F. Bongiorno

Observations of cosmic ray electrons and positrons using an imaging calorimeter

A ballon-borne magnet spectrometer system was flown for 5.5 hr at an altitude of more than 117,00 feet from Prince Albert, Saskatchewan (Canada), on 1989 September 5, when the Newark neutron monitor rate was 2952. The instrument was a modified version of the one used to observe antiprotons in 1979. The most significant modification was the addition of an imaging calorimeter, 7.33 radiation lengths thick. Inclusion of the calorimeter has significantly improved the ability to distinguish electrons and positrons from the other constituents of the cosmic rays. The absolute electron flux has been determined in the energy interval 1.3-26 GeV. The electron spectrum at the top of the atmosphere was found to be J(sub e-) = 177E(exp -(3.15+/-0.13)) electrons/ sq m/(sr s GeV) in the energy range 4.0-26 GeV. Below 4 GeV, the spectrum showed flattening, which is consistent with the effect of solar modulation. The e(+)/(e(+)+e(-)) ratio was found to be (0.11 +/- 0.03) in the energy range 5.2-13 GeV.

Absolute spectrum and charge ratio of cosmic ray muons in the energy region from 0.2 GeV to 100 GeV at 600 m above sea level

We have determined the momentum spectrum and charge ratio of muons in the region from 250 MeV/c to 100 GeV/c using a superconducting magnetic spectrometer. The absolute differential spectrum of muons obtained in this experiment at 600 m above sea level is in good agreement with the previous measurements at sea level. The differential spectrum can be represented by a power law with a varying index, which is consistent with zero below 450 MeV/c and steepens to a value of −2.7 ± 0.1 between 20 and 100 GeV/c. The integral flux of muons measured in this experiment span a very large range of momentum and is in excellent agreement with the earlier results. The positive to negative muon ratio appears to be constant in the entire momentum range covered in this experiment within the errors and the mean value is 1.220 ± 0.044. The absolute momentum spectrum and the charge ratio measured in this experiment are also consistent with the theoretical expectations. This is the only experiment which covers a wide range of nearly 3 decades in momentum from a very low momentum.

Performance of a balloon-borne magnet spectrometer for cosmic ray studies

Abstract This paper summarizes the performance characteristics of the balloon-borne magnet spectrometer operated by New Mexico State Universitys Particle Astrophysics Laboratory. Particular emphasis has been placed on the rigidity resolution, including both random and systematic errors of the magnetic spectrometer system. Measurement of the performance characteristics has been greatly enhanced through the use of an imaging calorimeter as an independent aid in the identification of cosmic rays.

WiZard 2: a proposal to complement WiZard detector with two further modules of tracking calorimeter and an accurate spark counter t.o.f. system

Among the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation.SummaryAmong the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation.RiassuntoFra tutte le varie proposte esistenti nell’ambito della ricerca di antimateria cosmica, il progetto Wi#x005A-0304;ard per la Stazione Spaziale americana Freedom si dimostra del piú grande interesse. Si presenta un possibile ampliamento dell’apparato Wi#x005A-0304;ard allo scopo di migliorare sensibilmente la capacità di rivelare nuclei di antielio nella radiazione cosmica.Among the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation. Fra tutte le varie proposte esistenti nell’ambito della ricerca di antimateria cosmica, il progetto Wi#x005A-0304;ard per la Stazione Spaziale americana Freedom si dimostra del piu grande interesse. Si presenta un possibile ampliamento dell’apparato Wi#x005A-0304;ard allo scopo di migliorare sensibilmente la capacita di rivelare nuclei di antielio nella radiazione cosmica.

Negative pion and muon fluxes in atmospheric cascades at a depth of 5-g-cm**(-2)

This paper reports observations of the absolute momentum differential fluxes of negative pions and muons between 4 and 15 GeV/c and between 0.3 and 15 GeV/c, respectively, at an atmospheric depth of 5 g . The data have been collected by the balloon-borne experiment MASS (matter - antimatter space spectrometer) launched from Prince Albert (Canada) where the geomagnetic cut-off is 650 MV/c. The instrument was flown on the 5th of September 1989, the duration of the flight was 5.5 hours at an altitude of more than 117 000 ft. The measured fluxes are compared to calculations. The muon spectrum follows a power law in momentum with a spectral index of 2.36 above 2 GeV/c.

\(Wi\bar Zard\) 2: a proposal to complement\(Wi\bar Zard\) detector with two further modules of tracking calorimeter and an accurate spark counter t.o.f. systemdetector with two further modules of tracking calorimeter and an accurate spark counter t.o.f. system

Among the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation.SummaryAmong the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation.RiassuntoFra tutte le varie proposte esistenti nell’ambito della ricerca di antimateria cosmica, il progetto Wi#x005A-0304;ard per la Stazione Spaziale americana Freedom si dimostra del piú grande interesse. Si presenta un possibile ampliamento dell’apparato Wi#x005A-0304;ard allo scopo di migliorare sensibilmente la capacità di rivelare nuclei di antielio nella radiazione cosmica.Among the several existent proposals for the cosmic antimatter search, the Wi#x005A-0304;ard project for the U.S. Space Station Freedom shows the greatest interest. A possible upgrading of the Wi#x005A-0304;ard apparatus, called Wi#x005A-0304;ard 2, is presented in order to sensibly improve the capability of detecting antihelium nuclei in the cosmic radiation. Fra tutte le varie proposte esistenti nell’ambito della ricerca di antimateria cosmica, il progetto Wi#x005A-0304;ard per la Stazione Spaziale americana Freedom si dimostra del piu grande interesse. Si presenta un possibile ampliamento dell’apparato Wi#x005A-0304;ard allo scopo di migliorare sensibilmente la capacita di rivelare nuclei di antielio nella radiazione cosmica.

Study of the granularity for a tracking calorimeter with optimal rejection of proton background in positron detection

SummaryIn this paper we present a Monte Carlo study of a calorimeter response for an experiment to equip the magnetic facility of the USA space station. Main purpose in the design of such a calorimeter is the efficient discrimination between eloctromagnetic and hadronic showers. The estimated rejection power results to be better than 1·10−3 p/e+ for incident particles with energy between 10 GeV and 100GeV.RiassuntoIn questo lavoro presentiamo lo studio, realizzato con un metodo di Monte Carlo, della risposta di un calorimetro progettato per un esperimento da inserire nel magnete della stazione spaziale USA. Il principale obiettivo, considerato nel progetto di questo calorimetro, è l’efficiente discriminazione tra sciami elettromagnetici e adronici. Il potere di reiezione è stimato migliore di 1·10−3p/e+ per energie delle particelle incidenti da 10 GeV a 100 GeV.РезюмеВ этой работе мы предлагаем исследование по методу Монте-Карло отклика калориметра, который сконструирован для экспериментов на космической станции США. Основная цель при конструировании такого калориметра заключается в эффективной дискриминации между электромагнитными и адронными ливнями. Оценивается степень устранения фона протонов, которая оказывается лучше, чем 1·10−3 p/e+ для падающих частиц с энергиями между 10 ГэВ и 100 ГэВ.

Application of silicon-detector technology to experiments in space. An option for the Astromag facility

SummaryCosmic antimatter search needs transportation systems of the apparatus outside the atmosphere. The Astromag facility on the NASA space station will be a great opportunity for such a search in the next future. Here we discuss the advantages achievable from silicon-detector technology in space research and we propose a silicon calorimeter as an ideal option to work in connection with the Astromag facility itself.RiassuntoLa ricerca di antimateria cosmica necessita di sistemi di trasporto e di apparati al di fuori dell’atmosfera. La facility Astromag, posta sulla stazione spaziale della NASA, costituirà nel prossimo futuro una grande opportunità per questo tipo di ricerca. Si discutono qui i vantaggi che si possono ottenera dalla tecnologia dei rivelatori a silicio nella ricerca spaziale e si propone un calorimetro a silicio come opzione ideale per operare in connessione con la facility Astromag stessa.РезюмеПоиски антивещества в космосе требуют транспортных систем для вывода экспериментальной аппаратуры за пределы атмосферы. Экспериментальная установка «АСТРОМАГ» на космической станции NASA представляет болышие возможности для таких поисков. Мы обсуждаем преимущества технологии кремниевых детекторов в космических исследованиях. Предлагается кремниевый калориметр, как идеальный прибор для установки «АСТРОМАГ».

Simulation of low-energy antiproton interactions in a sampling calorimeter

SummaryThis paper describes the Monte Carlo program used for the simulation of antiproton interactions at intermediate energy inside a brass streamer-tube tracking calorimeter, to be used in a search for antimatter in cosmic rays, in the high atmosphere. The calorimeter is sensitive in the kinetic-energy range (100 ⧀v 5000) MeV and the Monte Carlo is tuned in this energy interval both for proton and antiproton interactions. The detector geometry, which consists of a set of plane slabs, may be easily extended to other calorimeter structures.RiassuntoQuesto articolo descrive il programma Monte Carlo utilizzato per la simulazione di interazioni di antiprotoni ad energia intermedia all’interno di un calorimetro tracciante a tubi a streamer in ottone, da impiegare nella ricerca in alta atmosfera di antimateria nei raggi cosmici. Il calorimetro è sensibile nell’intervallo di energie cinetiche (100 ⧀v 5000) MeV ed il Monte Carlo è utilizzato in tale intervallo di energie sia per interazioni di protoni che di antiprotoni. La geometria del rivelatore, che consiste in una serie di piani soarapposti, può essere estesa in modo semplice a calorimetri diversamente strutturati.РезюмеВ этой статье описыва ется программа Монте-Карло для моделирования взаим одействия антипрото нов промежуточных энерг ий внутри трекового к алориметра, чтобы исп ользовать его для пои ска антивещес чтобы использовать е го для поиска антивещ ества в космических л учах в верхних слоях а тмосферы. Калориметр является чувствител ьным в области кинети космических лучах в в ерхних слоях атмосфе ры. Калориметр являет ся чувствительным в о бласти кинетических энергий от 100 МэВ до 5000 МэВ и Калориметр является чувствительным в обл асти кинетических эн ергий от 100 МэВ до 5000 МэВ и кинетических энерги й от 100 МэВ до 5000 МэВ и программа Монте-Карл о настроена на указан ный энергетический инте рвал для взаимодействий прот онов и антипротонов. Г еометрия детектора, который со стоит из системы плос копараллельных плас тин, может быть обобще на на плоскопараллельных пластин, может быть об общена на случай друг их структур. случай других структ ур.

GALACTIC AND ASTROPHYSICAL SIZES FROM SCALAR-TENSOR THEORY OF GRAVITY

We investigate the weak-field limit of scalar-tensor theory of gravity and show that results are directly depending on the coupling and self-interaction potential of the scalar field. In particular, corrections are derived for the Newtonian potential. We discuss astrophysical applications of the results, in particular the flat rotation curves of spiral galaxies.