Strong Reduction of the Effective Radiation Length in an Axially Oriented Scintillator Crystal

We measured a considerable increase of the emitted radiation by 120  GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline electromagnetic field. The data collected at the external lines of the CERN Super Proton Synchrotron were critically compared to Monte Carlo simulations based on the Baier-Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of 5 in the case of beam alignment with the [001] crystal axes. The observed effect opens the way to the realization of compact electromagnetic calorimeters or detectors based on oriented scintillator crystals in which the amount of material can be strongly reduced with respect to the state of the art. These devices could have relevant applications in fixed-target experiments, as well as in satellite-borne γ telescopes.

[Effects of helium-neon laser energy on the tissues of the middle ear in the presence of biological fluids and drug solutions]

By means of biophotometry the coefficients of absorption and penetration depth of helium-neon laser radiation with a wavelength of 632.8 nm were measured. Measurements were made in the inflammatory mucous membrane of the tympanic cavity, mucous membrane of the tympanic-cavity infiltrated with the saline solution, cortical bone of the mastoid, cartilage of the auricle, blood, serum, exudate, 0.02% furacillin, 3% boric acid, 0.9% and 10% NaCl. These observations were used to develop an efficient method of laser therapy of the inflammatory and wound surface of the middle ear biological tissue, which formed the basis of a new procedure of the laser treatment of "closed" cavities of the middle ear in an early postoperative period after debridement or hearing repair surgery of suppurative otitis media which were filled with a transparent antiseptic solution.