127546936
A low cost 100 KM**2 air shower detector
108859831
The PLASTEX Air Shower Tracking Detector Unit
124991249
Particle astrophysics in antarctica
9798249
A polarimetric study of the B[e] star HD 45677
We present new medium-resolution spectropolarimetric observations of HD 45677 in the B and R bands. A change in polarization is detected across Hα, Hβ and Hγ confirming that the ionized region around the star is aspherical. (Q, U) points associated with these emission lines occur away from the continuum, defining a polarization vector which points in the same direction for each of the lines at an average intrinsic polarization angle of 164°± 3°. 
 
 
 
These data were combined with past photometric and polarimetric data from the literature to investigate any variability. We find that HD 45677 is both photometrically and polarimetrically variable and that these changes are linked. We suggest that these variations may be caused by an aspherical blowout, and by deriving a least-squares fit to the B-band polarimetric data in the Q–U space, we show that the blowout occurs at an intrinsic polarization angle of 175°± 1°, along the same angle as the proposed geometry of the ionized region.
16884502
Post-Red Supergiants
The yellow hypergiants are found in a stage between the massive Red Supergiants and the Wolf-Rayet stars. This review addresses current issues concerning the evolution of massive stars, concentrating on the transitional post-Red Supergiant phase. Few yellow hypergiants are known and even fewer show direct evidence for having evolved off the Red Supergiant branch. Indeed, only two such rare objects with clear evidence for having gone through of a previous mass losing phase are known, IRC +10420 and HD 179821. We will review their properties and present recent results employing near-infrared interferometry, integral field spectroscopy and polarimetry. Finally, their real-time evolution is discussed.
13621763
What are sterile neutrinos good for
Taken at face value, current experimental data indicate the existence of a new particle, the sterile neutrino, which must be a singlet under the Standard Model gauge group. Although they are not detectable through traditional means, such particles have interesting observable consequences for particle astrophysics and cosmology. Here we examine these implications and discuss, in particular, sterile neutrino dark matter and the relationship between matter-enhanced active-sterile neutrino transformation and the synthesis of heavy elements in supernovae.
17884247
Performance of the LHCb RICH detector at the LHC
The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2–100 GeV/c. The operation and control, software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types (π, K, p) is achieved.
16952201
Magnetic shielding studies of the LHCb rich photon detectors
The LHCb experiment will use two RICH detectors to provide particle identification. The Hybrid Photon Detectors (HPDs) adopted for these detectors are required to operate in the fringe field of the 4 Tm LHCb dipole magnet. In fields in excess of 15 G, photoelectrons are lost from the active area of an HPD. Shieldingthe HPDs from the fring e field is therefore essential for the efficient operation of the RICH detectors. This paper describes the technique used to calculate the residual field inside the relevant magnetic shields. The size of the problem, together with the disparity in the geometric scales involved, makes the calculations intractable usinga finite element model of the entire mag netic environment. As a result, a sub-modellingmethod has been used. The model indicates that the photon detectors will operate efficiently.
121744643
Characterisation and compensation of magnetic distortions for the pixel Hybrid Photon Detectors of the LHCb RICH
Abstract The LHCb experiment at LHC, optimised for the study of CP violation, has two RICH detectors to provide particle identification in the momentum range ∼ 2 – 100 GeV / c . The stringent requirements on the photon detectors are met by the custom-made pixel Hybrid Photon Detector. The photon detectors need to operate in the fringe field of the LHCb dipole magnet which will produce distortions of the image detected on the pixel chip which is encapsulated inside the HPD. This paper reports on the experimental characterisation of the image distortions caused by an external magnetic flux density. These measurements allow for the development of a parameterisation of the effects and a compensation algorithm, which are also presented.