Kalendra Vidmantas, Turčak Justinas, Usevičius Gediminas, Karas Hugo, Hülsmann Miriam, Godt Adelheid, Jeschke Gunnar, Banys Jūras, Morton John J L, Šimėnas Mantas
Faculty of Physics, Vilnius University, Sauletekio 3, LT-10257 Vilnius, Lithuania; Amplify My Probe Ltd., London NW1 1NJ, UK.
Faculty of Physics, Vilnius University, Sauletekio 3, LT-10257 Vilnius, Lithuania.
J Magn Reson. 2023 Nov;356:107573. doi: 10.1016/j.jmr.2023.107573. Epub 2023 Oct 13.
Following the success of cryogenic EPR signal preamplification at X-band, we present a Q-band EPR cryoprobe compatible with a standard EPR resonator. The probehead is equipped with a cryogenic ultra low-noise microwave amplifier and its protection circuit that are placed close to the sample in the same cryostat. Our cryoprobe maintains the same sample access and tuning which is typical in Q-band EPR, as well as supports high-power pulsed experiments on typical samples. The performance of our setup is benchmarked against that of existing commercial and home-built Q-band spectrometers, using CW EPR and pulsed EPR/ENDOR experiments to reveal a significant sensitivity improvement which reduces the measurement time by a factor of about 40× at 6 K temperature at reduced power levels.
继X波段低温电子顺磁共振（EPR）信号预放大取得成功之后，我们展示了一种与标准EPR谐振器兼容的Q波段EPR低温探头。探头配备了低温超低噪声微波放大器及其保护电路，它们放置在同一低温恒温器中靠近样品的位置。我们的低温探头保持了Q波段EPR中典型的相同样品接入和调谐方式，还支持对典型样品进行高功率脉冲实验。我们装置的性能与现有的商用和自制Q波段光谱仪进行了基准测试，通过连续波EPR和脉冲EPR/电子核双共振（ENDOR）实验表明，在6K温度下降低功率水平时，灵敏度有显著提高，测量时间减少了约40倍。
