We report on the development of a versatile cryogen-free laboratory cryostat based upon a commercial pulse tube cryocooler. It provides enough cooling power for continuous recondensation of circulating 4He gas at a condensation pressure of approximately 250~mbar. Moreover, the cryostat allows for exchange of different cryostat-inserts as well as fast and easy "wet" top-loading of samples directly into the 1 K pot with a turn-over time of less than 75~min. Starting from room temperature and using a 4He cryostat-insert, a base temperature of 1.0~K is reached within approximately seven hours and a cooling power of 250~mW is established at 1.24~K.
@article{arxiv.1708.09434,
title = {High-power closed-cycle $^4$He cryostat with top-loading sample exchange},
author = {F. M. Piegsa and B. van den Brandt and K. Kirch},
journal= {arXiv preprint arXiv:1708.09434},
year = {2017}
}