Detectors bolometer

For the bolometer detector having the above characteristics and operating withf 1 optics (/ = 1) the peak to peak temperature change of the a-Si film is approximately 3 mK per one degree kelvin change in scene temperature. 

With regard to X-ray microanalysis in the AEM, the bolometer detectors can lower the detectability limits from 0.03 wt% to 0.006 wt% in 100 nm thick Cu-Mn specimens. Even in 10-nm-thick specimens, 0.02wt% will be detectable with these detectors. 

The Penn State measurements were made in a spectrometer constructed by Dr. H. Atwater in the Department of Electrical Engineering, which operated at a frequency of 9.11 X 109 c.p.s., and employed a Varian Type V 4612A magnet. Phase sensitive detection was used, in conjunction with a bolometer detector. The cylindrical cavity operated in the Hon mode. 

InSb bolometer detector will reduce these values of by about a factor of 4. 

The first detection of a vibrational transition in a cluster was performed using a bolometer detector. This device, which is maintained at 4 K, is... 

INFRARED-TaMILLIMETER, BROADBAND, SOLID STATE BOLOMETER DETECTORS. 

Infrared radiation was discovered by Herschel in 1800. The bolometer detector (sensitive resistance thermometer) was invented by Langley and was used by him for studying the infrared spectrum of the sun in 1881. Coblentz in Investigations of Infrared Spectra, published in 1905, described the infrared spectrum of several hundred compounds, measured point by point using a custom-made instrument containing a rock-salt prism, a mirror spectrometer, and a radiometer detector. Each spectrum took 3-4 h to obtain. Infrared spectroscopy only began to develop in more routine use in the 1930s initiated by needs of the petroleum industry. 

COMPARISON OF PHOTOCONDUCTIVE-BOLOMETER DETECTORS ON AN AIRBORNE SYSTEM... 

Fig. 7.21. Schematic diagram of the droplet beam apparatus used by the group of the late Roger Miller at the University of North Carolina to study isomerization of HCN HF van der Waals complexes. The HCN and HF molecules are first picked up separately to form oriented van der Waals complexes inside the droplets. The CH or HF stretch vibrations are used to excite the complex and after a flight time of 175 ns to probe the isomers formed. The corresponding laser resonances are monitored by the increase or depletion of the droplet signal at the downstream bolometer detector. Adapted from Ref. 57.

Fourier transform infrared (FTIR) spectra were performed on a Mattson Cygnus 100 FTIR spectrometer with a MCT bolometer detector. The available spectral range in practice is comprised between 600 and 4000 cm and the typical resolution used was 2 cm" ... 

IR spectroscopy is a valuable complementary technique to Raman spectroscopy. Synchrotron based IR micro-spectroscopy is a new technique that shows promising perspectives for studies of skin and human cells (28). At the Max-Lab synchrotron beam line in Lund, Sweden an IR microscope is now being installed (29). This instrument will allow IR-spectra to be recorded with a bolometer detector down to 50 cm (around 1,5 THz). In the R(v)-representation of the low-wavenumber Raman spectrum it is very difficult to quantify the amount of free water because the water band at 180 cm is weak compared to the protein hydrogen bond band at 110-120 cm" Hopefully the water band is relatively more intense in the IR spectrum allowing a detection of the free water at low concentrations. 

Recent advances in far I.R. instrumentation have been mainly in the area of detector improvement. Detection in the far I.R, is restricted to bolometric detection as opposed to the availability of photo conductive detection at wavelengths shorter than about 30 pm. An early standard for far I.R. detectors was the Golay bolometer detector. The periodic heating and cooling of a chopped I.R. beam is translated into expansion contraction of a small pocket of gas which in turn deflects a membrane. The membrane deflection is measured electro-optically and converted to the corresponding signal. 

Zwerdling, S., Smith, R. A., Theriault, J. P. (1968). A fast, high-responsivity bolometer detector for the very-far infrared. Infrared Physics, 8, 271-336. 

---