The results of 5 years of development of the inner tracking system of the HERA-B experiment and first experience from the data taking period of the year 2000 are reported. The system contains 184 ...chambers, covering a sensitive area of about
(20×20)
cm
2
each. The detector is based on microstrip gas counters (MSGCs) with diamond-like coated (DLC) glass wafers and gas electron multipliers (GEMs). The main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment. The observation of gas discharges which damage the electrode structure of the MSGC led to the addition of the GEM as a first amplification step. Spurious sparking at the GEM cannot be avoided completely. It does not affect the GEM itself but can produce secondary damage of the MSGC if the electric field between the GEM and the MSGC is above a threshold depending on the operation conditions. We observed that aging does not only depend on the dose but also on the spot size of the irradiated area. Ar–DME mixtures had to be abandoned whereas a mixture of 70% Ar and 30% CO
2 showed no serious aging effects up to about
40
mC
/cm deposited charge on the anodes. X-ray measurements indicate that the DLC of the MSGC is deteriorated by the gas amplification process. As a consequence, long-term gain variations are expected. The Inner Tracker has successfully participated in the data taking at HERA-B during summer 2000.
An estimate of the feasibility of the ultrahigh-energy cosmic ray and neutrino detection using a lunar satellite-borne radio receiver is presented. The data obtained in the proposed experiment will ...make resolving the current contradictions in the ultrahigh-energy cosmic ray spectra measured with the major ground-based instruments possible. Moreover, they will enable us to considerably extend the accessible energy range and to check predictions of various models of the origin of the highest-energy particles in the Universe. At the same time the lunar radio detector provides a means of searching for ultrahigh-energy neutrinos with a high sensitivity combined with a very large target effective mass.PUBLICATION ABSTRACT
The problem of detecting ultrahigh-energy cosmic rays (UHECR) and neutrinos (UHEN) is discussed. In this context, potentialities of orbital radio detection are examined. Estimates are made for ...apertures of space experiments using the Moon and similar-size natural ice satellites of Solar-System planets as targets for interaction of cosmic rays and neutrinos. The comparative analysis indicates the Moon as the most promising target.
The feasibility of using the Lunar Orbital Radio Detector (LORD) to detect radio signals from showers initiated by ultrahigh-energy particles interacting with the lunar regolith is studied. The ...design of the LORD space apparatus is presented. The simulation by the Monte Carlo method has shown the necessity to take into account the radio signal reflection from the lower Lunar regolith boundary. As a result, the increase of the observation efficiency of true events increases by several times. This fact greatly enhances the scientific potential of experiments with the lunar orbital radio detector
This article examines the idea of participatory democracy. The article provides case study of pilot projects aimed to engage citizens for public participation in different forms, such as: ...participatory budgeting, participatory modeling, public consultations and other participatory practices. The concept of public participation implied in most common methods of consultation as local meetings, public hearings, creation of working groups, public dialogue commissions, workshops, discussion forums on Web sites, contests of ideas and projects, crowdfunding projects, cooperation citizens initiatives and more consumerist type as polls and focus groups. The ability to work together becomes a resource for growth of civic consciousness, where citizens become active actors, who able to participate in public policy, resource mobilization, independent projects for realization and formation of social capital. The challenge for participatory democracy is maturity degree of civil society and examined examples of participatory practices are pilot projects that aimed formation of civic consciousness.
Current status of the LORD experiment Gusev, G.A.; Chechin, V.A.; Lomonosov, B.N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2009, Letnik:
604, Številka:
1
Journal Article
Recenzirano
The current status of the Lunar Orbit Radio Detector (LORD) experiment to search for ultra-high-energy cosmic rays (UHECR), using the Moon as both a target for the UHECR interaction and radiator for ...production Cherenkov radio emission. The scientific potential of this new technology is estimated for a reasonable configuration of experiment by analytic modeling. It is shown that such radio wave experiment can be competitive with modern projects in this field. The simplest technically realizable architecture for the first generation of the LORD instrument, disposed on a standard lunar space platform designed by Lavochkin association, is elaborated. A Monte Carlo simulation is performed, including effects associated with the finite depth of the regolith layer. The signature of the cascade signal is different from the background, and discrimination between CR and neutrino cascades might be possible.
Floristic investigations in south tundra subzone of east Taimyr Pospelova, E. B., Lomonosov Moscow State University, Moscow, Russia; FBGU “Reserves of Taimyr”, Norilsk, Russia. parnassia@mail.ru; Pospelov, I. N
Turczaninowia,
04/2015, Letnik:
17, Številka:
2
Journal Article
Recenzirano
The results of the floristic re-survey of two southern tundra of Taimyr areas are stated. In the issue of survey each check list was supplemented by more than 100 species. A general outline of the ...vegetation study area is provided. The annotated list of most interesting species findings with indication of collection sites coordinates, types of distribution and typical habitat is given. The remainder additions to local floras in list-form are sited.
A new technique of the Ionization Neutron Calorimeter (INCA) to be installed aboard a satellite or a space station is capable of opening new horizons for cosmic-ray physics. The main goal of the ...experiment proposed is studying local nearby sources of high-energy cosmic rays by measuring the spectrum and composition of the nuclear component with the energy resolution of better than 30% that is sufficient for solution of these problems in the energy range 0.1–10 PeV, i.e., in the so-called “knee” region, and the spectrum of primary electrons in the energy range 0.1–10 TeV with the proton-background suppression factor up to 10
7. In addition, this experiment can provide new information on the cosmic-ray gamma-radiation in the energy interval 30 GeV–1 TeV, neutrons and gamma-rays from solar flares, and the existence of very massive exotic charged particles in cosmic radiation. The INCA is a calorimeter combining properties of conventional ionization calorimeters and classical neutron monitors. It can measure both the ionization produced by charged particles and evaporation neutrons arising as a result of excitation of heavy-absorber nuclei by cascade particles. The advantages of the INCA are not only excellent electron–proton separation but a high geometry factor of about
2
m
2
sr/
ton
owing to the INCA optimized composition and shape, whereas conventional ionization calorimeters are usually limited by geometry factor on the order of
0.1
m
2
sr/
ton
. To verify the INCA concept, a prototype was constructed and exposed to pion and proton accelerator beams with energies of 4 and 70 GeV, respectively, and to an electron beam with an energy of 200–550 MeV. The experimental data obtained agree well with the results of a Monte Carlo simulation by the SHIELD code.
The feasibility of using the lunar orbital radio detector to detect radio signals from cascades initiated by ultra-high-energy cosmic rays interacting with the lunar regolith is studied. Simulation ...by the Monte Carlo method demonstrates that, with the regolith thickness randomly distributed in the range 2–12 m, the detection of radio signals reflected from the lower boundary of the regolith (for particle energies
W
≥ 10
20
eV) increases the number of valid events severalfold. The additional contribution due to the reflected radio-frequency radiation greatly enhances the scientific potential of experiments with the lunar orbital radio detector.
is a fixed target experiment working on the 920 GeV proton beam of the HERA accelerator at the DESY laboratory in Hamburg. During the last data taking period (2002-2003), about 150 million dilepton ...triggers, 220 million minimum bias events and 35 million hard photon triggers were acquired. These large statistics allow detailed studies on the production of charmonium states in proton-nucleus p-A collisions, which extend for the first time into the negative Feynman-x () region. Measurements of the inclusive , \(\Upsilon\) and open charm cross sections are also ongoing. After a brief discussion of the detector and of the data samples, we report on preliminary results obtained on these physics topics.
PDF
