Title :
High-Q niobium klyston cavities for use in gravitational wave detectors
Author :
Furtado, Sérgio R. ; Aguiar, Odylio D. ; Castro, Pedro J. ; Barroso, Joaquim J.
Author_Institution :
Astrophys. Div., Nat. Inst. for Space Res.-INPE, Sao Jose dos Campos, Brazil
Abstract :
The main purpose of this work was to measure the resonant frequency and the Q-factor for the niobium superconducting reentrant cavities to be used in parametric transducers of the gravitational wave detector Mario Schenberg. Many cavities were manufactured from niobium with high tantalum impurities (1420 ppm) and they were cryogenically tested to determine their resonance frequencies and unloaded electrical quality factors (Q0) related to the electromagnetic coupling. These cavities were closed using a niobium cover with tantalum impurities below 1000 ppm and the unloaded electrical quality factor Q0 = 2.65 Ã 105 was obtained. Another cavity similar to the one used by the Australian detector Niobe and made of niobium with low tantalum impurities was also investigated. The unloaded quality factor measured for this cavity was Q0 = 6.35 Ã 103. The experimental tests were performed in the laboratories of the National Institute for Space Research (INPE) and the Institute for Advanced Studies (IEAv-CTA).
Keywords :
electromagnetic coupling; gravitational wave detectors; klystrons; microwave parametric devices; niobium; superconducting cavity resonators; transducers; Nb; electrical quality factors; electromagnetic coupling; gravitational wave detectors; high-Q niobium klystron cavities; niobium superconducting reentrant cavities; parametric transducers; resonant frequency; Detectors; Frequency measurement; Impurities; Manufacturing; Niobium; Q factor; Resonance; Resonant frequency; Testing; Transducers; gravitational wave detector; klystron cavity; parametric transducer; superconducting niobium;
Conference_Titel :
Microwave and Optoelectronics Conference (IMOC), 2009 SBMO/IEEE MTT-S International
Conference_Location :
Belem
Print_ISBN :
978-1-4244-5356-6
Electronic_ISBN :
1679-4389
DOI :
10.1109/IMOC.2009.5427605