Detection and location of SRF bulk niobium cavities quench using second sound sensitive sensors in superfluid helium

26th International Cryogenic Engineering Conference & International Cryogenic Materials Conference 2016

材料科学;物理学

Fouaidy, M.^1 ; Longuevergne, D.^1 ; Dubois, F.^1 ; Pochon, O.^1 ; Yaniche, J.-F.^1

IPN Orsay, 16 rue Georges Clemenceau, Orsay

91406, France^1

关键词: 2 frequencies;    Critical size;    Different sizes;    Niobium cavity;    Resistive thermometer;    Sensitive sensors;    Sensors and instrumentations;    Sound spectrum;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/171/1/012110/pdf
DOI  :  10.1088/1757-899X/171/1/012110

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

We developed sensors and instrumentation dedicated to detection and location of thermal quenches in SRF cavities via 2nd sound events in HeII. We studied 2 types of Quench Detectors (QD): 1) Oscillating Super leak Transducer (OST), 2) LOw REsponse Time resIstive Thermometers (LORETIT). The QD were characterized in He II bath (Temperature T0= 1.6 K- Tλ. The SRF cavity quench is experimentally simulated using resistors of different sizes and geometries. High pulsed heat flux qP(qP0, qP, distance to heater). The OST were used for locating quench on different SRF cavities resonating at 2 frequencies f0(f0=88 MHz or f0=352 MHz). The quench dynamics and critical size of normal resistive area leading to quench were investigated. Furthermore, a Second Sound Resonator (SSR) equipped with a pair of OST at each extremity (2nd sound generator (G) and detector (D)), a low thermal capacity heater (G) and a LORETIT (D), was successfully operated in the resonating and in the pulsed mode. The measured 1st sound and 2nd sound spectra were compared theoretical results and a good agreement is obtained.