The direct observation of high-energy cosmic rays, up to the PeV region, will increasingly rely on highly performing calorimeters, and the physics performance will be primarily determined by their ...geometrical acceptance and energy resolution. Thus, it is extremely important to optimize their geometrical design, granularity, and absorption depth, with respect to the total mass of the apparatus, which is among the most important constraints for a space mission. Calocube is a homogeneous calorimeter whose basic geometry is cubic and isotropic, so as to detect particles arriving from every direction in space, thus maximizing the acceptance; granularity is obtained by filling the cubic volume with small cubic scintillating crystals. This design forms the basis of a three-year R &D activity which has been approved and financed by INFN. A comparative study of different scintillating materials has been performed. Optimal values for the size of the crystals and spacing among them have been studied. Different geometries, besides the cubic one, and the possibility to implement dual-readout techniques have been investigated. A prototype, instrumented with CsI(Tl) cubic crystals, has been constructed and tested with particle beams. An overview of the obtained results will be presented and the perspectives for future space experiments will be discussed.
The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this paper a ...measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10GeV/n to 2.0 TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z = 40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50 GeV/n to 2 TeV/ n our present data are compatible with a single power law with spectral index−2.60±0.03.
► Secondary beta-decaying isotopes as “cosmic clocks” for Galactic cosmic-ray propagation. ► Application of the FDIRC technique to the identification of cosmic-ray isotopes. ► Enhanced ...photostatistics for nuclei of charge
Z compared to particles with
Z
=
1.
Measurements of the relative abundance of cosmic isotopes and of the energy dependence of their fluxes may clarify our present understanding on the confinement time of charged cosmic rays in the Galaxy. Experimental studies of these
propagation clocks have been carried out by balloon and space missions at energies of a few 100
MeV/amu by means of detection techniques based on multiple d
E/d
x sampling, coupled with a measurement of the energy released in a thick absorber. At larger energies, the isotopic separation of light nuclei (as, for instance,
9Be/
10Be) can be achieved by combining a precise measurement of the particle’s rigidity with an high resolution determination of its velocity, via the observation of the Cherenkov effect in a radiator.
In this paper, we propose the introduction – for the first time in a space experiment – of the DIRC technique (Detection of Internal Reflected Cherenkov light) for the identification of cosmic-ray isotopes. This type of detector has been successfully used in electron–positron colliders for particle identification and in particular for
π–K separation. While for particles with unit charge the light yield is a limiting factor, in the case of a nucleus of charge
Z the larger photostatistics (due to the
Z
2 dependence of Cherenkov light emission) is the key to reach an adequate angular resolution to provide a mass discrimination for isotopes of astrophysical interest. We report on the early development phase of a DIRC prototype with a focussing scheme (FDIRC) to collect the Cherenkov light onto a detector plane instrumented with a Silicon PhotoMultiplier (SiPM) array.
The Calorimetric Electron Telescope, CALET, is an astroparticle physics mission installed on the International Space Station, ISS. The primary objective of the mission is studying the details of ...galactic cosmic-ray acceleration and propagation, and searching for the possible nearby sources of high-energy electrons and dark matter signatures. The CALET experiment measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei to 1000 TeV. The detector is an all-calorimetric instrument with a total vertical thickness of 30 radiation lengths and fine imaging capability, optimized for the measurement of the electron and positron (all-electron) spectrum well into the TeV energy region. It consists of a charge detector (CHD) with two layers of segmented plastic scintillators for the identification of cosmic-rays via a measurement of their charge over the range Z=1∼40, a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). The instrument was launched on August 19, 2015 to the ISS and installed on the Japanese Experiment Module-Exposed Facility. Since the start of operation in October, 2015, CALET has been collecting scientific data without any major interruption for more than eight years. The number of triggered events over 10 GeV is nearly 1.97 billion events as of November 30, 2023. In this paper, we present the results of the CALET mission so far, including the all-electron energy spectrum, the spectra of protons and other nuclei, gamma-ray observations, as well as the characterization of on-orbit performance. Some results on the electromagnetic counterpart search for LIGO/Virgo gravitational wave events and the observations of solar modulation and gamma-ray bursts are also included.
An array of Single Photon Avalanche Diodes (SPAD), fabricated in a 180 nm CMOS technology featuring a high voltage (HV) option, has been investigated in terms of radiation tolerance, in view of the ...design of low material budget dual-tier detectors for charged particle tracking based on the coincidence of signals coming from pairs of vertically aligned pixels. Each pixel in the array includes both the processing electronics and the sensing element in a monolithic structure. The test vehicles were irradiated with 10 keV X-rays up to a dose of 1 Mrad (SiO2) and with neutrons up to a fluence of 1011 neq cm−2. A selection of the characterization results are presented together with the main features of a new large scale SPAD array to be fabricated in a 150 nm CMOS technology and ready for vertical interconnection in a dual layer structure.
•Characterization of SPADs in a 180 nm CMOS technology.•Radiation tolerance evaluation involving ionizing and non-ionizing sources.•Design features of a new charged particle detector based on 150 nm CMOS SPADs in a dual-layer structure.
Iron and nickel cosmic ray nuclei play a key role in the understanding of the acceleration and propagation mechanisms of charged particles in our Galaxy. In fact, iron and nickel are the most ...abundant nuclei among the heavy elements and provide favorable conditions for a low background measurement thanks to the negligible contamination from spallation of higher mass elements. CALET, operating on the ISS since 2015, has excellent capabilities of charge discrimination up to nickel and can measure the energy of cosmic ray nuclei thanks to a lead tungstate calorimeter providing a direct and precise measurement of heavy charged nuclei spectra. In this contribution, a direct measurement of iron and nickel nuclei spectra in the energy range from 10 GeV/n to 2 TeV/n and from 8.8 GeV/n to 240 GeV/n, respectively is presented. More than five years of data collected by CALET were used. A detailed study of systematic uncertainties is also illustrated. The measured spectra are compared with the ones measured by other experiments and are compatible with a single power law fit in the energy region from 50 GeV/n to 2 TeV/n and from 20 GeV/n to 240 GeV/n for iron and nickel respectively. Also, the ratio between nickel and iron spectra is reported.
► Kinematical energy estimators for direct measurements of charged VHE cosmic-ray. ► Cosmic-ray energy resolution using the kinematical method. ► Required exposure vs. energy resolution for direct ...proton flux measurements at the PeV scale.
At an energy scale of 10
15–10
16
eV, a direct measurement of the energy carried by charged cosmic radiation is a real challenge for balloon-borne and space based instruments. As a consequence of the very small fluxes, a large collecting power is required which is difficult to accommodate with weight-limited instruments equipped with calorimeters. A different approach has been proposed that might allow for a sizeable reduction of the instrument mass. It is based on a kinematical technique, whereby the energy of the cosmic-ray is estimated on the basis of the measured angular distribution of the secondaries resulting from its interaction in a target. In this paper, we review the basic principles of the method and study the properties of different energy estimators by means of a full simulation of the interaction of the incident particle in a conceptual instrument. We also discuss the intrinsic limitations of the method and investigate its possible application to direct measurements of the cosmic-ray spectrum in the region of the ‘knee’.
We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from 8.4 GeV/n to 3.8 TeV/n based on the data collected ...by the Calorimetric Electron Telescope (CALET) during ∼6.4 yr of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy E_{0}∼200 GeV/n of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be γ=-3.047±0.024 in the interval 25<E<200 GeV/n. The B spectrum hardens by Δγ_{B}=0.25±0.12, while the best fit value for the spectral variation of C is Δγ_{C}=0.19±0.03. The B/C flux ratio is compatible with a hardening of 0.09±0.05, though a single power-law energy dependence cannot be ruled out given the current statistical uncertainties. A break in the B/C ratio energy dependence would support the recent AMS-02 observations that secondary cosmic rays exhibit a stronger hardening than primary ones. We also perform a fit to the B/C ratio with a leaky-box model of the cosmic-ray propagation in the Galaxy in order to probe a possible residual value λ_{0} of the mean escape path length λ at high energy. We find that our B/C data are compatible with a nonzero value of λ_{0}, which can be interpreted as the column density of matter that cosmic rays cross within the acceleration region.
Calocube—A highly segmented calorimeter for a space based experiment D׳Alessandro, R.; Adriani, O.; Agnesi, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Volume:
824
Journal Article
Peer reviewed
Open access
Future research in High Energy Cosmic Ray Physics concerns fundamental questions on their origin, acceleration mechanism, and composition. Unambiguous measurements of the energy spectra and of the ...composition of cosmic rays at the “knee” region could provide some of the answers to the above questions. Only ground based observations, which rely on sophisticated models describing high energy interactions in the earth׳s atmosphere, have been possible so far due to the extremely low particle rates at these energies.
A calorimeter based space experiment can provide not only flux measurements but also energy spectra and particle identification, especially when coupled to a dE/dx measuring detector, and thus overcome some of the limitations plaguing ground based experiments. For this to be possible very large acceptances are needed if enough statistic is to be collected in a reasonable time. This contrasts with the lightness and compactness requirements for space based experiments. A novel idea in calorimetry is discussed here which addresses these issues while limiting the mass and volume of the detector. In fact a small prototype is currently being built and tested with ions. In this paper the results obtained will be presented in light of the simulations performed.
The Cosmic Ray Energetics and Mass (CREAM) timing charge detector Ahn, H.S.; Allison, P.S.; Bagliesi, M.G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2009, Volume:
602, Issue:
2
Journal Article
Peer reviewed
The use of detectors based on plastic scintillator with photomultiplier tubes (PMTs) is common in cosmic-ray experiments to differentiate particle charges. However, in the presence of a calorimeter, ...the standard method of pulse charge integration over a time longer than a PMT pulse is hampered by abundant albedo particles. The Cosmic Ray Energetics and Mass (CREAM) instrument surmounts this problem by measuring the peak voltage of the PMT pulse within
∼
3
ns
of a threshold crossing in the readout of a timing charge detector (TCD). The design and performance of the TCD is presented. A charge resolution of
0.2
e
for oxygen and
0.4
e
for iron is obtained for through-going cosmic-ray particles.
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