Measuring track density of alpha particles emitted from human teeth and assess the resulting cancer risk

Two cylindrical forward TPC detectors are described which were constructed to extend the phase space coverage of the STAR experiment to the region 2.5 < |η| < 4.0. For optimal use of the available space and in order to cope with the high track density of central Au+Au collisions at RHIC, a novel design was developed using radial drift in a low diffusion gas. From prototype measurements a 2-trac...

Background: Radon, thoron and their progenies are the most important contributions to human exposure from natural sources. Radon exists in soil gas, building materials, Indoor atmosphere etc. Among all the natural sources of radiation dose to human beings, inhalation of radon contributes a lot. The work presented here emphasizes the long term measurements of radon, thoron and their proge...

The sources of lateral tape motion in a tape drive are reviewed. Currently used measurement methods and models for lateral tape motion are analyzed and compared. The effect of roller run-out, tape edge contact, and tape tension transients on lateral tape motion is discussed. A dual stage actuator tape head is investigated to improve track-following capability and increase the track density on a...

Background Sub-nanometer precision and accuracy plus high positioning bandwidth have made piezo nanopositioners essential for track profiling applications in spin-stand applications. However, (1) relentlessly advancing areal density requirements and (2) the advent of patterned media raise new issues for spin-stand integrators. These emerging needs require that the nanopositioner perform within ...

Figure 1: Conventional non-shingled writing, on the left, writes data in non-overlapping tracks, width w, with non-magnetized “guard regions”, width g, between tracks. Shingled writing, on the right, leaves residual tracks, width r, less than the width of the written track, width w’, before it writes the next track, largely overlapping adjacent tracks. This increases tracks per inch, increasing...