10 K Cryocoolers — Mössbauer Spectroscopy (CCS-8XX series)
Designed specifically for Mössbauer spectroscopy, the model CCS-8XX series include design features optimized specifically for this application. The most critical requirement for successful measurements is isolation of the sample from the refrigerator vibrations.
In order to achieve vibration isolation, a flexible bellows assembly is installed between the sample support flange and the refrigerator body. The support flange is mounted to an independent table or frame (either customer or Janis supplied), and the flexible bellows dampen vibrations before they reach the sample support. Typical line broadening of 0.01 mm/s is achieved through this technique. The sample support rod is suspended within a copper cylinder (with Mylar windows for maximum gamma transmission.) The sample is cooled indirectly, using static helium exchange gas inside the sample chamber. This arrangement permits samples to be quickly exchanged (via top loading access) without warming the entire cryostat. It is also ideal for uniform cooling of poor thermally conducting samples, such as foils and powders.
- Vibration isolation mounting stand
- Vibration isolation bellows
- Isothermal static helium gas sample chamber
- Optical vacuum jacket and radiation shield (with two Mylar windows)
- Gold-plated OFHC copper sample holder
- 10-pin electrical feedthrough for customer wiring into the sample area
- Two spare electrical access ports
- Evacuation valve and safety pressure relief
- Model 8200 compressor and 10 ft gas lines
- Additional electrical feedthroughs (BNC, SMA, multipin, and others)
- Additional optical window ports
- Larger or smaller diameter sample chamber
- Custom configurations
|Temperature||~15 K to 300 K|
|Sample change time||2 min|
|Initial cooldown time||~3 h to 15 K|
|System weight||87 kg (190 lb)|
|Compressor||59 kg (140 lb)|
|Cold head||14 kg (30 lb)|
|Power supply||208/220 VAC, single-phase, 50/60 Hz|
|Power requirements||2.0 kW, 8.5 A (water-cooled); 2.1 kW, 10 A (air-cooled)|
|Water-cooled compressor requirements|
|Flow||3.8 ± 1.9 L/min (1.0 ± 0.5 gal/min)|
|Temperature||32 °C (90 °F) maximum, 10 °C (50 °F) minimum|
Download the 10 K Cryocoolers Water-cooled Pressure Table
|Vibrational line broadening||0.01 mm/s (with proper mounting)|
This image shows Fe57 Mössbauer spectra (dots) of a 25 µm iron metal foil at 298 K with the CCR off and on. The velocity scan of ±2 mm/s covers only the innermost lines of the iron metal sextet. Also shown are least squares fits (lines) of a symmetric quadrupole pair with Lorentzian line shapes to each spectrum. The results of the fits were linewidth estimates of 0.234 mm/s with the CCR off and 0.241 mm/s with the CCR on. The uncertainty in the line width estimates due to the counting statistics is ±0.002 mm/s.
NOTE: Data provided by Science Engineering & Education Co. (SEE Co. — formerly Web Research Co.), http://www.seeco.us. Special thanks to Professor Darby Dyar, Mount Holyoke College.