Olin 2011

Keith Gendreau

Project #1: Electron Optics for X-ray source • • • • GSFC has been building new “Modulated” X-ray sources for various uses including instrument calibration and X-ray communication Source uses multiplied photoelectrons accelerated to high voltage to generate X-rays Up to now, no serious effort has been made to model the electron focusing or improve it Olin project is to model existing source and include an Einzel lens to improve it.

The World’s First Fully Controllable Modulated X-ray Source

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Characteristics:

• Rugged- no moving parts or fragile filaments- perfect for space flight.

• Modulates x-rays at same rate that one can modulate an LED •

Major NASA Uses:

•Timing Calibration •A “flagged” in-flight Gain Calibration Source: Have calibration photons only when you want them and increase your sensitivity by reducing the background associated with the calibration photons

This has evolved to include an electron multiplier LED HV for Target (~5-10 kV) HV for Electron Multiplier (~2-3 kV

X-ray “pinhole” image of X ray source

Existing data

“Burn” pattern of electron impact on target The output of the electron multiplier…

Why do we want to improve?

We want to couple to X-ray optics so we can project X-rays over a long distance. The current source is poorly focused and can only be very inefficiently coupled to X-ray optics

Tools and resources available

• • • • Simion – Charged particle modeling software CAD models of MXS Pinhole images of existing X-ray sources Lots of literature on Einzel lenses