PMT-RAS Turning the Clean Room Into a Dark Room Objective: Test to See if PMT-RAS is Focused for Blue Light Test output of PMT-RAS receiving light from a pinhole or open diode at different turns of the barrel. Graph data in Excel and calculate FWHM (full width half max). Calculate the field of view. Calculate the focus of the lens, using the data collected, for blue light focused at infinity. LED ~ Light Emitting Diode Photo Multiplier Tube Roll Angle Sensor (PMT-RAS) Oscilloscope readings (PMT-RAS output) Signal out of PMT-RAS Input into LED The Instruments Translation Stage Controller Oscilloscope High Voltage Power Supply Signal Generator Light refraction for different wave lengths Why was it important to focus the instrument for blue light? Blue 440nm Green 546nm Red 633 nm Shorter wave lengths have larger refractive indices Extending the barrel First Test (Green) Second Test (Green) Blue Diode Blue Diode Graphs Overlaid Calculating the Field of View Distance diode was observed Distance from diode to PMT- RAS 180 L y LL Calculating the focus of the lens for blue light focused at infinity Actual Values Conclusion: ~After the focus length was calculated according to blue light focused at infinity, it was established that the PMT-RAS is in focus and no extension of the barrel will be needed. Slide Show Created By: Laura Rydland