Planetary Environment Chambers

PEACh – Planetary Environment & Analysis Chamber

Chamber and feed-throughs

  • Chamber: 24” x 24” x 24” stainless steel
  • Viewport #1: 6” x 4” rectangular
  • Viewport #2:  circular 4.5” diameter
  • Electric Feedthroughs: three on the left wall
  • Optical fiber feed-throughs: four on the ceiling
  • Feedthroughs for valves and pressure meter: three on the right wall
  • Feedthroughs for coolant: two on the right wall

Vacuum system

  •  Scroll pump (Edwards XDS35i): Ultimate vacuum (total pressure): 0.008 Torr
  • Pressure meter:  convection-enhanced Pirani gauge (Kurt J. Lesker Company® model KJL300808)    Vacuum reached:  ~1×10-2 mBar when maintaining the continuous pumping

Input system for gas mixture

  • Ball and Needle valves
  • CO2 (or desired gaseous mixture) in the pressure range 1×10-2 mBar to ambient pressure

Sample temperature

  • Coolant: LN2
  • Delivery of coolant: evaporation of LN2 from a Dewar via the heating of an immersed electric resistor
  • T control: RTD and CN7600 autotune controller (OMEGA Engineering Inc.)
  • Cold plate: a toroid-shape double-wall copper block
  • Sample cups: 24 cups of 0.5” internal diameter × 0.4” internal depth made of cooper in good thermal contact with cold plate
  • T range: RT to -100°C
  • Sample T homogeneity:  ±0.5 °C at 0°C or ±5 °C at – 40 °C

Chamber T & RH monitoring

  • T & RH data logger (Extech Instruments RHT20)

Imager and Spectral Sensors

Raman Spectrometer

  • Laser: 532nm CW laser beam, ~ 10 mW at the sample
  • Raman Probe: 5 mm WD, ~ 20 µm Ø laser beam, 200 μm core Ø collecting optical fiber
  • Raman spectrograph: 100 – 4300 cm-1, 4-5 cm-1 spectral resolution

Plasma Spectrometer

  • Collecting optical fiber: 230 µm Ø UV enhanced optical fiber cable (Ocean Optics)
  • Spectrometer: three OceanOptics S2000, and an Echelle spectrograph with ICCD (Andor Company)