MIRAGE thermal cell

The MIRAGE thermal cell allows to reach temperatures up to 250°C and can be attached to the SHADOWS spectro-gonio radiometer.

MIRAGE thermal cell

Picture: MIRAGE thermal cell for SHADOWS spectro-gonio radiometer: top view showing the cell with the sample holder (black), the connection to the vacuum pump and the saphire window.

Description

Reference: Potin 2020 (PhD thesis)

Thermal cell

Inside the MIRAGE cell the sample holder is screwed onto a brass support. The temperature of the chamber is controlled by a PT100 thermal sensor and two heating resistances placed on 2 opposite sides of the support. These 25 ohm resistances are connected to an high accuracy temperature controller where the required temperature value can be configured to 0.1°C. It allows to measure and control the temperature up to 250°C. The temperatures are displayed with +/- 0.1°C uncertainty.  A 20mm diaphragm need to be installed on the detector (to avoid its saturation) for temperatures higher than 180°C.

A transparent sapphire window encircled by a metallic flange composes the cover.

A pumps and pressure controllers allows us to get high vacuum (<10-6 mb) or to introduce gas(es) of known composition and pressure (10-3 mb – 1 bar) over the sample.

There is a choice of 8 sample holders with different sizes (volume from 1.5 to 680 mm3) to accommodate different amounts of material.

Sample holders (black anodized aluminum):
– cylindrical, d=  2 mm, h= 0.5 mm (for micro-beam)
– cylindrical, d=  3 mm, h= 1 mm (for micro-beam)
– cylindrical, d=  7 mm, h= 1 mm
– cylindrical, d=  7 mm, h= 2 mm
– cylindrical, d=  10 mm, h= 1 mm
– cylindrical, d=  10 mm, h= 2 mm
– cylindrical, d=  12 mm, h= 3 mm
– cylindrical, d=  12 mm, h= 6 mm

Characteristics
– maximum temperature: 250°C (with a 20mm diaphragm)
– stabilisation time to 180°C: 6 min