摘要:

The Alpha Magnetic Spectroscoper (AMS) is a particle detector to be installed in the International Space Station to search for, among other, cosmic anti-nuclei. This instruments includes a silicon tracker immersed in the magnetic field for charge and sign assignment. The exponentially decreasing abundance of cosmic nuclei as function of atomic number (Z) requires accurate predictive power if dE/dx measurements are to be used in Z identification. We analyzed dE/dx from AMS prototype (AMS-1) flight test carried out on the NASA’s Discovery Shuttle in 1998. The data show appreciable deviations from theZ2dependence predicted by Bethe-Bloch equation. An interpretation of this phenomenon, based on our Energy Deposition by Secondary Electrons (EDSE) model, is proposed which reproduces the general features of the data. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378649

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We have used a LED (Light Emitting Diode) in the Ronchi tester in order to obtain two main improvements: a) we can choose one of 2 wavelength bands to illuminate and record the ronchigram, and b) we can change the irradiance of the illumination source according to the optical system under test and the detector array. This can be done by using an adequate electronic circuit. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378650

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The telescopes of the Pierre Auger Fluorescence detector will use a segmented mirror. To align the segments we have developed four methods, which use: a) the image of the stop border, b) the image of a screen with concentric circles and c) the Ronchi pattern. Adding to these, we have developed a new method d). Instead of the Ronchi ruling, we have used a circular grid. In this case we obtain a moire´ pattern for each segment by means of which the experimental setup is simplified and the sensitivity of the alignment is improved. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378651

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We study the magnetic properties of a degenerate neutron gas in equilibrium with a background of electrons and protons. The effective mass of one branch of the neutron spectrum become massless for magnetic fieldsB∼1020&hthinsp;G.At fields near and below that order, the neutron gas experiences a transverse magnetic collapse similar to the one described in paper Phys. Rev. Lett.84(2000), 5261 for the electron gas. We conjecture this collapse would provide a mechanism for production of highly energetic particles. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378652

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The focal plane of EUSO is designed to be comprised of multianode photomultipliers. A study of characteristics of the photomultipliers has been started to evaluate, in detail, the total performance of EUSO and its small-scale prototype (cEUSO). A result of one unit of multianode photomultiplier is reported. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378653

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

For the telescopes of the fluorescence detector of KLYPVE project we used a Fresnel mirrors. To reduce effects of diffraction we propose a small number of rings, and a stop which will avoid the coma aberration. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378654

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

In this paper we report the geomagnetic field effect on three photomultiplier tube (PMT) candidates for their massive use in the Pierre Auger Observatory surface detector array. The geomagnetic field effect could be manifest in the variation of the response of the PMT after this has been rotated with respect to its own axis on top of the surface detector. We measured the signal given by secondary cosmic rays and by a LED installed in the interior of the tank with one PMT. Data were digitized using a digital oscilloscope and an ADC-CAMAC module. We found no significant variation of the PMT response when the dynode axis direction changes with respect to the geomagnetic field orientation. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378655

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The design of the air Cherenkov detector array for the Cerro La Negra site (elevation 4300 m asl) is presented. The most important features of the array are: autonomous operation of the detectors, low power electronics, laser communication lines and power supplied by solar panels and batteries. The joint operation of the array with water Cherenkov extensive air shower (EAS) particle detectors will allow to obtain information on EAS core positions, primary energies, arrival directions of the primary particles, and temporal profiles of the EAS pulses in air Cherenkov and particle detectors. The study of the EAS development above the shower maximum is among the main goals of this experiment. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378656

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Here an attempt is made at summarizing the presentations, most of which were about the highest energy particles observed in nature. Particular attention is paid to the solutions to the Ultra High Energy Cosmic Ray particles, to the new and forthcoming data, to the new proposals for experiments and to the role of primary composition, that were amongst the most discussed subtopics. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378657

出版商:AIP    

年代:1901

数据来源: AIP