A method for forming a semiconductor device is provided. The image sensing pixel is disposed on the substrate and comprises a scan line, a data line crossing the scan line, a photo sensing element and a TFT element. The damping vent controls displacement of the valve piston by creating delta pressure in oil contained in a piston chamber in opposition to axial piston movement during opening and closing of the valve, to stabilize the axial movement of the piston thereby damping valve oscillation during valve opening and closing. Other orientations are anticipated including upside down as well as other operating modes such as flash enabled and flash disabled. This process gives -2-propyloctanoic acid having high optical purity without isomerization. This collimator sampling is accomplished through strategic placement of the detector heads relative to each other such that for any given projection, a complete imaging of the projection is acquired by summing the complementary contributions of the multiple detector heads at the projection under consideration.