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The δ 13 C profile of Globigerinoides ruber , measured in the GT90/3 shallow-water Ionian sea core and dated with high precision, is presented and analyzed using the Singular Spectrum Analysis and the Wavelet Transform. This time series covers the period 200–1979 AD, with a resolution of 3.87 years. The δ 13 C of foraminifera depends on the photosynthetic activity of the symbiontic algae living on the shells, strictly related to the illumination of the sea-surface. Both spectral methods, besides an 11-years oscillation in phase with the Schwabe cycle of the solar activity, show the presence of a centennial cycle that is in phase with the amplitude modulation of the sunspot number series in the last 300 years. Moreover, another climatic record, the tree ring δ 13 C of a Japanese cedar covering the time interval 125–1952 AD, shows a similar centennial oscillation and therefore suggests that this climatic variation is global and in phase with the solar activity.

We demonstrate the presence of solar flare as well as neutron capture effects in the isotopic composition of rare gases in the Fermo regolith breccia acquired on its parent body based on the measurements of tracks, rare gases and radionuclides. The track density along a 3.2 cm long core decreases by a factor of about 6 and by more than a factor of 13 within the meteorite, indicating small (2-9 cm) and asymmetrical ablation. Rare gases show a large trapped component; the isotopic ratios, particularly 20 Ne/ 22 Ne ≅ 11 and 20 Ne/ 36 Ar = 10 are indicative of a solar component. The galactic cosmic-ray exposure age is determined to be 8.8 Ma. Activities of a dozen radionuclides ranging in half-life from 16 day 48 V to 0.73 Ma 26 Al are consistent with their expected production rates. Track, rare gas and radionuclide data show that the meteoroid was a small body (≤ 120 kg) and had a simple, one-stage exposure history to cosmic rays in the interplanetary space. However, 82 Kr and 128 Xe show an excess due to neutron irradiation on the parent body of the meteorite. The presence of solar gases and the neutron capture effects indicate several stages of irradiation on the parent asteroid. The chemical composition of Fermo confirms that it belongs to the H group of ordinary chondrites with lithic clasts having varying compositions. δ 15 N is found to be 8.3 ± 1.2%0, close to the typical values observed in H chondrites.

The cross section for large p t jet production for transverse momentum 10≤ p t ≤20 GeV/c and rapidity 1.6≤ η ≤2.6 in p – N ( p –`air') interactions is studied from the analysis of multicore Extensive Air Showers recorded in the EAS–TOP calorimeter. The projectiles are the leading particles interacting at atmospheric depths between 250 and 480 cm −2 , the CMS energy of interaction being s ≈500 GeV. The slope of the p t distribution agrees with the expected one from the p – p collider data at the same CMS energy. The measured jet production cross section in p – N interactions with respect to p – p interactions is (dσ/dp t ) pN jet =(dσ/dp t ) p p jet ·A α with α =1.56±0.07 for A =14.7 (average mass number of `air' nuclei). Such value is compatible within the experimental uncertainties with the one obtained in p –nucleus accelerator measurements at s ≃30 GeV in the same range of transverse momentum and rapidity. No indication of increase of α with energy, i.e. of the entity of the `Cronin effect', is found.

The cosmic ray energy spectrum in the range E-o = 10(15)-10(16) eV (including the region of the steepening, "knee") is studied by means of the EAS-TOP array (Campo Imperatore, Gran Sasso Laboratories, atmospheric depth 820 g cm(-2)). Measurements of the electromagnetic size (N-e = total number of charged particles at the observation level) are performed as a function of zenith angle with statistical accuracies of a few percent. The change of slope of the spectrum is observed in each bin of zenith angle at size values decreasing with increasing atmospheric depth. Its attenuation is compatible with the one of shower particles (Lambda(e) = 219 +/- 3 g cm(-2)). This observation provides a consistency check, supporting a normal behaviour of showers at the break, that make plausible astrophysical interpretations based on an effect on primaries occurring at a given primary energy. The break has a "sharp" shape (i.e., within experimental errors is compatible with two intersecting power laws) that represents a constraint with which any interpretation has to match. The change of slope of the power law index reproducing the size spectrum is Delta gamma = 0.40 +/- 0.09. The derived all particle energy spectrum is in good agreement with the extrapolation of the direct measurements at low energies and with other EAS data at and above the knee. Power laws fits to the energy spectrum below and above the knee give tin units of m(-2) s(-1) sr(-1) TeV-1) S(E-o) = (3.48 +/- 0.06) x 10(-10) (E-o/2300)(-2.76+/-0.03) for 900 TeV < E-o < 2300 TeV and S(E-o) = (3.77 +/- 0.08) x 10(-11) (E-o/5000)(-3.19+/-0.06) for 5000 TeV < E-o < 10(4) TeV. The systematic uncertainties connected to the interaction model and the primary composition are discussed. (C) 1999 Elsevier Science B.V.

The amplitude and phase of the first harmonic of the sidereal anisotropy of cosmic rays at E 0 = 2·10 14 eV have been measured by the EAS-TOP experiment (Campo Imperatore, 2005 m a.s.l., LNGS, Italy) and are respectively (at the equatorial plane): A sid = (3.73±0.57)·10 −4 ; φ sid = 1.82±0.49 h lst, with significance 6.5 s.d. The result is supported by different consistency checks. From the comparison with lower energy data, it follows that the amplitude and the phase of the cosmic ray anisotropy are constant over the energy range 10 12 – 2·10 14 eV. This implies at these energies a constant influence of the local interstellar medium on the propagation of cosmic rays.

We have previously shown that the very low activity of the cosmogenic 44Ti in meteorites records the galactic cosmic ray (GCR) flux over a century time-scale (Bonino et al., 1995). The heliospheric magnetic field (HMF) variations are the principal source of the GCR modulation in the heliosphere. We present here new measurements which extend our investigation over the last two centuries. The 44Ti activity at the time of fall has been obtained on the basis of the recently revised value of its half-life of 59.2 years. We basically confirm our earlier findings (Bonino et al., 1997). The 44Ti profile, with the time of fall of the meteorites, shows variations in phase in agreement with those expected. The magnitude of oscillations is ∼ 4 times higher than expected (∼ 6%) on the basis of the GCR flux over the past centuries deduced from sunspot number since 1700 and by the neutron monitor and balloon measurements in the last decades. The higher 44Ti production rate during prolonged solar quiet periods (Gleissberg minima) may imply that during these minima the HMF was weaker than during the recent minima of the 11-year solar cycle.

The primary cosmic ray (CR) proton, helium and CNO fluxes in the energy range 80-300 TeV are studied at the National Gran Sasso Laboratories by means of EAS-TOP (Campo Imperatore, 2005 m a.s.l.) and MACRO (deep underground, 3100 m w.e., the surface energy threshold for a muon reaching the detector being Eμth~1.3 TeV). The measurement is based on: (a) the selection of primaries based on their energy/nucleon (i.e., with energy/nucleon sufficient to produce a muon with energy larger than 1.3 TeV) and the reconstruction of the shower geometry by means of the muons recorded by MACRO in the deep underground laboratories; (b) the detection of the associated atmospheric Cherenkov light (C.l.) signals by means of the C.l. detector of EAS-TOP. The C.l. density at core distance r>100 m is directly related to the total primary energy E0. Proton and helium (``p+He'') and proton, helium and CNO (``p+He+CNO'') primaries are thus selected at E0~=80 TeV, and at E0~=250 TeV, respectively. Their flux is measured: Jp+He(80TeV)=(1.8+/-0.4)×10-6 m-2s-1sr-1TeV-1, and Jp+He+CNO(250TeV)=(1.1+/-0.3)×10-7 m-2s-1sr-1TeV-1, their relative weights being: Jp+He/Jp+He+CNO(250TeV)=0.78+/-0.17. By using the measurements of the proton spectrum obtained from the direct experiments and hadron flux data in the atmosphere, we obtain for the relative weights of the three components at 250 TeV: Jp:JHe:JCNO=(0.20+/-0.08):(0.58+/-0.19):(0.22+/-0.17). This corresponds to the dominance of helium over proton primaries at 100-1000 TeV, and a possible non-negligible contribution from CNO. The lateral distribution of Cherenkov light in Extensive Air Showers (EASs), which is related to the rate of energy deposit of the primary in the atmosphere, is measured for a selected proton and helium primary beam, and good agreement is found when compared with the one calculated with the CORSIKA/QGSJET simulation model.

Production of cosmogenic radioisotopes in meteorites depends on the galactic cosmic ray flux, which is controlled by the heliospheric magnetic field (HMF), which, in turn, depends on the solar activity. The radioisotopes can, therefore, serve as proxy records of the behaviour of the heliosphere in the past, in particular over prolonged solar quiet periods, such as during Gleissberg or Maunder minima, when the production rate of radioisotopes is expected to change significantly. For this purpose we have measured the 44 Ti (T 1/2 =66.6 yr) in ten stony meteorites, which fell between 1840–1992. The results indicate that the production of 44 Ti was significantly higher when the solar activity was persistently low, indicating that the HMF was weak during such periods, enabling higher flux of cosmic rays to enter the inner heliosphere.

An accurate dating of recent Ionian Sea sediment cores has been performed by the210Pb radiometric method and by a detailed tephroanalysis. The markers of the historical volcanic eruptions which occurred in the Campanian area (Vesuvius, Phlegrean Fields, Ischia) during the last two millenia have been identified along the cores. Among the others, the famous Plinian Vesuvius eruption of 79 AD, which buried the Roman town of Pompei, has been recognized. Direct210Pb dating is limited to the last two centuries. The tephroanalysis demonstrates that the sedimentation rate estimated by the210Pb method is correct and it is constant, at least for the last 2 ky. The presence of the137Cs peak due to the intense activity of nuclear-weapon testing in the atmosphere in 1963–64 AD assures that the top of the core is present and not disturbed. The high precision of the core dating allows to transform the depth scale into a time scale with an accuracy of ∼1%. The analysis of several cores taken in the same area demonstrates that the results presented here are of general validity, at least in this region. The carbonatic mud deposited in the last millennia in the Gallipoli Terrace can be successfully utilized for investigating the environmental conditions in the recent past.

We describe and discuss the operation, calibration and stability of the EAS-TOP calorimeter (Campo Imperatore, National Gran Sasso Laboratories), a large area hadron and muon detector devoted to cosmic-ray physics. It consists of iron slabs (for a total thickness of 818 g cm(-2)) and Iarocci tubes as sensitive layers, operating in the streamer mode and the "quasi proportional" regime. Using a model describing the operation of the "quasi proportional" chambers, we derive a calibration curve in the energy range 50-5000 GeV, whose reliability has been indirectly checked through on-site measurements, by means of an accelerator beam run (up to similar or equal to 600-700 GeV) and by comparing the model predictions on hadron shower transition curves with the data. (C) 1999 Elsevier Science B.V. All rights reserved.

The authors confirm and extend the results previously reported on the carbonate profile of the GT14 Ionian Sea core (Cini Castagnoli et al., 1990). A second, much longer core (2.81 meters) named GT89/3, has been taken about 1 km apart from the previous one. The carbonate profiles of the two cores are impressively similar; the details of the CaCO{sub 3} variations in the two sediments match on the scale of the sampling interval {Delta}d = 2.5 mm used for both cores. The authors show that {Delta}d corresponds to the mud deposited in a time interval {Delta}t = 3.87 {plus minus} 0.04 years, a value which is constant throughout the entire length of the cores. This precision is achieved by the tephroanalysis of the two cores. In this approach the markers of well-known historical eruptions in the Vesuvius area are recognized (Pompei, AD 79, Pollena, AD 472, Ischia, AD 1301), providing a precise dating which accurately tunes that obtained by the radiometric method. The correlation between the carbonate profile of the GT14 core and the tree-ring radiocarbon record has been discussed in (Cini Castagnoli et al., 1990); here the authors extend these results and show that the same correlation holds atmore » least up to 1690 BC. Due to the longer length of the GT89/3 time series, they also show that three periodic components at about 206 yr, 228 yr and 179 yr may now be resolved in the carbonate series, in close agreement with the results already found for the radiocarbon record.« less

The calcium carbonate (CaCO{sub 3}) profile of a recent sediment core, drilled in the Ionian Sea in 1979, is studied. The CaCO{sub 3} content of the sediment has been measured at regularly spaced intervals of {Delta}d=0.25 cm corresponding to {Delta}t=3.87 yr from AD 170 to the present. The CaCO{sub 3} profile of the core closely resembles the radiocarbon time series as deduced from tree ring data. The two records have a correlation coefficient of about 0.8 and show strikingly similar long-term variations. This result presumably follows from the fact that both systems take part in the carbon cycle. The spectral analysis of the CaCO{sub 3} time series reveals the presence of the well known periodicity with period ca: 200 years, characteristic of the {Delta}{sup 14}C record. Since the CaCO{sub 3} content of sea sediments is governed by biological, physical and chemical processes in surface sea waters, which in turn are strongly influenced by climatic conditions, and since the {approx}200 yr {Delta}{sup 14}C wave is known to be governed by solar modulation of galactic cosmic rays, the tuning of these two records on the same frequencies suggests a strong Sun-climate relationship.

The heliospheric magnetic field (HMF) is controlled by solar activity, as established by measurements over the last few decades, but its characteristics when the sun was quiet for prolonged periods, such as during Gleissberg or Maunder minima, are not known. Titanium-44, produced in meteorites, provides a monitor of the galactic cosmic ray (GCR) flux and allows estimation of the modulation effect of the sun for the period 1883 to 1992. The titanium-44 activity is consistent with the expected value, but the increase, due to the last Gleissberg minimum, is four times greater than expected for a GCR modulation based solely on sunspot numbers. This result implies that the HMF was weaker than at present and as a result the GCR flux (for energy greater than 1 gigaelectron volt) was higher between 2.2 to 3.6 protons per square centimeter per second per 4π steradians at 1 to 3 astronomical units in solar cycles 12 to 15.

The flux of cosmic ray hadrons at the atmospheric depth of 820 g/cm^2 has been measured by means of the EAS-TOP hadron calorimeter (Campo Imperatore, National Gran Sasso Laboratories, 2005 m a.s.l.). The hadron spectrum is well described by a single power law : S(E_h) = (2.25 +- 0.21 +- 0.34(sys)) 10^(-7)(E_h/1000)^(-2.79 +- 0.05) m^(-2) s^(-1) sr^(-1) GeV^(-1) over the energy range 30 GeV-30 TeV. The procedure and the accuracy of the measurement are discussed. The primary proton spectrum is derived from the data by using the CORSIKA/QGSJET code to compute the local hadron flux as a function of the primary proton spectrum and to calculate and subtract the heavy nuclei contribution (basing on direct measurements). Over a wide energy range E_0 = 0.5-50 TeV its best fit is given by a single power law : S(E_0) = (9.8 +- 1.1 +- 1.6(sys)) 10^(-5) (E_0/1000)^(-2.80 +- 0.06) m^(-2) s^(-1) sr^(-1) GeV^(-1). The validity of the CORSIKA/QGSJET code for such application has been checked using the EAS-TOP and KASCADE experimental data by reproducing the ratio of the measured hadron fluxes at the two experimental depths (820 and 1030 g/cm^2 respectively) at better than 10% in the considered energy range., Comment: 16 pages, 9 figures, accepted for publication in Astroparticle Physics

We present evidence for a dependence of the average deep underground muon energies on shower size in the coincident EAS-TOP and LVD data at the Gran Sasso laboratories. The measured relation agrees with a mixed chemical composition of the cosmic ray primary spectrum at energies around 10(15) eV. (C) 1998 Elsevier Science B.V.

In this letter, we report the profiles (∼160 samples) of 10Be, 9Be, Zn in a Mediterranean sediment core spanning the last 60 kyr. We show the existence of a 10Be peak, whose absolute age is estimated to be 34±3 kyr BP, based on its stratigraphic position between two tephra layers originating from two volcanic eruptions (Campanian Ignimbrite and Citara), dated by K-Ar, 40Ar-39Ar and 14C methods. This peak is similar to the increase in the 10Be concentration observed in Vostok and Dome C ice cores at the same age. The increase with approximately similar amplitude in both ice and sediment cores at different latitudes and hemispheres cannot be explained by changes in the archives. The present result supports the view of a well defined global enhancement of the 10Be flux, related to an increase of the 10Be production rate and not to a redistribution of the 10Be fallout between different latitudes.

The EAS-TOP extensive air shower array has been operating since 1992 in the search for gamma-ray bursts at primary energies E(1) greater than or equal to 10 GeV and E(2) greater than or equal to 80 TeV. The study is performed by searching for short transients in the cosmic-ray intensity in the single particle (E(1)) and extensive air shower (E(2)) counting rates at mountain altitude (2005 m above sea level). We discuss the method and the results obtained both in sky survey and in correlation with BATSE events. In both energy ranges, the observed fluctuations in the event rate obtained in the sky survey during similar to 800 days of live time are compatible with the statistical fluctuations of the cosmic-ray background. A single candidate of time duration Delta t similar to 2 s and energy fluence F(10 < E < 100 GeV) = 1.7 x 10(-4)/(cos theta)(10.5) ergs cm(-2) (where theta is the unknown zenith angle) has been observed on 1992 July 15 at 13:22:26 UT in the energy range E(1) greater than or equal to 10 GeV with significance 10.6 and 20.1 sigma in two measurement channels. In the analysis made in correlation with similar to 50 events detected by BATSE, no burst candidate was found in time coincidence or in the 2 hr interval, around the BATSE detection time. The following ranges of upper limits F-max to the energy fluence in the time interval Delta t(90) in which BATSE detected 90% of the counts are obtained: F-max = 2.3 x 10(-5)-7.4 x 10(-3) ergs cm(-2) (10 < E < 100 GeV) F-max = 1.6 x 10(-6)-3.3 x 10(-5) ergs cm(-2) (100 < E < 1000 TeV).

A meteorite shower fell at Torino, Italy on May 18, 1988. Petrographic studies indicate that the stone is an H6 chondrite having features of moderate to severe shock. Chemical analyses of the meteorite are reported. Cosmic ray produced He-3, Ne-21 and Xe-126 yield an exposure age of about 48 Ma. The cosmic ray track densities in three fragments range between 1.8 to 5 x 10 to the 5th/sq cm suggesting about 99 percent mass ablation in the atmosphere,. Twelve radioisotopes with half lives ranging between 5.6 days to 7.3 x 10 to the 5th years have been measured with high precision. Marginal signals were observed for several short-lived nuclides and upper limits were obtained for the activity levels of eight radionuclides, some of which have not been hitherto detected in fresh falls. The data are generally consistent with the nuclide production by galactic cosmic rays when modulation due to the solar cycle is taken into consideration. 23 refs.

Cosmic-ray intensity measurements have been carried out during the last year at a depth of 70 m.w.e. in the Monte dei Cappuccini laboratory in Torino, using solid vertical semicubical scintillator telescopes with a total area of 2 m2. Hourly data for 245 days corrected for barometric changes have been analyzed for the solar, apparent sidereal, and antisidereal daily variations whose harmonics are as follows:[Formula: see text]The true sidereal diurnal variation is estimated to have an amplitude of 0.019% with a time of maximum at 1720 h local sidereal time. The solar diurnal variation at different depths underground follows the energy dependence calculated with Axford's theory. The solar semidiurnal variation shows instead a fairly constant value at different μ energies. Its order of magnitude agrees with that expected as a result of Fermi acceleration in collisions of primaries moving in roughly solar and antisolar directions with solar wind inhomogeneities.

The cyclogram method of time series analysis has been used to analyse 10Be data (1181–1800 AD) and δ18O data (1181–1960 AD) from an artic ice core and thermoluminescence data (1181–1960 AD) from a Mediterranean sediment core. The10Be concentrations were determined at the ETH Zurich. The δ18O values were measured at the University of Copenhagen. The TL measurements were performed at the Istituto di Cosmo-geofisica del C.N.R., Torino. Common mean periodicities of 10.75 y are found for the period 1505 to 1710 AD in TL and10Be and of 11.4 y for the period 1715 to 1880 in TL and δ18O. This periodicity was found in the solar sunspot (R z) series analysed in the same way, from 1825 to 1905. This supports the argument that the common periodicities found in the long-running series are peculiar of the solar activity in the past.

Experimental results on the shapes of atmospheric Cherenkov light images from Extensive Air Showers at E(0) = 10(13)-10(14) eV are presented, The results are based on data obtained by the first element of the Cherenkov light array of the EAS-TOP experiment at Campo Imperatore (2005 m a.s.l., National Gran Sasso Laboratories, Italy), Images are obtained with pixel field of view omega = 1.5 x 10(-5) sr and full field of view Omega approximate to 10(-3) sr. The shapes of the images agree with the expectations and their fluctuations are large and significant, Experimental data on the dependence of the image shapes on the detection geometry are reported, The images are well reproduced by two independent side by side detectors, within measured accuracies, Such accuracies (approximate to 15% for large photoelectron content) define the level at which each pixel content is related to the shower structure, The presence of events characterized by patterns with multiple structures is proved, It is shown that such features are related to physical fluctuations of the shower structure.