The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. The GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ~0.01 deg (E{\gamma} > 100 GeV), the energy resolution ~1% (E{\gamma} > 10 GeV), and the proton rejection factor ~10E6. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for the Dark Matter Searches

The field of astroparticle physics started with the discovery of cosmic rays in 1912 by Victor Hess. Cosmic rays, which initially led to important advances in the field of Particle Physics, provide precious information about the violent phenomena in the Universe producing such high-energy particles and the mechanisms of their propagation in the interstellar medium. In the last years, Cosmic Ray Physics has profited from the rise in space research,and space-based experiments are currently providing direct measurements with unprecedent precision. In this context, recent measurements of the spectra of several cosmic ray species cannot be fully explained within the current paradigm of cosmic ray origin and propagation, and constitute an open window into new phenomena. In particular, AMS-02 has provided the most precise measurement of the positron fraction, and the positron and electron fluxes. These results allowed an accurate description of the rise in the positron fraction and led to a plethora of models proposed to explain the so-called positron excess non consistent with the standard secondary origin of antimatter in cosmic rays. For most cases, the observation requires the inclusion of primary sources, which are typically classified into two scenarios: dark matter or astrophysical origin...

Measurement of the large scale anisotropy in cosmic ray electrons, positrons and protons with the AMS-02 detector on the ISS

Results of 2007 test beam of AMS-02 Electromagnetic Calorimeter

The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a fine grained lead-scintillating fiber sampling calorimeter that allows precise, 3-dimensional imaging of the longitudinal and lateral shower development, providing high electron/hadron discrimination ( ~ 106) in combination with the other AMS-02 detectors and a good energy resolution: ?E/E ? 10%/?(E( GeV)). The ECAL is instrumented with several custom developed electronics subsystems. In addition to the front-end electronics mounted directly on the calorimeter, specific custom boards were developed for supplying high and low voltages and for data acquisition, slow control and trigger. In this article, the ECAL data acquisition, slow control and trigger electronics are described. These boards are composed of two completely independent and separately powered sectors, each capable of carrying out the same functionality. In the case of any fault it is possible to switch from one sector to the other while maintaining full functionality of the ECAL. As for the entire AMS detector, these cards are Space qualified and have been constructed to meet the performance requirements on orbits during 3-5 years of operation.

The Space Qualified Read-Out Electronics for the e.m. Calorimeter (ECAL) of the AMS-02 Experiment

From the observation of the Universe, it has been demonstrated that the mass associated to visible matter represents only few percent of its energetic budget, while the remaining part is composed by dark energy, responsible to the cosmological expansion, and by some hidden matter, the dark matter. The likeliest particles family used to describe this dark matter is called WIMP (Weakly Interacting Massive Particles). That kind of particles could be directly detected by measuring nuclear recoil during an elastic scattering inside a scintillating material. For this, the XENON Collaboration has developed a detector consisting in a time projection chamber (TPC) using xenon dual phase (liquid and gas) detector, and placed underground. The different ionization density of nuclear recoils induced by WIMPs, and electronic recoils induced by b particles or g rays background source, leads to different ratio between both signals, in the liquid and in the gas phase, and is used to discriminate WIMPs from background. A good knowledge of the ionization signal is strongly required for such a detector. In this context, the XENON100 response to single electron charge signals is investigated. They correspond to very tiny signals emitted in the gas phase by one or few electrons extracted in time coincidence. Thanks to this analysis, an innovative method to establish the extraction yield of electrons from the liquid to the gas phase has been drawn, allowing to explore a key information to reject electronic recoils from nuclear
ones.

Study of the single electron charge signals in the XENON100 direct Dark Matter search experiment

The electromagnetic calorimeter (ECAL) of the AMS-02 experiment is a 3-dimensional sampling calorimeter, made of lead and scintillating fibers. The detector allows for a high granularity, with 18 samplings in the longitudinal direction, and 72 sampling in the lateral direction. The ECAL primary goal is to measure the energy of cosmic rays up to few TeV, however, thanks to the fine grained structure, it can also provide the separation of positrons from protons, in the GeV to TeV region. A direct measurement of high energy photons with accurate energy and direction determination can also be provided.

The electromagnetic calorimeter of the AMS-02 experiment

AMS-2 is an astroparticle experiment designed for a very precise measurement of primary cosmic rays spectrum. The experiment will operate on board of the ISS at a 400 km altitude for a period of about 3 years. The main scientific goals of the experiment are the search for antimatter, for dark matter and the study of gamma rays. In AMS the electromagnetic calorimeter plays a key role for its high capability to measure e/sup +/, e/sup -/ and gamma spectra and to suppress the background generated by p and He nuclei. To directly detect photons the calorimeter is requested to provide a stand alone trigger. The proposed trigger, presented in this article, will have the capability to detect photons with energy above 4 GeV with an efficiency of about 100 %. The hardware implementation foresees an analog section, comparing the photomultiplier signal with a given threshold, and a digital section applying the trigger selection algorithm.

The Electromagnetic Calorimeter Trigger System for the AMS-02 Experiment

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Z. H. Li

Author Tools

Chat about Author

Papers

The electromagnetic calorimeter of the AMS-02 experiment

The Electromagnetic Calorimeter Trigger System for the AMS-02 Experiment