Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
The NUCLEON space experiment for direct high energy cosmic rays investigation in TeV–PeV energy range
Introduction
The “knee” energy range 1014–1016 eV is a crucial region for the understanding of the cosmic-ray (CR) origin, acceleration and propagation in our galaxy. It is important to obtain more data in this energy range with elemental CR resolution. The “knee” area is interesting for astrophysics.
Currently available data are not enough for the creation of a final adequate interpretation of “knee”. Indirect methods using registration of atmospheric showers with energy levels higher than 1014 eV are dependent on interaction models. There are different hypotheses explaining the phenomenon of the “knee”. Direct measurements of the chemical composition of cosmic rays are necessary to solve this problem.
Another important problem is the secondary to primary nuclei ratio at high energies (>100 GeV/nucleon). It is connected with a study of mechanisms of the cosmic-ray propagation in the galaxy.
The cosmic-ray anisotropy is a fundamental problem too. For example, the anisotropy can depend on stochastic character of supernova explosions [1].
Thus new experiments over a wide charge and energy range are needed. It would help to test existing theoretical conceptions and would become a basis for further studies in this very important field of knowledge. Long-duration balloon experiments like ATIC [2], [3], [4], TRACER [5], and CREAM [6] have begun to solve the above-mentioned problems. But a real solution to the problems would be possible only with a long-term large aperture satellite experiment. Some important results were obtained by the PAMELA satellite [7], [8], AMS02 [9], [10], and Fermi-LAT [11], currently taking data.
The high energy electrons spectrum depends on actual nearby sources of cosmic rays. For high energy electrons the dominant energy loss mechanism is the synchrotron radiation when traversing through the galactic magnetic fields. Therefore, the propagation distance for ultrarelativistic electrons is limited.
There are sufficient differences in experimental results obtained by different experiments [2], [3], [7], [8], [10], [11] at high energies. New experimental data are necessary.
The main difficulty of high energy cosmic-ray direct investigations is to lift primary particles energy detectors outside the Earth׳s atmosphere. Now the most universal energy measurements technique is ionisation calorimeter. This method is reliable but a calorimeter needs a heavy absorber to register high energy showers. Weight restrictions limit the application of ionisation calorimeters for cosmic-ray investigation on board of satellites at energies >100 TeV.
A new energy measurement method KLEM (Kinematic Lightweight Energy Meter) was proposed [12]. The primary energy is reconstructed by registration of spatial density of the secondary particles. The particles are generated by the first hadronic inelastic interaction in a carbon target. Then additional particles are produced in thin tungsten converter by electromagnetic and hadronic interactions. The main difference between the proposed KLEM method and ionisation calorimeters is that the KLEM technique does not need heavy absorbers for the shower measurement. Thus it is possible to design relatively light cosmic rays׳ detectors with a large geometric factor.
The NUCLEON experiment was proposed [12], [13], [14], [15], [16], [17], [18], [19], [20], [21]. The basic concept of the experiment is to design a scientific device with a relatively small weight (300–400 kg) and volume (<1 m3). The device must provide information about some of the most fundamental questions in astroparticle physics today. The main aim of the experiment is to investigate cosmic-ray nuclei energy spectra from 100 GeV to 1000 TeV and electrons spectrum from 20 GeV to 3 TeV by direct methods.
The NUCLEON experiment does not need a special satellite. The device will be exposed on board the serial Russian satellite by means of an application of weight reserve. Such weight reserve exists on some serial satellites. This approach should reduce the costs of the experiment.
Section snippets
Experimental technique
The main idea is to use a new experimental method KLEM in the NUCLEON project for the CR energy measurement to achieve above-mentioned aims.
The proposed technique can be used over a wide range of energies (1011–1016 eV) and gives an energy resolution of 70% or better according to simulation results [15], [18], [21].
The kinematical method for the determination of the primary particle energy was proposed by Castagnoli [22] and gives large errors between 100% and 200%. To overcome this problem, a
NUCLEON design
The NUCLEON device will be placed on board the RESURS-P satellite. The spacecraft will be launched on a Sun-synchronous orbit with inclination 97.276° and a middle height above Earth׳s surface of 475±5 km. The effective geometric factor is more than 0.2 m2 sr for the KLEM system and near 0.1 m2 sr for the calorimeter. The surface area of the device is equal to 0.25 m2. The charge measurement system must provide resolution better than 0.3 charge unit. The NUCLEON device must permit separation of the
Testing an integrated circuit for read-out signals
The Geant4 Monte-Carlo simulation of showers from different particles (protons, nuclei) with energies from 103 to 104 GeV gives the energy deposit in one strip up to 25,000 mip. Hence, to achieve the experiment׳s minimal physical goals, the readout system must have a dynamic range of 25,000 and a signal-to-noise ratio (SNR) of at least 2.
A classical charge sensitive amplifier (CSA) chip with linear transfer function with such requirements would have a too high power consumption, which would
Beam test of charge measurement system
The NUCLEON device and its different systems were tested by accelerator beams, including the charge measurement system tests by ions beams. The tests were performed at the SPS accelerator in CERN in 2005 [20] and 2013. A beam of indium nuclei with an energy of ~158 GeV/nucleon was directed toward a 4-cm-thick beryllium target. The secondary charged particles and nuclear fragments were then separated according to their rigidity by means of a magnetic deflection system. In the experiment,
Beam tests of energy measurement system
The main energy measurement system of the NUCLEON experiment is based on the KLEM method. The practical applicability of the proposed technique was estimated using the results of the simulation employing the GEANT 3.21 [26] software package complemented by the QGSJET [27] nuclear interaction generator to describe high-energy hadron–nucleus and nucleus–nucleus interactions.
Different spectrometer structures were investigated to choose an optimal design of a detector operating according to the
Calibrations of the NUCLEON calorimeter
Energy deposit in the calorimeter can be determined by reconstruction of cascade curves. To reconstruct primary energies for electrons, correction coefficients determined by simulation were used. Calibration curves are presented in Fig. 6.
Two approaches of energy reconstruction were applied to consider leakage of energy out of the calorimeter. In the first case the cascade curve was approximated (circles, dotted line), and in the second one the full energy deposit was multiplied by a constant
Separation of electron and hadron events
Hadron and electromagnetic events can be separated by the shape of the cascade in the NUCLEON device. Two similar approaches were developed for such separation, both based on a similar set of variables but using different methods for their analysis.
The spatial resolution of microstrip detectors is equal to ~0.5 mm for the KLEM energy measurement system and ~1 mm for the calorimeter.
Microstrip detectors data can be applied to reconstruct longitudinal and transverse cascade ionisation distributions
Conclusions
The NUCLEON device was designed and tested. The expected performance is confirmed by simulation and beam test results. All scientific objectives are achievable. The launch of the satellite is planned for 2014.
Acknowledgements
The reported study was supported by the Supercomputing Center of Lomonosov Moscow State University [32].
References (32)
- et al.
Astroparticle Physics
(2006) - et al.
Advances in Space Research
(2006) - et al.
Advances in Space Research
(2008) - et al.
Advances in Space Research
(2004) - et al.
Advances in Space Research
(2013) Physics of the Dark Universe
(2014)- et al.
Advances in Space Research
(2001) - et al.
Astroparticle Physics
(2011) - et al.
Nuclear Physics B (Proceedings Supplements)
(1997) - et al.
Nature
(2008)
Astrophysics and Space Sciences Transactions
Physical Review Letters
Physical Review Letters
Physical Review D
AIP Conference Proceedings
Physics of Atomic Nuclei
Cited by (44)
The cosmic ray all-particles spectrum from the NUCLEON experiment in comparison with ground-based experiments data
2022, Advances in Space ResearchCitation Excerpt :The aim of the experiment was to measure the charge composition and energy spectra of cosmic rays in the region of 2–500 TeV. Energies were measured using both a traditional ionization calorimeter and a new KLEM technique (Kinematic Lightweight Energy Meter) (Atkin et al., 2015; Bashindzhagyan et al., 2005). The effective geometric factor was >0.2 m2sr for the KLEM system and about 0.03 m2sr for the calorimeter.
Review of the results from the NUCLEON space mission
2022, Advances in Space ResearchSpectra of cosmic ray carbon and oxygen nuclei according to the NUCLEON experiment
2020, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy PhysicsCitation Excerpt :The energy spectra of these components are presented in [8]. Energy measurements were performed by the new KLEM method (Kinematic Lightweight Energy Meter) [9]. This method is based on the registration of the spatial distribution of secondary particles after the first nuclear interaction of a primary particle with a target in the spectrometer.
Energy spectra of abundant cosmic-ray nuclei in the NUCLEON experiment
2019, Advances in Space ResearchCitation Excerpt :The highest measured energy is equal to 900 TeV. The NUCLEON device (Atkin et al., 2015a; Vasiliev et al., 2014; Bulatov et al., 2010; Voronin et al., 2007a, 2007b; Podorozhnyi et al., 2007) was designed and produced by the collaboration of SINP MSU (the main investigator), JINR (Dubna) and a number of other Russian scientific and industrial centers. Currently, it is placed on board the RESURS-P №2 satellite.
Secondary cosmic rays in the NUCLEON space experiment
2019, Advances in Space ResearchThe HERO (High Energy Ray Observatory) detector current status
2019, Advances in Space Research