The Prototype of GAMMA-400 Apparatus Arkhangelskiy, A.I.; Arkhangelskaja, I.V.; Kheymits, M.D. ...
Physics procedia,
2015, 2015-00-00, Volume:
74
Journal Article
Open access
Scientific project GAMMA-400 (Gamma-Astronomy Multifunction Modules Apparatus) relates to the new generation of space observatories for investigation of cosmic γ-emission in the energy band from ∼20 ...MeV up to several TeV, electron/positron fluxes from ∼1GeV up to ∼10 TeV and cosmic-ray nuclei fluxes with energies up to ∼1015 eV by means of GAMMA-400 gamma-telescope represents the core of the scientific complex. The investigation of gamma ray bursts in the energy band of 10 keV–15 MeV are possible too by means of KONUS-FG apparatus included in the complex. For γ-rays in the energy region from 10 to 100GeV expected energy resolution changes from ∼3% to ∼1% and angular resolution from ∼0.1% to ∼ 0.01% respectively, γ/protons rejection factor is ∼5·105. The GAMMA-400 satellite will be launched at the beginning of the next decade on the high apogee orbit with following initial parameters: apogee altitude ∼300000km, perigee altitude ∼500km, rotation period ∼7 days, inclination to the equator plane 51.4°. The active functioning interval will be 7-10 years. The scientific complex will have next main technical parameters: total weight ∼4100kg, power consumption ∼2000W, information quote 100 GByte/day. During the project development, the prototype of apparatus was created for working-off of the main apparatus construction units in laboratory conditions. The main distinctive features of the prototype are presented.
Fermi-LAT has made a significant contribution to the study of high-energy gamma-ray diffuse emission and the observations of 3000 discrete sources. However, one third of all gamma-ray sources (both ...galactic and extragalactic) are unidentified, the data on the diffuse gamma-ray emission should be clarified, and signatures of dark matter particles in the high-energy gamma-ray range are not observed up to now. GAMMA-400, the currently developing gamma-ray telescope, will have angular (∼0.01∘ at 100 GeV) and energy (∼1% at 100 GeV) resolutions in the energy range of 10–1000 GeV which are better than Fermi-LAT (as well as ground gamma-ray telescopes) by a factor of 5–10. It will observe some regions of the Universe (such as the Galactic Center, Fermi Bubbles, Crab, Cygnus, etc.) in a highly elliptic orbit (without shading the telescope by the Earth) continuously for a long time. It will allow us to identify many discrete sources, to clarify the structure of extended sources, to specify the data on the diffuse emission, and to resolve gamma rays from dark matter particles.
The satellite-borne PAMELA experiment studies cosmic ray spectra over a wide range of energies. The instrument was placed in orbit in June 2006 and remains there to the present day. A ...position-sensitive calorimeter is one of the main parts of the PAMELA instrument. The calorimeter data are used to determine the energy of particles that interact within it, separate the electron component of the detected radiation from the nuclear component, and reconstruct the tracks of particles passing through the instrument. The special calorimeter and S
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scintillation shower detector triggers enables us to expand our statistics considerably. Using the calorimeter data in generating these triggers means we can study the anisotropy of cosmic rays with energies in excess of tens of GeV. This method of anisotropy detection is based on reconstructing the direction of a particle’s arrival from the axis of the secondary particle cascade in the calorimeter.
This work presents the results of measuring the deuteron spectrum of Galactic cosmic rays (GCRs) with the PAMELA experiment. The PAMELA is an international experiment. Its main objectives are to ...search for antimatter and measure proton, helium nuclei, electron, and positron spectra over a wide range of energies. In addition, the experimental setup allows the detection of deuterons and the reconstruction of their spectra at low energies. Cosmic ray deuteron spectrum and the deuteron-proton ratio measured in the PAMELA experiment in the energy range of 50–650 MeV/nucleon are presented below.
This paper presents precise measurements of the differential energy spectra of quasi‐trapped secondary electrons and positrons and their ratio between 80 MeV and 10 GeV in the near‐equatorial region ...(altitudes between 350 km and 600 km). Latitudinal dependences of the spectra are analyzed in detail. The results were obtained from July until November 2006 onboard the Resurs‐DK satellite by the PAMELA spectrometer, a general purpose cosmic ray detector system built around a permanent magnet spectrometer and a silicon‐tungsten calorimeter.
The task of selecting neutral γ rays from the background of charged particle fluxes, which arises in investigation of high-energy (>50 GeV) cosmic rays, is complicated by the presence of the ...backsplash effect. The backsplash is composed of a great number of low-energy (~1 MeV) particles produced in an electromagnetic shower being developed in the calorimeter of the γ-ray telescope. A technique of charged particle rejection using an anticoincidence system has been developed. A method for discriminating events of charged particle detection from γ-ray detection events accompanied by the backsplash phenomenon is proposed. This method is based on the difference of the signals in time and makes it possible to maintain a high detection efficiency even for high-energy γ rays.
The PAMELA magnetic spectrometer was launched into a near-Earth orbit on board the Resurs-DK1 satellite in June 2006; in December 2006, it recorded the last strong solar high-energy particle event of ...the 23rd solar cycle. A deficit was thereafter observed in solar energetic particle events because of the lengthy solar activity minimum and the weak evolution of the next (24th) solar cycle. As a result, only a few solar events involving protons with energies of more than 100 MeV were recorded between 2010 and 1012. This work presents the preliminary results from measurements of charged particle fluxes in these events, recorded by the Pamela spectrometer.
A method for antiproton selection against a background of electrons, based on a mathematical model of data classification using variations in interparticle interaction in a calorimeter, and a method ...for excluding events accompanied by scattering in the inner detectors of a tracking system (which result in errors in the measured trajectory’s curvature and charge sign) from analysis are discussed in this paper. Antiproton spectra and antiproton/proton flux ratio at energies of 0.06 to 350 GeV with statistics of events surpassing those in 1 are obtained. The results can be used to create models for the generation and distribution of particles in the Galaxy, and for searching and studying the nature of hypothetical dark matter particles.
Some features of scintillation anticoincidence system (includes ACtop detector section located upper the converter-tracker and four AClat ones placed from its lateral sides) of the GАММА-400 ...gamma-ray telescope, related to joint operations with another fast scintillation systems: SDC (scintillation detector system of calorimeter) and TOF (time-of-flight system) are considered. The main problem for high-energy (over 50GeV) gamma-rays registration by gamma-telescopes is the presence of so-called «backsplash current» (BS) of particles from massive calorimeter when detecting of particles is provided. BS is a set of low energy particles, moving up from the calorimeter and producing triggering of the anticoincidence detectors, imitating detection of a charged particle. As an additional indicator of BS particles presence of in the ACtop detector, we offer the value of energy release in the S3 scintillation detector placing between two parts of the calorimeter (CC1 and CC2). Fast trigger signal in the main aperture for gamma-quanta is composed of analysis of TOF system signal, showing that charged particle or particles move in the direction from up to down, and ACtop energy deposition taking in to account specially designed for GAMMA-400 algorithms of backsplash rejection.
In-flight performances of the PAMELA satellite experiment Papini, P.; Adriani, O.; Ambriola, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2008, Volume:
588, Issue:
1-2
Journal Article
Peer reviewed
PAMELA is a satellite-borne experiment designed to study with great accuracy charged particles in the cosmic radiation with a particular focus on antiparticles. The experiment, housed on board the ...Russian Resurs-DK1 satellite, was launched on June 15, 2006 in a 350×600km orbit with an inclination of 70∘. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon–tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows charged particle identification over a wide energy range. In this work, the detector design is reviewed and the in-orbit performances in the first months after the launch are presented.
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