The document summarizes the commissioning of a TE011 cavity for surface resistance measurement using a calorimetric method. It describes the motivations, principles, and first tests of the cavity at IPN. The cavity allows for highly accurate surface resistance measurements over a wide temperature range of 1.8-4.2K. Initial RF tests showed higher than expected surface resistance due to suboptimal chemical treatment, but thermometric measurements achieved good sensitivity up to 52mT. Further cavity conditioning and thin film sample characterization are planned to fully realize the system's measurement capabilities.

3. Principle of the method For radius r>40mm P STAT =P RF   T STAT =  T RF  Determination of R S coefficients (a, b, c) by least square method R=0 Rcav=55 Rseal=58 q HF Nb Cavity RF part LHe Thermometric part q STAT Vacuum Heater

6. Cavity design TE012 TE011

8. Reception of mechanical parts Thermometric chamber and niobium cavity has been received (august 2009) Dedicated system developed for chemical treatment and HPR process Design of a new nozzle to prevent electrical discharge

9. Conditioning for RF test Discs support for chemical treatment (“handmade” process) Cavity handling frame for chemical treatment and clean room assembly Preparation for HPR treatment of the sample and the cavity

10. RF results for the TE011 cavity Estimated Q0 value and dissipated power for theoretical R BCS (Nb RRR300) : @4.2K: 1.6 10 8 (1.1 10 8 ) and P cav =152W (62mT) @1.8K: 2.0 10 10 (1.4 10 10 ) and P cav =1.2W(62.mT) Huge residual resistance due to bad chemical treatment (80µm BCP, T ≈20°C)

11. Thermometric measurement Bpeak=52mT @ 4.2K reached! Good sensitivity (200mT/W for Nb@4.2K)