8 to the Bar 8 to the Bar 8 to the Bar is a studio album released by Pete Johnson and Albert Ammons in 1941 on Victor 78rpm set P-69, record numbers 27504 through 27507. It was recorded in two sessions, May 7 and June 17, 1941. It was reissued by RCA Victor in 1952 as a 10-inch LP record as LPT-9. In the United Kingdom, this LP was released by the Gramophone Company as HMV DLP 1011. It was also released as a set of four 45rpm discs, WPT-14. The album peaked at number 2, in 1945, on Billboard's album chart. All titles
Beam diameter fraction of total beam power encompassed by the beam width depends on which definition is used. The width of laser beams can be measured by capturing an image on a camera, or by using a laser beam profiler. Beam diameter The beam diameter or beam width of an electromagnetic beam is the diameter along any specified line that is perpendicular to the beam axis and intersects it. Since beams typically do not have sharp edges, the diameter can be defined in many different ways. Five definitions of the beam width are in common use: D4σ, 10/90 or 20/80 knife-edge, 1/e,