MOHD ALQAMA SHAIKHrobotics & embedded systems / project log
bash — guest@aPR0T0: ~/projects/sem
./projects/sem · monthly review

A scanning electron microscope, built one gate at a time.

A practical system map for a home-built SEM inspired by Ben Krasnow / Applied Science. Select a component in the cross-section to see its role, BOM quantity, sourcing lead, and reference.

The SEM budget and milestone review runs monthly from 26 September 2026. The living workbook is the source of truth.

System map / vacuum to pixels

hover, click, or tab through the parts

interactive cross-section
vacuum chamber filament Wehnelt anode lens 1 aperture objective lens scan plates sample stage scintillator PMT diffusion pump rough pump scan amplifierX / Y high voltage ADC / PCimage acquisition
electron beamdetector signalvacuum line

12-month project plan

₹10k monthly envelope · carry forward unused balance

milestone gates
windowgaterelease condition
26 Sep 2026review 01freeze scope, safety checklist, chamber survey
months 1–3vacuumleak-tested chamber and stable roughing
months 4–6electron gunrepeatable emission with interlocks
months 7–9optics + scanfocused beam and calibrated X/Y sweep
months 10–12detectorfirst stable image, logged settings
success criteria
vacuumrepeatable operating pressure and recorded pump-down curve
beamstable emission without uncontrolled arcing
imageone reproducible scan of a conductive sample
engineering logdate, spend, pressure, voltage, filament, sample, result
procurementprefer surplus; verify ratings before purchase; keep ₹2k buffer
Safety: this project combines high vacuum, hot hardware, kilovolt supplies, stored energy, and possible X-rays. The map is a planning aid, not a substitute for pressure-vessel, HV, grounding, interlock, or radiation-safety engineering. Review the full workbook ↗