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نتایج جستجو برای Barium Fluoride

تعداد نتایج: 15617  
1992
Da-an Ma, Ren-yuan Zhu,

Barium fluoride (Baf2) crystals were considered by the GEM Collaboration, to be used in constructing a precision electromagnetic calorimeter at the SSC [1] . The key issue of using this crystal at the SSC is its radiation resistance [2] . An Expert Panel was assigned by the SSC laboratory to review the radiation damage problem of BaFz. The Panel met in December 1991 and again in January 1992 fo...

1994
H. Newman,

This report presents results of optical bleaching for barium fluoride crystals to be used to construct a precision electromagnetic calorimeter at future hadron colliders. A practical technique for in situ bleaching by illuminating crystals with light from a UV lamp through an optical fiber is established. The light attenuation length of current production BaF, crystals can be set to around 200 ...

1994
Ren-yuan Zhu,

This report summarizes the quality requirements to the barium fluoride (BaF 2 ) crystals for constructing a high precision electromagnetic calorimeter at future hadron colliders . The basic property of BaF2 crystals and the design and performance of a BaF2 calorimeter are presented . The emphasis of the discussion is in the radiation resistance of the current production BaF2 crystals. An approa...

2007
V. M. CARR, A. V. CHADWICK,

We have measured the a. c. conductivity of pure BaFz single crystals up to 1 336 K. At the higher temperatures we observed polarisation effects possibly due to a reaction of the crystal with the atmosphere in the cell. The defect energies derived from the low temperature region agree well with those obtained by Barsis and Taylor [27, 281. The effect of the high temperature phase transition on t...

1991
Wei, H. Newman, Z. W. Yin,

We report on a study of the light yield and surface treatment of barium fluoride (BaF2) scintillation crystals. Using a bialkali photocathode the photoelectron (p.e.) yield of BaF, crystals was measured to be 130 p.e./MeV for the fast components and 700 p.e./MeV for the slow component. A somewhat hygroscopic nature for the BaF, is found. Teflon film was found to be the best wrapping material fo...

2006

The International Programme on Chemical Safety (IPCS), established in 1980, is a joint venture of the United Nations Environment Programme (UNEP), the International Labour Organization (ILO), and the World Health Organization (WHO). The overall objectives of the IPCS are to establish the scientific basis for assessment of the risk to human health and the environment from exposure to chemicals, ...

2011
Y. C. Li, S. C. Tjong, R. K. Y. Li,

Binary polyvinylidene fluoride/barium titanate(PVDF/BaTiO3) and its nanographite (GN) doped ternarynanocomposites were fabricated using a simple solution casting process followed by compression molding. The dielectricbehavior of such hybrids over a wide frequency range was studied. Additions of GN with contents close to the percolationthreshold were found to be very effective to...

2002
T. A. DeVol,

Application of the barium fluoride (BaF 2) scintillator for characterization of intense radiation fields has been pursued since the fast component was discovered in the early 1980's. Unfortunately, ~ 80% of the scintillator emissions have a slow ~ 600 ns decay time constant. The long decay time hampers the use of BaF 2 at high count rates because the slow emissions appear as an afterglow which ...

1997
J. M. Vail, E. Emberly, T. Lu, M. Gu, R. Pandey,

Barium fluoride is an example of a high-density scintillator for detecting high-energy radiation. In use, its luminescent transmission is seriously degraded by radiation damage. This effect is associated with oxygen, among other impurities. At one time it was suspected that oxygen O, having been dissociated from a defect complex by radiation damage, absorbed some of the luminescent energy of th...