Bolometer is a total radiation detector designed to measure energy losses. Bolometer should have a flat spectral response i.e. it is equally sensitive to radiation of any wavelength and any particle fluxes.

PYROELECTRIC BOLOMETER SYSTEM

EXPORTED TO: Japan, NIFS National Institute for Plasma Physics, Toki

Pyroelectric bolometer is based on a Pyroelectric crystal (usually LiTaO3 or PZT) covered by absorbing layer (silver or silver blackened with carbon). Once the radiation is absorbed by pyroelectric bolometer and its temperature rises the polarization of dipolar domains inside the crystal changes to more chaotic which results in an electric current flowing across the crystal.

The current (typically very small: 10-11 10-12 A) can be amplified by current to voltage converter based on operational amplifier. The amplifier should be placed as close as possible to the detector to reduce the noise. Pyroelectric bolometer is cheap and fast, has a real flat spectral sensitivity. Special precautions should be taken to avoid the noises caused by detector, cable and amplifier vibrations as well as electromagnetic noises.

TUAP pyroelectric bolometer is coupled by a special low-noise cable, amplifier in a non-vibrating housing and data acquiring military computer working in a hard conditions closely to thermonuclear reactor.

Number of channels

2 detector arrays, 4 detectors in each array

Dynamic range

0 2 W/cm2

Sensitivity

510-5

Frequency range

10 4000 Hz

Working temperature of sensor head

15 200 C

Storing temperature of sensor head

5 230 C

Power supply

100 V / 60 Hz / 40 W

Length of cable inside vacuum

1.5 m

Length of cable outside vacuum

5 m