A system, method and computer program product for enabling a plurality of users engaged in real-time voice communications over a wireless communications link to collaboratively select one or more musical media files and to jointly listen to the collaboratively selected musical media in approximate synchronicity as a mutually perceivable background musical stream. The method includes providing a mold assembly with an exterior mold and an interior core. The multiple fins are each in the form of a rhombic column and provided on the plate part in a lattice pattern in the manner that the longer diagonal of the rhombic column extends along the cooling water flow path. The second filter is located in the second direction and separates the first reflected lights into second lights that are in a second wavelength band and second reflected lights. Once calibrated, the single-look complex amplitude data are sufficient to form all Stokes parameters, which fully characterize the radar backscatter. On a sensor substrate on which a pixel array is formed, a scintillator layer that covers the pixel array, a sealing layer that covers a side face of the scintillator layer, and a protection layer that covers an upper face of the scintillator layer and an upper face of the sealing layer are formed.