MIRAGE thermal cell

Description

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

References: Potin 2020 (PhD thesis)

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.

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