TL Cryogenic oven

The cryogenic vacuum oven is designed to cold and to heat the samples during the thermoluminescence analyses in a controlled atmosphere.
Cooling is achieved through liquid nitrogen: a copper tank is inserted into the oven and it is filled with liquid nitrogen. Two thermal elements allow making cold a thermal bar that supports the sample during the measurement. The thermal insulation of the copper tank filled with liquid nitrogen is achieved through the vacuum.
The thermal bar on which the sample is placed is inside a camera in the oven where the atmosphere is controlled by using a vacuum root pump to remove the air and replace it with pure gaseous nitrogen from a supply line.

To achieve the cryogenic temperature the oven must be connected to liquid nitrogen under pressure cylinder: a temperature on the sample of about -140°C will be reached in about 30 minutes, starting form environmental temperature and with an empty copper tank. Once the cryogenic temperature is reached the first time and the copper tank for liquid nitrogen is full, even after a heating cycle on the sample at +300°C, the temperature of -140°C for a new analysis is reached in few minutes. To reach a lower temperature on the sample area, the oven can be connected to liquid helium, because the oven can work till -270°C. In this case, a temperature of about -200°C in the sample area can be reached*.

The thermal bar allows also to heat the sample up to +500°C.

*To use the oven with liquid helium for the inlet and the outlet a proper pipe not provided with the system must be used. The pipes provided with the system are suitable only for the use with liquid nitrogen.