Transcript Power supplies
Power supplies Will need power supplies to power : APDs PMs Silicon PMs Signal amplifiers. Characteristics: of power requirements. -12 v; -6v; + 6 v 1 A each for amplifiers. Up to 2kV, positive and negative, from 0 up in at least 1V increment for APD, 23mA (for 2-3) Up to 1.5kV, 10mA for PMT (all 6) All of above should have the smallest ripple voltage possible (around 1-4 mV) High Voltage power supplies Model 556 from ametek-online.com Double-NIM crate size, from ±10 to ±3000V, 2 output channels. 10 mA, output voltage remotely controlled by applying from 0 to 6.5V, noise <10mV Not a smooth voltage increments but rather a step change on voltage – not good for APDs but sufficient for PMT Current price as of 7/4/2003 - $1615.00 HV power supplies J4-2P and J4-2N from Matsusada Precision Inc. 2P – positive 2000V, 2N – negative 2kV. Ripple of 2mV. 2mA output current. Voltage regulated by multi-turn built-in potentiometer or remotely. Recommended for APD. Non-standard size. Current price as of 3/26/2003 is $252.00 (on picture it’s the left unit) Low Voltage power supplies S7-001 Herbach&Rademan power supply (www.herbach.com) 0 - ±30V (positive and negative simultaneously, 0.5mV ripple RMS. Current limit 5A. Regulated. Dual Panel meters. Current price is $238.95 APD Box design #3 # 4 above shows the housing of APD and not the actual box which will the shows later. for cooling the APD using the peltier elements. This method will require a current of few Amps (up to 3-5A) to get the APD down to about –40 degrees Celsius. (doesn’t require very stable power supply. Can use a spare AT computer power supply.) Peltier Elements Low-cost – about $35 per each element or less Allows good temperature control, as precise as 0.1 degree at around 20oC, Performance and precision somewhat degrade at negative temperatures because the element will require a large current ( 5A) in that range, which is not easy to control. Box design The above shows the right and left sides of the box that are just smooth surfaces. box design of the APD allows up to two peltier elements for better control and allowing to achieve lower temperatures (theoretically down to –30o C or even lower if 4 elements are used stacked. Usage of 2 elements allows to minimize currents for better controllability and stability. Box Design The front side allows two standard optical connectors to be used for greater flexibility of the design. Box Design Bottom and top parts of the box allow the connectors and holders and the amplifier box to be attached. Box Design #8 #6 #13 #5 This is an “artistic” representation of the box that will have APD inside and the box with preamplifier (which is not being cooled as of current scheme but the ability to do this has been integrated into this particular design).