The DAMPE silicon–tungsten tracker

Abstract

The DArk Matter Particle Explorer (DAMPE) satellite has been successfully launched on the 17th December 2015. It is a powerful space detector designed for the identification of possible Dark Matter signatures thanks to its capability to detect electrons and photons with an unprecedented energy resolution in an energy range going from few GeV up to 10 TeV. Moreover, the DAMPE satellite will contribute to a better understanding of the propagation mechanisms of high energy cosmic rays measuring the nuclei flux up to 100 TeV. DAMPE is composed of four sub-detectors: a plastic strip scintillator, a silicon-tungsten tracker-converter (STK), a BGO imaging calorimeter and a neutron detector. The STK is made of twelve layers of single-sided AC-coupled silicon micro-strip detectors for a total silicon area of about 7 m 2 . To promote the conversion of incident photons into electron-positron pairs, tungsten foils are inserted into the supporting structure. In this document, a detailed description of the STK construction and its performance on orbit are reported.

Solution of Heliospheric Propagation: Unveiling the Local Interstellar Spectra of Cosmic-ray Species

“…Launched in 1977 at the dawn of the space era, Voyager 1, 2 spacecrafts (Stone et al 1977) demonstrate unbelievable scientific longevity providing unique data on the elemental spectra and composition at the interstellar reaches of the Solar system, currently at 138 AU and 114 AU from the Sun, correspondingly. Other highexpectations missions are recently launched (like the CALorimetric Electron Telescope -CALET, Adriani et al 2015 -and the Dark Matter Particle Explorer -DAMPE, Azzarello et al 2016) or are awaiting for launch (Cosmic-Ray Energetics and Mass investigation -ISS-CREAM, Seo et al 2014).…”

The DAMPE experiment: first data from space

“…Also a beam of argon fragments was used for testing the detector response to nuclei. Details of the test-beam results as well as the features of the qualification module can be found in [1][2][3][4][5][6]. Furthermore many tests (namely energy response to MIPs, efficiencies, detector alignment, etc.)…”

“…The STK analog readout can also provide an independent measurement of the incident particle charge, at least up to medium mass nuclei. It is a compact system where readout and power supply electronics are mounted on the sides [2,5].…”

The DAMPE silicon tungsten tracker

“…The main objectives of STK [2,3,4] are: the reconstruction of the trajectories of charged particles, the absolute ion charge identification and the photon conversion in electron-positron pairs. The tracker profits of the well established silicon micro-strip detector technology already used in space experiments such as PAMELA [5], AGILE [6], Fermi [7] and AMS-02 [8].…”

“…The sensors have the same geometry as the ones used by AGILE [10], but with different thickness, bulk resistivity and backplane metallisation. The detector size is of 95 × 95 × 0.32 mm 3 and each sensor is segmented in 768 strips. The strips are 48 µm wide and 93.196 mm long with a pitch of 121 µm.…”