Simulations for the PAMELA space experiment

The Payload for Antimatter Matter Exploration and Light Nuclei Astrophysics (PAMELA) apparatus is in orbit since June 2006 on the Russian satellite Resurs-DK1. One of the main scientific goals of the experiment is the precise measurement of the positrons energy spectra. Robust particle identification and an accurate background extimation are required. To achieve this goal a new simulation program, which describes the entire PAMELA apparatus, based on GEANT4 was optimized and tested. This simulation is used in a multivariate analysis to extract the positron signal from a vast background of cosmic-ray protons

24 mJ Cr+4:forsterite four-stage master-oscillator power-amplifier laser system for high resolution mid-infrared spectroscopy

We present the design of a Cr:forsterite based single-frequency master-oscillator power-amplifier laser system delivering much higher output energy compared to previous literature reports. The system has four amplifying stages with two-pass configuration each, thus enabling the generation of 24 mJ output energy in the spectral region around 1262 nm. It is demonstrated that the presented Cr:forsterite amplifier preserves high spectral and pulse quality, allowing a straightforward energy scaling. This laser system is a promising tool for tunable nonlinear down-conversion to the mid-infrared spectral range and will be a key building block in a system for high-resolution muonic hydrogen spectroscopy in the 6.8 \u3bcm rang

Positron fraction, electron and positron spectra measured by AMS-02

A precise measurement by AMS-02 of the electron spectrum up to 700 GeV and of the positron spectrum and positron fraction in primary cosmic rays up 500 GeV are presented. The combined measurement of the cosmic-ray electron and positron energy spectra and fraction provide a unique tool to improve our understanding of the production, acceleration and propagation mechanism of cosmic rays

Messung der Polarisationsobservablen am COSY-TOF Flugzeitspektrometer

In this work the (pol)p p --> p Kaon+ Lambda reaction is studied. Data were taken at the COSY-TOF experiment in 2002 with a polarised proton beam at the momenta of 2.75 GeV/c and 2.95 GeV/c. The calculated beam polarisation was 39.8% and 61.9% respectively. The experimental setup covers the whole phase space of the Lambda reaction. The exclusive measurement allows the extraction of polarisation observables not only in the beam fragmentation region (x_F>0), but also in the target fragmentation region (x_F p Kaon+ Lambda Reaktion untersucht. Die Messung mit polarisiertem Strahl bei 2.75 GeV/c und 2.95 GeV/c Strahlimpuls fand 2002 an COSY-TOF statt. Die ermittelte Strahlpolarisation ist 39.8% bzw. 61.9% für die Strahlimpulse von 2.75 GeV/c und 2.95 GeV/c. Das Detektorsystem deckt den vollen Phasenraum der Lambda-reaktion ab. Die Exklusivität der Messung ermöglicht die Extraktion von Polarisationsobservablen sowohl im Strahlfragmentationsbereich (x_F>0) als auch im Targetfragmentationsbereich (x_F<0). Bei 2.75 GeV/c Strahlimpuls wurden 11991 p K+ Lambda Ereignisse rekonstruiert, bei 2.95 GeV/c 19243 Ereignisse. Die Lambda-Polarisation, die Lambda-Analysierstärke und die Spintransferobservable wurden extrahiert. Die Lambda-Polarisation hat einen negativen Verlauf. Die Lambda-Analysierstärke und der Spintransfer D_{NN} sind mit Null kompatibel. Das Ergebnis für den Spintransfer steht in Widerspruch zu den einzigen bisher veröffentlichen Ergebnis bei verglieichbaren Strahlimpulsen

Photodiode Read-Out System for the Calorimeter of the Herd Experiment

HERD is a future experiment for the direct detection of high energy cosmic rays. The instrument is based on a calorimeter optimized not only for a good energy resolution but also for a large acceptance. Each crystal composing the calorimeter is equipped with two read-out systems: one based on wavelength-shifting fibers and the other based on two photodiodes with different active areas assembled in a monolithic package. In this paper, we describe the photodiode read-out system, focusing on experimental requirements, design and estimated performances. Finally, we show how these features lead to the flight model project of the photodiode read-out system

Design of an Antimatter Large Acceptance Detector In Orbit (ALADInO)

International audienceA new generation magnetic spectrometer in space will open the opportunity to investigate the frontiers in direct high-energy cosmic ray measurements and to precisely measure the amount of the rare antimatter component in cosmic rays beyond the reach of current missions. We propose the concept for an Antimatter Large Acceptance Detector In Orbit (ALADInO), designed to take over the legacy of direct measurements of cosmic rays in space performed by PAMELA and AMS-02. ALADInO features technological solutions conceived to overcome the current limitations of magnetic spectrometers in space with a layout that provides an acceptance larger than 10 m2 sr. A superconducting magnet coupled to precision tracking and time-of-flight systems can provide the required matter–antimatter separation capabilities and rigidity measurement resolution with a Maximum Detectable Rigidity better than 20 TV. The inner 3D-imaging deep calorimeter, designed to maximize the isotropic acceptance of particles, allows for the measurement of cosmic rays up to PeV energies with accurate energy resolution to precisely measure features in the cosmic ray spectra. The operations of ALADInO in the Sun–Earth L2 Lagrangian point for at least 5 years would enable unique revolutionary observations with groundbreaking discovery potentials in the field of astroparticle physics by precision measurements of electrons, positrons, and antiprotons up to 10 TeV and of nuclear cosmic rays up to PeV energies, and by the possible unambiguous detection and measurement of low-energy antideuteron and antihelium components in cosmic rays