Gerardo E. Cornejo M. Bonner Denton Scott Tilden Roger Sperline Denton Research Lab Department of Chemistry University of Arizona 07-08

 Secondary Ion Mass Spectrometer  Function  Objectives  Application to Space Exploration  Remote Sensing  Function  Objectives  Application to Space Exploration

 Works by the principle of charge-to-mass ratio, separation of masses in magnetic sector analyzers –provides quantitative and qualitative analysis  5 Major Components  Primary ion source  Primary ion column  High vacuum sample chamber  Mass analyzer  Ion detection unit

Increase the sensitivity, stability and dynamic range of Secondary Ion Mass Spectrometry  Current methods to detect ions  Faraday cups  Ion multiplier  Capacitive Trans-Impedance Amplifier Faraday Cups

 Gain is stable and precisely known (gain=1)  Bandwidth is consistent with use in sector-based mass spectrometry  Useful for I ion  amp (1 ion/sec  1.6  amps)  Implies that one needs about 6250 ions/sec for detection by Faraday cup Faraday Cage Collector Electrode Out to Amplifier Load Resistor Out to Amplifier

Operates only when free mean path of the electrons is large ie. a high vacuum Statistically unpredictable

 CTIA is ideal for SIMS  Fast (1 MHz or higher per pixel)  Low read noise  10,000 x sensitivity improvement over current SIMS detectors  Expect further improvement with 3rd generation differential devices and cooling

 CTIA -1 A 32 channel device adapted from astronomy  CTIA -2 (DM01) A 4 channel single ended input device – demonstrated high sensitivity - but was also highly sensitive to environmental noise  CTIA -3 (DM03) A 128 channel wire bonded mass spec. detector  CTIA -4 A 64 channel wire bonded mass spec. detector with novel noise reduction circuitry by ADIC  CTIA -5 (DM04) A 4 channel differential device designed to reject environmental noise  CTIA -6 (DM013) A 48 channel monolithic electrode mass spec. detector  CTIA -7 (DM016) A 4 channel differential device with X1 & X100 gain levels, programmable bandwidth & advanced low noise input FETs  CTIA -8 (DM 015 ) A512 channel monolithic electrode mass spec. detector (currently under test)  CTIA -9 A 512 channel monolithic – fixes clocking problem on CTIA -8 (under fab)  CTIA -10 A 1696 channel monolithic 12.5 micron pitch mass spec array (under fab)  CTIA – 11 A 4 channel differential with 2 to 4 fold increased sensitivity (under fab)

 Currently in use in many missions  “Stardust” mission employs SIMS to perform isotope ratio of oxygen analysis  Used to analyze return samples and obtain chemical composition from mass spectrum

 Diverse forms and methods of applications depending on field of research  Fluorescent tag is placed on object that one may wish to observe  Taggant fluoresces by near IR excitation from laser diodes and/or ambient light and is detected by InGaAs focal plane arrays

 Produce a signal that is observable from a long distance  Vary collection optics to optimize the signal return  Minimize background noise with software controls

 Possibility to track errant satellites/spacecraft that have lost communication and also space debris  Applications to tracking animal migration patterns if taggant is placed on animal groups

 Dr. M. Bonner Denton  Dr. Scott Tilden  Dr. Roger Sperline  The Denton Research Group