Pole aimed at detecting these neutrinos via their interactions with Antarctic ice and subsequent electromagnetic emission in radio frequencies. At the end of 2014, 3 ARA stations have been deployed. When completed, ARA is projected to consist of 37 in-ice stations and cover up to 200km$^{\mathrm{2}}$ while providing high sensitivity from 10PeV to 10EeV. We report here the current status of operation and preliminary results of initial data analysis.   

The JEM-EUSO mission

The mission of Extreme Universe Space Observatory (EUSO) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) will be to study the origin of extreme energy cosmic rays (EECRs) above 100 EeV. JEM-EUSO will measure the energy spectrum and arrival directions of EECRs over the full sky with a single instrument designed to achieve an exposure an order of magnitude above ground-based detectors. A wide-field (60 degrees) telescope with 2.5 m diameter entrance aperture will look down on the earth from the space and record data during night segments of the ISS orbit. It will detect near UV photons emitted by the extensive air showers created by EECRs that impact the earth's atmosphere. The arrival direction map of these air showers will allow the identification of the nearest EECR sources with known astronomical objects and the understanding of the acceleration and propagation mechanisms. If their fluxes are sufficiently large, neutrinos and gamma rays may also be observed.   

EUSO angular resolution based on Pierre Auger Observatory reconstruction methodology

Ultra high energy cosmic rays (UHECRs) are astro-particles with energies above $10^{18}$ eV and are a readily detected phenomena. Their origin is yet undetermined due to the exceedingly low flux, 1 particle per km$^2$ per century at $10^{20}$ eV. The proposed Extreme Universe Space Observatory (EUSO) utilizes the bottom $20$ km of the atmosphere as a detection volume resulting in a detection area of nearly $150,000$ km$^2$ in nadir mode. We have developed an UHECR angular reconstruction algorithm based on the methodology developed at the Pierre Auger Observatory. This algorithm shows improved angular resolution over previous EUSO methods and has been applied to simulated showers over the expected energy and zenith angle ranges.   

The Non-Imaging CHErenkov (NICHE) Array: A TA/TALE extension to measure the flux and composition evolution of Very-High Energy Cosmic Rays

Co-sited with TA/TALE, the Non-Imaging CHErenkov (NICHE) Array will measure the flux and nuclear composition of cosmic rays from below 10$^{15}$ eV to over 10$^{18}$ eV in its eventual full deployment. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. Prototype detectors are under construction and will form an initial prototype array (jNICHE) that will be deployed in 2015, co-measuring air showers with TA/TALE. This development forms the foundation for the full NICHE array that is designed to have sufficient area and angular acceptance to have significant overlap with the TA/TALE measurements, which provides energy cross-calibration. Simulated NICHE performance has shown that the array has the ability to distinguish between several different composition models as well as measure the end of Galactic cosmic ray spectrum. In this talk, the NICHE design, array performance, prototype development, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.