Noise Characterization of the SIDECAR ASIC Readout Chip

Noise Characterization of the SIDECAR ASIC Readout Chip for SNAP Martin Diaz Stanford Linear Accelerator Center August 14, 2008

Our Expanding Universe n The expansion history of the universe can be mapped out n What is causing it to accelerate?

Dark Energy n Believed to be the reason for the accelerating expansion n Dark n Yet, energy dominates our universe little is known about it

Dark Energy

Super. Nova Acceleration Probe n Part of the Joint Dark Energy Mission (JDEM) n Between NASA and DOE

Super. Nova Acceleration Probe n Weak gravitational lensing N. Kaiser

Super. Nova Acceleration Probe n Measure changes in the expansion rate with the help of type Ia supernova

Type Ia Supernova n No observed Hydrogen n Found n Outer in spiral and elliptical galaxies stellar layers missing prior to explosion

Type Ia Supernova n Binary System n Matter is transferred n Causes white dwarf to implode

Type Ia Supernova n Luminosity is from radioactive decay of Cobalt and Nickel into Iron n Same n Act Fuel = Same Luminosity as “Standard Candles”

Super. Nova Acceleration Probe n SNAP n Peak brightness n n will measure: Distance away Redshift n Expansion factor

Super. Nova Acceleration Probe SIDECAR ASIC

SIDECAR n System for Image Digitization Enhancement, Control and Retrieval Application Specific Integrated Circuit (ASIC) n Alternative to discrete electronics

SIDECAR n Converts Analog signal from image detector to digital signal n Easily transmitted and stored

SIDECAR n Problem: Reduce noise n Method: Optimization of microcode n Compare multiple images n Without image sensor

SIDECAR n Procedure Two consecutive images n Take difference in pixel value n Collect to form histogram and obtain RMS n n Results

SIDECAR n Procedure n After some modification to the Amplifier Reset n Results

SIDECAR n Procedure 100 images n Compare a single pixel n n Results

SIDECAR n Procedure 50 images n 256 pixels n n Results

Conclusion n After testing the SIDECAR in 32 channel mode n Microcode optimization n RMS value as low as 4. 8

Future Work n Operation under cryogenic temperatures n Integration with Hybrid Visible Silicon Imager (Hy. Vi. SI) imaging sensor.

Acknowledgements n Thank you to my mentor Leonid Sapozhnikov and the rest of the SNAP team. I would also like to thank the Department of Energy and the SULI staff.

Resources http: //snap. lbl. gov n C. Bebek, “The SNAP Space Mission”, Nuclear Instruments and Methods in Physics Research, Vol. 579, Issue 2, pp. 848 -852, 2007. n M. Loose et al. , “The SIDECAR ASIC – Focal Plane Electronics on a Single CHIP”, Cryogenic Optical Systems and Instruments XI, Proc. n SPIE Vol. 5904, pp. 293 -302, 2005.