17,594 research outputs found
Polyethylene naphthalate film as a wavelength shifter in liquid argon detectors
Liquid argon-based scintillation detectors are important for dark matter
searches and neutrino physics. Argon scintillation light is in the vacuum
ultraviolet region, making it hard to be detected by conventional means.
Polyethylene naphthalate (PEN), an optically transparent thermoplastic
polyester commercially available as large area sheets or rolls, is proposed as
an alternative wavelength shifter to the commonly-used tetraphenyl butadiene
(TPB). By combining the existing literature data and spectrometer measurements
relative to TPB, we conclude that the fluorescence yield and timing of both
materials may be very close. The evidence collected suggests that PEN is a
suitable replacement for TPB in liquid argon neutrino detectors, and is also a
promising candidate for dark matter detectors. Advantages of PEN are discussed
in the context of scaling-up existing technologies to the next generation of
very large ktonne-scale detectors. Its simplicity has a potential to facilitate
such scale-ups, revolutionizing the field.Comment: 6 pages, 3 figure
A formulation of a (q+1,8)-cage
Let be a prime power. In this note we present a formulation for
obtaining the known -cages which has allowed us to construct small
--graphs for and . Furthermore, we also obtain smaller
-graphs for even prime power .Comment: 14 pages, 2 figure
Axial dependence of optical weak measurements in the critical region
The interference between optical beams of different polarizations plays a
fundamental role in reproducing the optical analog of the electron spin weak
measurement. The extraordinary point in optical weak measurements is
represented by the possibility to estimate with great accuracy the
Goos-Haenchen (GH) shift by measuring the distance between the peak of the
outgoing beams for two opposite rotation angles of the polarizers located
before and after the dielectric block. Starting from the numerical calculation
of the GH shift, which clearly shows a frequency crossover for incidence near
to the critical angle, we present a detailed study of the interference between
s and p polarized waves in the critical region. This allows to determine in
which conditions it is possible to avoid axial deformations and reproduce the
GH curves. In view of a possible experimental implementation, we give the
expected weak measurement curves for Gaussian lasers of different beam waist
sizes propagating through borosilicate (BK7) and fused silica dielectric
blocks.Comment: 16 pages, 7 figure
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