# Vibrations on pulse tube based Dry Dilution Refrigerators for low noise measurements

## TL;DR

This paper investigates vibration levels in pulse tube based dry dilution refrigerators, evaluates damping solutions, and assesses their impact on low-temperature detector performance, highlighting the challenges and solutions for low-noise measurements.

## Contribution

It provides detailed vibration measurements on three commercial DDRs and evaluates damping strategies, demonstrating their effects on detector noise at low temperatures.

## Key findings

- Vibration damping solutions significantly reduce high-frequency vibrations.
- Vibrations impact germanium bolometer performance at low temperatures.
- Effective damping improves measurement stability and noise levels.

## Abstract

Dry Dilution Refrigerators (DDR) based on pulse tube cryo-coolers have started to replace Wet Dilution Refrigerators (WDR) due to the ease and low cost of operation. However these advantages come at the cost of increased vibrations, induced by the pulse tube. In this work, we present the vibration measurements performed on three different commercial DDRs. We describe in detail the vibration measurement system we assembled, based on commercial accelerometers, conditioner and DAQ, and examined the effects of the various damping solutions utilized on three different DDRs, both in the low and high frequency regions. Finally, we ran low temperature, pseudo-massive (30 and 250 g) germanium bolometers in the best vibration-performing system under study and report on the results.