Presentation + Paper
5 May 2017 Attenuation of cryocooler induced vibration using multimodal tuned dynamic absorbers
Alexander Veprik, Vladimir Babitsky, Avi Tuito
Author Affiliations +
Abstract
Modern infrared imagers often rely on split Stirling linear cryocoolers comprising compressor and expander, the relative position of which is governed by the optical design and packaging constraints. A force couple generated by imbalanced reciprocation of moving components inside both compressor and expander result in cryocooler induced vibration comprising angular and translational tonal components manifesting itself in the form of line of sight jitter and dynamic defocusing. Since linear cryocooler is usually driven at a fixed and precisely adjustable frequency, a tuned dynamic absorber is a well suited tool for vibration control. It is traditionally made in the form of lightweight single degree of freedom undamped mechanical resonator, the frequency of which is essentially matched with the driving frequency or vice versa. Unfortunately, the performance of such a traditional approach is limited in terms of simultaneous attenuating translational and angular components of cooler induced vibration. The authors are enhancing the traditional concept and consider multimodal tuned dynamic absorber made in the form of weakly damped mechanical resonator, where the frequencies of useful dynamic modes are essentially matched with the driving frequency. Dynamic analysis and experimental testing show that the dynamic reactions (forces and moments) produced by such a device may simultaneously attenuate both translational and angular components of cryocoolerinduced vibration. The authors are considering different embodiments and their suitability for different packaging concepts. The outcomes of theoretical predictions are supported by full scale experimentation.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alexander Veprik, Vladimir Babitsky, and Avi Tuito "Attenuation of cryocooler induced vibration using multimodal tuned dynamic absorbers", Proc. SPIE 10180, Tri-Technology Device Refrigeration (TTDR) II, 101800F (5 May 2017); https://doi.org/10.1117/12.2271147
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Cryocoolers

Cryogenics

Infrared imaging

Imaging systems

Resonators

Head

Packaging

Back to Top